I've known for a long time that in the sun four hydrogen atoms fuse to make a helium atom. I never really thought about it much, but just recently I realized that four protons fusing together should make beryllium, not helium. I read some of the article Nuclear fusion and it had a pretty cool pic...Image:FusionintheSun.png, but I didn't understand most of it. Also, the pic shows the creation of a positron. What in the heck is a positron? (Supposedly the anti-matter of an electron, whatever that means) Lol! Again, over my head. Anyway, I was just wondering. Thanks to everyone in advance!
Dimblethum03:14, 1 December 2005 (UTC)Dimblethum[reply]
I'm not a physicist, but the figure seems to indicate that you can produce a neutron by releasing positron from a proton. A positron is the antiparticle of an electron. --JWSchmidt03:35, 1 December 2005 (UTC)[reply]
That's also right, there's also a neutrino involved, but they're pretty damn hard to see. There are two weak decays that affect nuclei, and they are:
You're correct that four protons in a nucleus would make beryllium; however it is more complicated than that; a nucleus with four protons and no neutrons would be highly unstable. The reactions are detailed in proton-proton chain reaction and are too complex for me to fully explain here, but I'll try summarize. The key is the initial proton-proton reaction. Two protons come together, and one proton is converted into a neutron (an up quark transforms into a down quark I believe). In the process, a positron is emitted, which as JWSchmidt indicates is the antiparticle of an electron (see that article, or antimatter if you are not familiar with the concept—basically each particle has a corresponding antiparticle with opposite charge, spin, etc.; when a particle and antiparticle collide, they annihilate each other and produce energy via E=mc2. This, for instance, is the basis of the matter-antimatter reactor that powers the Enterprise in Star Trek and in other science fiction. Antiparticles are normally simply named by adding anti- to the particle name; positrons are a historical exception). Also emitted is an electron neutrino. The positron will quickly meet an electron and mutually annhiliate. The rest is covered in proton-proton chain reaction; if there are specific questions you have or concepts you don't understand, ask them here. — Knowledge Seekerদ03:47, 1 December 2005 (UTC)[reply]
All stable nuclei have a ratio of protons to neutrons that falls within a certain range (see Isotope table (divided)). If there are too many protons, some can turn into neutrons by beta decay, and vice versa. A proton can change into a neutron by emitting a positron (beta plus), and a neutron can change into a proton by emitting an electron (beta minus). —Keenan Pepper03:59, 1 December 2005 (UTC)[reply]
I'm looking to build an electrotheremin, which as I understand it is just an audio oscillator with a slide potentiometer determining pitch. However, I don't really have experience with electronics, so I can't just "wing it." Is there a place on the internet or something where I could find the schematic for such an oscillator? Or, is there a simple step for replacing a resistor in an existing oscillator circuit with the slide potentiometer? Thanks in advance. --ParkerHiggins03:17, 1 December 2005 (UTC)[reply]
Yes, if you already have an oscillator circuit you could replace the resistor with a slide potentiometer. Or even simpler, you could just add the potentiometer in parallel with the resistor, which wouldn't require breaking the original circuit. —Keenan Pepper15:24, 1 December 2005 (UTC)[reply]
I'm doing a school project for my grade 12 biology class and I need to make a physical insulin structure. Within my structure, needs to be the appropriate sequence of amino acids to form an insulin protein. So far, the types of insulin structures I've found on the web consist of the "leader chain, A-chain, B-chain, and C-chain". These descriptions are not what I'm looking for. I need to know the exact sequence of amino acids in these chains that make up insulin.
Thank-you very much for your help.:)
See this page. The structure shown is bovine insulin; if you want to make a model of human insulin be sure to make the substitutions shown at the top of the page. You also have to decide on what form of insulin you are modeling: the kind that is found in the circulation (insulin proper, which is shown there) or the one which is transcribed from the RNA and processed to become that form (proinsulin). The leader-chain and C-peptide won't be found in the circulating form. (BTW, searching for "insulin amino acid sequence" would find this for you). - Nunh-huh03:54, 1 December 2005 (UTC)[reply]
Any conductive material, if wrapped around the appliance without large holes, forms a Faraday cage that blocks low-frequency electromagnetic radiation. The maximum allowable hole size depends on the highest frequency that needs to be blocked. —Ilmari Karonen (talk) 16:55, 1 December 2005 (UTC)[reply]
How can I treat a middle cerebral artery aneurysm?
Well, I advise you seek professional help on this one. All I can do is mention the treatment section of aneurysm, and point out also the article on cerebral aneurysms. I didn't notice either of them specifically mentioning middle cerebral artery aneurysms. --ParkerHiggins07:17, 1 December 2005 (UTC)[reply]
How can one convert a .m4a file format (songs from iTunes) to *.wma file format (so i can play them in windows media player...)?
There's a winamp plugin that lets it play m4a. So you can use winamp to play them, or you can use winamp to decode it to a wav (and then you can use any of a dozen programs to reencode it as an mp3) Raul65410:58, 1 December 2005 (UTC)[reply]
Does anyone know why the term "cookie" was used in the first place? (I can see the link for developing the brownie project, but why did he choose "cookie" to start with)?
All ideas gratefully accepted.
Jax1402
I have a magnetic base for a measuring device that allows you to attach the measuring device to metal objects. The magnetic base has a switch that allows you to turn the magnet on or off. When on, the magnet is very powerfull, and when off, it will attract and hold a paper clip but nothing bigger.
I dissassembled the magnetic base on found that it consists of a block of metal with a cylindrical hole drilled thru its center. In the hole is a cynlindrical magnet. The switch rotates the cylindrical magnet 90 degrees. The outer block does not have any measurable magnetism.
Your description is a bit value, but I'll assume the dipole axis of the magnet is perpendicular to the axis of the cylinder, i.e. that rotating the magnet in the hole moves the poles, and that in the "on" position one of the poles points towards the bottom of the base. That pole then strongly attracts adjacent ferromagnetic objects. When you rotate the magnet 90°, both poles as now facing the sides of the base (where there is presumably quite a lot of padding between the magnet and the exterior of the base), while the side of the magnet produces only a weak residual attraction. —Ilmari Karonen (talk) 16:44, 1 December 2005 (UTC)[reply]
Actually, it's usually the opposite way around. When the magnet is "off", the dipole points up and down. When it is "on", the rotating magnet has its N pole in one half of the base, and the S pole in the other half. The two halves of the base plus the rotating magnet form a sort of horseshoe magnet. When its attached to a piece of metal (across the two halves of the base) it makes a magnetic circuit which it is very strong. When it is switched off, there's a much smaller residual magnetism. These sort of bases are used a lot in optical experiments to position devices on optical benches. See here: U.S. patent 4,251,791 for one design. --Bob Mellish21:34, 1 December 2005 (UTC)[reply]
I agree with Eye - what you want to do is to disrupt the alignment of the dipoles in some manner. Nothing quite like heating or hitting the magnet. --HappyCamper03:32, 3 December 2005 (UTC)[reply]
I should point out that heating it up will permanently destroy the magnetism. (Well, for a given value of "permanently". You can make it magnetic again, but it won't become magnetic again by itself.) DS01:03, 10 December 2005 (UTC)[reply]
Last week an article about a guy with a dozen satellite dishes outside his house was linked everywhere on the internet. This morning I stopped by my mothers house and they recently had their DirectTV dish replaced with one that can pick up local channels. They got to keep their old dish...until I stole it from them. What do I need to do to set this sucker up on my apartment balcony and start getting news feeds, local channels from other states, and shows in languages I don't speak?
I know I need a receiver but could I just use a computer and some software made for this?
Is there any other fun things I can do with this dish?
What is the maximum number of vertices with 15 edges and three components?
If you have V vertices and E edges, the minimum number of components is V − E (because if there are no edges, each vertex is its own component, and each new edge can only reduce the number of components by one). In this case we need , so the maximum value of V is 18.
Today I took of water from a water fountain. After I had lowered my head towards the faucet, I could smell cleaner fumes. This upset me because I inhaled the fumes while being close to the source of the fumes. I'd like to know if this is the equivalent of huffing, because I'm scared of being brain damaged from the fumes.
Wikipedia does not generally give medical advice, so if you're really worried, go talk to your doctor. However, I suspect it was harmless. The effects of inhalants are usually acute rather than chronic, which means you get dizzy and even pass out before doing any permanent damage (unless it becomes a habit, of course). —Keenan Pepper18:32, 1 December 2005 (UTC)[reply]
I think there are bigger problems if your water fountains are producing fumes. Water vapor is not a fume, nor ought it to have a smell. --YixilTesiphon06:19, 2 December 2005 (UTC)[reply]
If you live anywhere near a sizeable built-up area you'll likely be inhaling exhaust fumes all the time (every breath you take, day and night). Living next to a busy road is like being a heavy smoker. I base this on tests done on children in Maastricht, not quite a big town. The traffic is nothing compared to that of a modern big city, let alone the ones in the US (eg LA) or third world countries. If you want to worry about something worry about that. DirkvdM10:43, 2 December 2005 (UTC)[reply]
How does an alkaline/base component of detergents and cleaners make a stain more soluble? In other words, how does it dissolve the stain?--Just Wondering
This is sort of a trick question, because it really depends on the chemistry of the laundry detergent. Which brand are you using? --HappyCamper03:29, 3 December 2005 (UTC)[reply]
Dear Happy Camper,
The laundry detergent used was good old fashioned Arm and Hammer Washing Soda.
A 1/2 tablespoon was put in 16 ounces of hot water with no other detergent (water is "soft") to remove an olive oil stain from cotton. A half an hour later, Voila,! No stain. How did it dissolve the stain.
For some reason the Wikipedia search engine that came with the previous version of Mozilla's Firefox browser (I'm using the most recent update) is now gone! Why is that, and does the company plan on bringing it back? I can't seem to find a place to ask at its website. --71.103.127.11400:18, 2 December 2005 (UTC)[reply]
You can add the Wikipedia search engine plugin by clicking on the "Wikipedia" link on the following page: Search Engines. Be sure you have JavaScript enabled. You can also go to the same page by selecting "Add Engines..." from the drop-down list in the Firefox search box. -- Mark Bornfeld DDS dentaltwins.com Brooklyn, NY 01:07, 2 December 2005 (UTC)
How would I go about writing a program to extract data from a website (ie the sales rank of books on amazon.com)?
In principle, you'd write a program that simulated a browser connection to fetch information from a web site, perhaps using URLs you list in advance, or a web spidering system. Then you'd parse the HTML, assuming unchanging formats, to get the book info and rank. Then analysing it would be easy. In practice, if you plan to get all books rather than just a handful, this would hit Amazon's servers hard (perhaps as hard as thousands of customers). They are likely to have methods in place to detect this, assume they are under attack, and block your connection temporarily or permanently. Not recommended. Notinasnaid09:41, 2 December 2005 (UTC)[reply]
Not sure what you mean, but HTTrack will let you download the entire Internet if you wish. Careful though, it's extremely powerful and you may get more than you bargained for. DirkvdM10:49, 2 December 2005 (UTC)[reply]
It's also good to check if the website has an RSS feed available that you can easily extract data with; PHP has some good XML parsing functions you could use. Though if Amazon doesn't issue RSS i'd suggest the above. -Benbread15:40, 2 December 2005 (UTC)[reply]
If a pregnant women, who uses cell phones / mobile phones in her daily life, will the fetus (unborn baby)inside her will be affected if she continues using cell phones?
Can you please answer this question, as early as possible?
According to Mobile phone radiation and health, the risk of radiation from cell phone use is, as yet, unsubstantiated. However, as the article says "the World Health Organization has recommended that the precautionary principle could be voluntarily adopted in this case." So, I would say that the baby will be fine, provided the mother isn't always on the phone. I hope that helps to answer your question. --ParkerHiggins07:04, 2 December 2005 (UTC)[reply]
Even if phones provide a health risk, the radiation it cause is only powerful enough to reach the woman's own brain which shouldn't have any direct influence on the fetus. Of course, effects on the mother will eventually affect the child psychologically if they turn out to be severe in the long run. I would recommend cutting down phone usage anyway. - Mgm|(talk)09:40, 2 December 2005 (UTC)[reply]
Unless there's a problem passed to the next generation, like making the baby infertile. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 16:35, 7 December 2005 (UTC)[reply]
No, the solubility of most gases (I want to say all gases, but there may be weird exceptions?...) decreases as temperature increases. A common example of this is carbonated water, which quickly goes flat on a hot day but keeps its carbonation for a long time when chilled. The reason for this is that, at a higher temperature, the gas particles move faster, and they can more easily escape from the surface of the solution (the vapor pressure is higher). So, the capacity of hot water to contain dissolved air is less than that of cold water. —Keenan Pepper18:47, 2 December 2005 (UTC)[reply]
Bad phrasing on my part. Gasses are already dissolved (unless they are forming bubbles), so Suprm401's question doesn't make any sense. --YixilTesiphon03:16, 3 December 2005 (UTC)[reply]
Huh? Let's take a step back and see:
Does hot water contain air more than cold water? The answer is no - this is because the solubility of air (ie, mostly nitrogen and oxygen) in water decreases as you increase the temperature. Keenan's example of soda is an excellent everyday example of this general observation - hot coca cola certainly doesn't have quite the fizz as a cold one! Ditto with beer.
As for the ice cubes - that's also the reason why boiled ice cubes look clearer - during the boiling process, most of the dissolved gasses escape. Hence, when you make ice cubes, no bubbles come out during the freezing process.
An alloy is an example of a solid solution. And yes, things can "dissolve" in a solid - however, it's a bit more of a subtle concept here. In this case, it depends on how you define "dissolve" - it may not necessarily mean "solvation". However, in certain fields of chemistry, it is desirable to restrict the definition to liquid solutions. I hope this clarifies things! --HappyCamper03:23, 3 December 2005 (UTC)[reply]
Almost forgot: REgarding Superm401's question - yes, some air will redissolve back into the water when it cools, but the difference is that the rate of freezing is significantly higher than the rate at which the air dissolves. --HappyCamper03:24, 3 December 2005 (UTC)[reply]
They look clear because the freezing is incremental - but if you slice one, you will notice that there is a tendency for these bubbles to form in the center...so I guess they aren't really clear... --HappyCamper03:40, 3 December 2005 (UTC)[reply]
A common practice indeed for children in the northeast US anyway. Icicles from roofs in particular because they can get pretty big. --hydnjotalk15:51, 3 December 2005 (UTC)[reply]
Ironically the picture at the bottom of Ice shows icicles formed on a roof in Australia, even though I live in Austrlaia (and have never seen snow/ice) and was unware of the use of icicles.--Commander Keane17:56, 3 December 2005 (UTC)[reply]
What happens when a liquid is inserted between a convex lens of focal length 20 cm and a plane mirror?plz give a detailed answer.
There's no general answer; it depends on the liquid (in particular its refractive index), what material the lens is made out of, the exact form of the lens (e.g. radius of curvature of each surface), and the distance between the lens and the mirror. Very roughly, adding the liquid will increase the optical path length between the lens and the mirror; but the exact effect will depend on the parameters above. --Bob Mellish17:36, 2 December 2005 (UTC)[reply]
What do you mean by inserted? Is a tank of water placed between the lens and the mirror, or is the whole setup submerged in water? It makes a big difference. —Keenan Pepper18:58, 2 December 2005 (UTC)[reply]
Do your own homework. It's a little offensive when you give exact numbers (thus indicating that this is a homework problem), and say "plz give a detailed answer." --YixilTesiphon00:14, 3 December 2005 (UTC)[reply]
Hmm..."offensive" might be going a little bit over the top here I think. We need more background information about the question in order to help you better. Are you trying to find the effect of looking through the combination of lens-water-glass, as opposed to lens-air-glass? --HappyCamper03:15, 3 December 2005 (UTC)[reply]
I think you guys are overthinking this one a little. It seems pretty straightforward to me.
Q. What happens when liquid is inserted between a convex lens and a plane mirror?
There seems to be some dispute over the numbers of the groups in the Periodic Table - I live in the UK and i've always been taught there are groups 1-0/8 and the transition metals, with these being named because of the number of electrons in their outer shell. While wikipedia and other sources state there are 18 groups. I'm assuming that the 18 groups is correct, but where is there some difference of opinion among people?
Well, looking at periodic table I discovered, as I hoped, a section explaining this, albeit briefly. Basically, it seems the 1-8 plus transition metals scheme isn't entirely unambiguous, so is officially "deprecated" by the shadowy bodies that get to decide such things... - IMSoP19:48, 2 December 2005 (UTC)[reply]
The naming isn't so much a "dispute" - it is more a reflection of our better understanding of chemistry from a quantum mechanical perspective. In particular, the IUPAC recommended the renaming a few years ago. The old grouping of systems is still useful for teaching purposes though. --HappyCamper03:14, 3 December 2005 (UTC)[reply]
I am a 44 year female. I was diagnosed 3 years ago with RSD. Since then I have been diagnosed with ulner noropathy degenerative disc disease rhumatoid arthritis (severe 242) fibromyalgia have bulging disc in c4567 and sudden platelett count drop any ideas. Doctors here are stumped and can't seem to offer any new help. You may e-mail me at <email removed>.
Please read the instructions at the top of the page. Leaving your email address here will almost certainly get you loads of SPAM. - Mgm|(talk)22:09, 2 December 2005 (UTC)[reply]
I am sorry for your combination of problems, which sounds like way more than any one person deserves. It is difficult to give you a simple answer to your question for many reasons:
You may actually have a combination of problems and there is no unitary answer to be had. It is always more gratifying for both patient and doctor if a single disease can be recognized that explains all of a person's problems, but that is unfortunately the exception rather than the rule.
But having said that, it is still likely that some of them are connected to each other, statistically if not causally. For example, a common cause of platelet drop (thrombocytopenia) can be a drug effect. Have you started anything new recently? You might want to check whether thrombocytopenia is listed as a side effect of any of the drugs you take. That doesn't prove a causal relationship, but it gives you some choices of what to do. Another cause of sudden platelet drop is a viral illness. The platelets usually return to normal within a couple of weeks. Some people can develop autoimmunity to their own platelets, especially when they have other autoimmune or inflammatory diseases like rheumatoid arthritis.
If you have not asked your primary doctor for referral to a rheumatologist you might try that. They get lots of people referred for mysterious inflammatory conditions.
You know when you type in the name of something and save it and it says 'do you want to replace the article of the same name', is there any way you can get the article you deleted back? Its very important and I couldn't possibly do it again. Thanks! ----XenoNeon18:47, 2 December 2005 (UTC)[reply]
Doubtful. Try searching and see, maybe it's stored somewhere in temp files (remember to look in hidden and system files), but you're in bad straits here. --YixilTesiphon13:34, 3 December 2005 (UTC)[reply]
Norton Antivirus 2004 offers a recycle bin which 'catches' and files deleted by whatever means (even non-manual) technically the file will probably still exist on your hard drive, but recovering it can be difficult and expensive, however, if the file is very important it is probably worth looking into professional help to recover it. The police use this method all the time, if a file is deleted it will still exist on your harddrive, however, the more times it is overwritten the harder and more expensive it is to recover it. - Unregisterd User 18:13 3 December 2005
A Question regarding paraffin...from e-mail address removed
All I'm really asking is, how did all these dangerous epidermic happened? I mean, if we could go back in time, and say there are 100,000 males and females divided equally, all are all healthy individuals, how can STI and AIDS (or HIV) happened/started??
The answer is in evolution and mutation. Depending on how far back you want to go, we could assume bacteria, viruses, and protozoa exist (for simplicity we'll ignore multicellular organisms that live as parasites). Mutations in these agents can alter their virulence and transmission (medicine)--that is, the amount of damage they do and their ability to move from one host to another. As such, a virus or retrovirus that infects one type of organism could mutate to infect humans. This is believed to be the origin of the HIV strains that infect humans (see AIDS article) and is the crux of the recent global fear of an avian influenzapandemic.
The origins of infectious disease in general are older and less clear. But biological interactions are as old as life itself, and are seldom friendly (see food chain). Viruses may have arisen from a bit of host genome mutated to produce large amounts of a virion even at penalty to the host.
IlliniWikipedian is absolutely correct. There was likely no time in the past where the entire population was disease-free. Bacteria and viruses predate the origin of humans. Disease is ancient. Our primate ancestors had infections before we evolved. Furthermore, even suppose you were granted a wish and you wished all disease-causing entities to instantly die, it would not be the end of (infectious) disease. Vast niches would now be free, and it would only be a short time before some of the remaining, innocuous bacteria evolved to parasitize and cause disease in humans and other organisms. With regards specifically to HIV, the virus that causes AIDS: there is a related virus, a simian immunodeficiency virus, which causes an AIDS-like disease in monkeys. One strain of this was transmitted from chimpanzees (our closest relatives) to humans in sub-Saharan Africa and evolved into what we now call HIV-1, the predominant form of HIV. A different strain evolved into HIV-2, which still only exists primarily in Africa. — Knowledge Seekerদ23:10, 2 December 2005 (UTC)[reply]
A problem here might be black and white thinking, the idea that certain organisms are purely bad. Where organisms live together they are likely to start interacting in some way. Sometimes this will result in one predating on the other, not with malicious intent, that's just the way things work. These we then call diseases when they're small (unless we want to consider ourselves a disease for the world's population of cows and such). At other times the interaction will be to the benefit of both, which we then call symbiosis. These interactions will always have happened, so there will always have been and always will be diseases (as already pointed out). DirkvdM09:53, 4 December 2005 (UTC)[reply]
Help figuring out the components of a chemical reaction
Once I was flipping through a book of chemistry abstracts. I found one that described a reaction, the by products of which where C02 (sry don't know how to make subscript) and ethanol.
There was some discussion following that it could be used to make alcoholic soda pop tablets.
(Reagents + Flavoring)Compressed into a tablet + Glass of Water = Adult Soda.
I saw this year ago, and have gone back to the science library and tried to find it, but to no avail.
Does anyone have any idea what would have been used?
Are you thinking of the powdered 'alcopop' beverages being sold in Europe? One of the brand names is Subyou[3], but I imagine that there are or will be others.
My understanding is that the powdered just-add-water beverage is based on ethanol encapsulation. Droplets of mixed water, ethanol, and starch (dextrin or the like—something water soluble and flavourless) are dried under controlled conditions. The starch traps most of the ethanol molecules but allows the smaller water molecules to escape. The 'dry' Subyou powder is about 30% ethanol by weight. Adding water redissolves the dextrin and releases the alcohol back into solution. There are several variations on this encapsulation scheme.
As YixilTesiphon mentions above, there are lots of chemical reactions that will generate CO2 when you add water. A powder containing a mixture of dry acid and dry carbonate or hydrogen carbonate (bicarbonate) compounds will certainly do it. TenOfAllTrades(talk) 01:16, 3 December 2005 (UTC)[reply]
I think the powdered alchopop thing is closer to what I was thinking of. It was years ago that I saw it, but in my memory the chems in it actually reacted in solution to produce the ethanol and the CO2. That may not have been hte case though.
"Point" might be misleading, because it's fairly arbitrary: "When glass has been heated to a high enough temperature, it must be cooled by a controlled schedule of time and temperature or it will crack simply because of the strain inside the glass from the outside cooling faster than the inside. The sound of cracking glass in the waste buckets is common in glass studios. The thicker the glass, the longer the cooling time must be, days and weeks in the case of really thick castings. The annealing temperature is determined by slowly heating a long thin piece of glass supported at the ends until it just starts to sag (the sag temperature) and the annealing temperature is taken to be 50°C (90°F) below that, usually about 900F (480C). When scientific measurements are possible, the annealing point is a specific viscosity. "annealing point, AP—the temperature corresponding to a rate of elongation of 0.0136 cm/min when measured by ASTM Method C 336, Test for Annealing Point and Strain Point of Glass by Fiber Elongation. This test prescribes a rate of cooling of approximately 4 C/min with a fiber of approximately 0.065 cm in diameter, and a suspended load of 1000 g. The annealing point numerically approximates log = 13.0 poises, where internal stress is substantially relieved in a few minutes."" [4] - Nunh-huh23:48, 2 December 2005 (UTC)[reply]
Hi, I'm helping my daugther with a tree project-Red Maple Tree and there are a few questions we needed to research to be able to do this project. First of all we had to pick a tree in our area to do the study on (Red Maple Tree). 1.How do you estimate the age of the tree by it's circumference? 2.The tree's habitat would be what (Where we live?)? The Red Maple's connection to technology and human wants and needs? 3.And very important the lif cycle of R.M.T.-this is a must have, all we could find are a basic tree cycle not necesary for R.M.T. And any other useful information that we could use in her report and Hypothesis-whether it blossoms flowers and what the seeds look like. We did find some general info, but not enough.
Thank you so much for any information that you can provide. 12/2/05--71.66.123.248 posted 00:33, December 3 2005 (UTC)
Here are a couple of places to start where I found nice pictures of all the parts of red mapels: seeds, leaves, bark, etc. [5][6] The habitat is where it is likely to be found in the wild, something like "northern temperate zone hardwood forest". Estimating the age from tree circumference can be done by finding a table of typical annual thickness increases for particular tree species [7][8]. Or you can find a stump of a red maple, count the rings, and divide the radius by the number of rings to get the usual increase in diameter per year (remember diameter is twice radius). The circumference is about 3.14 x the diameter [9]. Or you could call your state forestry service and ask if they can tell you how to do it. Good luck. alteripse01:09, 3 December 2005 (UTC)[reply]
I like "If you know when the tree was planted, you can easily and accurately determine its age." at [10]. The list members at [11] apparently believe width is not a very good measure of age. I'm inclined to think alteripse's suggestion of contacting the state forestry service might be better. Your IP indicates you live in Virginia, so the phone number of the Virginia Department of Forestry is 434.977.6555 . If you don't, you can look it up. Superm401 | Talk02:45, 3 December 2005 (UTC)[reply]
Esmé, a South African reader has sent the following question to the Wikimedia Help mailing list.
Please could you find out for me whether there is a specific term for a baby tortoise – so far the only term which has been presented is “baby tortoise” – surely there must be a more specific term?
I have advised her that it seems to be commonly used but I would be grateful if anyone could offer additional suggestions.
According to dictionary.com the baby turtle is called a hatchling. They don't have an entry for tortoises, but maybe that can be used for them as well? I expect it could be used for anything that hatches out of an egg. It does say what the collective noun for a group of tortoises is: a creep. I didn't know that, that's fun. -lethetalk02:41, 3 December 2005 (UTC)[reply]
Cecily, an Australian Wikipedia user has asked on the Wikipedia help mailing list.
I am buying a uhf radio to use to communicate while skiing. Can you tell me if I am able to use a pair of uhf radios bought in australia overseas. I am particularly interested to know if I can use them in Poland.
Also what about Canada and the USA. I believe they will work but is it illegal to use one that is on australian frequencies.
If you could help me with Poland I would be most grateful.
There are three zones for frequency allocations. In some regions those zones are divided across national borders. Generally, radios from one nation are only to be used there. An allocation in one nation for family talk UHF radios, could be used for Military communications elsewhere. Dominick(TALK)15:54, 3 December 2005 (UTC)[reply]
So if I want to listen to military communications all I need to do is find out in which country those frequencies are used for domestic purposes and buy a radio there? Well, I suppose that if I were bent on that it might be easier to modify a radio to receive those frequencies. So the military won't be so stupid to use radio communication for 'classified' information. (Then again, ....) DirkvdM09:59, 4 December 2005 (UTC)[reply]
Hello everyone! I am not sure if I recall this correctly, but I remember there is an enzyme in human saliva which helps with digesting glucose. The question I have is, if the time between chewing and swallowing is relatively short, what is the advantage of the body producing an enzyme which would only perform what seems to be a very very small part of digestion? --HappyCamper03:35, 3 December 2005 (UTC)[reply]
Salivary amylase begins the digestion of starch to glucose. Even a small amount of glucose will begin to trigger insulin release so that the insulin is rising as food is being digested. Salivary amylase is not necessary to digest starch but it helps amplify the speed of metabolic response, as well as providing a small burst of glucose as you begin to eat. Finally, conversion of even a small amount of starch to glucose in the mouth enhances the taste of carbohydrates in our mouths. alteripse03:51, 3 December 2005 (UTC)[reply]
Oh, I see...this sounds quite interesting...I didn't know that insulin is so sensitive to this. Would this be a reasonable example of a positive feedback system then? (From a controls perspective, "useful" positive feedback systems are almost unheard of, so it is excellent if this is considered one!) --HappyCamper03:54, 3 December 2005 (UTC)[reply]
I don't think salivary amylase is an example of positive feedback—where did you see the loop? Another biological example of positive feedback is during the menstrual cycle, such as the LH surge. — Knowledge Seekerদ04:22, 3 December 2005 (UTC)[reply]
As I understand it, the contribution of salivary α-amylase (ptyalin) to overall starch hydrolysis is a relatively small fraction of overall carbyhydrate digestion; the lion's share of this task is performed by pancreatic amylase. Salivary amylase is rapidly inactivated by stomach acid, so its action is very brief. (By the way, the product of the action of salivary amylase on starch is maltose (a disaccharide), which would not be expected to directly stimulate insulin secretion). Salivary amylase is thought to take on a more important role in infancy, prior to the maturation of pancreatic exocrine function. It may also assume a bigger role in the adult in cases where pancreatic exocrine function is compromised. For a scholarly dissertation on the role of saliva in digestion, see: [http://tinyurl.com/7qkq6 Saliva and gastrointestinal functions of taste, mastication, swallowing and digestion] -- Mark Bornfeld DDS dentaltwins.com Brooklyn, NY 05:30, 3 December 2005 (UTC)
I wouldn't characterize the insulin effect as positive feedback, but as early triggering or amplification of effect. Most food starch has a glycemic index almost as fast as glucose, indicating that hydrolysis of starch does not ordinarily contribute much to the time of absorption of many carbohydrates. There are a number of physiologic responses to the onset of eating that do not depend on waiting until substantial amounts of nutrients are already digested and absorbed and I suspect that the generation of a little glucose in the first minute of eating carbohydrates enhances some of metabolic and digestive responses as well as providing positive taste feedback to us. alteripse12:54, 3 December 2005 (UTC)[reply]
Hey, this is a bit of a hard question, and I looked but couldn't find what I was looking for. What are the chemical compounds/atomical mass/ect. of Blood, Bone, Skin, and Nail? Any help would be just wonderful, thank you.
~Ryan.
The chemical composition by element has been available for decades and is easy to find: [12]. The atomic masses of the elements you can easily look up. There is no list of all the molecules comprising blood, blone, skin, and nail because new ones are being continually discovered and it would run to the thousands. Of the four tissues you mentioned, nails are the simplest and are comprised mainly of a protein called keratin and water molecules but even the nails contain small amounts of many other things. As far as skin goes, you might just as well ask for a listing of every molecule in a human body. alteripse12:36, 3 December 2005 (UTC)[reply]
I have checked out the defination of nanobiotchnology from wikipedia, but I do not understand what it is saying. Can anyone please tell/explain to me what nanobiotechnology is really?
For example the use of tiny biosensors that can be implanted under the skin and monitor things like blood glucose level. These use an enzyme to break down the glucose, a biological recognition layer to record the amounts of the products of the enzyme-substrate interaction, and a transducer to convert this into an electrical signal - very clever really! --Unregistered user 18:07 3 December 2005
I am not sure that I understand the extent of this process, digitizing library collections. Is it simply creating a digital catalog, or the larger process of scanning documents and entering data?
Thanks so much for clarification.
Usually, it's scanning entire books. (I'm assuming you're referring to projects such as Google Book Search.) Some library whose name I can't remember in Egypt which has a large collection of rare Islamic texts recently scanned its entire collection. --YixilTesiphon15:37, 3 December 2005 (UTC)[reply]
How long did people need to train with weights to lower their risk of coronary heart disease by 23%?
The question is like above. I searched but they couldnt find anything. So here goes, how long did people need to train with weights to lower their risk of coronary heart disease by 23%? A) 30 minutes b)55 mins c)80 minutes
Second one,
After what age would people start losing muscle mass and strength caused by hormonal changes? A)30 b)40 c)50
I need it to be very accurate. BTW, thanks to everyone who helps me with the question. Many thanks ppl.
The precision of the desired answer tells me the answer was produced by a specific research study which you were supposed to read. How do you expect us to know which study that was? alteripse18:25, 3 December 2005 (UTC)[reply]
I was trying to run the Ubuntu 5.10 live CD on my older PIII 800 Mhz 128 MB RAM Dell Inspiron 2500, but it is glacially slow. I'm assuming it's because 128 MB is not enough to run with all the default software the live cd has on it, but it's so slow (10 min to open a terminal window) that I can't even kill processes to free up memory. Is there an easy way to get the 5.10 live cd to use a file on the Windows partition as swap? Or do I just have to wait till I get a terminal window and set up a swapfile manually? (Which I'll have to go search to remind myself how to do that again.) Thanks - TaxmanTalk15:53, 3 December 2005 (UTC)[reply]
If you are using Windows XP, your windows partition is probably a [NTFS] partition, which Ubuntu/Linux cannot write to, only read it. If you have a FAT32 partition, I don't know, it might be possible. --WS01:35, 5 December 2005 (UTC)[reply]
XP on a machine of those specs? Surely you jest. No it was ME, but I decided to just bite the bullet and install, and it worked out all for the better. Everything works amazingly well including the sound, power management, and wireless. I'm assuming the winmodem won't but oh well. It's still slow, so I'm planning to figure out how to slim it down a lot. I guess the first step would be a lighter window manager. I'll try to haunt some Ubuntu forums and learn the ropes, but if anyone has some info on good ways to slim down the ram requirements, I'd be interested. - TaxmanTalk14:23, 5 December 2005 (UTC)[reply]
It's difficult to configure Linux distros on Live CDs to access the hard disk for its swap files. Alternatively, you could use Damn Small Linux, which is only 50 MB in total, but fits a GUI and a surprising number of programs onto it. Surely 50 MB can fit into 128 MB of RAM. :) -- Daverocks11:25, 5 December 2005 (UTC)[reply]
Well I had an older DSL disk, but I couldn't get it to boot properly, the 2.4 kernel would hang at some point. And with the compression those livecd's use 50 MB could be made to overwhelm 128 MB of RAM too :) - TaxmanTalk14:23, 5 December 2005 (UTC)[reply]
What is the difference between global warming and climate change? Why did the media, which used to call it global warming, suddenly all start calling it climate change in unison? Who made them change? —Preceding unsigned comment added by Zzzzz (talk • contribs)
Have a look at Global warming and Climate change; basically climate change describes the broader phenomenon which includes not only the current anthropgenic warming but other fluctuations such as past glaciation, etc. In addition, while warming is the major phenomenon, other things like altered rainfall regimes are also part of the picture. Guettarda16:14, 3 December 2005 (UTC)[reply]
I'd say that last bit is probably the most important. Global warming is just one aspect and it's arguably not even the worst. And to a layman (especially one living in a moderate or cold climate) it might even sound like a good thing. Also, warming is the most likely effect. Other theories say we could be creating a new ice age. So calling it warming is a premature conclusion. That there will be a (major) climate change is however beyond doubt by now. Finally, with global warming you may still get local cooling. DirkvdM10:07, 4 December 2005 (UTC)[reply]
As future-proofing, it hardly seems urgent. But that doesn't make it political either; I think we all agree that the list would include women if there were any, so the astronauts' sex is not relevant to their inclusion and doesn't need to be mentioned in the title. --Trovatore22:57, 3 December 2005 (UTC)[reply]
The article includes the 12 Apollo astronauts who went near the moon but did not land as well as the 12 who did land, so in any case the "walked on the moon" part would be wrong. --Anon, 07:52 UTC, December 4, 2005
Nunh-huh is probably talking about this article. A little hard to find, because the link he gave was capitalized differently. It wasn't actually moved; it was redirected as a duplicate article. --Trovatore08:00, 4 December 2005 (UTC)[reply]
No one's responded to this question on Talk:Photon, so I thought I'd ask here.
What is the status of the possibility that photons have nonzero rest mass? I remember seeing an old Scientific American article on it, showing how Maxwell's equations would have to change, among other things. As I understand it, current observations have put an upper bound on photon rest mass, but have not ruled out its existence. However, supposedly (I don't understand why), the discovery of a magnetic monopole would refute a nonzero rest mass for photons.
Anyone know anything about this? Have there been any theoretical or experimental developments that bear on the question since the article I remember (which probably would have been from the '70s or so)? --Trovatore19:37, 3 December 2005 (UTC)[reply]
It is impossible, in some sense, to rule out the photon mass. But there are upper limits, set by experiments where we'd see the changes to Maxwell's equations if it had a mass above some value. At current, the recognized upper bound on the photon mass is
Or about 0.0000000000000000001 times the mass of the electron, the lightest particle whose mass is known. I don't know anything about magnetic monopoles ruling out photon masses, but it is the sort of strange thing that finding magnetic monopoles would do—they also explain charge quantization, which I saw a proof of once but have since forgotten. Well, that's a start at least. -- SCZenz19:46, 3 December 2005 (UTC)[reply]
Thanks. Might make an interesting note in Photon. --Trovatore 20:00, 3 December 2005 (UTC
Anyway, particle physicists don't refer to "photon mass" in this manner, since by E=mc² it would be completely redundant with the energy. Photons that are internal lines in Feynman diagrams can have non-zero mass (which can't be directly observed), but this is completely different. -- SCZenz23:29, 3 December 2005 (UTC)[reply]
I don't think a monopole would refute a nonzero mass of the photon. It would probably depend on what kind of mass it was. For example, if the photon mass were due to a Higgs mechanism, monopoles would still be allowed. As for whether monopoles are allowed in the Proca equation, or if the mass is from a topological term, I'm not sure. -lethetalk23:22, 3 December 2005 (UTC)[reply]
"Or about 0.0000000000000000001 times the mass of the electron, the lightest particle whose mass is known. I don't know anything about magnetic monopoles ruling out photon masses, but it is the sort of strange thing that finding magnetic monopoles would do—they also explain charge quantization, which I saw a proof of once but have since forgotten. Well, that's a start at least. -- SCZenz 19:46, 3 December 2005 (UTC)"
With that being said, photons would have to have infinite inertia, according to GR. Photons travel at C, and any mass would have infinite inertia at C. Do photons have infinite inertia?
If photons have positive rest mass, then they don't travel at c, but rather at different speeds depending on their energy. Since no such speed difference has ever been observed in vacuo (or at least I assume I'd have heard about it if it had been observed), the experimental error of these observations provides one way of putting an upper bound on their rest mass. --Trovatore20:12, 6 December 2005 (UTC)[reply]
"A fast-moving object moving at near to the speed of light cannot be accelerated to, or faster than, the speed of light, regardless of how much energy we put into the system. As we apply a force, and hence do work on the object, its speed does not appear to increase by the amount specified by Ekinetic = 1/2 mv2. Instead, the energy provided to it is converted to mass, and its relativistic mass increases, in what is known as mass dilation. The relativistic mass of an object is expressed as a function of its relative speed." If a particle has any mass at all, at rest or in motion, it's inertia would be infinite if it were to travel at C. Photons do not have infinite inertia. You can keep reminding me of the bandaid Einstein used to keep GR together, but every attempt you make will only reinforce my argument against it. Rather than have me show you proof of photons not existing, why don't you offer definitive proof of photons existing. You cannot, without "funneling" light waves through a lens or aperture. It is because in every conceivable method of detecting a "photon" you must use a lens or aperture, which "focuses" the wave into a point, (be it in your eye, or in a camera). For this reason, and because it holds GR together, do people assume they exist. Kevin E Carman
"the mass of the electron, the lightest particle whose mass is known"
Just a note, but I believe the mass of a neutrino is far lighter than an electron - apparently about a 10 millionth the mass.
A note to any who would be confused (this means you K carmen): if photon's have a slight bit of mass, this means that they do not travel at "c" the "speed of light" (poorly named). We do not know for absolute certain whether "light" travels at the "speed of light". For this reason, "c" has become a word in itself to describe the universal speed maximum. Photons could conceivably have another 10billionth the mass of a neutrino - we wouldn't know because its too small to measure. The only reason we found neutrino's mass is because we found that in a super-nova event, the neutrino's reached us slower than the photons - meaning only that neutrinos are slower and thus have mass. Since theres nothing faster than photons - such a discovery simply won't happen. Fresheneesz22:54, 7 April 2006 (UTC)[reply]
I run Windows XP, and I always have a lot of processes running. Right now, for example, I have 54, and I think that's low for today. Some I recognize (such as firefox.exe, or WINWORD.exe), but others I do not. Is there a program I can get, or a website to which I could refer, that would help me eliminate some of the extra ones I'm sure I'm running? Thanks! --ParkerHiggins20:26, 3 December 2005 (UTC)[reply]
Just copy the process name into Google. You will quickly find many sites discussing each process. Windows XP has MANY programs that run in the background. It isn't like Windows 98 where you could safely kill everything except systray and explorer. As you find out what is running, you may find services running you don't want (like wireless network detector, pcmcia monitor, or firewire support). You can disable those services in the control panel somewhere. I don't remember exactly where. I gave up on Windows a couple years ago. --Kainaw(talk)02:09, 4 December 2005 (UTC)[reply]
One place is in Control Panel > Administrative Tools > Services. In the right hand pane will be a list of services, their names, a long description, and whether they're started or not. George03:32, 4 December 2005 (UTC)[reply]
To turn off running processes, go to "Run..." in the start menu. Then type in "msconfig". This should bring up a window titled "System Configuration Utility". Click on the "Startup" tab. There should be a list of processes there that you can check or uncheck to startup with windows. Hope that helps!--Dimblethum05:12, 4 December 2005 (UTC)[reply]
The Wikipedia Help mailing list received an inquiry from a reader as follows.
I bought DVD X copy program the last day they could sell them at Best Buy and when I went to activate it they said it was not longer allowed to activate the programs so I was out $119.00 and left with a program that I could not use I would really like to know if there is anything that I can do I guess this is what happens when you are computer stupid. My license ID:2641969 and I also have a pass word for it but need an activation key for it
From the DVD X website... "CAUTION: Authentic DVD X Copy software is no longer being sold anywhere. Many "closeout", clearance, auction and discount websites are selling fake DVD X Copy Software products and "patches" that are not authentic, CANNOT be activated or are cracked versions that DO NOT WORK properly and/or that contain spyware. Beware of any sites that continue to sell version 4.0.3.8 and that guarantee activation. DVD X Copy products purchased from these sites are not authentic, not eligible for support or updates and should be returned for a refund." --Kainaw(talk)02:05, 4 December 2005 (UTC)[reply]
I can't remember what are the command line utilities for changing the locked status of files under Mac OS X on an HFS plus volume. -lethetalk23:04, 3 December 2005 (UTC)[reply]
When a penguin swims vs. walks, they have different heart rates due to a different intake of oxygen.
When it swims, it needs more oxygen right?
Is there any new information(from the past 3 years) on this topic, so i can base my essay on that?
Thanks alot
Your assumption is most likely incorrect. While I am not a penguin expert, semi-aquatic animals have a slower heartrate in water than on land. A quick google search confirms the same for penguins [14]. The issue is oxygen use. Penguins don't want to consume more oxygen while swimming - they want to consume less. So, over time, penguins who have slower heartrates while swimming are able to swim longer and deeper and get more fish. --Kainaw(talk)02:03, 4 December 2005 (UTC)[reply]
I was only assuming that penguins would have a similar reflex to mammals. As for the avian diving reflex, according to Ponganis (I don't know who he is), many avian species have diving aerobic activity that exceeds the calculated diving aerobic limit - requiring a slowed use of oxygen during diving. [15] --Kainaw(talk)04:20, 4 December 2005 (UTC)[reply]
One comsideration. You probably mean oxygen consumption in time. But a swimming penguin is of course much faster than a walking one (what, twenty times faster or so? - 1 km/h vs 20 km/h). So the consumption per distance (ie the efficiency) will be much higher when swimming. DirkvdM10:21, 4 December 2005 (UTC)[reply]
One of your problems is that you haven't justified your assumption that penguins need more oxygen while swimming than while walking/waddling: if I were forced to walk like a penguin, then allowed to swim naturally, I think I would find the latter less tiring... Another, more complex point is to look at thermal regulation in penguins: in which environment is their overall heat loss the greatest? Finally, if you're still stuck, consider the oxygen equilibrium in large aquatic mammals (e.g., whales): this won't give you the answer, but it will at least convince you that the answer is out there somewhere! Physchim62(talk)13:15, 4 December 2005 (UTC)[reply]
The Wikimedia help desk received the following question from Carey, a Wiki administrator.
I am wanting to do a little administration on the Wiki I installed internally but I didn't see anything concerning my idea. I want to limit a specific user or group to only be able to edit specific pages and their contents. Basically this user is going to be updating one specific page but I don't want that user to be able to edit any other pages.
I know there is a protect option to protect pages but my current Wiki has several thousand pages and protecting each one would be very time consuming not to mention not a suitable solution. If anyone knows of a way or if this isn't possible, I would like to know. Thanks in advance!
Can you guys help me find a good and reliable databases that features 2 dimensional molecular structures? An example of a 2 dimensional structure would be the image in the AMP article. I've found some databases on 3-dimensional structures of proteins [16], but am having a harder time finding something similar for 2 dimensional structures. KBi03:31, 4 December 2005 (UTC)[reply]
The Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) will probably not always have the structure you're looking for, but it is not bad. Otherwise there is ChemFinder, or PubMed, or several others depending on the compound you're looking for (Google as a last resort, but it can be useful for this type of problem)... A little bit more details about the type of compounds you're interested in would help to answer your question more specifically. Physchim62(talk)13:23, 4 December 2005 (UTC)[reply]
I suggest getting an engineering textbook. For example, Coulson & Richardson's Chemical Engineering, Volume 1: Fluid flow, Heat transfer and Mass transfer. There is no simple formula, except for heat transfer through radiation (Stefan-Boltzmann law). For non-radiative heat transfer (convection), you've get a lot more work to do. And the subject can't really be covered properly in anything smaller than a book. (And there are quite a few available) --BluePlatypus23:52, 4 December 2005 (UTC)[reply]
If the system consumes 200W in power, unless it comes out in another form, almost all of it is heat. If a mythical board in a 10V system draws 20A, and has an output that sends a signal with 200Vrms and 1A almost no heat would be converted. ALmost all computers make heat from all the power they consume. Now a 200W powersupply does not always generate 200W, but has a maximum rating of 200W.Dominick(TALK)15:51, 6 December 2005 (UTC)[reply]
I've been looking for information on how a CD is produced and read. In particular I am interested in the optics involved in reading the CD. Can anyone refer me to a source that discusses exactly what the interference is that reduces the light reflected at a pit-land boundary? Is it reflections from the two surfaces on either side of the boundary?
The article at http://en.wikipedia.org/wiki/Compact_disc contains a wealth of information, but there is one portion that bothers me. In the 4th paragraph under "Physical details" it is stated that the 125 nm pit depth is about one-sixth of 780 nm wavelength of the laser, and then "The sixth, 125 nm, (and not a quarter) of the wavelength was chosen to have a good trade-off between the push-pull radial tracking signal and the full-aperture read-out signal."
The relevant wavelength has to be that in the bottom polycarbonate layer. The pit depth would be one-fourth of the wavelength in the material for a refractive index of 1.56, close to what I find (1.55 to 1.58) listed in various places, so this is consistent. This raises a question about the rest of that sentance regarding tracking. I am seeking info on the subjest, and am not comfortable editing the article at this time. Apologies if I've violated any protocals here. --StanH06:22, 4 December 2005 (UTC)[reply]
You're right. That change (from one quarter to one sixth) was made by user Dsc a short while ago. It appears to be purely wrong, perhaps he doesn't understand how wavelength is reduced in a medium, and assumed a reason for it. The rest of the info would seem to be suspect. --Bob Mellish06:39, 4 December 2005 (UTC)[reply]
On the back of your Voice over IP equipment, there should be two ports: LINE and PHONE. The line port should be connected to the phone line, and if you have a phone handset, that can be connected to the phone port.
Lol, interesting question. Usually it is white, but, from what I've heard, it can be yellowish, grayish, or brownish and still be fine.Dimblethum04:46, 6 December 2005 (UTC)[reply]
The answer to point 3 is suggested by this UN report: "photosynthetic energy capture is estimated to be ten times that of global annual energy consumption". The latter was 3.8×1015BTU in 1999 according to US DOE EIA. The UN report also calculates the efficiency of photosynthesis to be between 3% and 6%. --Heron21:35, 4 December 2005 (UTC)[reply]
Photosynthesis is not the only variable that is under the influence of living organisms. The composition of the atmosphere can be altered by living organisms, changing the ratio of energy entering and leaving the biosphere. --JWSchmidt02:53, 5 December 2005 (UTC)[reply]
Yes; very generally, I'm curious whether the relatively small amount of energy available to the biosphere is enough to control global energy variations to a significant degree. I suppose altering Earth's chemistry is probably the easiest method. ‣ᓛᖁᑐ04:27, 5 December 2005 (UTC)[reply]
I was watching a tv programme recently that performed an experiment where room temperature and near boiling water was placed in different ice cube trays, when placed in a freezer, x minutes later the hot water had frozen faster than the cold water. I've yet to try this so don't know if this is true, but if it is, why would this be the case? I can't think of any logical reason why this would happen, so i'm wondering if anyone else knows why? Thanks in advance 84.64.138.23422:00, 4 December 2005 (UTC)[reply]
I've made a table in my LaTeX document that's narrower than the page, but wider than the page margins. LaTeX keeps aligning it with the left margin instead of centering it horizontally on the page. How can I get the table centered horizontally? I'm using the "tabular" environment at the moment. Thanks. -- Creidieki23:49, 4 December 2005 (UTC)[reply]
Have you tried resizing the table to the margin size or less?
Dear Help Desk
There is a new construction tunneling method is called New Austrian Tunneling method which we have read it from your website we are going to do a research program on this subject. This method is based on using a single lining of sprayed concrete using HPP fibres. Could you please advise me if there is some paper published about this method and how we can reach to any projects details using this method.
With Best regard
Dr Hamid Abbasi (FRPRC)
Check the "Internal links" section of the article you're referring to. If there's nothing there, click on the "history" tab above the article, and scroll down to the creator of the article. Click on his/her name, then click on the "talk" tab above his userpage, then click on the "+" tab to leave him/her a message. --YixilTesiphonSay helloConsider my Wikiproject idea22:26, 5 December 2005 (UTC)[reply]
Bluetooth techology sounds like a good way to increase distance between my head and the phone thereby making them safer choices.
Questions...
What type of "waves" do the ear pieces give off?
Is there a SAR for these waves, like there are for Dig/Analog phones
What is considered an acceptable (i.e., safe) level of emission?
Is bluetooth any safer than regular dig/analog cell phones from a emission stand point?
A flint is composed of mischmetal, iron oxide and magnesium oxide. However, why is German flint much better than the Chinese flint? What are the differences? Does the purity of mischmetal make the difference? Or, the process of making the flint matters? Please kindly answer my questions, or kindly provide any references to me. Thank you very much.
In a standard 9-5 work environment, what is the annual cost in wasted energy of leaving a PC monitor switched on overnight and at weekends, if the PC itself is switched off at those times (so the monitor will be in standby mode, not displaying anything)? Assume a fairly standard 15" CRT monitor, and UK energy prices. I'm trying to convince my work colleagues that this is worth bothering with (I work for a charity and saving money is important), but they all think that the cost is utterly negligible. I've tried Googling but couldn't find anything that quantified it in hard cash, though others may have more luck with different searches. --194.73.130.13216:19, 5 December 2005 (UTC)[reply]
A search for "monitor power consumption" comes up with useful information. For example, this 15" IBM monitor eats 70 watts when its in regular use, and 10 watts in standby -- and 5 watts in "VESA off", which I imagine is how things would be with the computer turned all the way off. Using this UK power cost calculator: assume, then, 128 hours standby per week, ~512 hours standby per month will run you £0.14 -- about the equivalent of leaving a 100-watt lightbulb on for a day. Wasting any energy, of course, is not a good thing, but you won't be able to make a hard cash argument for it. --jpgordon∇∆∇∆16:39, 5 December 2005 (UTC)[reply]
And it seems to vary by monitor make/model/age; my Optiquest Q71 (a 17" CRT) claims less that 3 W consumption in standby/powersaving mode. The Energystar specs may prove helpful. --Bob Mellish18:47, 5 December 2005 (UTC)[reply]
We have several posters at work that say that leaving a [CRT] monitor on overnight wastes enough energy to laser print 800 A4 pages. How accurate this is (or indeed how much energy it acutally is) I don't know, but I would suspect it is a useful rule of thumb. Thryduulf01:51, 6 December 2005 (UTC)[reply]
I would expect a printer running for that long to use a lot more energy than a CRT monitor left on at night, but that might just be reflection of my ignorance. -04:27, 6 December 2005 (UTC)
5 Watt over 1 year is 5 x 24 x 365 = roughly 40 kWh. A 200 horsepower car engine delivers 147 kW. So the yearly power consumption of one monitor would let a car engine run for less than 20 minutes (is this correct?). Convincing one colleague who lives nearby, but commutes by car, to go to work by bicycle (or a more distant one by public transport) just one day per year would have a similar, if not bigger, effect. The goodie bit about this is that you can do it yourself (providing you don't already), so you don't need to convince anyone. And you could even do it every day. Wow, think of the effect that would have! And then you could also try to convince your colleagues to follow that example. In other words, consider barking up the right tree :) .
I would love to commute by public transport, but 2-3 hours on three busses with a 5-10 minute walk each end vs 50 mins-1 hour door to door by car is no contest unfortunately. Thryduulf11:49, 6 December 2005 (UTC)[reply]
Which makes me think. Shouldn't we have an article that lists the power consumption of different household items and such (and the power cost of making them). I bet the car would be at the top of the list in a very isolated position. I've searched for 'power consumption', which didn't give any results. And ecological footprint doesn't help either. DirkvdM11:29, 6 December 2005 (UTC)[reply]
Repair Cost ... is there a relationship between how often you turn on & off the equipment, aggregate how long it is powered up, with its life span, After all, the equipment does not last forever, stuff wears out.
Human costs ... you show up for work, and power up your PC ... then you have to wait, and you are on the employee clock while you are waiting, unless your work load is such that you have something else to do while waiting.
I have metrics based on friends who manage networks and did unpublished tests.
Designate 100 PCs to be turned off outside work day.
Designate 100 to be left on 100% of the time,
Designate various sets of 10 where some parts of the hardware turned off outside the work day & other parts left on.
Designate 10 to be turned off during lunch hour.
Compare repair replacement hardware statistics by how the equipment is being treated, and include what kind of temperature extremes if the PC in an area without air conditioning or heat when no humans present.
What was found was that turning on & off at lunch time ... those machines had the MOST frequent trouble with stuff wearing out (electronic switches). The next MOST common problem was the stuff left turned on all the time. The equipment with the least trouble was that which was on during the work day, off during evenings, weekends, holidays.
The virus article states that vaccination is "the process of administering live, albeit weakened, microbes", though it also states that the cowpox virus is "a relatively benign virus that, in its weakened form, provides a degree of immunity to smallpox"
Firstly, obviously these sentences seem to contadict eachother. Is the virus weakened, or are the microbes containing them?
In the context of the source article, the term "microbe" refers to the microscopic causative disease agent-- in this case, the virus. It does not refer to some host organism (although there are bacteria, which are microbes, that are parasitized by viruses, which are also microbes). Smallpox vaccine is actually live vaccinia, or cowpox virus, and is not an attenuated virus. It is, however, sufficiently antigenically similar to smallpox that a cowpox infection (the intent of administering the vaccine) will confer protective immunity in a person who is immunologically competent. There are (other) vaccines that are live attenuated virus vaccines, such as the Sabin polio or the FluMist influenza vaccines, in which the virus is alive but modified so that it does not cause a full clinical infection.
Viruses are sometimes attenuated by culturing them in an environment that is different from the that found in the intended recipient of the vaccine. For example, a virus is cultured in a progressively colder environment, which selectively favors successive generations of the virus that are adapted to an environment that is below body temperature. These viruses would presumably find normal physiologic body temperature to be inhospitable, but would survive long enough to cause a mild infection and provoke an immune response. Denaturation of viruses usually results in a killed virus vaccine. -- Mark Bornfeld DDS dentaltwins.com Brooklyn, NY 18:04, 5 December 2005 (UTC)
Is there such a bird in china as the Xu? I find mention of it in two articles by the same anonymous user (nullaby and orange flavor chicken) and I can't decide if he or she is just making it up. I've googled it as thoroughly as I can and find no mention of it, and while I know that isn't a substitute for actual research, it usually turns up something. So if there are any naturalists or bird afficionados out there I'd appreciate some information.
thnx. Jasongetsdown18:37, 5 December 2005 (UTC)[reply]
I'm not sure what bird the person was referring to. They mention the loon, which is lan ren in Chinese. Then, nightingale is mentioned, which is ye ying in Chinese. The first thing that comes to mind is the use of xu for fake. As such, xuguo means to make something up and xuwei means false. But, another use of xu is to indicate an animal is domesticated. But, it is commonly pronounced chu when used that way (the proper pronunciation is xu, but because it is often followed by sheng, it becomes hard to say xusheng). Finally, there is a surname Xu. Since the person capitalized Xu every time it was used, perhaps the family Xu has a special bird named after them. All in all, there is no bird named Xu in my dictionary. --Kainaw(talk)01:00, 6 December 2005 (UTC)[reply]
What is the mechanism by which all things get buried with time? Is it always slowly raining soil out of the sky? it seems that the older a thing is, the deeper it is buried. Why is this so?
It is not the case that old things are always buried. Some things are pushed to the surface over time. For example, I live on an old plantation where multiple civil war battles were fought. When I work in the yard, I still find old things being pushed up to the surface after every rain. I'm sure some things are pushed down as well. --Kainaw(talk)20:36, 5 December 2005 (UTC)[reply]
I don't think Civil War-era artifacts are "old" in the context of the question. But sure, buried things sometimes get unburied. Then they usually don't last very long. I think that's part of the answer to the question: Things get either buried or destroyed, and we don't find the destroyed ones.
But no, it's not about "soil raining from the sky", mainly. Successive layers of sediment are generally added by water—either at the bottom of a body of water (since perhaps disappeared), or by flooding of rivers in an alluvial plain. Lots of different things can happen after that. With luck, maybe a geologist will come along and explain more specifically. --Trovatore20:50, 5 December 2005 (UTC)[reply]
Gravity tends to push things downward, especially if they are relatively dense and the soil is moist, but more generally things tend to get buried as material accumulates on top of them. Dead leaves, soil that gets moved around, dust. Things tend to be exposed by erosion, but what erodes somewhere has to deposit somewhere else. Plant roots can bury something (imagine a tree growing up on top of an object) or expose them (imagine the tree falling over and the roots tearing the object out of the ground). Then add the magic factor of time... Guettarda20:50, 5 December 2005 (UTC)[reply]
Erosion is the mechanism where broken down rock or soil moves around the place. Where I live, the local "hills" are weathering and eroding (ie moving) down towards the city. I guess in a long time the city will get buried. Basically the weathered rock, sediment, can be pushed around by wind or water (if you are under the ocean or a river) and will bury stuff. --Commander Keane20:54, 5 December 2005 (UTC)[reply]
"Is it always slowly raining soil out of the sky?" It a way, yes. Plants take carbon dioxide from the atmosphere and use the carbon in it to make their bodies (wood, leaves, etc). When a plant dies it falls to the ground where it rots. The action of the rotting returns quite a lot of that carbon back to the atmosphere (as carbon dioxide again). But some gets buried by more dead plant material (leaf litter and stuff) before it has had a chance to fully decay. Buried, there's little oxygen; it keeps decaying, but without oxygen the bacteria that decay it can only work very slowly, and they never manage to finish the job. Over the years and centuries new plants grow and die and partially decay, and each summer adds another thin layer of material, piling up on what's underneath. So eventually things that once were on the surface are covered by metres of material. Peat is formed this way, and is often many meters thick. A similar process happens in the sea, with little plants and animals that live in the photic zone (near the surface, where there's lots of light) dying on the surface; their little bodies rain down on the sea floor (that's marine snow) and it piles up, year after year. Sometimes this piles up for tens of millions of years, and eventually becomes chalk. -- Finlay McWalter | Talk
Which still leaves the question where the material comes from (the net result). I suppose part of it is the trees with deep roots that 'suck up' material from the ground and then dying, falling and depositing it on the ground (as Finlay pointed out), effectively turning the ground upside down. By the way, I believe Darwin investigated this too (measuring accumulation in his back yard), but I don't remember what he found. I vaguely remember it was something to do with snails. DirkvdM12:40, 6 December 2005 (UTC)[reply]
The material comes from the atmosphere, like I said. It's rather counterintuitive, but trees and other plants are made of atoms they obtained from the atmosphere. If they got those atoms from the ground, trees would sit in little depressions - but they get it from the air, and trees sit on little bumps. This is why planting more trees will absorb atmospheric carbon dioxide (see Carbon_sink#Natural_sinks). -- Finlay McWalter | Talk17:00, 7 December 2005 (UTC)[reply]
A little-known aspect of this is that the attraction between an oil molecule and a water molecule is actually stronger than the attraction between two oil molecules. The reason they don't mix is because the attraction between two water molecules is much stronger than either of those (because of hydrogen bonds). It's like the water molecules form a clique and although the oil molecules want to join, they can't because the water molecules don't think they're cool enough. (Silly little metaphor, but it helps. =P) ——Keenan Pepper22:06, 5 December 2005 (UTC)[reply]
Maybe because removing the gases affects pressure, and would affect the self-ionization of water, or something. Do hydronium and hydroxide ions play a part in the solution formation? I would imagine. Of course this is only a wild guess. -- Natalinasmpf22:46, 5 December 2005 (UTC)[reply]
The mixing should not be any surprise...in an oil and water mixture, there is always a slight amount of one substance dissolved in another - it just might not be an appreciable amount. --HappyCamper01:18, 6 December 2005 (UTC)[reply]
It was complete, like salt and water.
In what proportions? Now this is very interesting. Perhaps the water had some sort of chemical in it, or perhaps it was not water at all, maybe hexane? --HappyCamper02:07, 9 December 2005 (UTC)[reply]
Everything is harmful to humans in excess. You can overdose on water and oxygen. Petroleum jelly has a long history of providing health benefits. It has also been consumed in small quantities by some who believe it is good for the digestive system. If taken in excess, it is harmful. --Kainaw(talk)00:32, 6 December 2005 (UTC)[reply]
Are you asking why it might contain polysaccharides and monosaccharides? If so, then here is my answer. Sugars are usually stored as polysaccharides (why that is, I'm not exactly sure); glycogen is the main storage form in animals, and cellulose is for plants. To be used for an energy source the polysaccharide has to be broken down into a monosaccharide (usually glucose). So when a cellulose molecule in a plant is broken down, you could have both polysaccharides and monosaccharides at the same time.Dimblethum05:02, 6 December 2005 (UTC)[reply]
That's only half the reason. The other reason is that glucose is quite small, so it can be easily lost by the plant to the environment, along with your oxygen and carbon dioxide. -- Natalinasmpf22:07, 6 December 2005 (UTC)[reply]
What's up with these errors?? I have no idea why i'M getting them, AOL has always installed just fine in the past (AOL spyware not withstanding), and now everytime I start the process I get these..
As an alternative, would anyone know where I can find a much older aol installation? online? something like AOL 5.0 or 6.0, so I don't have to put up with all the addweary goodness that is 9.0b-SE--Aolanonawanabe23:49, 29 November 2005 (UTC)[reply]
Well, I can't help with the error message, but there appears to be an AOL 5.0 version for download at this site. I've never used it before, but it looks to be fairly legitimate. --ParkerHiggins01:06, 30 November 2005 (UTC)[reply]
Well, a quick google determined that "AOL 5.0 has resident broadband support capability" (from this site with the annoying pop-up). I think that means you're a go, but I can't be sure. You can check on the article, if you're in doubt. --ParkerHiggins01:27, 30 November 2005 (UTC)[reply]
Windows is a very broken thing hobbled by having to be backward compatible and a certain amount of poor design and failure to iron bugs out, so I'm surprised you would even ask why. On top of that, various installs and uninstalls of other software could easily leave your system in a broken state, that could interfere with the current install. The only solution to some windows failures is a clean install, but people will tell you that can be very risky as the distributor that installed in the first place had worked out all the driver issues etc, and probably had an image they ghosted onto the drive. You don't have that, so the reinstall could be risky. That said, I've used the OS reinstall disks that come with dells several times and they general work pretty well. So I'd say backup backup, get all your application install cd's and have a clean go at it. - TaxmanTalk13:59, 6 December 2005 (UTC)[reply]
Hey, this probably isn't the right place to ask this, but I have a question re mental health,fulfillment, and psychiatric meds.
I've got a great psychiatrist. He brought me back from a really bad place. I'm taking four different meds every day to keep things in the old brain operating normally, and as long as I do so I am able to deal with my feelings that life is utterly meaningless and lagerly devoid of pleasure and happiness.
That's what the meds are supposed to do - allow me to handle my feelings. Here's the thing - I'd like to enjoy life and be happy sometimes, not just not be overcome. I'm currently in therapy, and practicing cognitive behavior therapy. It is interesting but not efective in making me happy.
Is there any medicine that makes you happy? I have a _large_ family to support, and would rather not just exist as the food, shelter, and cash producing machine. I'd really like it if I could enjoy life as well.
I wouldn't say there was. Besides, medicines that make you "feel" happy IMO would be kind of an empty, meaningless happiness....I am reminded of the "happiness" induced in Huxley's "Brave New World". Medication to relieve depression is one thing, but to seek happiness I would indulge in philosophy, metaphysics and Nicomachean Ethics, not medication. -- Natalinasmpf04:51, 6 December 2005 (UTC)[reply]
I think there's a middle ground in there. I agree with Natalinasmpf that there are no psychiatric medications that make you happy, nor would you likely want them if there were. At the same time, many people, myself included, have better experiences with meds than something that merely allows you to function while still having depressive feelings. It's a fine line to draw, I know, but my experience is that the medicine didn't make me happy, it allowed me to be happy. On medication, I wasn't some unnaturally cheery person who was always happy regardless of the circumstances; but I was happy some of the time, more or less when you would expect a normal person to be, whereas when I had been depressed and not on any medication, I was constantly sad, even when I had no reason to be. If that's something you want to explore with your psychiatrist, talk to him/her about either increasing your dosage or switching medications. The danger is that the reaction to psychiatric medications varies greatly from person to person--what works wonders for one person is completely ineffective for another, and vice versa--and the only way of knowing what works best for you is experimentation. So if you do try switching medications, the danger is that you may give up even the functionality you've achieved so far. Whether that's a risk you're willing to take is between you and your psychiatrist. 12.223.56.10609:26, 6 December 2005 (UTC)[reply]
Taking medication that makes you feel happy is just kidding yourself. Perhaps if the therapy works your psych will decide to lower the dosage somewhat. Still, the best way to feel happy is to do stuff you like to do with friends and family. - Mgm|(talk)11:20, 6 December 2005 (UTC)[reply]
Meds, shcmeds. Philosophise. "Depressed" is a feeling; that "life is utterly meaningless and lagerly devoid of pleasure and happiness" is a thought, and it's obviously wrong. Think it through....
It can take a long time to develop an optimitic philosophy that can stand up to negative influences, and a longer time to translate that philosophy into positive emotions.... start by accepting that your happiness is your number one priority, more important even than "the truth". Exclude negative influences from your life (a friend of mine now refuses to watch the news; he's ill informed, but it doesn't matter, and people like him a lot more....) Learn to nip all negative emotions in the bud.... they're highly addictive, and entirely useless. TheMadBaron02:02, 10 December 2005 (UTC)[reply]
This might sound a bit trite but I'm happy if I wake up in the morning. My life is hard. My work is hard. I also feel that I am just a machine to produce money, food, shelter, for a bunch of leeches but when I look back to my dad I can see that he too must have felt the same. In time I have grown to understand that I was not as considerate as I could have been when I was young. That keeps my hopes up as regards my own little leeches in that over time they will be more considerate. In the mean time I take pleasure in the little things and those odd moments when I get to watch the sun going down. Take pleasure in the little things and the big problems are easier to handle.--Eye23:16, 10 December 2005 (UTC)[reply]
Is it possible to implement an equality check for "arrays" in Prolog? I am running into a problem where my particular version of Prolog is comparing memory addresses instead of the actual array contents in the recursive check. Any tips? --HappyCamper03:11, 6 December 2005 (UTC)[reply]
If you're using "A == B" (A identical to B) you might try "A ?= B" (A unifiable to B). If you're actually using lists, and they're fully instantiated (no uninstantiated elements), "A ?= B" should tell you whether the lists contain the same elements (recursively, all the way down to atoms) in a single expression. -- Rick Block (talk) 03:24, 6 December 2005 (UTC)[reply]
Will the air pressure different inside and outside a building?For a building near the sea,will the air pressure different too?
For the most part, no, there will be no difference. Buildings are not airtight, and even if they were, the pressure would rapidly equalize as soon as anyone opened a door. One exception to the general rule would be inflatable domed sports stadiums, such as the RCA Dome, where a roof of flexible fabric is held up by air pressuree. In these, the pressure is retained while people enter and exit via revolving doors. There are also conventional doors which can be used as emergency exits, but the pressure difference does create a stiff breeze if these are opened. Chuck09:09, 6 December 2005 (UTC)[reply]
Skyscrapers also seem to have a stiff breeze when doors are open; perhaps they have trouble equalizing pressure because the external pressure is different between the top and bottom? -- SCZenz09:15, 6 December 2005 (UTC)[reply]
It shouldn't be because of the pressure difference between top and bottom, either externally or internally. The difference in pressure due to altitude is an effect of gravity, and it would have the same effect both inside and outside the building. (That is, the external pressure at the top of the building will be less than the external pressure at the bottom, but at the same time the internal pressure at the top will be less than the internal pressure at the bottom.) I'm just guessing here, but I suspect that skyscrapers, while not perfectly airtight, have few enough spaces for gas to escape that it is possible for a pressure differential to build up, just as a result of ventilation, possibly with effects due to heating or cooling the air inside the building too. Note that skyscrapers also generally don't have windows that can be opened, limiting the ways in which the external and internal pressures can equalize. Chuck09:32, 6 December 2005 (UTC)[reply]
No, tornado damage is caused by the wind. It was at one time thought that when a tornado was approaching, one should open a window to "equalize the pressure," it's now known that this is unneccessary, and in fact it is strongly recommended that one not open a window. See here and here for examples. Chuck13:46, 6 December 2005 (UTC)[reply]
All that says is that openning a window is pointless and would just scatter broken glass anywhere, it doesn't say anything about there not being a preasure difference, not to mention wind is a preasure difference--Aolanonawanabe15:43, 6 December 2005 (UTC)[reply]
Air flow, such as wind, causes pressure to drop (this principle is also used in wings). So if a wind starts blowing, there will be a difference in air pressure, causing air to flow out at a rate dependent on the size (and location?) of apertures. And when, after satbilising, the wind (suddenly) drops, there will again be a pressure difference. About the location of the apertures. Suppose they are all at the windward side. Then I suppose air will get blown in, causing air pressure inside to actually increase despite the decreased outside pressure. DirkvdM14:25, 6 December 2005 (UTC)[reply]
That is very correct. A house cannot adjust pressure immediately. Wind also creates lift on the roof. Combined, many roofs give way and blow down the road. --Kainaw(talk)16:57, 6 December 2005 (UTC)[reply]
If your building is large enough then you may notice a Helmholtz Resonator. If this is the case then pressure in the building will periodically move up and down. For the Helmholtz Resonation to work, you need a dominant opening (ie a big door) and for the rest of the building to be virtually sealed (note: a shopping centre provides perfect conditions). When wind hits the opening it goes into into the building and sqeezes/compressses the air inside - increasing the pressure. The air then expands back, and the pressure drops. The process repeats itself.
Helmholtz resonation occurred at a local shopping centre. When it was raining it was noticed that the rain was getting "sucked" about 10 metres into the building - and stores were getting soaked. In the neighbouring post office the rain was only getting sucked in a couple of meters - the large, sealed nature of the shopping centre was allowing resonation which periodically sucked in air (and rain), and peridocially forced out air (but not the rain, which was saturating the store displays). The solution was to reduce the size of the dominant opening, with a glass wall replacing to old big door, and a side door installed. This is illustrated below, not to scale.
_______________
| |
| |
| |
| |
| |
|____ ___|
new door => /_______|
It is worth noting that the barometer is one of the few weather data recording instruments that meteorologists prefer to have indoors. Obviously instruments such as thermometers need to be outdoors, but for one that would get the same reading both indoors and outdoors, why expose the instrument (or, for that matter, the human observer) to the elements? EWS23 | (Leave me a message!)03:59, 10 December 2005 (UTC)[reply]
I have searched everywhere but was not able to find the answer I was looking for.
If I pour kerosene (ordinary kerosene) into a cup (a standard cup in which you drink tea) and then bring a lighted matchstick over it, will it burn? I am sure it will not, but my friends at work say it will and have bet me one cup of tea. I also remember doing this exact thing when I was a young kid and it did not.
Various web pages, such as this one, give the flash point of kerosene as 110° Fahrenheit (which is 43° Celsius) or somewhat higher. In order to start it burning you would have to warm some of the kerosene to at least that temperature. A match held very close to the liquid might very well do it: after all, people light kerosene lamps easily enough. But a match held "over" the cup at a short distance might not (even though a more dangerous fuel like gasoline would ignite). I would not want to speculate as to how close you bring it in safety. Indeed, I'd say "don't try this at home, kids." --Anonymous, oh my look at the time, 10:10 UTC, December 6, 2005
I think the vapour pressure of kerosene at room temperature in low enough that it is actually pretty hard to light. I have seen someone demonstrate this by dropping a lit match into a container of kero. The match went out. Kero lamps use presure or wicks to help vaporise the kerosene before burning it. --Martyman-(talk)11:03, 6 December 2005 (UTC)[reply]
Keep in mind that the liquid does not burn. The vapor/fumes/gasses burn. In a lanp, you light the wick, which heats the kerosene that has crept up the wick. At first, you are burning cotton (or something similar). As the heat builds up, you begin burning fuel instead. On a similar topic, I did an experiment with lighting a milk carton full of gas and one with just a little gas in the bottom. The full one caught on fire and made a mess. The empty one exploded and left a hole in the ground. Once again, the reason was that the fumes burn - not the liquid. So, going back to the original question, holding a match over the liquid to try and get it to start evaporating should get a flame started, assuming the match doesn't burn your fingers first. --Kainaw(talk)16:52, 6 December 2005 (UTC)[reply]
No, the kerosene will not light. Also, at normal atmospheric temps and pressures one match will not be sufficient to heat the kerosene to a point where the vapours ignite and the flame is self-sustaining. If you include some kind of wick (even a rag will do) then its quite easy to ignite kerosene. Otherwise it is actually fairly difficult and you need to compress/heat it quite a bit. This makes kerosene much safer and is why it is preferred to gasoline in many applications. So go collect your cup of tea. If your friends don't believe you, go buy a bit of diesel (chemically almost identical to kerosene) and show them. I promise you it won't ignite. -User:Lommer | talk02:46, 15 December 2005 (UTC)[reply]
I would say we are still very far. Computer vision is widely regarded as an AI-complete problem, and right now I doubt there's a program that can even reliably tell if a face is frowning or smiling (anyone want to contradict that?), much less tell whether two images are of the same person. —Keenan Pepper17:47, 6 December 2005 (UTC)[reply]
I think face recognition was implemented commercially at many major american events after September 11. I believe the first case I can think of was at the superbowl. I seem to recall there is a proposal to implement it as part of the London Tube security upgrades. See: Facial recognition system. Of course the reliabilty of these systems is questionable. --Martyman-(talk)21:11, 6 December 2005 (UTC)[reply]
There must be differenced between Computer vision (which allow computers to "understand" image content or content of multidimensional data in general) and a Facial recognition system (that works by comparing selected facial features in the live image and a facial database) which is a lot easier to realise. --helohe(talk)14:38, 11 December 2005 (UTC)[reply]
I do not have Mkicrosoft word on my computer and I wish to have it as what I currently have isn't getting me anywhere. Does anyone know any sites that you can download Microsoft Word, not some update, on to their computer. I really need it. Thanks!--XenoNeon17:59, 6 December 2005 (UTC)[reply]
Hm, I use OpenOffice; didn't know about AbiWord. Anyone care to compare the two? Does AW have sufficient advantages over OO to make it worth my time to download it, set it up and try it out? --Trovatore19:33, 6 December 2005 (UTC)[reply]
Abiword is merely a word processor - OpenOffice.org also contains functions for spreadsheets (like Excel), presentations (like PowerPoint), databases (like Access), among others. What will work for you depends on what you want - sometimes the multi-tool is ideal, sometimes you want something specialized. Just download and try it to check if it suits you - it won't cost you very much unless you're on dialup or pay per megabyte downloaded. TERdON20:41, 6 December 2005 (UTC)[reply]
There's also a free Microsoft Word Viewer available for download from Microsoft.[17] It won't let you edit documents, but it's a convenient little tool for reading them. —Ilmari Karonen (talk) 23:32, 6 December 2005 (UTC)[reply]
I wasn't sure how to answer your response to my December 1, 2005 , 1.15 question, so I edited it there and wrote this as a "new" question to a question. If wrong, I am sorry since I am new to this.
The laundry detergent used was good old fashioned Arm and Hammer Washing Soda.
A 1/2 tablespoon was put in 16 ounces of hot water with no other detergent (water is "soft") to remove an olive oil stain from cotton. A half an hour later, Voila,! No stain. How did it dissolve the stain.
Hi again! Sorry, I almost missed your question! I have been dabbling around different places on Wikipedia lately. No need for apologies - I'm glad to see you're around and enjoying the reference desk :-) Regarding your question, this is what my hunch is regarding what is happening -- Washing soda is really just sodium carbonate. It acts as a water softener. It also does a few other things too. When it dissolves in water, you get some carbonate ions (CO32-) through this process:
Na2CO3 -> 2Na+ + CO32- -- The sodium ions doesn't really do much. In this case, they are known as spectator ions. What happens to the carbonate ion? It reacts with the water in an equilibrium:
CO32- + H2O <-> HCO3- + OH-.
What does the hydroxide (OH-) ion do? It encourages the trans fatty acids in olive oil to dissociate. Let's represent this trans fatty acid with this:
/\/\/\/\/\/\COOH
and what happens is this:
/\/\/\/\/\/\COOH + OH- -> /\/\/\/\/\/\COO- + H2O
What is /\/\/\/\/\/\COO- ? Not exactly soap, but something that acts pretty much like soap.
In other words, the washing soda is slowly converting the olive oil into something that acts like soap, and this helps remove more olive oil from the shirt. This process happens continually until the entire stain is removed, or the washing soda is used up. The result is an emulsion of oil in water, stabilized somewhat by the washing soda. I must be a bit honest here - I'd be interested to test this out myself under more controlled conditions, as I think most of the work is actually being done by the hot water, and not so much the soda. The preference for the olive oil to stick to the cotton seems marginal to me based on just chemical structure alone. Finally, why is washing soda a good choice for things this? For one thing, it is a rather gentle compound - you would not want to wash cotton in a strong base, say something like lye - otherwise, the shirt might get damaged! I hope this helps, but if not, I hope it encourages you to learn a little bit more about the fascinating world of chemistry! --HappyCamper01:38, 13 December 2005 (UTC)[reply]
In types of decay which emit neutrinos or antineutrinos (beta decay, I believe), where's the neutrino come from, and why does it get emitted?
Also, with types which involve a neutron becoming a proton (such as in beta decay) or vice versa, what causes the change?
I never was able to get an answer to these in any of my science classes.
--Mr. Fluffles20:24, 6 December 2005 (UTC)[reply]
One reason, I believe, is that it's necessary for spin to be conserved. The neutron, proton, and electron each have spin 1/2, meaning their spin in a given direction can have a value of +1/2 or -1/2. If you only had n -> p+ + e-, you wouldn't be able to conserve spin; the left half of the equation would have a spin of either +1/2 or -1/2, while the right half would have a total spin of 1, 0, or -1. Photons have spin 1, so throwing one of those in wouldn't help. The electron antineutrino produced in the decay of a free neutron also has spin 1/2, so once that's added to the equation, spin can be conserved.
As for the question of why a free neutron decays, I'd say that If it can happen, it will. The neutron is more massive than the proton, electron, and antineutrino combined, so it gives off the excess mass as energy--in the form of a photon--when it decays. For contrast, compare the deuteron, an atomic nucleus consisting of one proton and one neutron. Because of the binding energy between the two, the deuteron has less mass than its possible decay products of two protons, an electron, and an antineutrino, so the deuteron doesn't break up unless you throw some energy at it. Chuck22:29, 6 December 2005 (UTC)[reply]
Also, lepton number must be conserved. In β decay, you start with a neutron: there are no leptons, so the lepton number is zero. Afterwards, you end up with a proton (lepton number zero), electron (lepton number 1), and an electron antineutrino (lepton number -1); this adds to zero. The antineutrino also carries away some of the momentum and energy of the reaction; the masses and momenta of the products are insufficient to account for the mass and momentum of the reactant neutron. Free neutrons are inherently unstable and will undergo decay by this process. The "converse" reaction, a proton being converted into a neutron with emission of a positron and an electron neutrino, is much more difficult; since the neutron has more mass than the proton, energy must be supplied to drive this reaction. A variant of this reaction occurs in the proton-proton chain reaction, one of the fundamental nuclear processes of our sun. According to that article, a proton waits an average of one billion years before being converted into a neutron (and combining with another proton to form a deuteron. Hope this helps (and hope I'm on the right track)! — Knowledge Seekerদ05:01, 7 December 2005 (UTC)[reply]
If you want real anonymity, use Tor (anonymity network). AOL's shifting doesn't really give you much anonymity - we see the same AOL IP address vandalise the same article for days sometimes (I guess others share that address too, and the vandal sometimes gets other addresses too, but by no means is it a "new IP guaranteed for each transation". -- Finlay McWalter | Talk01:36, 7 December 2005 (UTC)[reply]
Noting, of course, that Wikipedia blocks editing from the Tor proxies precisely because there is no way to tie an individual to his anonymous edits. (There's no way for us to deal with vandals using those proxies, so we block them from editing.) TenOfAllTrades(talk) 04:55, 7 December 2005 (UTC)[reply]
It isn't what you asked but I wonder if what you meant was the way in which AOL users typically have an IP address that changes? If so, the answer is no: AOL are following the standard procedure for ISPs with dial-up users. A few ISPs reserve IP addresses for dial-up users, but this is felt to be a waste of scare resources. Notinasnaid21:04, 7 December 2005 (UTC)[reply]
It depends; was your assignment more specific? :D See our article on DNA for details—bonds joining nucleotides along one strand of DNA are of one type, and the bonds that join two DNA strands together are of another. TenOfAllTrades(talk) 04:51, 7 December 2005 (UTC)[reply]
Yvonne, a reader, has sent the following question to the email help desk.
"Supposedly there is only one company in the USA that is allowed to enrich uranium and can you tell me their name? They are a publicly traded company. I am doing stock research. Thank you and best regards."
United States Enrichment Corporation, which was privatized in the 1990's. At the moment, they still use the high-cost gaseous diffusion process for isotope seperation, but they are apparently planning to build a centrifuge plant. See their website for details. I don't know whether there's any rule that says other companies couldn't get a license to start up an enrichment plant, but there would be very, very high regulatory hurdles to climb. --Robert Merkel05:08, 7 December 2005 (UTC)[reply]
Reader Andy has sent the following e-mail to the Wikipedia help e-mail desk.
"My phalaenopsis orchid is doing quite well and I was wondering how to
go about growing new plants by either forcing a keiki or by self
germination and growth on a nutrient gel."
grin*, Gandalf. Computers are fickle things, and it happens (with surprising regularity) that data on them gets lost. Your computer might crash, you could drop a brick on it, spill coffee on your laptop, or accidentally hit the delete key. If you have backups, you can get the data back. Just imagine what would happen if, tomorrow, your entire hard drive was emptied. What would you no longer have? Your documents? Your music? Your photos? Your programs? So that's why you make backups, so that when (yes, when not if) your computer crashes or dies on you, you will still have your documents stored somewhere safe. — QuantumEleven | (talk)10:07, 7 December 2005 (UTC)[reply]
In the same direction, but with a different emphasis. In business, people put a lot of things on computers. Lists of customers, for example, or phone numbers of all the important suppliers. Banks put the details of your account. These days, many businesses, large or small, will simply be unable to work, and go bust, if they lose the information on their computers. So a backup doesn't just spare them from inconvenience: it keeps them in business. I read a news story about a medical researcher who had years of vital research on a laptop that was stolen, and it was all lost. I think the news story was supposed to make us sympathetic, but I think: what an idiot: I hope he has to pay back his research grants. Notinasnaid19:05, 7 December 2005 (UTC)[reply]
Thanx guys the info was of some use and it even put a 'smile' on my face. Charné168.209.97.34
I have an HP R707 digicam. I want to know if it can capture the infrared and ultraviolet spectrum parts. If yes, would I need to use an image editing software to modify the levels etc to view the images? Thanks, =Nichalp«Talk»=10:02, 7 December 2005 (UTC)[reply]
I don't know if your specific camera is sensitive to the Infra Red or Ultra Violet, though many digital cameras are so there is a good chance it has some response at at least on end of the spectrum. The way that this is normally achieved is through the use of a filter that will block all visible light from entering the lens. A peice of totally exposed developed black and white film actually works as a pretty acceptable filter for IR photography. Surprisingly it is hard to predict what colour CCD elements will respond most strongly to these wavelengths that depends on the composition of the CCD filters used in the particular model camera. Some cameras (for example many nikons) can be disassembled and the IR filter removed from in front of the CCD. This greatly increases their Infra Red sensitivity and means normal shutter times can be used, otherwise you can expect shutter times signifacntly longer than for visable photography. --Martyman-(talk)10:27, 7 December 2005 (UTC)[reply]
The CCD is sensitive to IR. A typical digicam has an optical filter to restrict IR exposure. You need to remove the IR filter and Bayer mask (for the absolute majority single CCD color models) and then install a filter that blocks visible light. This is surely not an easy job to most models. You could damage your digicam if you don't have the required resources (manuals, tools, cleanroom, skill ...). Anyway, you will lose you warranty. And if you want to do serious IR photography, you need cooling. However, withour proper tools, your digicam can be spoiled by condensation. Some videocams have a low light mode. I think that's IR photography at work. Maybe you can find yourself a cheap or used grayscale surveillance camera and modify it. -- Toytoy14:47, 7 December 2005 (UTC)[reply]
Note that with a typical CCD camera, even in the best conditions you'll only get sensitivity in the near-IR up to about 1.1 μm. You won't be able to see anything in the dark unless you illuminate the scene with something like an IR LED (camcorders that have "nightshot" capabilities do this sort of thing.) For real "thermal vision", you need a cooled camera sensitive to mid-IR, which is an order of magnitude more complex and expensive. --Bob Mellish17:04, 7 December 2005 (UTC)[reply]
Then how do we get a filter that only has one window at near-IR so it blocks visible light and mid-IR as well? I also don't know if a peice of totally exposed developed black and white film can be used as the filter because I am not sure if the silver particles would block all the light. Anyway, the wavelength of near-IR is longer so it can be less of a problem. You may want to attach the filter on the surface of the CCD to prevent loss of optical resolution. -- Toytoy00:27, 8 December 2005 (UTC)[reply]
What article titles would you say that is an interesting, important one for electronic devices and circuits, especially talking about analogue devices and circuits?
Oh, I know why. The chloride is a better leaving group than the trihalomethyl group, so it leaves giving you trihaloacetic acid and chloride, instead of haloform. —Keenan Pepper02:23, 8 December 2005 (UTC)[reply]
(since this might be an interesting addition to Lava lamp)
I purchased a desktop USB lava lamp during the summer, and was disappointed that the "lava" (in this case little reflective dots that are convected around in the denser fluid) would settle out of suspension after a few days. However, with the onset of winter and a colder office on average...the lava stays suspended and all is well.
I'm wondering why that is. Nothing else has changed in the setup. The lavalamp stays on all the time because my computer stays up all the time, so its not a case of thermal interia. The temperature drop in my office is at maximum perhaps 4 degrees (77F to 73F).
My guess is: unlike a normal lavalamp, the USB lamp is much smaller. The temperature difference between the area heated by the bulb and the outside surface of the lamp isn't that great, so larger convective patterns cannot develop in a warm office and the dots settle out.
The problem is that lava lamps are highly dependent on specific gravity. The density of the lava must be carefully balanced with that of the remaining fluid; otherwise the lava will have the wrong buoyancy and either float or settle. Changes in temperature will change the density ratio between the lava and fluid. ‣ᓛᖁᑐ16:42, 7 December 2005 (UTC)[reply]
...but if the colloid is broken down by heat it seems like a poor design for the lavalamp. There probably isn't much of a delta in the overall temperature of the resevoir when the lamp is placed in an environment that is 4 degrees colder, in comparison to the heat generated by the bulb itself? ie would the put a colloid in there that breaks down at say 79 degF but is stable at 76 degF? --Syrthiss21:40, 7 December 2005 (UTC)[reply]
I was curious as to what year this information came to light?
"With chronic low-level exposure, similar neurologic injury may occur. Carbon monoxide acts as a potent neurotoxin, creating irreversible lesions in the brain's white matter (i.e., the myelin sheath). Such lesions, which are similar to those found in multiple sclerosis, can result in severe cognitive impairment."
I wouldn't believe it without sources. The article is pretty awful in many other parts and gives no impression of being well researched. Some information can be gained at Carbon monoxide and the pages it links but I have never seen any claim that carbon monoxide is neurotoxic in the true sense of the term. Physchim62(talk)15:55, 9 December 2005 (UTC)[reply]
Where do people find the Bacteria that are used for cleaning the sewge.I can not fully understand the biological stage in sewage treatment.Could someone explain it to me?
Thank you
I suspect they are just there, in the environment. I did hear an interesting tale about cheese: apparently the hygiene requirements on cheese makers are tending to eliminate the bacteria which are otherwise just everywhere; this can stop the cheese from making correctly. Don't know it's accurate. Notinasnaid21:01, 7 December 2005 (UTC)[reply]
The term cyborg, a portmanteau of cybernetic organism, is used to designate an organism which is a mixture of organic and mechanical (synthetic) parts. Generally, the aim is to add to or enhance the abilities of an organism by using technology. - From the cyborg article.
But what about the other way around? What would you call a computer that uses biology to enhance its function? For example, look at this news story of a group of 25,000 rat neurons hooked up to a flight simulator program. Imagine that a robotic drone or missile would use such a biological part (or even regular computers in addition to a synthetic CPU). Would you call these cyborgs or something else? Biocomputers maybe?
I recently installed an update of tabbrowser extensions which broke my version of firefox. I'd love to keep using this extension but it's just too unstable. Does anyone know of other extensions that have a similar range of features? The ones I'm most interested in are Duplicate tab (opens new tab with an identical history) and being able to reorder tabs in the tab bar (via drag 'n drop). I've checked the mozilla site but nothing seems to offer the reorder tabs feature... -User:Lommer | talk23:30, 7 December 2005 (UTC)[reply]
Ok, grabbed the newest version and all is good. Still missing that duplicate tab function though. I'll see if I can find an extension that fits the bill. -User:Lommer | talk23:45, 7 December 2005 (UTC)[reply]
I went through the same process with Tabbrowser Extensions; it was great for a while, then kept getting more complex and less stable. Check out Duplicate Tab and Tab Clicking Options from Twanno's Mozdev page. —HorsePunchKid→龜2005-12-07 23:54:08Z
Hmm, that looks interesting. Incidentally, I use tabpreview, which gives you a nifty pop-down thumbnail of each tab when you mouseover it, making it easier to find the tab you want, particularly when you have dozens of tabs with the same title open at once. -- Finlay McWalter | Talk00:03, 8 December 2005 (UTC)[reply]
Ok. A little question. What are the 3 most abundant of "Phosphorus's" isotopes? And at www.webelements.com, it said Phosphorus's crystal form is triclinic. So what could I rely more on, this site or webelements? I guess the majority who say a certain thing wins. Please help. (71.253.225.174)
I think he/she was referring to our page on Phosphorus, which says it's monoclinic, in contradiction to www.webelements.com. Both are misleading because the crystal structure of phosphorus is so complex — it has at least three allotropes (different crystal structures of the same element) and probably more weird hybrid forms and stuff. So, it can be either monoclinic or triclinic. —Keenan Pepper02:00, 8 December 2005 (UTC)[reply]
It tells right there at isotopes of phosphorus that 31P is the only naturally occurring isotope, for all practical purposes. (The articles themselves aren't the proper place to leave comments, by the way, use the talk pages.) 32P and 33P are also created in trace amounts as decay products by cosmic radiation. Femto12:53, 8 December 2005 (UTC)[reply]
How long can the hepatitis B virus live in a droplet of blood?
I'm having difficulty verifying the information cited on the Ohio State University site, but according to this source, "...The hepatitis B virus (HBV), on the other hand, can remain infective for days in dried blood, months in serum stored at room temperature, and even decades when frozen."-- Mark Bornfeld DDS dentaltwins.com Brooklyn, NY 04:50, 8 December 2005 (UTC)
hy i am in grade seven and my text book doesint say why so if you could help me out than ...yah :-p why are some volcanoes more explosive than others?--24.64.223.20303:59, 8 December 2005 (UTC)[reply]
if this could be answered by ...tomorow that would be wonderful thankyou
by the way GREAT website its helped me with sooooo much stuff :-)
oh and how do i find the answer to this LOL ha well anyways thxs
The explosiveness of the volcano tends to be due to the amount of gas that is dissolved in the magma, or how easily the magma plugs up causing pressure build up, and this is directly influenced by how viscous the magma itself is, which itself is strongly influenced by the mineral content of the magma at the particular location. Volcano is a good article to be reading, as well as the links at the end of it.--Fangz06:18, 8 December 2005 (UTC)[reply]
There is a great variety of possible causes for your pain. Wikipedia does not give medical advice, nor can conditions be easily diagnosed over the Internet. Please speak with your physician. — Knowledge Seekerদ06:19, 8 December 2005 (UTC)[reply]
Most abdominal pains (including chest pains) are digestive (stomach/intestines). That creates a problem - when do you have a heart attack and when do you just have bad gas? --Kainaw(talk)21:02, 8 December 2005 (UTC)[reply]
What is a "V/f curve" or "V/f characteristic curve? Is there a WP article where I could read more about it? --Angr (t·c) 09:19, 8 December 2005 (UTC)[reply]
On second third thought, my answer is making less and less sense the more I think about it, since molar volume over fugacity, wouldn't actually have any significance that would make such a notation useful--Aolanonawanabe02:04, 13 December 2005 (UTC)[reply]
I suck at science. And I really have no idea what your talking about, however. Maybe this Link may have some relavancy? :D --Yardan \ Talk
More details about context would of course be helpful but let me point out a commonly known application where the V/f curve (voltage to frequency curve) is important: FM radio. The WP article doesn't mention the V/f curve but in short the relevancy is the following: FM is frequency modulation, which means that the signal (music e.g.) is broadcast by varying the frequency of a carrier wave. The receiver must than take this variaton in frequency and change it into variation in voltage. The loudspeakers will then take the variation in voltage and produce sound. If there is to be no distortion the receiver should have a linear V/f curve, i.e. if a change in frequency by one unit causes a change in voltage by one unit then a change in frequency by two units should cause a change in voltage by two units. The link [19] seems good, take especially a look at the section Receiving FM. Stefán Ingi14:55, 8 December 2005 (UTC)[reply]
To make it clearer: The V/f curve is used in frequency inverters to control the relation of the frequency and the voltage of the electrical energy pushed to the motor. A three-phase asynchrone induction motor generally can't be fed with nominal voltage when running in subnominal speed. That would mean the current through the motor would be higher (there is a classical curve on the connection between rotation speed of an induction motor and the motor current available, unfortunately it's not depicted in the induction motor article). Basically, if you wouldn't use a lower voltage at speeds below nominal, the motor current would grow much larger, resulting in some black smoke and a broken motor. Because of that, you use a V/f pattern (in simple frequency inverters) to make sure the motor isn't treated badly. Sometimes it could be preset, sometimes you have to make one for yourself (specifically tuned etc). More advanced frequency inverters implementing motor current supervision aswell, not always need this setting to be made (they use other control types than a simple V/f pattern - like open loop / flux vector / pulse generator feedback etc). TERdON 23:41, 8 December 2005 (UTC) PS: Regular inverter (the digital, negating kind) as far as I know, aren't related in any way), they only deal with digital logic. TERdON23:44, 8 December 2005 (UTC)[reply]
For example, I am now in the C drive, I want to go to the folder "WINDOWS" in the c drive, so I type "cd Windows", and the command line intepreter turned into "C:\>WINDOWS>. I then do the stuff I need to do, and want to leave this directory to go back to C:\, how do you leave a directory and go back to the original directory? i tried "cd C:", and "C:" but it didn't turn out to be working... How does one return to the previous directory?
please correct me if i am wrong, but i came across the fact that electromagnetism is a stronger force, compared to gravity.
for instance, i have a negatively charged piece of material, and throw a positively charged material into the negatively charged piece (both have same size, mass). The negatively charged material is placed on the floor, and one drop the positively charged materil above the negatively charged material, will it repel? by repel i mean the positively charged would be "bounce" off from the negatively charged.
if this is true, we human, when falling off a cliff, should be able to survive. because we are composed by atoms, and at the exterior of the atoms there are electrons. the floor is bonded so that the electrons are circuling the floor. in theory, when i fall, the electrons in my body should repel the floor's electrons as both is at the exterior, am i right?
In response to your first question, "electromagnetism is stronger than gravity" is not exactly true. More correctly, you would say that "electromagnetism prevails at small distances, gravity at large distances". It's true that, for two object close to each other, the electromagnetic forces between them will be stronger than the gravitational forces between them ("electromagnetism prevails"). However, for the same two objects at very large distances from each other, the electromagnetic forces are much smaller than the gravitational forces between them ("gravity prevails").
In response to the second half of your question, you are correct: the repulsive forces between the electron shells in the atoms of the ground and the electron shells in the atoms of your body repel each other. But all this means is that the two will not pass through each other - you stop when you hit the ground, instead of passing through it. All the atoms composing your body will come to rest at ground level (your body will still be there!). What kills you when falling off a cliff are the forces acting on your body to cause you to stop so suddenly - your body will be crushed and deformed, and this kills you.
(aside: what happens when two atoms are mashed together strongly enough to overcome the repulsive forces between their electron clouds is called nuclear fusion, and it's the process which powers the sun. But the energy needed is much, much greater than someone falling off a cliff!) — QuantumEleven | (talk)10:33, 8 December 2005 (UTC)[reply]
Sorry, I screwed up on my first explanation (and I didn't read your question properly :( ). Whether or not the object will "bounce" depends on how much charge it has - the repulsive force between it and the object on the ground must be stronger than gravity. However, in most everyday situations, you should be able to give an object enough charge so that it will be repelled by an identical object lying on the floor. It won't 'bounce' straight back up - that kind of repulsion is not stable - it will most likely be deflected and land to the side of the object on the floor.
Concerning whether the electromagnetic force is 'stronger' than the gravitational force, yes it is (see Fundamental interaction) - by about a factor of 1036. So for objects which have about the same amount of mass as they have charge (so on the order of 1 Coulomb per kg), the electrostatic forces between them will greatly outweigh the gravitational forces between them. For many everyday objects, this is the case, so the electrostatic force between them will dominate the gravitational force (why, for instance, your hair will stick to a balloon which you've rubbed on your sweater). However, when you start talking about very large objects (planets, stars, solar systems, galaxies...) they have much, much more mass than they have charge, so despite the fact that electromagnetism is stronger than gravity, the gravitational forces between them dominate, and the large-scale structures of the universe are almost entirely determined by gravity alone. — QuantumEleven | (talk)11:00, 8 December 2005 (UTC)[reply]
I don't know much about these forces, but I thik there is another problem here (we know there is a problem, since we don't survive falls from high cliffs in general). This is assuming that if you bounce you aren't hurt. It's easy to assume that the bouncing is what matters (e.g. jumping from a cliff onto a trampoline.) But you could also jump into soft materials and not bounce and perhaps survive. What injures and kills on a fall is the sudden stop. The edge of your body stops, and your bones and organs keep going, smashing into the bit between themselves and the ground. They damage other parts of your body, and themselves. By making a stop less sudden, we reduce this injury. In some cases, the thing we land on takes up our energy and we bounce, but that's just a side effect. Subatomic forces might stop you (well, I guess they do: it's really hard to make the atoms from two solids mix; but I don't know if they are the same forces as mentioned). But they will probably not take effect until you are a fraction of a millimetre from impact, and so the stop will still be sudden and uncomfortable or fatal. Notinasnaid11:17, 8 December 2005 (UTC)[reply]
I personally believe that the whole "gravitational force" theory is bunk. You can produce the same effect and keep all the same gravitational formulas using kinetic force of atomic and subatomic particles without gravity. But, until Einstein is reincarnated and says so, nobody will consider it. --Kainaw(talk)15:48, 8 December 2005 (UTC)[reply]
From strongest to weakest, the fundemental forces of nature are the strong nuclear force, teh weak nuclear force, EM, and gravity. Their strength is also inversly proportional to the distance they act over -- the strong nuclear force acts across distances proportional the size of a proton; on the other end of the scale, graivtyu acts across billions of kilometers. Raul65416:18, 8 December 2005 (UTC)[reply]
'Sup,what is spam and how do you delete it? Can you also tell me how messages in the email system managed?what's the difference between spam and junk mail? could you possibly list the default settings on a computer and kinda explain them to me? thanks a million...i will appreciate any feedback and assistance a.s.a.p Charné168.209.97.34
What is spam? Mail you don't want.
How can you delete spam? In your e-mail program there will be a delete button or similar.
What you didn't ask: how can you prevent spam? You can't completely, but there are many programs and services which screen your mail and try to recognise spam, then delete it. These will unfortunately sometimes delete real mail (e.g. a joke from a friend that mentioned viagra). You can also prevent or reduce spam by keeping your e-mail address a secret and making sure it can't be guessed.
Spam and junk mail are probably the same thing for your purposes.
No, I don't think we could list the default settings on your computer. Firstly, you don't tell us what kind of computer you have, and what software you have on it. Second, modern computers have thousands, or tens of thousands of settings. This is a major series of books, not a reply! If you have more specific questions, please ask.
Spam is electronic junk mail — a bit more precisely, spam is e-mail you don't want and didn't ask for. It can be any number of things - advertisements, invitations to fraudulent schemes... (we have very good articles on Spam and E-mail spam). To delete spam, (assuming you're using an e-mail client, such as Outlook Express or Mozilla Thunderbird), just click on the offending message and press the delete key on your keyboard. :)
As to the rest of your question, I'm not entirely sure what you mean. Which "e-mail system" are you referring to? Which e-mail program do you use? I am going to go out on a limb and guess that you are getting lots of Spam mail and want it to stop. Welcome to the wonderful world of the internet...
Dark humour aside, spam is a real nuisance to many e-mail users. The spammers (people who send you the trash now cluttering your inbox) probably got your address by 'harvesting' (reading) it off a messageboard or something, so, first rule for avoiding spam: never post your e-mail address on the internet if you can (in chat rooms, messageboards, on wikipedia...). Perhaps get a second e-mail address for "internet stuff", you know, to sign onto websites and such, and keep your main e-mail address for e-mailing your friends - that way, your main e-mail address stays clean of spam. Free e-mail services like Hotmail are great for getting a second (or third, or fourth) e-mail address.
Spammers use other evil tricks to get your address. They will send out messages to millions of e-mail addresses, most of which will be wrong or nonexistant. The messages they send often include a link to "unsubscribe" - but what often happens is that, by clicking the link, all you do is tell the spammer that your e-mail address is 'real', so encouraging more spam. Therefore: never click on any link in a spam e-mail (and, for heaven's sake, never buy anything advertised in spam!)
Check with your ISP (the company you get your internet connection from) - many now offer spam filters for their e-mail addresses, see what they offer. Alternatively, you can try to do some e-mail filtering on your own computer. Filtering is a fancy name for an automated process whereby your computer tries to guess if an e-mail is Spam or not, and then does something to it if it thinks it is (deletes it, moves it to a different folder...). It's still not 100% accurate, but getting better. However, if you want to set up filtering yourself (as opposed to just using your ISP's filter) it up can be a bit tricky, and it's hard to recommend a specific program without knowing more about what kind of computer you have, what kind of e-mail you use (from your ISP, web-based...). Maybe some of the more informed people on here can give you a few tips.
One last word of advice: be wary of anti-spam solutions that look too good (yes, I know, that's a very vague criterion) - scammers are now trying to bait you with phony "anti-spam" programs which, at best, do nothing (but sometimes costing you money!), and, at worst, install all sorts of nasties on your computer. Check with any computer-savvy friends (or ask here!) before installing any anti-spam program you're not sure about. Good luck! — QuantumEleven | (talk)11:27, 8 December 2005 (UTC)[reply]
I have actually received spam advertising anti-spam software. Aside from their mere nerve to do it annoying the hell out of me, I am sure that if I were to buy and install their software, all it would do would be to purposefully attract more spam. — JIP | Talk11:51, 8 December 2005 (UTC)[reply]
Lots of good advice up there. There's several approaches you can do.
Help put a SPAMMER in the SLAMMER ... visit www.ftc.gov to see how you can help your government apprehend criminals ... there's various things you can do when you get spam that is obviously criminal, to help see to it that the criminals get reported to agencies interested in apprehending those criminals ... be prepared to be frustrated, the e-police are often like keystone cops.
Learn how to communicate on the Internet without publicizing your e-mail address to lots of strangers, which is a huge topic by itself. Then after having done so, go thru the process of changing your e-mail address to one in which you will practice what you learned. Notify legitimate contacts of your new e-mail address, and discontinue using the one that is now glutted with spam. Expect to have to change e-mail addresses every few years just because of this problem.
It may be of interest to you how I protect myself. Incidentally I have been using the Internet since the 1970's and have been using computers since the 1960's. I have a multi-leveled defense against viruses, hackers, spam, and other variations of malware.
I use an ISP which intercepts a lot of this garbage before it even gets to my home.
I have a hardware firewall that intercepts a lot of this garbage before it even gets to my PC.
I use a lot of tools connecting to the Internet which involved encrypted communications so that anyone listening in on my Internet communications is going to have a hard time, and be tempted to move along and attack some easier target.
I have a suite of Internet security tools running in the background on my PC all the time to try to intercept this garbage before it can do any damage.
I have more than one anti-spyware product on my PC which I run periodically.
I keep my anti-virus definitions up to date and run a total scan periodically.
I stay informed on the inadequacies of these tools so that false positives are less likely to bite me.
Ouch!i'm new at this computer geek thing so don't bite my head off plz?Could you at least list 5 common default settings.Could you also help with the procedure on what to do if your computer is infected with a virus(and what not to do)? what precautions should you take when opening an email message? my research report has to be in by 15h00!THANX Charné168.209.97.3411:36, 8 December 2005 (UTC)[reply]
I'm not going to bite off your head, but I will ask you to DYOH (Do Your Own Homework) - see the instructions at the top of this page. To get you started on your second question, you can try reading our article on computer viruses, or this. A Google search can probably help you with your third question. Good luck! — QuantumEleven | (talk)12:52, 8 December 2005 (UTC)[reply]
If your computer is infected, run a virus scan with a anti virus software (ie norton, kaspersky.) What not to do? Well, it greatly depends on what kind of virus your infected with. Don't send emails (cuz' virus may auto attach to them and infect the receiver.) To be on the safe side, don't do anything at all.. run teh virus check! precautions before opening a email, well.. check the subject line, if the subject looks doubtful, don't open it? I'm far from any security expert myself, and I doubt the 'random' pc user is. But these tips just seem logical. --Yardan \ Talk
Since you said your report has to be in by 15:00, I'm assuming you're writing this on the same day it has to be finished. Usually, it's a good idea to start these kind of things earlier. It makes finding the required information a lot easier. - 131.211.210.1608:45, 9 December 2005 (UTC)[reply]
There is something to be said for learning how to do things at the last minute. In the real world when someone asks us for something in business, they usually expect it done IMMEDIATELY and they REALLY need it YESTERDAY. So people, who can learn to do assignments exceptionally well in next to no time, will have a great competitive advantage in the modern business world. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 20:37, 14 December 2005 (UTC)[reply]
This has been bugging me for a while. As a space enthusiast, I love looking at pictures of features on other planets and moons. However, often I find that when I look at pictures of three-dimensional objects (such as the caldera of Olympus Mons, on the right), about half the time my eyes seem to suddenly 'shift', and I'm seeing things 'inside out' (in this case, it seems as if the caldera depressions are suddenly hills!). I know that they're supposed to be depressions, and sometimes I can force my eyes to 'shift' back to seeing them as depressions, but not always. Is there something wrong with my vision? Or is it a peculiar features of pictures taken from high altitude? — QuantumEleven | (talk)13:21, 8 December 2005 (UTC)[reply]
This is a pretty common bit of visual trickery - I've a map-reading manual from the twenties which discusses it in some depth, suggesting it's common, but never thought to look for it elsewhere. Try finding a topgraphical map and looking at it, not paying attention to anything but the contours, and you'll find that the valleys suddenly become ridges, the hills bowls... It's normally not a problem in the "real world", as we have things like rivers and streams and puddles - glancing at the watercourses always makes it obvious which way is down. It is pretty neat, though. Shimgray | talk | 13:57, 8 December 2005 (UTC)[reply]
I can't remember the name of it but it is a noted thing in psychology. There is a way of using this to test how introvert/extrover you are. Basically you get a drawing of a wire frame cube and put x marks in the top corners of one of the squares, over the course of a minute you then note how many times the crosses switched from being on the front square to the back square and vice versa (its easiest if you signal to someone else when it changes and get them to count and time). I don't know how reliable it is, but it seemed to work for our class of ~25. IIRC the range was from about 30 to about 115 flips per minute, with introverts at the low end and the extroverts at the high end. I'll look this up when I get home this evening, unless someone has beaten me to it. Thryduulf14:16, 8 December 2005 (UTC)[reply]
It doesn't just "help", it's the answer to the question. If you know the direction of the light you can easily distinguish between the two, because it tells you whether a lit surface is interior or exterior. --Fastfission21:34, 8 December 2005 (UTC)[reply]
Normally when we look at geographic features, there are additional depth cues on which we can rely. The little bit of scattering provided by atmospheric dust and haze–even under very 'clear' conditions–is enough to let us know which parts of a scene are farther away. (Artists use this all the time in painting landscapes, see atmospheric perspective). If you're moving, parallax gives you an additional cue—relative to the surrounding terrain, a hill will 'move' differently from a crater.
When you look at an overhead photograph of Mars, the Moon, or some other astronomical object with little or not atmosphere, you don't get either clue. There's no way for your brain to decide which part of the image is nearer to the observer, so it pops back and forth.
I notice that if I rotate the image to have the lighed parts facing up the features look like hills and just the opposite if rotated 180° (lighted parts facing down the fearures appear to be depressions). --hydnjotalk15:34, 8 December 2005 (UTC)[reply]
That's probably just because it is less intuitive to assume light coming from the "bottom" of a picture (even though in reality, with 2D aerial maps there is no reason to assume one direction over any other). --Fastfission21:34, 8 December 2005 (UTC)[reply]
I have tried and tried, but whenever I look at the image I just see hills, I can't get it to flip to craters. I have looked at Image:Olympus Mons.jpeg, so I know they are really craters. I have also tried different rotaions. Is there something I can do? I know I have trouble seeing stereoscopic images, so can someone tell me if it still flips with one eye open.--Commander Keane23:57, 8 December 2005 (UTC)[reply]
oh, I remember this picture... I see hills usually, but occasionally they become craters instead. It's an interesting phenomenon; if you're attentive enough, you may notice the flat surfaces seem to drift in a particular direction when the image flips, indicating there's some postprocessing going on in your visual system. If you have trouble seeing both orientations, try focusing on a small area until you can get that part to flip; the rest may follow. Defocusing your eyes briefly may help too. ‣ᓛᖁᑐ03:41, 9 December 2005 (UTC)[reply]
Here's another instance of this sort of reversal. Go to the Google Maps web site and choose a large city that you're familiar with, and a location in the city with tall buildings. Zoom in all the way, and go to the satellite image. (This won't work everywhere in the world, as their coverage is uneven. Note that in some places, like Paris the last time I looked, they have good satellite coverage but not good map coverage.) Anyway, if the location is in the northern hemisphere, when you look at the satellite image the buildings are likely to look weird. In some places where tall buildings are close together, you may see buildings in what are actually the spaces between them. This is because they show north at the top, but the sun, being over the tropics, is lighting the images from the south. If you have a program that can invert the image, putting south at the top, it will look more natural that way. --Anonymous, December 9, 2005, 07:15 UTC.
Are oil or fat stains converted to "soap" (saponification) when detergents or cleaners (such as sodium ccarbonates, percarbonates, etc.) are dissolved in water? Is this an ester and/or process of hydrolysis? Thank you.
I was reading about gluons on this site, and I found that there are 8 types. There are 3 "colours" in quarks and gluons: red, green, and blue. I already know 6 types of gluons:
Red-Antigreen,
Red-Antiblue,
Green-Antired,
Green-Antiblue,
Blue-Antired, and
Blue-Antigreen.
What other types could there be? Can someone please help me?
Thanks-Max
P.S. Do photons have volume?
As to whether photons have volume, well, the question is pretty much meaningless. Photons aren't like little spheres; they don't have an inside and outside, so they can't really take up space. They are governed by a probability wave which says what location they would most likely be if you measured it, but you can't really call that a "volume"... —Keenan Pepper23:57, 8 December 2005 (UTC)[reply]
And while you're at it. Most atoms aren't really spheres either even though they're often depicted as such for ease of use. The area in which the electrons can be found (around the nucleus) may differ depending on other atoms in the area. A lot of it is empty though, so it wouldn't really be fair to count that space as volume either. - 131.211.210.1608:50, 9 December 2005 (UTC)[reply]
First, recognize that you don't know what a particle is. In quantum theory, a fundamental particle is something that might be either wavelike or a particle-like, but not both; or else it might be both wavelike and particle-like, or else it might not be either. Dig deeper, and realize that a fundamental particle is an irrep of a symmetry group (or rather, a quantum field valued in an irrep of a symmetry group). Then, follow electroweak theory and QCD to see why the symmetry group in question has to be SU(3). The gluons follow. It's a long path, so be patient. -lethetalk14:47, 9 December 2005 (UTC)[reply]
It has been suggested that running a hot shower will raise the humidity in your bathroom (assuming thats where your shower is) and in turn the humidity will drive dust out of the air, making it a semi-clean environment. Is that possible? Logic would suggest that more humidity would raise the Specific gravity of the air and in turn make it easier for dust to stay airborn. It would raise the temperature (and hence lower the sp.grav.), or possibly the humidity would condense on the dust particles and cause it to precipitate. Which one of these theories is correct? As a bonus, what are some low cost methods someone could use for running a clean room, aside from a hot shower? WP does have a moderately informative article on Clean Rooms. Thanks! --Jmeden200000:07, 9 December 2005 (UTC)[reply]
The trick isn't the elevated humidity precisely; what's useful are the very fine droplets of water created by the shower. The droplets are pretty big relatively to most of the other dust and crud in the air, and they fall fairly rapidly. So if you run the shower for a while and then turn it off, you get two handy effects. First, the dust in the air will tend to get stuck to the droplets and get pulled down with them; this gives you nice clean air, relatively speaking. Second, the droplets–as well as any water vapour that condenses–will form a temporary barrier that binds and settles dust on the room's surfaces. Hmmm...I'm not sure precisely how much benefit you get from dust particles acting as nucleation sites for new droplets; the importance of that process probably depends on how efficiently your shower generates its own aerosolized water droplets.... TenOfAllTrades(talk) 02:03, 9 December 2005 (UTC)[reply]
Interesting... So in essence you need to make it rain in your bathroom, by creating a warm humid air mass circulating into a colder region so that the vapor condenses into a mist and precipitates taking the dust with it, in much the same way that full scale rain pulls pollen out of the air. I wonder how effective this is compared to doing something like running a low-micron air filter taped to a box fan (a trick i used when painting cars in my garage). --Jmeden200014:39, 9 December 2005 (UTC)[reply]
Is there any easy way to do this? Or do I need to use sql? I want to load a bunch of books to a website to let people purchase them.
You should be able to use an Excel database as a data source in ASP. You need to instantiate an ADO Connection object, and install the Microsoft Data Access Components on your Web server. You will need to use SQL as part of the ASP script to query the database. --Canley06:02, 9 December 2005 (UTC)[reply]
I'm searching for a category name for explosives that could be made at home. Best idea at the moment would be "Homemade explosives". Anyone has a better idea? --helohe12:07, 9 December 2005 (UTC)[reply]
We done most of this dangerous stuff at school and therefore its quite legitime to have this as a category. Also its up to the one who creates this stuff if he wants or not. Also the articles are not step by step instructions so you need a chemical knowledge anyway. I think it is quite interessting what can be made at home with very simple things.
99% of all explosives produced by mankind was made only for the killing of people. Why would you want to make explosives? --Eye23:38, 10 December 2005 (UTC)[reply]
"Es gibt viele Arten zu töten. Man kann einem ein Messer in den Bauch stechen, einem das Brot entziehen, einen von einer Krankheit nicht heilen, einen in eine schlechte Wohnung stecken, einen durch Arbeit zu Tode schinden, einen zum Selbstmord treiben, einen in den Krieg führen usw. Nur weniges davon ist in unserem Staate verboten." - Bertolt Brecht. -- helohe(talk)02:31, 11 December 2005 (UTC)[reply]
Snakes don't have external ears, but they can sense sound. I remember hearing (HA!) that they pick up vibrations through the ground with their bodies. TheSPY18:05, 12 December 2005 (UTC)TheSPY[reply]
I humbly apologize for this intrusion into your life.
I am in need of your assistance.
I have tried to search the web and other material, in relation to an experiment or a paper.
The nature of which: - a group of particals in one part of the world were interacted on to alter their spin. As a result a group of particals in an other part of the world were observed to change at similar instance.
For visualization purpose of the article I seek : -
That is to say that the particales at one end were red and blue at the other end.
At the moment of change the red turned blue and the blue turned red.
Could you please send me a link to a page were I might find said such.
I thank you for your time and patience. And shall at all times remain in your debt.
Bows b4u i am humbled by you. I have been to look at your pro.......very nice indeed oh wise one.
Smiles.....I have not forgoten this deed you have done... and shal get back to you.
Yes this link has helped........I still search for this latest paper as describe...bows Bless'ns.
Can you tell me what possible birth defects could be involved if a father had extreme exposure to agent orange? Specifically lung envolvement in the son.
My e-mail is (email removed). Anything would be helpfull. Thanks Kim
Our agent orange article says "The VA has listed prostate cancer, respiratory cancers, multiple myeloma, type II diabetes, Hodgkin’s disease, non-Hodgkin’s lymphoma, soft tissue sarcoma, chloracne, porphyria cutanea tarda, peripheral neuropathy, and spinal bifidia in children of veterans exposed to Agent Orange as side effects of the herbicide." -- Finlay McWalter | Talk14:48, 9 December 2005 (UTC)[reply]
Wikipedia does not give authoritative medical advice. If you are personally worried about this, I recommend you consult a doctor. --Fangz02:46, 10 December 2005 (UTC)[reply]
usually such extreme cases aren't that useful for normal use and as it's the best very expensive. also i believe there is more to a good digital camera then just a high resolution. Boneyard13:37, 12 December 2005 (UTC)[reply]
Shure high resolution is not everything. But it is very useful if you want to create real big images of landscapes etc... . Btw. I just found that Phase One has a digital back (P 45) with 39 MP. helohe(talk)14:24, 12 December 2005 (UTC)[reply]
What protocol/encription is used in the communication with sattelites that are used by live tv broadcast teams (mostly mounted on tv-cars)? Is it possible to capture/'listen' to this signals with help of some computer equipment? Is it possible to transmit custom data to this sattelites? Are there differences by country? Where (coordinates) are this satellites located.
And in general does there exist any software that can be used for data-capuring with as input a card for the pc with connection to a satellite dish so this data can be analysed? helohe(talk)16:12, 9 December 2005 (UTC)[reply]
For many of your questions the answers are YES this is technically feasible AND to do so is illegal in most of the western world, unless you are a technician with the company providing the infrastructure services, or are armed with a warrant signed by a judge granting you permission to do this access. Now if I was to say HOW to do this stuff, I could be charged as an accessory to someone doing the crime. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 20:43, 14 December 2005 (UTC)[reply]
The limits to colour vision could not be the exact same for everyone. So there must be some wavelengths of UV and IR that only some people can see but would be invisible to others. Is there anything that effects one's limit? Would a baby exposed to wavelengths above red or below violet have more sensitivity? Wouldn't they make the ultimate spies? And is there somewhere (e.g. a website) where one could test their vision limit.
I'd like these questions answered about sound also. Thanks. EamonnPKeane18:35, 9 December 2005 (UTC)[reply]
For vision I the range is limited by the absorbion spectra of rhodopsins, although I don't know if age-related changes in the availablility of the photoreceptor cell cause a preceptual change. As to sound, young humans can (theoretically) hear in the 20 Hz to 20KHz range, and that top value reduces as the child ages. I don't know why, but I'd guess it's due to the increasing size (and thus mass, and thus inertia) of the ossicles. There's a bit more at the hearing (sense) article. -- Finlay McWalter | Talk18:45, 9 December 2005 (UTC)[reply]
(1) I've been told that newborn babies see in the ultraviolet range, but lose this ability within a few days. (2) The outer edges of human vision occur at/around 400 (very dark red) and 700 nanometers (violet). As far as people who can see this, I am not sure. (3) As far as sound, it has been claimed that certain children can hear up to 25 Khz, but those claims are debatable. Once sound gets to a certain very high frequency, it becomes less about "hearing it" than percieving it (I can say this first hand -- I had the precise range of my hearing tested a while back. I heard up to 16,750 hz, but above 15,000 it was virtually impossible to localize the noise) Raul65418:50, 9 December 2005 (UTC)[reply]
The short-wavelength limit of vision is about 390 nm and is set by the UV-opacity of the cornea. (The S-cones are actually sensitive down below that, but no light can get to them). People who have corneas thinned due to disease or surgery can reportedly see some UV light down to about 300 nm. The long-wavelength limit is less sharp - about 780 nm is just visible, but sufficient intensities (e.g. lasers) up to about 800 nm can be seen (though this is very dangerous to your eyesight). --Bob Mellish18:59, 9 December 2005 (UTC)[reply]
That said, there is one group of humans who have different colour perception than most. Although our color vision article doesn't mention it, there is a rare mutation which (only in women) causes the formation of a fourth cone cell type. This cell's spectrum peaks in at a point between blue and green. Such people can perceive the difference between a blob of light from a bluegreen laser and one made from the mixing of the light from a blue laser with a green one (something we mere trichromats can't). Most of the people who have this mutation don't know they have it, and scientists find them by looking for a specific genetic disease in men - in their fathers and brothers, for whom the same mutation has pathologic effects instead of interesting quadchromatism. Darn, we really need an article about this (or we have it, and I've not found it yet). -- Finlay McWalter | Talk18:55, 9 December 2005 (UTC)[reply]
Thanks. It's impossible to google for things when you don't know what they're called, but armed with tetrachromat I found a rather preliminary thing about women (well, a woman) with tetrachromatism: http://www.cs.utk.edu/~evers/documents/tetraChromat.txt It seems the affliction the males have is just a special kind of colour blindness, which isn't as dramatic as I remember. -- Finlay McWalter | Talk00:09, 10 December 2005 (UTC)[reply]
Early cataract (?) treatments, IIRC, involved removing the lens and replacing it with an artificial one made of polymethyl methacrylate. This had the same optical properties with regard to visible light, which is why they used it, but was co-incidentally transparent to some UV; as a result, the patients were able to make out UV lights. This proved very useful - a couple found a job in wartime, reading "invisible" signal lamps on dark coasts... Eventually, it became common practice to treat the new lens with a UV-opaque coating, to prevent this (UV isn't very good for the retina) and eventually changed to a different material.
The retina can see the near-UV okay (at least in some people), but the lens cuts it out, so as Bob says above the variation in sensitivity between individuals is irrelevant, because that light just can't reach you to be seen. Shimgray | talk | 17:13, 10 December 2005 (UTC)[reply]
I wish to make an old Italian cookie recipe that calls for 'Bitter Almonds', any suggestions for substitution?
Do you have any idea if apricot kernels can be a substitute, and/or are they also illegal in the U.S.?
Last question, in my search I have found information explaining that these two things, bitter almonds and apricot kernels, can be toxic. Are the seeds of apples, pears, grapes...things commonly sold in stores also toxic if eaten in quantity, and if so, what quantity?
Thank you in advance for any help in answering these questions.
MRI
Both bitter almonds and apricot pits (and other seeds of the genus Prunus) contain amygdalin, which can decompose into hydrogen cyanide when acted upon by certain acids or enzymes. Bitter almonds (but perhaps not apricots?) contain such an enzyme, so they contain free cyanide, according to our article Almond as much as 8%.
Amygdalin was actually explored, under the name laetrile, as a cancer treatment (the cancer cells have more of a certain enzyme that breaks down the amygdalin into cyanide, killing them), but it wasn't shown to be effective enough. So, it might kill you, but it might stop you from getting cancer.
I don't see how apricot kernels could be illegal, because there's one in every apricot, but IANAL. Apple, pear and grape seeds should not contain any amygdalin or cyanide because they are not from the same genus, but for the same reason, they might not taste or smell the same. Cyanide itself has an unmistakable almond smell.
IIRC, the recommendation here in Sweden (where bitter almonds are available) is not to eat more than one of them a day, to be sure not to get poisoned. (insert medical disclaimer here, I'm not sure). Also, I would guess sweet almonds are the best substitute for bitter ones, if you don't really have the choice to use bitter ones. I'm not sure what apricot kernels taste like, but sweet almonds are probably closer than them... TERdON01:32, 11 December 2005 (UTC)[reply]
Actually you would have to consume a great deal of bitter almond kernels to get cyanide poisoning to the extent that it would seriously harm or kill you. Having consumed them myself I felt no ill effect from eating over a dozen kernels at a time. The only time that you can reliably induce cyanide poisoning is from eating a lot of kernels. According to http://www.botanical-online.com/alcaloidesametllerangles.htm the maximum recommended adult dose is twenty. Having taken ~ 500 and survived (albeit with treatment) I suspect that the hype exceeds the toxicity, also I have come to wonder if the onset of localised cyanide poisoning slows the digestion of the kernels, and therefore the release cyanide salts to limit poisoning in a negative feedback system. What would be more interesting would be to remove and isolate the HCN salts into a purer form of cyanide (potassium or sodium) which would then be lethal.
the psychological term for believing that one is satan....
Not sure if there is a term specifically for this type of delusional disorder. Try Narcissistic personality disorder.-- Mark Bornfeld DDS dentaltwins.com Brooklyn, NY 22:32, 9 December 2005 (UTC)
I have a little hand-generated, solar-powered, battery operated radio. (It's one of those "survival radios".) It's quite portable in my room. However, I notice that it's very susceptible to changes in reception. Plane flies by (at about medium-low altitude) - some noticable interference - I actually heard a few seconds of muffled talking when it was supposed to be classical radio! But that's not the main thing I'm interested about. Apparently, if I put my hand on it, it might either help it, (louder), or soften it immediately. If it's sunny, it will change frequency (it's analog) to a higher one, but drop in volume - if it is night-time, it will drop in frequency, but raise in volume. If I touch it, it will either drop or raise in volume, or either both remove or add static. It's so very fickle. I have found there are certain intervals. If I walk away - it might become softer. I walk some more, it becomes louder. I walk away more, it becomes very loud - then very soft, then very loud, then very soft again (as distance). The intervals are about roughly a cubit (which it itself differs but that is just the idea of how long it is) - is that roughly how long radio waves are? I know some are kilometres in length but I haven't checked the EMF scale recently. 1-10 metres sounds about right, although I'd say it would be closer to a metre. I was wondering if my body was affecting the amplification or resonance of the incoming signal. Note that most experiments I've done with this is linear - I have not brought measuring tape, not tried experimenting in the second or third dimension (in the sense of making detailed observation) - although I've noticed effects. I *know* it has something to do with wave mechanics. I just don't know how my body is affecting the resonance and harmony of the incoming signal. -- Natalinasmpf20:21, 9 December 2005 (UTC)[reply]
Well I understand that sort of stuff is mighty complicated. But there's some purty pitchers (interactive applets) at this here site: [23]. You'll probably only need the first couple for wave mechanics, there's a whole bunch of topics covered there. Tzarius22:28, 9 December 2005 (UTC)[reply]
I'd say exhaustion played a big role. Did the guy eat properly and did he go to the toilet? I'd say lack of enough food and drinks for 10 days could contribute as well. Not going to the toilet could stop his body from cleansing itself from harmful products. - Mgm|(talk)12:48, 10 December 2005 (UTC)[reply]
It is imaginable that someone might die of uremic complications of complete physical obstruction of the urethra or bladder within 10 days, but not imaginable that he would have continued to play games nor that he would not have involuntarily urinated or defecated long before that. I think a pulmonary embolism is not a bad guess, but the sleep deprivation may have had more to do with it than the immobility. The cause of death isnt obvious. alteripse23:29, 10 December 2005 (UTC)[reply]
Tuned Length Exhaust Systems In Four Stroke Internal Combustion Engines
What is the theory and how can one calculate the length of exhasut system downstrean of the manifold or header for maximum (or optimum) power delivery in a naturally aspirated four stroke internal combustion engine?
This question also relates to the positioning of crossover pipes in systems with two exhaust pipes.
A full answer to this question would cover at least the common four, six and eight cyliner engine configurations.
I think These guys can help. The problem is that it's a very complicated thing to model, the math involved is rather intense. In a 4-stroke engine, you have the exhaust valve(s) opening on a regular basis, from different cylinders. As each one opens, it releases a lot of pressure which in turn compresses the air in the exhaust system to its elastic peak, and the air then gains momentum as it lunges outward toward the exit. There is a brief moment when there is actually a drop in pressure, at a certain point in the pipe, due to this momentum. It travels like a massive sound wave, the pressure building and cascading outward. If the exhaust pipes are arranged in just such a way, this effect (known as Scavenging, a stub article sadly) will cause the pressure in the exhaust system to drop at the right point just as the next cylinder is ready to open, so that the exhaust gains momentum on its way out and creates an even stronger wave for the next cylinder. This is a basic rundown, the actual considerations for an exhaust system are many, from cam timing, header size and arrangement, total length to muffler, muffler design, and H-pipe or X-pipe design (often only done for efficiency and aesthetic reasons). Its important to remember that any exhaust system is merely a balance between power optimization and aesthetic efficiency (sound deadening), since for extreme power applications the exhaust is deleted from the car allowing the most flow possible. --Jmeden200002:33, 13 December 2005 (UTC)[reply]
I am writing a C++ utility that takes its input from the command line. So when someone types
myprogram < input.txt
it works fine. However, I want the code to be able to tell when someone has just typed
myprogram
so that it can print an appropriate help message. However I can't work out how to tell whether cin is attached to a console or a file. How do I do this? Thanks Dmharvey04:29, 10 December 2005 (UTC)[reply]
I'd use _isatty(_fileno(stdin)) to be sure, but basically the same idea. Likewise, I've no idea if the C++ cin/cout stuff works differently. (printf for ever!) --Bob Mellish04:55, 10 December 2005 (UTC)[reply]
Thanks so much peoples. I checked out the "Hackers' Lament" -- it's pretty hardcore. I think the simpler solutions will do just fine for what I need. Dmharvey05:27, 10 December 2005 (UTC)[reply]
I have just bought a new computer with Windows XP Media Center as its operating system. I also installed Microsoft Outlook 2003 on this computer.
How can I move the contacts, journal entries, notes, tasks, etc. to this new computer from my old computer? My old computer is also a desktop with the Windows XP operating system. Of course, my Outlook stuffs on the old computer are on Microsoft Outlook 2003 as well.
I have an external hard drive (Maxtor) and rewritable disks; I don't have a cable to use the Files and Settings Transfer Wizard; I have got USB cables, though. Can someone enumerate the steps?
--John Doe on 9 December 2005
I believe the F&ST Wizard has "removable media" as one of it's options, so you should be able to just use it to save the settings to your external HD, and transfer them that way. --Bob Mellish05:06, 10 December 2005 (UTC)[reply]
Thanks. It did not work; maybe I don't know how to use my external hard drive properly. Right now, both of my computers have Microsoft Outlook 2003 and the e-mails are working. Is there an easy way to send the 100+ contacts from the Outlook on one computer to the Outlook on the other computer? I don't have a PDA to synchronize it with the old computer and then sync the new computer with the PDA.
What do they mean by "see" in this snippit from the google article:
Position: name, age, compensation in USD (as of June 2005)
CEO: Eric E. Schmidt, 50, $1 see [12]
CFO: George Reyes, 51, $781K
President of Technology: Sergey Brin, 31, $1 see [13]
President of Products: Larry E. Page, 32, $1 see [14]
Sr. VP of Worldwide Sales: Omid Kordestani, 41, $572K
VP of Corp. Development, Secretary and Gen. Counsel: David C. Drummond, 42, $776K
I think this might be a table of earnings after the IPO. --Shanedidona05:01, 10 December 2005 (UTC)[reply]
And as for what it means, if I recall, Brin and Page both decided to take $1 as salary as a gesture of their faith in the company — all of their income is through stock holdings, so if the company went down the tube they'd have nothing. Or something like that. --Fastfission15:05, 10 December 2005 (UTC)[reply]
we know that the heliocentric orbit of earth is an ellipse. what is the heliocentric orbit of earth's moon and is it a periodic or aperiodic orbit? dhtcpalyer
The Moon orbits in an ellipse around the Earth, but its period is incommensurable with that of the Earth's orbit around the Sun, so in relation to the Sun it traces out a weird loopy path that doesn't repeat. —Keenan Pepper07:14, 10 December 2005 (UTC)[reply]
Well, I bet that if you look over a long enough period, it will repeat itself. Unless you measure really precisely, but then if you measure really precisely, nothing ever repeats itself (on this scale). Sorry about being such a nitpicker :) . And while I'm at it, can this really be called an orbit? DirkvdM20:54, 10 December 2005 (UTC)[reply]
Good point. Nothing ever exactly repeats, it just gets close to repeating at some period, and then that correspondence drifts off and comes back around so it's better approximated by a longer period, and the whole thing is determined by the continued fraction of an irrational number. Isn't that neat? —Keenan Pepper05:16, 11 December 2005 (UTC)[reply]
An interesting factoid is that, despite being a satellite of the Earth, the Moon's orbit around the Sun is still convex, i.e. it always curves towards the Sun, never away.[24] This, and the fact that there are about thirteen sidereal months in a tropical year, suggest that the Moon's heliocentric orbit should resemble a rounded triskaidecagon — although, as stated above, the figure isn't quite closed and will form a spirograph-like pattern over several years. In practice, however, the distance between the Moon and the Earth is so much smaller than their distance from the Sun that even the Moon's heliocentric orbit is very close to circular. —Ilmari Karonen (talk) 12:46, 11 December 2005 (UTC)[reply]
I understood that the Moon doesn't rotate about the Earth, but that both rotate around their common C of G; however, since this is well inside the Earth, Luna appears to rotate around the Earth. Add in the fact that the Earth rotates around the Sun and you may well observe retrograde motion. Alphaxτεχ07:52, 12 December 2005 (UTC)[reply]
As the distance between the earth and moon is increasing, the annual path around the sun should always increase, right? I would imagine that it never repeats ever.
How come the Adobe Acrobat 7.0 Standard has about 20 patents on the bottom of its box, yet Microsoft Excel or the Windows XP operating system are only copyrighted? Shouldn't all softwares be either patented or copyrighted?
--John Doe
In the U.S., software can be protected by copyright, patent and trade secret as well. Copyright protection is mainly used to against piracy. Software patents and trade secrecy are used to keep competitors from copying an inventor's solutions. Trade secrets may include many undocumented features. Adobe is actually a holder of lots of software patents. You can visit the USPTO patent database and input "Term 1: Adobe" and "Field 1: Asignee Name" and see for yourself.
Would it be possible and beneficial for Microsoft to obtain patents for the Windows operating system? --John
Aren't very simple, almost trivial, things, like double clicking on an icon, patented in the United States? I have sometimes thought I'd file a patent for branching instructions in programming languages. — JIP | Talk10:02, 10 December 2005 (UTC)[reply]
You can only patent novel solutions that help people in someway which have not been invented before. They could've patented the windows layout when they created it, but now other OS systems use it, so double-clicking and the like can't be patented. Clicking is related to a mouse, not the software. - Mgm|(talk)12:51, 10 December 2005 (UTC)[reply]
But there are plenty of frivolous patents related to computer software. Because such actions can be described in purely functional terms rather than necessarily referencing any existing technology, they seem ripe for this sort of thing. See for example Amazon.com's 1-click patent (clicking a link once with a mouse allows you to purchase the product! so innovative!), or SBC's attempt to cash in on a patent for HTML frames. --Fastfission15:02, 10 December 2005 (UTC)[reply]
Microsoft have lots of patents. Far too many to list on the box. Here are some that can be licenced: http://www.microsoft.com/mscorp/ip/tech/. They aren't under any obligation to tell you about them. But, if you accidentally copy any patented idea or invention, you can be sued. Really, Adobe are just being helpful by drawing your attention to patents. I guess. Notinasnaid13:38, 10 December 2005 (UTC)[reply]
Just a note: Software patents don't just keep competitors from copying an inventor's solutions, they also prevent people who independently developed the idea from using it. Ojw14:26, 10 December 2005 (UTC)[reply]
I read somewhere that the future low cost versions of Windows would be able to run only three applications at a time compared to any number of applications other standard editions can run.
I just want to know why such a move by Microsoft?
>Is it technically not possible to create such a software
Or
>Is it a canny move by microsoft so that people who could afford standard versions of Windows will not buy low cost versions?
While I don't have any links to the version right now, I do remember the discussion you're talking about, and it seemed to be in response to African schools deciding to use Linux-based operating systems (for various reasons: cheaper software, better software, able to use cheaper computers, and no danger of "we're not supporting that any more, buy the new version!").
e.g. there were schemes like the $100 laptop project which are linux based and in danger of becoming quite popular. I imagine Microsoft didn't like the idea that a generation of children would grow up to be experts at using a non-Microsoft system.
The software wouldn't replace any "low cost" Windows (e.g. Windows 98, Windows XP Home) that you can buy here, it would be a completely new product, intentionally crippled to avoid competing with anything sold in developed countries, and aimed squarely at African schools.
The obvious question is why would somebody used it when they can get something like Ubuntu Linux (which is developed by an African, b.t.w.) for free, which is so powerful that many people are using it as an alternative to Windows XP Professional or Windows 2003 Server
The software you're referring to is called the starter edition (see our articles, XP and Vista). In addition to being aimed at emerging markets (mainly the East/Southeast Asia, but also Africa), not only as a way to fight open-source OSs (such as Linux), but also against pirated copies of Windows. Piracy is rampant in many of the markets targetted, and Microsoft thinks that one of the reasons is the high cost of Windows. It's of the opinion that many of the users in these areas have no need for the advanced features of a 'full' version of Windows, so they're selling them a severely stripped-down version more cheaply. Of course, they don't want to impact their profit margins in the wealthier parts of the world, so this Starter Edition won't be available in wealthier countries. — QuantumEleven | (talk)21:57, 10 December 2005 (UTC)[reply]
The formula for force of an impact is the well-knowen F=ma. A photon has no mass, but it can impact with measurable force. However, it accelerates to the speed of light instantly. Therefore, it has infinite acceleration. The wikipedia article Infinity states that 0 times infinity is undefined. How can a particle have undefined force. Please help. Thanks 216.209.153.1414:11, 10 December 2005 (UTC)Max[reply]
With the example of the photoelectric effect, whether the photon is able to move something or not depends on its frequency. Various other properties such as polarization, amplitude and other properties of a photon might be a factor. Because of the entire anti-classical nature of wave-particle duality, the classical definition of F=ma does not fit in, and there is no 1-1 correlation between mass, acceleration and the properties of light/photons, although these properties will factor in towards whether a photon has enough "force" (in the now technically incorrect sense of the word) to knock out an electron. -- Natalinasmpf14:59, 10 December 2005 (UTC)[reply]
Photons are not little balls which hit something and bounce off. When a photon hits something, it is absorbed by an electron (usually) and it is entirely converted into energy. In fact, you can think of a photon as a little packet of electromagnetic energy. F=ma is not involved. —Keenan Pepper17:22, 10 December 2005 (UTC)[reply]
If it's unobservable, invisible, and totally unprovable? If so why does science always rush to the defense of Darwinists? Do they have ulterior motives? Political motives? Are they being paid off? Don't want to lose their cushy 'science' jobs so they spread this pointless banter to make their side look like it ears a living?--152.163.101.1215:08, 10 December 2005 (UTC)[reply]
Some people are just narrow minded hypocrites, don't let them get under your skin so easily, they can keep pushing their evolutionary theory, and intelligent people every where will keep pushing it back in their faces, 'scientists' ha, some people watch too much TV--Ytrewqt15:26, 10 December 2005 (UTC)[reply]
Evolution is not "unobservable, invisible, and totally unprovable". It is well supported by a wealth of evidence. It is science, it's at the core of all biological sciences. And science jobs are not cushy - earning $30,000-$60,000 a year after 7 years of grad school and as a postdoc is not cushy. Guettarda15:39, 10 December 2005 (UTC)[reply]
Why do Christians insist upon the existence of some unobservable, invisible, and totally unprovable god? why must they inflict their mythology upon everyone else and cause hatred in the world? Why are they afraid of science? --Nelson Ricardo17:00, 10 December 2005 (UTC)[reply]
Because of the incredible amount of evidence in favour of the existence of God. It's people like yourselves who claim to know what the other side thinks but in actual fact have no idea whatsoever that cause the hatred. Alphaxτεχ07:59, 12 December 2005 (UTC)[reply]
Just because something is invisible and can't be directly observed doesn't mean it's impossible to know anything about it. Do you believe in quarks? You can't observe an individual quark, almost by definition, but the quark model has predicted things later shown to be exactly right. —Keenan Pepper17:15, 10 December 2005 (UTC)[reply]
Nothing is provable (outside mathematics, where that only works because you create the world in which you want to prove things). I don't know what you are thinking of when you say 'Darwinists', but evolution (if that's what you're thinking of) is not unobservable. Fruit flies are very popular for genetic research and one reason is that is that they have such short lives. So in the course of one year (let alone one lifetime or the lifespan of science itself) one can go through many generations, enough to see evolution at work. But bacteria are even better for this because their generations are extremely short. Why do antibiotics not work anymore where they did before? Because the bacteria have evolved to survive in an environment with antibiotics. On a much larger scale, though, domestic animals are a nice example of evolution put to work for humans. In stead of letting nature do the selecting we've started doing it and lo and behold we can create our own species. Hmm, am I exaggerating now? Of course in the end we could create new species, but have we technically? Domesticated cows can still create offspring with wild ones (ehm, bulls, I mean :) ). Any better examples? DirkvdM21:07, 10 December 2005 (UTC)[reply]
One criteon that makes something scientific is measurability. Does Darwin's evolution have more measurements and numerical approximations or traditional religious accounts of creation? Lord Kelvin (1824-1907) astutely stated:
:"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of Science, whatever the matter may be."
--John Doe
Also, radio waves are invisible to the naked eye, yet they can be detected and measured with instruments unlike ghosts.
--John Doe
We turned our backs on god when we started to embrace science. When science can no longer provide us with the answers we seek then we will turn to face god again. Such is the human need to find answers to life, the universe, and everything. But for the time being I'll stick with the science thing.--Eye00:00, 11 December 2005 (UTC)[reply]
The original question makes me wonder "Does this person know anything about the data sets that are the basis for the theory of evolution?" Such strong statements about science are worthless unless you are up to speed on the topic. I suggest you go and do research before making assertions that expose your own ignorance of the topic at hand. Actually there is a good article in wikipedia, evolution, why don't you read it? Then come back and rephrase your question. David D.(Talk)00:45, 11 December 2005 (UTC)[reply]
If you ask a scientist about something that hasn't been discovered, then your answer will be, "I don't know." If you ask a religious scholar about something, then you always get an answer. So then you might say, "What is the catch?" It is quite simple: Religion is a system of uproveable statements. Bertrand Russell
--John Doe
Troll or not, the question "How can something be scientific?" is an extremely good one. It's not always obvious how science actually "works", and some of its most important aspects are not widely known. Our article on the Scientific method contains some good discussion, but needs more work.
Besides observability and testability, another vitally important aspect of science is an element of doubt. Science is always supposed to be able to question its assumptions and its prior results, is always supposed to be open to new explanations, is never supposed to take anything on faith. (One might note that there are other modes of thought with just about exactly the opposite traits.) Now, it's true, scientists are people too and don't always manage to uphold these lofty goals perfectly (which is to say, there is unfortunately more than a little inertia and politics and fashion and unquestioned faith when it comes to the day-to-day practice of science), but good scientists do at least try, and over the long run, scientific truth will out.
Some might ask, "if science is really open to new interpretations, why is it so opposed to Intelligent design?" But what you have to realize is that ID is not some brand-new idea that was first hatched in Dover, PA a few months ago. The "intelligent design theory" we've heard so much about recently is merely a rehashing of several ideas which have been debated (in stodgy, acedemic style) in the evolutionary biology community for decades. (Indeed, William Paley was musing about a watchmaker -- the same watchmaker Dawkins discusses in his popular book -- over two centuries ago, in 1802.) Those ideas have been put forth, held up, analyzed, dissected, explored, elaborated, and discussed at great length. Some have resulted in changes to the current state-of-the-art in evolutionary "knowledge", some have been rejected. They have not been rejected out-of-hand, and if in their "renaissance" during the Dover trial they seemed to be rejected out-of-hand, it was only out of exasperation given the wholly unscientific nature (the courtroom drama, the media circus) of the reemergent "debate".
meaning because we are arrogant enough to think our ignorance makes us clever, religionists interpretation) that make religion look like childish gibberish compared to the growing adulthood of science. Darwinism has testable hypotheses, and creates a theory with explanatory power; without dwelling on the point, that would be above the head of a theist anyhow,
Jesus would follow the golden rule and respect both views of how things came to be. Scientific and metaphysical are mutually exclusive concepts. People who are trying to be like Christ should make note of his methodical use of parable: Doesn't it stand to reason that biblical texts can retain or even improve a person's faith when they can be read and interpretted with the same spirit of "student seeking spiritual nourishment"; as opposed to narrow, my-way-or-the-highway minded, hypocritical "literal interpretation?" More than all else, Jesus railed against hypocrites. Even the most pious should bear witness to the scientific method's inherent checks for fraud or deceit. What does your spiritual guide offer?
Science is science because it always starts from a position of agnostic ignorance, religion always starts from singular arrogance which explains why such a nonsensical position can be proposed and the devious nature of religion to try to mask a ludicrous statement as a question. IF ONLY theists would spend longer trying to create a testable hypothesis for their claims and less time trying to undermine the scientific theories (yes that is -theories- the scientific word not the - oh let's deliberately misinterpret this word with the colloquial meaning because we are arrogant enough to think our ignorance makes us clever, religionists interpretation) that make religion look like childish gibberish compared to the growing adulthood of science. Darwinism has testable hypotheses, and creates a theory with explanatory power; without dwelling on the point, that would be above the head of a theist anyhow; religion doesn't.
When a proton transforms into a neutron, it goes through the process: P -> N + e+ + νe. P=Proton, N=Neutron, e+=Positron, and νe=Electron Neutrino. When a neutron becomes a proton, it goes through the process: N -> P + e− + . e−=Electron and =Electron Antineutrino. So P -> P + (e− + ) + e+ + νe by substituting P + e− + for N. P + (e− + ) + e+ + νe = P + (e− + e+) + (νe + ) = P + ENERGY (The particles and antiparticles annihilate). Doesn't that violate the conservation of energy? 216.209.153.14417:22, 10 December 2005 (UTC)Thanks - Max[reply]
As for the answer to your question, the decay of the neutron happens spontaneously and energy is released, but the decay of the proton is not spontaneous and requires energy input to occur. That's why the hydrogen nucleus (a single proton) is stable. See beta decay. Energy is always conserved. —Keenan Pepper17:42, 10 December 2005 (UTC)[reply]
This is a reply to the above question. If , then wouldn't be endothermic, not exothermic (P=Proton, N=Neutron, e+=Positron, and Ve=Electron Neutrino)? Can someone help? Thanks 216.209.153.14418:27, 10 December 2005 (UTC)Max[reply]
Fusion of hydrogen into helium is very exothermic, because of the strong nuclear force, which you are not taking into account. Two protons changing into two neutrons would be endothermic, but the energy released when the two protons and two neutrons fuse into a helium nucleus far outweighs that. —Keenan Pepper19:07, 10 December 2005 (UTC)[reply]
Recently, Google is offering free Wi-Fi in Mountain View in California.
Is it supported by advertisements?
If yes, then what type of advertisements are they serving?
You may want to write out your question more fully in the future (I'm having to guess what you mean...). In my opinion, you mean bit and byte by your first and third items - the articles on these subjects are pretty good. kbps and Mbps and units of data transmission rate - the speed at which information is transmitted. They stand for kilobit per second (1000 bits per second) and Megabit per second (1000000 bits per second). As for snd, I'm afraid it could be any number of things. If you saw it in the context of computers, it could be an abbreviation of send... — QuantumEleven | (talk)22:05, 10 December 2005 (UTC)[reply]
Snd is a powerful sound file editor that can be customized and extended using the Scheme programming language.[25] I definitely think it was a typo though. =P —Keenan Pepper05:07, 11 December 2005 (UTC)[reply]
I too feel Snd in this context is a punctuation typo, SND means SEND in the IBM AS/400 operating system. Basically 95% of the commands in OS/400 are constructed out of 2 and 3 letter abbreviations for objects, and do what with them. SNDMSG to send a simple message for example. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 20:54, 14 December 2005 (UTC)[reply]
Sorry I had to post three questions in a row, but if nuclear
fusion gives off energy via the strong force, then why does nuclear fission also give off energy. Wouldn't the opposite process have the opposite effect? I heard that it has something to do with iron. Please help 216.209.153.9221:42, 10 December 2005 (UTC)Max[reply]
The answer is rather complicated, but to give a greatly simplified version: Fusion of light elements (to heavier elements) gives off energy, as does fission of heavy elements (to lighter elements). Fission of a light element or fusion of a heavy element is endothermic - it requires more energy than it outputs. If you keep fusing light elements, eventually you will get to iron, at which point further fusion becomes endothermic. The same happens when you fission heavy elements - the reaction gives off energy until you get to iron, at which point is becomes endothermic.
The reason for this strange phenomenon is that, for elements lighter than iron, the binding energy in the nucleus increases as the element gets heavier, so that energy is released in the fusion reaction. As you go down the periodic table, the binding energy increases until you get to iron (the most stable nucleus, with the greatest binding energy), and then it starts decreasing again (so fissioning heavy elements also moves from less bound nuclei to more bound nuclei, releasing energy).
More or less, of course a zero potential system would't have enough energy to form 'clumps' so probably a better word for it would be an infinitely dispesed cloud of inert metal at temperatures near 0K.--Aolanonawanabe01:48, 13 December 2005 (UTC)[reply]
If you were to create larger atoms, like carbon, with kaons instead of electrons (like kaonic hydrogen), would there be no analogy of electron shells because kaons, being bosons, are not subject to the pauli exclusion principle?
And so wouldn't molecules made form kaonic atoms be much denser than normal molecules?
And wouldn't the strong force help two kaonic atoms to bond?
That's what I thought; thanks. The article hadn't made it clear that it was talking about the residual strong force. ‣ᓛᖁᑐ01:28, 12 December 2005 (UTC)[reply]
At a distance, the interactions would be primarily electromagnetic, i.e. mediated by photons, just like between protons and electrons. However, at close range protons and kaons will also interact via the nuclear force (residual strong force, mediated by light mesons) as well as the weak force (W and Z bosons). At even closer distances the component quarks may interact via the strong force (mediated by gluons), although at this point it may no longer make sense to speak of the proton and the kaon as separate particles. —Ilmari Karonen (talk) 07:11, 12 December 2005 (UTC)[reply]
Heh, thanks. What I was really after is the mesons that should mediate the nuclear force between them; which should those be? Would they have to be kaons as well? ‣ᓛᖁᑐ07:29, 12 December 2005 (UTC)[reply]
I have 4 computers set up with a KVM. I am adding a BEEP in the programs that I will run on them to let me know what it needs me to answer a question. The problem is that I don't want to have 4 sets of speakers. So, which is best: get a 4-way splitter and plug one set of speakers into all 4? Since all have a line-in and line-out, can I jumper from one to another to another and put the speakers on the last one? It isn't just which setup makes noise. I don't want to mess up the soundcards (or speakers). --Kainaw(talk)23:25, 10 December 2005 (UTC)[reply]
If the computers are in the same room as you, you could make your program use the built-in speaker in the computer instead? The one that is connected to the mainboard. TERdON01:46, 11 December 2005 (UTC)[reply]
It may be too late, but there are KVM units that include audio switching. I am doubtful that you can just combine the signals with a simple splitter: that doesn't sound a good thing, even if the computers take it in turns to speak. Combining audio is of course possible, though a mixer unit. But daisy chaining line out-line in? That does sound attractive. Notinasnaid19:03, 11 December 2005 (UTC)[reply]
I'd go beyond Notinasnaid's "doubtful" and say that trying to use a 1-to-4 splitter "backwards" would almost certainly not work properly, since you'd have four speaker outputs all trying to drive the same line to different voltage levels. I'd guess the effect would be that you'd get sound from one of the computers, but which one would essentially be random. I'd either go with daisy-chaining the line-in/line-outs, or if you want a solution which doesn't need all the computers to be on, I'd get a 4-to-1 mixer cheap off eBay. -- AJR | Talk19:51, 11 December 2005 (UTC)[reply]
I need to know how to make an icebox - used to keep food cool in the 19th Century by farmers in South Africa who had no electric power. It involved using charcoal. Any suggestions? --
Large ice boxes are not popular in rural/desert areas of Africa where electricity is unavailable. Instead, they use clay pots wrapped in moist cloth. The heat evaporates the water from the cloth, removing heat from the clay pot. The pots can be very large, but a walk-in icebox would be unreasonable to keep moist. --Kainaw(talk)05:33, 11 December 2005 (UTC)[reply]
Ever since my reformat I've been getting a system redunancy check any time I try to copy/move/download any file greater than 200MB,
yes I know, I know your hard drive is bad, well it doesn't seem to be, it just seems like one of those settings that gets messed up/reset to default after a reformat..
..is there any way to disable system redundancy checks?--Cyclic check01:57, 11 December 2005 (UTC)[reply]
It's probably a cyclic redundancy check performed either by the filesystem or the drive controller (you've not said enough about the context of this message to make it clear which). Either way, the drive is definately bad, and you should chuck it away. There's no way to disable the CRC checks: they've at the very fundament of how data is stored on magnetic media, and they're there for a very good reason. --
It can't be the hard drive. becasue the same thing happens when I try to save/copy/download anything to an entirly different external drive, it has to be an OS thing, can I just turn it off? at my own risk?--Cyclic check02:09, 11 December 2005 (UTC)[reply]
It doesn't really have to be the disk (especially if you have the same problem with several different ones). You could also have a problem with the disk controller. Or the RAM. Or the CPU. Or the mainboard in general. Possibly connected to high load of the computer as you don't get errors when dealing with small files. What is sure though, CRC errors mean something really doesn't work, and if you get them often something in your computer doesn't work as it should (it could possibly be the OS, but then it would be really unusally severe and I don't really think it's likely...) TERdON02:17, 11 December 2005 (UTC)[reply]
It could be aproblem with your DMA settings of the hard drive controller. Check the device manager and turn of, or lower your DMA setting. —R. Koot02:29, 11 December 2005 (UTC)[reply]
I had a very similary problem due completely to DMA. I fixed it by getting a proper UDMA IDE cable (one with a blue plug on the end). I know it sounds stupid (a cable is a cable), but the UDMA IDE cables have a ground-wire for each pin and that does make a difference. --Kainaw(talk)20:54, 11 December 2005 (UTC)[reply]
Whatever your real problem is, you definitely don't want to fix it by disabling the system checks.
That's like dealing with a false fire alarm by cutting the wires to the fire alarm horn,
or dealing with a persistently blowing fuse by putting a penny under it.
Steve Summit (talk) 18:02, 13 December 2005 (UTC)[reply]
How would I go about automatically retrieving information from a website at regular intervals, more specifically, the Wikipedia statistics (number of articles, etc.)?
--Borbrav06:47, 11 December 2005 (UTC)[reply]
Me, I would write a shell script to invoke a noninteractive webpage fetcher, such as wget, or lynx -dump. I would then arrange to have the shell script invoked periodically by putting it in my crontab. I would do this under Linux or Unix. I tend to suspect none of this will be applicable for you, but since you didn't say which operating system you're using, I can't be sure. Steve Summit (talk) 18:08, 11 December 2005 (UTC)[reply]
Create an empty text file, and rename it to a filename ending in .bat or .cmd. Then, edit it using something like Notepad, and put in the commands you want to run, one per line, just as if you were typing them at the command prompt. If you don't already have software for automatically downloading data, I second the recommendation for wget. As for running your script at regular intervals, you'll probably find that Windows' Scheduled Tasks feature works pretty well. —David Wahler(talk)01:25, 12 December 2005 (UTC)[reply]
for instance, i created a questionnaire, and i written it in qbasic. one must run the program to see the questions. how do you save the answers the people insert?
You'd have to save them in and load them from a separate file. The QBasic help files should provide you with help on handling of external files. - Mgm|(talk)11:10, 11 December 2005 (UTC)[reply]
i don't want to sound too negative, but we live in 2005 (almost 2006), do you really want to have people fill in a questionnair made in qbasic? if you are starting programming then it would be wise to do it in something that supports drawing windows and such. you could do something like this with a webpage and some scripting also. Boneyard13:44, 12 December 2005 (UTC)[reply]
Hey! I program in QBasic just for fun! As for the question in hand, you need to save them to an external file, because I'm afraid that there is no way to have them stored in memory. You should do something like this:
outFile$ = "Insert name and path of output file"
.
.
.
OPEN outFile$ FOR OUTPUT AS #3
.
.
.
PRINT #3, varToPrint$
i often heard of the word firewall, i know it means it sort of get rid of the viruses and allows us to read the correct message, but what exactly is a firewall? how do people bypass a firewall?
actually, if a person filters certain webpages, and you desperately need to use that filtered website, how do you go to it? i tried using different web browsers and it seems it has no use...please tell me! i am desperate! i need to do my work in www.ibiblio.org and somehow my school administrator filtered this web!
If you want to connect to blocked sites, talk to your school administrator or connect from somewhere else (like home or an internet cafe). If you start trying to bypass this stuff you could get in serious trouble. Notinasnaid11:18, 11 December 2005 (UTC)[reply]
How do I create access to an item from C:\Program Files on the All Programs menu of the start button on the Windows XP taskbar?
My Norton SystemWorks program is in the Program Files folder, but it isn't on the All Programs menu.
--John Doe
The "All Programs" menu is located at %userprofile%\Start Menu\Programs. %userprofile% is usually something like C:\Documents and Settings\Joe or your username. Stuff in Program Files do not necessarily appear on the Start Menu unless the installers put them there. Try putting the program in C:\Documents and Settings\Joe\Start Menu\Programs or similar. -- Daverocks11:56, 11 December 2005 (UTC)[reply]
I was able to add Norton SystemWorks to the All Programs menu of the start button. However, it is not like the other programs. It is impossible to actually launch the program and start using it. When I click on Norton SystemWorks, I see sub-menu items like NSWRes.dll, readme, wgsplugin.nsi, and lots of other items with the .dll extension.
I copied Norton SystemWorks from my old computer, which is not networked to the new computer I am currently using, on an external hard drive. Then I connected the external hard drive to the new computer and pasted Norton SystemWorks in C:\Program Files. I prefer not the use my installation CD for Norton SystemWorks. Is there any method to launch the Norton SystemWorks program on my new computer?
--John Doe
You need to install SystemWorks from the original CD. Just copying the files from one computer to another is not sufficient, as there are registry entries which are not so simple to copy, and there may be configuration files which are specific to the first computer. This advice applied to most Windows software.
You should also consider whether you have a licence to run SystemWorks on a second computer. Most likely, you had a licence to run it on the first computer only, and the licence is not transferable to another one.-gadfium00:37, 12 December 2005 (UTC)[reply]
Do I have a license to completely delete the Norton SystemWorks from my old computer and install it from the original CD on my new computer -- since I have a license to use the utility software on a single computer; so by deleting it on the old computer, then I will still be using the software on a single computer, that is, the new computer?
I can't tell you what your licence says. Most likely, the licence agreement for Systemworks varies from one release to another, and may have different clauses for different countries. Anyway, I don't have a copy here. You may consider that you have a reasonable moral right to delete it from one computer and install it on another, and you most likely have a legal right to reinstall it if your hard disk crashes and you replace the disk, but you probably don't have the legal right to reinstall on a new computer even though you are uninstalling it on the old one. I am not a lawyer, so this doesn't constitute legal advice. The licence agreement may make claims which limit your rights which are not legally enforceable. The safest advice is for you to consult a lawyer, but that will likely cost you more than the software is worth. It's up to you to decide what's right.
Depending on the version of SystemWorks (after 2003 if I recall correctly), you'll have to reactivate it after installation. It is possible that you won't be able to do this because the licence key is tracked and has already been used. In this case, there is probably a mechanism for you to contact Symantec and explain the circumstances of the reinstallation to get a new licence key or unlblocking of the old one.
Newer versions of the Norton products not only come with cool stuff not on prior versions, but also
If you can show proof that you owned earlier version, you can get a significant $ rebate against purchase of the new version which is like an upgrade.
So, armed with the proof of ownership on the old computer, you can legally buy very inexpensively the latest version, which you then install on the new computer.
Most computer software companies are well aware of their customers periodically needing to upgrade hardware to a replacement computer, and want to keep those customers happy, and not so annoyed that they will go to a competing vendor for similar services on their next computer, so most will be happy to walk you through how to get THEIR software onto your NEW computer at minimum hassle for you and minimum cost. So any time you do an upgrade from an old computer to a new one, it can be well worth your while to contact the tech support associated with each of the products you depend upon on your old computer, to ask them whether it is legitimate under their license to move your whatever to your new computer, and if so, can they tell you how. Be sure to give details on the old and new computers like version of Operating System involved.
Another common scenario is people having a computer at home, at work, a portable laptop, in which they want to have much of the same software on all their computers, and they not want to have to pay full retail price each time. After all, they are ONE customer with X computers. Similarly in big business, you have an office with X computers each with one employee ... the company wants a discount or group buy. Some homes are now getting computers networked, so that multiple family members computers share some resources. Many computer software companies have deals for such customers such that you can get the same software licensed to more than one computer AT THE SAME TIME, for much less money than paying for the software for each and every computer involved. You need to contact your individual software suppliers to ask if they have such a multi-computer software license and what would be involved for you to get one. This applies to everything: Windows or other OS, Word Processing, Security, everything ... so bear that in mind if you plan to be operating two or more computers in your home or office, concurrently.
Does the Bering Strait ever freeze over, so you could theoretically walk across it? This picture makes it look like the strait is covered with ice in the winter, but I'm not sure. Has anyone actually walked across it, or driven a sled, etc.? —Keenan Pepper22:56, 11 December 2005 (UTC)[reply]
While it may be possible for it to freeze over, I don't believe it is allowed to do so due to naval traffic. It is a major seaway for oil tankers from northern Russia, Alaska and Canada. --Kainaw(talk)22:58, 11 December 2005 (UTC)[reply]
Why do my downloads begin at a relatively high speed and then progressively slow down, usually by 1 KB at a time? I'm using DSL if that has any bearing, and the last time this occurred nothing else was using my connection at the time. --Impaciente00:11, 12 December 2005 (UTC)[reply]
It may be due to a number of factors. One possible factor is that when you click on a link, but before you find the location to put it in and click Save in the dialog box, some data has been downloaded by your computer, thus accounting for the apparently increase in speed initially. It may also be due to your ISP or other points along the way between your computer and the server slowing the connection down. Enochlau01:52, 12 December 2005 (UTC)[reply]
Keep in mind that the "speeds" you see in KB/s are usually calculated by taking the total amount of data downloaded and dividing that by the total amount of time elapsed. An unusually high speed at the start of a download is often an inaccurate reading if data has already been downloaded with less time elapsed. This is particularly noticeable with my artificially limited 256k DSL where there is no way the speed should go over 32 KB/s, but seems to anyway sometimes at the start of a download from the inaccurate reading. The "slowing down" you are experiencing is caused by the total time elapsing at a constant rate, but the download speed being a lot slower. The actual download rate hasn't slowed down, but the KB/s reading is, as a result of naturally correcting (through time elapsed) the original misreading at the start of a download. -- Daverocks09:44, 12 December 2005 (UTC)[reply]
Could someone please tell me what a magnetic field is made of. Wikipedia doesn't seem to say. By "made of" I mean communication between two points. Photons? Electrons? Virtual particles that come in and out of existance and "touch hands" as a way of communication? If it's a wave, what frequancy? Thanks 153.111.60.1500:47, 12 December 2005 (UTC)[reply]
The four fundemental fources of nature (the strong nuclear force, weak nuclear force, electromagetnic force, and gravity) all form fields of potential, and each has an associated particle which mediates its force. (See List of particles). For the electromagnetic force, the force is carried by photons. Raul65400:51, 12 December 2005 (UTC)[reply]
I have read the beginnings .dll article, but I got confused. Can someone delineate to a layperson the importance and function of .dll via an analogy or another way for explaining it? I know about computer applications software and use them well, but I am not a computer scientist.
Reading the article (I'm no expert on this), it seems that each DLL is a module (piece of a program) containing often-used code that can be shared among lots of programs. It saves memory because different programs that use the same instructions don't have to store those instructions over and over. --AySz88^-^02:26, 12 December 2005 (UTC)[reply]
The Dinosaurs article has a section on extinction theories. According to that, an asteroid crash could have caused mass extinction, so in a way, yes gravity did cause the death of dinosaurs. - Akamad10:50, 12 December 2005 (UTC)[reply]
I've always understood that in eucaryotes, the DNA was only transcribed in the nucleus of the cell, because the necessary transcription proteins only occurs on the nucleus. How then does a DNA virus manage to get its genome transcribed and translated? Does it carry its own transcription proteins (or catalyse its own transcription in some way), or are there such proteins available within the cytoplasm too. Or does it somehow move its genome into the nucleus?
Yes, thank you, but how does the retrovirus get its genome into the nucleus? I understand that it enters the cell's genome, but not how it can reach said genome. I can imagine no cellular system for the transport of genetic material into the nucleus (what would be the point?). -- Ec561809:22, 13 December 2005 (UTC)[reply]
Virusses have a long needle-like tip with which they can inject their genetic material into the cell. But there's also virusses (like HIV) which remain intact as they enter the cell by endocytosis, which means they can use their needle to inject their material into the nucleus. I'm not sure how loose DNA would get in. Perhaps some channel? - Mgm|(talk)09:33, 13 December 2005 (UTC)[reply]
I think it differs from virus to virus, but for the herpesvirus it goes as follows: The virus envelope fuses with the cell membrane and releases the virus with its nucleocapsid into the cytoplasm. The nucleocapsid then 'docks' with the nuclear membrane and releases the DNA into the nucleus. --WS15:08, 13 December 2005 (UTC)[reply]
Just so we can all have some sense of closure: it's true that different viruses work in different ways. Just as there are different ways for a virus to penetrate the cell membrane, there appear to be different ways for them to penetrate the nucleus.
Not all viruses have needlelike tips (indeed, some 'burn' through the cell membrane using a lipid destroying enzyme), but I suppose its possible some viruses that enter the cell through endocytosis may still carry a needlelike tip, to use them to penetrate the nuclear membrane. Other viruses may simply use channels and gates to allow the DNA to be absorbed into the nucleus.
I'm afraid that for most viruses the mechanism is unknown or unclear: HIV (according to the above link, thanks WS) "Although the exact mechanism that HIV uses to transport its genetic cargo into the cell nucleus is still unclear, viral protein R (VPR), which is carried by HIV, may facilitate the movement of the preintegration complex to the nucleus."
I've found similar quotes for other viruses. What we do know is that plasmids and loose DNA or RNA introduced into cell does get expressed, so it's not all that hard.
My question is: My understanding about the herpes virus, after reading much about it, is that the virus hides in the nucleus of the nerve cell.
Then when the body is stressed, etc or when the virus itself "decides" to shed some of its cells through the surface of the skin, how long does it live? In other words how long can it live outside the body?
I am not asking about the virus that comes out of an active lesion although that would be pertinent and important information.
However, I am more interested in "shed virus cells". How long do they live when they are on the surface of the skin or on your towel or toilet seat or whatever?
The issue of whether a virus manifests "life" per se is a bit controversial; perhaps a more relevant question is the period of time the virus remains infective outside the body. Also, viruses are not composed of cells; I assume you mean "cells that are infected by virus" rather than "shed virus cells". In any case, the survival time of herpes simplex and other viruses of the herpes virus group (herpes zoster, Epstein-Barr, cytomegalovirus, and human herpesviruses 6 & 8) outside the body is quite brief. Infectivity of the viruses depends on their glycolipid envelope, which is destroyed by desiccation. The speed with which that occurs depends on the ambient environmental conditions-- heat, light, air convection, and atmospheric humidity.-- Mark Bornfeld DDS [Brooklyn, NY 17:31, 12 December 2005 (UTC)
The article doesn't suggest that cells are released from the body, but rather that individual viral particles are expelled. These particles are susceptible to desiccation and denaturation through various means, including heat, acids, bases, detergents, alcohols, heavy metal salts, reducing agents or certain chemicals such as urea. Additionally, virusses can be destroyed by radiation or other mutating agents which can rip apart the rather unstable (RNA-)genome quite easily.
I would appreciate if someone with a chemistry background could help me. I plan to do a science fair project where I will dissolve just sodium carbonate (washing soda) in hot water to remove an olive oil stain from cotton fabric. No other detergents or laundry boosters will be added and the water is soft and the sodium carbonate will not have to worry with "neutralizing" the magnesium and calcium deposits, etc. I plan to use different amounts of the sodium carbonate to see if a larger amount will dissolve the stain faster.
My dilemna is that per my research via the internet, science dictionaries and even "Wikipedia's" archives, I could not get an explanaation on the chemical process. I do not have access to university libraries and the public library is limited in their science/chemistry information. Either none was offered or advanced for my purposes. I have had some chemistry, but will not have a complete chemistry unit until next year in 10th grade.
Per my research, several scenarios should occur:
1) the sodium carbonate should create an emulsion that will list the stain from the fabric;
2) this process is the result of hydrolysis; and
3) a mild saponification could occur and convert the stain into "soap."
Over the years I have found that the colder I get, the more frequently I need to pee. Why is that? Additionally, I am assuming that pee gets warmed up pretty well while collecting in the bladder (I suspect we've all seen it steam under the right circumstances), so why do I find that I am significantly warmer following urination? I would think that having a sac of warm liquid inside you, as well as the constant muscle tension required to hold a full bladder, would generate a bit of heat.
I don't know why it is, but I find much the same (in terms of frequency, that is). Why warmer? A possibility is that your job is sendentary, and you just sit getting cold. The exercise involved in getting up and walking to the toilet might break the ice. Notinasnaid22:24, 12 December 2005 (UTC)[reply]
I have experienced the same sensation and wondered about it as well. I'm not sure about the increase in frequency, but I think the warming sensation must be a percieved change in temperature, not an actual change. When you pee you may be losing heat energy, but you're losing mass too. The average energy of the particles in your body, which is what we percieve as temperature, does not change (edit: unless you include the heat lost when exposing yourself in the cold. This loss could be quite large if you're a lady and need to bare your entire bum to pee. Which makes me wonder, do women get the same sensation?). When I get the sensation it is often accompanied by a shiver. Could this generate the heat? Jasongetsdown22:42, 12 December 2005 (UTC)[reply]
Body temperature is closely regulated by the hypothalamus, which also produces antidiuretic hormone (ADH). One of the responses of the hypothalamus to cold is the inhibition of ADH secretion, with a resulting diuretic effect. -- Mark Bornfeld DDS Brooklyn, NY 23:11, 12 December 2005 (UTC)
As mentioned by Jasongetsdown, shivering is a basic warming function. Activating muscles consumes energy and creates heat. As for ADH, a reduction of ADH will reduce water absorbtion in the kidneys. Since they are not absorbing water, it passes into the bladder and you urinate more often. Does being cold cause the hypothalamus to reduce ADH production? That appears to be what Mark Bornfeld suggested. I do not know. --Kainaw(talk)01:50, 13 December 2005 (UTC)[reply]
Possibly weirder: why do I get hot when I play the piano? The physical activity is negligible, so could mental activity cause it? If so, why don't I get hot when answering questions here? :) DirkvdM10:49, 13 December 2005 (UTC)[reply]
Interresting thought. I've never heard of heat sensation being a synaesthetic sense (and the article doesn't seem to mention it either), but if sound, taste and sight can 'synaesthetise' then why not the other senses? DirkvdM09:12, 14 December 2005 (UTC)[reply]
What is the subfamily of siamangs, according to scientific classification? Also, do siamangs have sexual dimorphism in body size? Do they have prehensile tails?
Wheat isn't synthetic, but alive. So its chemical make up is only a little less extensive than that of humans. It contains various enzymes, plant sap, water and a variety of other chemicals I can't name because I'm not an expert on wheat. - Mgm|(talk)09:36, 13 December 2005 (UTC)[reply]
I'm running a batch file at regular intervals using Windows's Scheduled Tasks. However, each time it runs, a console window shows for a split-second. Is there a way to prevent the console window from being shown? --Borbrav04:03, 13 December 2005 (UTC)[reply]
I haven't tried this myself, but I think this should work. Create a shortcut to the batch file and get Scheduled Tasks to run the shortcut. Now, right click on the shortcut, choose Properties, Shortcut tab. In the Run field, where it normally says "Normal Window", choose "Minimised". Enochlau04:16, 13 December 2005 (UTC)[reply]
Something else I meant to mention: now that you're getting this working, make sure you're polite and don't hammer the server (whichever server you're querying with it) too frequently. Once a day is almost certainly fine, but if you're tempted to do it more frequently than that, consider carefully whether it's reasonable. Steve Summit (talk) 04:22, 13 December 2005 (UTC)[reply]
Steve Summit is right, but I'm only retrieving ~8kB (Notice the "split second"), so it's reasonable (And if I weren't doing it automatically, I'd do it manually, so no difference there). As for the creating a shortcut method, it doesn't work. If in the Schedueled Tasks I select the shortcut to be run, then there is not change. If I run the link (i.e. by copying its location) nothing at all runs. --Borbrav05:16, 13 December 2005 (UTC)[reply]
One way is to download NSIS[27] and compile this small script:
Change mybatch.bat to the name of your batch file.
Save it as "script.nsi" (including the quotes, to ensure the proper extension is used).
Find script.nsi in Explorer, right-click the file, and choose Compile. This will take a second or two.
Copy the resulting .EXE into the same directory as your batch file, and change your task to run that instead. You may also add a path in step 3 and place the EXE accordingly (if you use a relative path).
If the file/path contains spaces, you must write it like so: '"my batch.bat"'.
If you need parameters, use this syntax: '"mybatch.bat" param1 param2 param3 (...)'. For parameter values that contain spaces, wrap them in "".
My father has enormously large mass lesion , which involves the right lobe. It appears to involve segment VIII, segment VII , segment VI as well as segment V.The mass lession has a cephalo-caudal extent about 17cm. In the transverse plane ,the hepatic mass lesion measures about 12.0 x10.2 cm. Along the inferior aspect of the right lobe it projects exophytically from the hepatic surface.It extends up to the hepatic capsule as well.The arterial phase demonstrates evidence of mild tortuosity of right hepatic artery.Marginal dilatation is also seen of the same vessel.Lobular surface of the liver is observed,especially of the right lobe.There is evidence of thrombosis of the right portal vein.The thrombosis extends into the proximal portion of the left portal vein as well.partial thromobosis of the main portal vein is also seen.The superior mesentric vein is normal,the splenic vein is also normal.In the segment IV of the lever there is a subtle 1.0 to 1.4 cm hypoattenuated lesion,which is best appreciated in the portal venous phase and in the delayed phase.In arterial phase of the evalution ,this lesion is marginally hypoattenuated to hepatic parenchyma.The caudate lobe is normal.
Minimal dilatation of the right lobe intrahepatic biliary radicals is seen.The CBD is not dilated .The gall bladder is normal.The pancreas shows no feature of note,The spleen is not enlarged.
Both adrenal glands are normal.Both kidneys are normal.There is no ascites or adenopathy.
You didn't really ask a specific question, but I'm guessing you want something like a translation into non-medical terminology. But that won't help you much. You need to ask your father's physician what the findings on the CT mean in terms of treatment recommendations. Is partial removal of liver (partial hepatectomy) an option? (The involvement of the main portal vein suggests it is not, as does the large size.) Is liver transplant? Would chemotherapy be of use? (Usually not.) Many many factors will go into this medical advice (including your father's age, state of health, other illnesses, etc.). So you'd be best off asking the physicians directly involved - and they may be hepatologists, radiologists, medical oncologists, radiation oncologists, and surgeons. They can give you medical advice, and we can't; and they have the facts they need to give you that advice, and we don't. - Nunh-huh04:44, 13 December 2005 (UTC)[reply]
I just want to know the survial of this,yes physician has given tests to understand the stage.
Incase the remedy is not available in india where we can approach.
This is still a question your physician should be able and willing to help you with - though really no one can give you a specific number. In general the survival time for a non-resectable hepatocellular carcinoma is months rather than years. - Nunh-huh05:23, 13 December 2005 (UTC)[reply]
If when your vision has glaucoma it gets better with medicinal THC, theni f you don't have any glockoma vision problems, wouldn't THC actually make your vision a lot better? like 200 or three hundred times better? If it can make bad vision from near blind to be able to see, then couldn't it make good vision to VERY good vision? with reular doses? What other medicical problems require treatment with medical THC? Do you know what symptoms they have and where or what kind of doctors prescrime them? Couldn't you say if it makes good seeing intp great vision that THC is like a vitamin and could be given prescription over the counter like a normal eyesight fixing vitamin? - amon
My understanding is that glaucoma is the result of optic nerve damage caused by elevated intraocular pressure—high pressure within the eye compresses the optic nerve and surrounding tissue, causing damage. THC has been demonstrated to lower intraocular pressure (the pressure within the eye) for some patients, which may arrest or delay further vision loss.
It reduces Glaucoma, but it won't make a non-Glaucoma-ed eye get even better. A walking stick may help someone with only one-leg walk, but it won't help a two-legged person run. smurrayinchester(User), (Ho Ho Ho!)20:49, 13 December 2005 (UTC)[reply]
What kind of human is described by the Human Genome Project?
I was going to ask whether the Human Genome Project was the genome of a single person or a group of people, but the article says it's "the combined genome of a small number of anonymous donors". What would the imaginary human described by this composite genome look like (what color skin, hair, etc.)? I assume they've sequenced both X and Y sex chromosomes, so it could be male or female.
Well rumour has it that Craig Venter is one of the anon donors.
With regard to the amount of variation, below is quoted from the HapMap project:
"Genetically speaking, humans are incredibly similar to one another. Any two unrelated genome sequences differ at only one position in a thousand, on average. The 0.1 per cent difference, which amounts to about three million base pairs of DNA in total, is what makes each of us genetically unique." [28]David D.(Talk)07:01, 13 December 2005 (UTC)[reply]
But what do they do for these 1 in 1000 genes? Mark them with a question mark (AATCGC???CAT)? Fill them with a random letter? But to your X/Y question, if both are sequenced, the subject would turn out male. smurrayinchester(User), (Ho Ho Ho!)20:52, 13 December 2005 (UTC)[reply]
Its not a difference of 1 in 1000 genes, it is a difference of 1 base pair every 1000 base pairs. So each gene may have a few diferences between two people. Many of these differences will have no effect on the gene function, although some will and this is why we all look different. When the difference is limitied to a 1 nucleotide difference it is known as a single nucleotide polymorphism (SNP). Other differences include small deletions or additions. Are severe example of this is the trinucleotide repeats that are responsible for many diseases. Current research is designed to find as many of the differences that are present in the human population. Such differences could be used to predict a person susceptability for certain disesases such as heart disease and cancer. The positions of known SNPs are stored in a data base not as an X in a unified human sequence. Currently there are 5.8 X 10^6 unique human SNPs (called RefSNPs and identified by an "rs" number). For more info see the following two web sites [29][30]. David D.(Talk)23:51, 13 December 2005 (UTC)[reply]
The idea is to identify all human genes, that everybody may not have but similarly is common enough (ie. whether it be sickle cell anemia or polydactyly) to be notable to include, ie. not just some random mutation, unless it's a random mutation that has been carved in stone and is now widespread. The differences, are therefore included. It's not the genome of one person; the concept of the "human genome" is all the possible genes in human beings. If we were to put the entire HGP into a to clone single organism, there would probably be a severe amount of conflict and that organism wouldn't be viable. For example, take an address book. The HGP is like a telephone book - every single notable phone number (where notability is judged by the publisher) - it's unlikely that it's your personal address book, and that you know everyone in that address book. However, if you were to put say, every single person's address book together for a single city, or area, then that is what the telephone book would look like. The HGP can run by this analogy - it would be unlikely - even impossible to include the HGP into a person's genome, because just as you don't know everybody in the telephone book, there is likely to be cases where you have two different versions of a trait, so having both (an absence or presence) would be impossible. If you get my drift. -- Natalinasmpf21:29, 13 December 2005 (UTC)[reply]
can anyone explain the concept of the wave function and schrodinger's equation in simple laymen's terms? it has too many mathematical terms in wiki, and it's really confusing!
Oh dear heavens. Wave function and Schrödinger's Equation in layman's terms. Yikes. I will give it a shot, but be warned that I am simplifying in the extreme.
Mathematically, physicists describe these "particles" as solutions to differential equations, typically, the abovementioned Schrödinger equation. These solutions are called wave functions, because mathematically they look like equations of waves (other, very simple examples of "wave functions" are the equations describing sound waves, for instance). So, even though these functions are describing a "particle", they have the form of a "wave", leading to the wave-particle duality concept. One of the properties of the wave function is that, if you square it, you get the probability of the particle in question being in any one place. This may sound odd, but you can't define the position and speed of a subatomic particle with 100% certainty (as expressed in the Heisenberg uncertainty principle), so the best you can do is say "there is a 20% probability that the particle is at A, a 30% probability that it is at B," and so forth.
This all sounds very abstract, I know, so I'll try an example. Take an electron around the nucleus of an atom. If you solve the Schrödinger equation for this scenario, you get a wave function describing the electron. If you square the wave function, you get the probability of where the electron could be. The result is that the electron is most likely to be found in an area a certain distance away from the nucleus (think of a shell around the nucleus, and the electron is likely to be found on that shell), with only a very small probability that it's found anywhere else. This concept of "electron shells" meshes nicely with the observations of the properties of atoms (see the Bohr model), and can explain, for instance, emission lines.
As I said, this topic is fiendishly complicated, and a thorough understanding often requires years of study at university level. However, I hope I've managed to at least give you an idea of what it's all about. I seem to recall it was Niels Bohr who said "people who claim to understand quantum physics are either lying or deluded." *grin* — QuantumEleven | (talk)09:36, 13 December 2005 (UTC)[reply]
Are you saying the position of an electron is only defined as the probable distance to the nucleus and nothing else? In other words, is an electron sort of a pulsating sphere (getting bigger and smaller very fast) in stead of a 'linear wave' (or what should I call that?). I've long imagined it that way and your explanation seems to support it. DirkvdM10:59, 13 December 2005 (UTC)[reply]
No, I don't think that's quite right. If you take just one electron around a nucleus of one proton (so, Hydrogen), then the electron is most likely to be found in an area that looks like a shell around the nucleus. It is possible that the electron could be elsewhere (the probability function is not 0 in other areas), but the probability is relatively small. In terms of waves, what this represents is a three-dimensional standing wave (no, the human brain cannot hope to visualise a three-dimensional standing wave). Trying to imagine what this "looks like" in real life is futile - we can't know what it looks like because it's outside of what we can picture in our minds. So the best we can do is an approximation - for instance, you can consider the electron as a particle, whose position you cannot determine exactly, but you know it's probably somewhere on this "shell" around the nucleus. Or you can "picture" (used in the loosest sense here) the electron as a three-dimensional standing wave around the nucleus. In reality, the electron is a bit of both, but we need these approximations to get around the limits of human perception. — QuantumEleven | (talk)11:10, 13 December 2005 (UTC)[reply]
Well, isn't a three dimensional standing wave the same as a pulsating sphere? But if that were the case and it were a 'normal' wave then the probability would have to follow a sine function. But I imagine it would be more like a normal distribution. I'm sorry, my math isn't good enough to express this clearly. Let me put it this way. Does the probability drop to zero (absolute, mathematical zero) at some point (on the inside and on the outside)? And if so, does that happen fairly suddenly (sine) or does it 'peter out' (normal distribution)? DirkvdM10:02, 14 December 2005 (UTC)[reply]
See atomic orbital and hydrogen-like atom for the details, but the lowest-energy orbital for hydrogen (1s) has a radially symmetric probability density that's fairly simple:
Where r is the distance from the centre and a0 is the Bohr radius. The probability is zero at the centre of the atom (r=0) and tends to zero as r -> infinity. The peak probability is at r=a0. Higher-energy orbitals are more complex. Note that there's no concept of the electron "pulsing" as such; the (square of the) wavefunction just tells you the probability of finding the electron at any given position.--16:10, 14 December 2005 (UTC)
The Feynman QED book is based on lectures given to the general public, and gives an appealing description of theory even beyond the wave equation. One reason for the mathematics usually seen is that it is our attempt to retain sanity while nature has other plans.
Earlier physics is most easily summarized according to Newton. If we shoot a bullet towards a wall with a vertical slit, the bullet either hits the wall or goes straight through the slit. If we spray many bullets and mark where they hit on the other side of the wall (if they get through), we get a picture of the slit. If the wall has two slits side by side, we get a picture of two slits. On the other hand, if we sink the wall into a pond and replace the gun by a bobbing ball sending out waves, what we see on the other side is waves spreading out from a single slit. More interesting still, with two slits the waves on the other side combine to give ups and downs that here reinforce and there cancel each other (interfere).
But something very strange happens if we scale down the experiment to the level of small particles like electrons, neutrons, or photons (light particles). We can perform a bullet-style experiment, marking the hits of individual particles arriving one by one. However the pattern we see, in particular the two-slit pattern, is that of a wave-style experiment! There is no way to explain this fact of nature in terms of classical bullets or waves. How could a bullet go through both slits to produce a wave-like interference pattern, and how could a wave register individual hits? This is the physical situation that the wave equation is meant to describe.
The trick that resolves the contradiction is to use probabilities. Where Newton would give the precise position and motion of the particle, so that it definitely goes from point A to point B, the wave equation is more vague. It says if the particle is at point A it is likely to end up any number of places, with the distribution of likelihood following a wave pattern.
Yes, it's a strange kind of theory. However, every time someone finds a disturbing prediction of the theory and tests it, nature replies, "I am that strange; get over it". --KSmrqT22:11, 13 December 2005 (UTC)[reply]
I have now split my contributions to this thread in two threads, so what is the probability of me being here now? (whenever 'now' is, but that was another thread some time back.) Anyway, if I may continue my 'pulsating sphere' visualisation. Let's assume that that sphere can only pass through one of the slits when it is small (does the size of the slits matter?). That would mean that some (most) particles would hit the first wall (with the slits) and not pass through the slits (if so,are these (and their location) ever measured?). It would also mean that they hit the back wall in 'pulses' (as particles). But would they follow a stochastic distribution on the wall? If they're 'pure mathematical' spheres one would expect a 'blurred' impact zone. For them to hit a more precise spot there would have to be an underlying structure. Which there is, because they are made up of quarks. Am I making any sense? DirkvdM10:02, 14 December 2005 (UTC)[reply]
Forget the pulsating sphere, it's a bad mental model. There's no pulsating, there's no sphere. A neutron is made of three quarks (with gluons), but we see no evidence of internal structure for an electron or photon. For purposes of this discussion, visualize a photon or an electron as a mathematically ideal point, and don't worry about neutrons.
The probability distribution has the form of a wave, and a wave has a wavelength (distance between peaks), or equivalently, a frequency (number of peaks in an interval). We also talk about light having a wavelength (which our eyes notice as color); the two kinds of wavelength happen to agree. In fact, the theory says that wavelength is inversely proportional to momentum, which for Newton is mass times velocity. Since blue wavelengths are shorter than red, we conclude that blue light packs a greater wallop. Since the speed of light is constant, blue light is also more massive, in some sense. (Here we see Einstein's fingerprints on quantum theory.) But electrons, though slower, are much more massive than visible photons. Thus electrons have greater momentum, and consequently shorter wavelength, than light. If the wavelength of the particle is substantially greater than the width of the slit, essentially nothing gets through. (We can confirm this with ordinary water waves. But nature is exceedingly strange, and theory says that even if the wall has no slits, a particle can have a measurable probability of being on the other side when the wall is thin enough, even if it can't get through! This is called "quantum tunneling", and is routinely used in electronic devices today.) Anyway, an electron can squeeze through tighter spaces than a photon, and so an electron microscope can reveal details too small for a light microscope. In the kitchen, microwaves have a wavelength longer than visible light, so the door of a microwave oven can use a grill that stops the microwaves from escaping, but lets visible light through just fine.
Do these details make quantum theory easier to understand? Maybe not. The mathematics is actually fairly simple in structure, but the more we look at the predictions, the stranger nature seems. --KSmrqT11:11, 16 December 2005 (UTC)[reply]
Thanks for the illumination. So the size of the slits matters, but it's the wavelength that matters. This seems to support my pulsating sphere, but that wouldn't work with the water, so I'll have to ponder on this a little more. Yet another thing to loose sleep over. Thanks a lot! :) DirkvdM10:23, 17 December 2005 (UTC)[reply]
Is there any empirical equation for pressure-altitude?How does the pressure change with altitude in the real world?
According to our article on Atmospheric pressure, a "best-fit" formula for pressure based on altitude is
where P is in Pascals and h in meters. It's a relatively good fit, but the results produced won't be as good during "extreme" weather conditions (eg a hurricane). Also, don't forget that ground pressure will vary with the weather and time of day, so that will have an effect too.
The only way you can find out the pressure change with altitude "in the real world" would be to take a plane and measure it - the mechanics governing pressure variations are complicated and calculating them is virtually impossible. However, we can (and do) simulate them as part of weather forecasting calculations - however, this is obviously not 100% accurate, and needs copious quantities of computer power. — QuantumEleven | (talk)09:46, 13 December 2005 (UTC)[reply]
The article also says: As a rule of thumb, the pressure decreases by about 1% for every 80 metres increase in altitude. An alternative rule of thumb, density decreases by half every 20,000 feet below the tropopause, and every 15,000 feet above the tropopause to the stratopause.
Supposedly the phone company knows where you are, pretty close geographically, with or without GPS when your mobile phone is powered up, so that the rest of the wireless phone network can talk to yours. Supposedly law enforcement can tie into that to get a map like data base of where all the phone subcribers are.
Have you seen movies of Air Traffic Control where they have like radar screens having symbols of different aircraft located where? Well think of that concept except instead of planes on the map, it is people. Of course this Big Brother technology not to the point yet where they know WHAT you are doing, but your ISP communications could get recorded. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 21:25, 14 December 2005 (UTC)[reply]
I use Internet Explorer,Opera Browser as well as Mozilla Firefox.The problem I have is that after opening a webpage once,the updated page for the next day doesn't open.
eg I opened the page www.arsenal.com about 3 months ago.Now,whenever I open arsenal.com again,the page from 3 months ago opens.Why does this happen and how can I undo this?
I've already deleted all of my history,temporary internet files and cookies.It did't work.My PC does not have ANY sort of Spyware or Adware(I use 6 different softwares).
Please,help needed.Thanx in advance.
PS: I use a proxy server.Does that matter?
The proxy server could be your problem - it could be caching pages and not fetching refreshed pages correctly. Try doing a forced refresh (CTRL+F5), this forces your browser to get the latest version of the page.
Have you tried a direct connection, bypassing the proxy? If that solves the problem, then you've found the cause (the proxy server). If it doesn't, it could be a problem with your browser, although you must have customised the settings quite heavily for this to occur. In IE, you can check Tools -> Options -> Temporary Internet Files -> Settings, and set this to "every visit to the page" or (better) "automatic". Although if you say that it's a problem with every browser you use, to me that's screaming "proxy server". — QuantumEleven | (talk)11:29, 13 December 2005 (UTC)[reply]
Thanks for replying,QuantumEleven.Ctrl+F5 didn't work.Disabling the proxy server did.[:)]Thnx.But now (as expected) the speed of my net has taken a nose-dive.Is there any other way?
Well, that depends - do you run the proxy server? If so, then you can take a look at its configuration to see where it's going wrong, because the behaviour you're describing is not the way a proxy server should operate! A proxy server should store copies of web pages so you can access them quickly, but it should also be checking to see if its copies are the most up-to-date - this is something it doesn't appear to be doing. Is there a good reason why you're running a proxy server? What kind of connection do you have?
(obviously, if you're not the one administering the proxy server, then this discussion is moot - you'll need to talk to the person running your proxy server and get them to sort it out! :)). — QuantumEleven | (talk)10:58, 14 December 2005 (UTC)[reply]
"(obviously, if you're not the one administering the proxy server, then this discussion is moot - you'll need to talk to the person running your proxy server and get them to sort it out! :))."
My career is involved with this. You might want to post questions separately on my User talk:AlMac talk page.
Assuming you are at a place with an AS/400 where you have been granted security access to sign on to the system.
F1 is the universal help key. Any place you have a question, or need to get documentation, just put the cursor on what you want to know more about, and press F1. A lot of screens are cursor sensitive. Depending on where the cursor is on the screen, different places plus F1 will give you access to different facets of the documentation.
Note that on the IBM keyboard the function keys go from F1 to F24 while on many PC Keyboards they only go from F1 to F12. Often you can get at F13-F24 on a PC keyboard by doing upper shift corresponding F1-F12. There are numerous other cheats out there to make this easy to remember which is which. It can be useful to check any manual on any IBM "dumb" terminal, since the keystroke combinations are pretty standard.
Example, suppose you are at a PC keyboard connected to an AS/400 ... upper shift ESCAPE key then ENTER is often the same as doing a SYSTEM REQUEST on an IBM keyboard, which gives you access to a ton of system stuff. I think one of the coolest keys is the HEX key, which gives rapid access to HEXADECIMAL data. Basically, your starting point is to get your hands on a manual for ANY IBM dumb terminal, because the stuff in there about basic keyboarding applies across the board to just about any interface available to you.
All the IBM manuals are on_line freely accessible, if you know how to navigate them.
Client Access for example is the most common way people connect (via a PC) to AS/400 nowadays ... we can also access via Web pages, "dumb terminals", FTP, TELNET, lots of ways. Basically a useful skill is learning how to navigate IBM documentation on-line.
Spoiler warning ... IBM is constantly trying to improve their on-line documentation, but they are not real good at this, so invariably any skills you aquire learning the old way of accessing are not much help to you the new way.
There are hundreds of thousands of AS/400 users around the world in various discussion groups. My favorites are at midrange dot com but there are many others, mostly hosted by magazines about AS/400 such as IT Jungle.
Just about every AS/400 magazine web site is rich in resources. Forums, Articles, Archives, White Papers, Manuals, you name it ... but in most of them you have to register, and in some cases join for a nominal fee.
I belive the chief difference is that a hub transmits all data it receives to all of its output ethernet wires, while a switch examines the packets it receives and tries to transmit them only to the output where it is destined. So a hub is simpler, but a switch conserves bandwidth. In case of a hub, the machines connected to it (either computers or switches) will examine the packet and throw it away if it's not destined for them. I'm not sure in all this though. – B jonas20:10, 15 December 2005 (UTC)[reply]
That used to be the distinction, until dual-speed hubs came along. Those don't necessarily send all data to all outputs, because otherwise high-speed data destined for a high-speed recipient would be unnecessariloy bogged down by the need to throttle it for low-speed non-recipients. I used to think that "dual speed hubs" were therefore really switches, although the section on "Dual speed hubs" in the Hub article suggests I was wrong. Steve Summit (talk) 14:05, 17 December 2005 (UTC)[reply]
Surface ocean currents are generally wind driven and develop their typical clockwise spirals in the northern hemisphere and counter-clockwise rotation in the southern hemisphere. Deep ocean currents are driven by density and temperature gradients. Thryduulf23:19, 13 December 2005 (UTC)[reply]
The direction of current, in terms of engineering is defined as in the opposite direction to the flow of electrons. Therefore the electrons in a circuit flow from low to high voltage, which means the current flows from high to low. - Akamad08:58, 14 December 2005 (UTC)[reply]
PLEASE TELL ME, HOW TO MAKE AN AUTOMATIC TRANSMISSION FOR A CAR, AND WHAT MATERIAL FOR MAKE IT?
With great difficulty. Building a one-off, custom automatic transmission would be an enormously complex task; you'd have to build an entire geartrain, a torque converter chamber, probably software to control it...if this is for a custom car project, try to find an existing one with the right size and characteristics and figure out how to adapt it to your purpose. If this is some kind of engineering exercise for an individual, building a toy torque converter *might* be on the ragged edge of feasibility, though getting it to work right will be very challenging (as I understand it, it would depend very much on the viscosity of the fluid you used). Access to some computational fluid dynamics software, and learning how to use it, might help a lot. Finally, if you want to go into the automatic transmission manufacturing business, hire a bunch of engineers, preferably ones who've worked in the transmission divisons at companies like ZF Friedrichshafen AG or Borg-Warner. Start by taking apart a bunch of existing designs, and prepare to spend a lot of time dealing with patent lawyers if you want to sell the results in developed countries... anyway, see automatic transmission for some basic information on how they work. They're mostly built of various grades of steel. --Robert Merkel22:17, 13 December 2005 (UTC)[reply]
I expect it'll come off eventually by itself as your epidermis renews itself. Scrubbing with a brush and some soap should help the process along. I don't know if rubbing alcohol will help, but I don't see what harm it could do (in moderate amounts) either. —Ilmari Karonen (talk) 22:15, 14 December 2005 (UTC)[reply]
Rubbing alcohol won't work any better than water. The silicone film will take between hours and days to come off, papers towels are the best bet if it is too irritating. Physchim62(talk)17:54, 15 December 2005 (UTC)[reply]
If all particles are pointlike and they have no real volume, then wouldn't all particles with mass have infinite density and be black holes? Please help 216.209.153.11522:34, 13 December 2005 (UTC)Max[reply]
Your problem is you're misunderstanding the nature of division. The density of something is mass divided by volume. The volume of a point particle is 0. mass/0 is undefined (indeed, anything/0 is undefined). It is not infinite. So the density of a point is undefined - they don't have a density because they don't have a volume. Check out division by zero. -- Finlay McWalter | Talk23:04, 13 December 2005 (UTC)[reply]
That's wrong though. A Black Hole can (in theory) be said to have infinite density. See the article. Just because it's a division by zero doesn't necessarily mean it's "undefined". The density is mass/volume, and the limit as volume goes to zero is that the density goes to infinity. There are plenty of singularities in physics, and they aren't usually treated as something simply 'undefined'. Taking the limit certainly makes most sense. --BluePlatypus00:10, 14 December 2005 (UTC)[reply]
(edit conflict) You are misunderstanding what a black hole is; a black hole is not defined by an object having "infinite" density. A black hole, instead, is an object whose mass is so great that the gravitational field it produces is strong enough to capture even light. Particles, being very small, aren't able to create massive gravitational fields on their own, and as such aren't black holes. Enochlau23:07, 13 December 2005 (UTC)[reply]
I guess you could think of elementary particles as being tiny black holes. Many properties of a black hole are also true of, say, an electron (for example the no hair theorem — electrons have no hair either). But I don't know what good that would do you... —Keenan Pepper23:22, 13 December 2005 (UTC)[reply]
I'm wondering whether Hawking radiation would really matter. After all, exactly what particles would a charged black hole with the mass of an electron radiate? To vanish, it would need to radiate something charged, and it can't radiate away more mass than it has. (Of course, this is all idle speculation. Without a proper theory of quantum gravity, we can't very well be expected to reason rigorously about the properties of tiny black holes.) —Ilmari Karonen (talk) 14:35, 15 December 2005 (UTC)[reply]
The concept of Maxwell's demon was proven to not be able to lower entropy because it creates more entropy in the process (see link). What if instead of a demon there was just a small slit? If a high-energy particle happened to slip through, wouldn't that violate entropy? Thanks, Max 216.209.153.1400:59, 14 December 2005 (UTC)[reply]
Sure, a high-energy particle can slip through. But so can a low energy one. In order for a Maxwell's Demon-type thing to work, there has to be some kind of sorting going on - but I don't see what characteristic a slit has which sorts fast particles from slow ones; it's not as if fast particles are thinner than slow ones. -- Finlay McWalter | Talk01:14, 14 December 2005 (UTC)[reply]
If a very high or low energy particle did happen to slip through first, entropy would be violated, at least temporarily. Additionally, according to quantum physics, higher energy particles have a more concentrated probability field - so they are thinner. Max 216.209.153.1401:27, 14 December 2005 (UTC)[reply]
Also consider: Your particle has gone through the slit. Now there's a greater concentration of high-energy particles on one side, and so there's a greater probability that one of them will go back through the slit to the other side. Statistically, it will even out. --Bob Mellish17:49, 14 December 2005 (UTC)[reply]
When a lemon is cut in half you can see that it is actually made up of several smaller sections. For example this lemon is made of nine sections. Is this the same for all normal lemons? Does this relate also to the number of petals the lemon tree's flowers have? - Theshibboleth02:44, 14 December 2005 (UTC)[reply]
I suspect that, like with oranges, the number of sections can differ be specimen. According to our article: "In botany, a fruit is the ripened ovary--together with seeds--of a flowering plant." The number of petals on the flower appear not be included in the formation of the fruit and are thus unlikely to affect the number of sections in it. - Mgm|(talk)09:33, 14 December 2005 (UTC)[reply]
The number of petals on most plants is not variable. Flower structures are often used to differentiate between speicies, thus more petals would denote a different species (although this is not always true, otherwise "she loves me/she loves me not" would be rather predictable). If you look around for pictures of orange blossoms [31] you'll note that they all have five petals.
In fact, [László Mérő] mentions this in his book ""Mindenki másképp egyforma"" (the English translation apparently has the title ""Moral Calculations""). In chapter 11, he states that the ""loves me, loves me not"" game is indeed sort of deterministic for this exact reason (most flowers have flowers have an odd number of petals), but it's not entirely deterministic as often one or more petals have fallen off the flower. – B jonas19:59, 15 December 2005 (UTC)[reply]
Ever since I installed the Norton SystemWorks 2006, Norton Firewall 2006, Norton Antispam 2005, I have been getting the following window every time I turn on my computer.
Managed MAPI Service Catastrophic Failure
Unknown error
The only button on the small pop-up window is OK. How do I stop the window from popping up? My operating System is Windows XP Media Center Edition 2005.
Symantec's solution is downloading and installing updates for Norton Antispam 2005, but my update gets aborted whenever I try to get the update -- this only happens for Norton Antispam. I get the following error message.
Windows XP 5.1.2600 Service Pack 2
AntiSpam Feature 2005.1.02
LiveUpdate was not able to complete this update.
Please contact Technical Support and provide all information displayed on this screen.
For contact information, go to Help->Technical Support from your Symantec product.
The files below could not be updated by LiveUpdate:
Have you tried uninstalling and reinstalling Norton Antispam? That might solve your problem (you may need to uninstall and reinstall the rest of the suite as well, I don't know how tightly integrated it is). — QuantumEleven | (talk)08:32, 16 December 2005 (UTC)[reply]
I'm not an expert in the field of vaccination, but I believe that it's a common way of vaccinating infants (in India as well as the Western world). It may be because the veins in her arm were hard to see (so they used her foot instead), or perhaps, she already had several vaccinations in her arm, so they used her foot to give the arm time to heal. - Mgm|(talk)09:37, 14 December 2005 (UTC)[reply]
I have never heard of vaccinating on the sole. This of course does not mean it is not "common" in Asia, but I doubt it is "common in the Western world." The most common site in the US in the years it was being done was the upper arm. Smallpox vaccination involved scratching the skin (which is why it left a visible scar), not finding a vein or giving an injection, so the vein explanation or multiple injection explantion is irrelevant. alteripse18:13, 14 December 2005 (UTC)[reply]
When I said infants I'm referring to kids no older than 1 year. I've heard of such a practice and I'm not claiming it's common practice for anyone over that age. - Mgm|(talk)20:37, 14 December 2005 (UTC)[reply]
I think everyone has stopped doing smallpox now. Just for my own education, where and when was foot vaccination in infants common? alteripse21:48, 14 December 2005 (UTC)[reply]
My research adviser from undergrad was vaccinated on the sole of her foot so that the scar wouldn't show if she wore something sleeveless. She was still kind of bitter that her doctor was that sexist; he vaccinated boys on the arm, where it hurts much, much less. I was never quite impolite enough to ask her age directly, but I think this practice has been discontinued, and I know it wasn't widespread; my mom's vaccination scar is on her arm. --Joel13:30, 21 December 2005 (UTC)[reply]
what is the bandwidth required for on-demand computing
what is the bandwidth required for on-demand computing where processer is far away and only input and output devices are here?
It depends on the application(s) in question. You need enough bandwidth to make the use of a distant (presumably more advanced) processor preferable to a local one. — Lomn | Talk / RfC14:19, 14 December 2005 (UTC)[reply]
Where does the word cancer come from? I heard it is originated from hippocrates, who investigated breast cancer and the spiny venes reminded him of a crustacean. But how does that explain the word cancer?
Thanks, Meike
This seems to be about right; according to Paul of Aegina, Hippocrates made the connection because "the veins stretched on all sides as the animal the crab has its feet". According to Webster's Revised Unabridged Dictionary, "It was so called, perhaps, from the great veins which surround it, compared by the ancients to the claws of a crab." The tumor meaning has been attached to cancer for a very long time. [32]‣ᓛᖁᑐ13:39, 14 December 2005 (UTC)[reply]
In some languages (Danish, Norwegian and 19th century Swedish come to mind as I'm scandinavian) - the name actually is the native name of a similar (but not identical, compare crab) animal, the crayfish. (it's "kræft" in da, "kreft" in nb, "kräfta" in 19th century Swedish but "cancer" in modern Swedish). Unfortunately, I don't know the origins. It might a mistranslation or have its own origin. TERdON23:57, 14 December 2005 (UTC)[reply]
Plus/minus refers to the presence of the Rh factor. Rh is an antigen which may or may not be on the surface of red blood cells. If you have it then your blood type is (+), if you don't then it is (-). Why we have a gene for this antigen? We do not really know, it may be some evolutionary remnant. Nrets19:34, 14 December 2005 (UTC)[reply]
WHAT DOES A DATA BASE MANAGEMENT SYSTEM ALLOW US AS USERS TO DO?
Nothing. It organises data. But if you add in applications that use the DBMS, then you as end users gain the ability to work with that data. Most business processes these days involve dealing with large amounts of data, from contact lists to human genomes, and the DBMS is charged with storing, organising, and providing efficient access to that data. Does that hope with your homework? Notinasnaid16:06, 14 December 2005 (UTC)[reply]
It also depends on the system. Many computer infrastructure providers use similar terminology for systems that have extremely different capabilities. AlMac|[[User talk:AlMac|<sup>(talk)</sup>]] 22:06, 14 December 2005 (UTC)[reply]
The latest issue of e-week has a truely fascinating article on how NASA presents different kinds of data for people to utilize.
NASA has defined 12 different domains in which Earth Science Satelites has beneficial applications, organizing that data into different collections optimized to the needs of those applications.
I would hope that there are Wiki articles some place on some of these concepts.
Many services offer free SMS from PC (say messenger) to mobile.
Is there mobile to PC service apart from the service which offers users ability to reply to PC-to-mobile messages?
Yes, my GSM provider offers such a service [34]. All you have to do is send an SMS to a special number, and they'll send an e-mail, so this is available from any old mobile phone. The recipient address, the subject of the message, and its body are all specified in the same message. This, of course, limits you to short e-mails only. It costs the same as a normal SMS I think, but I'm not sure. – B jonas19:42, 15 December 2005 (UTC)[reply]
The "section edit" form on Wikipedia contains a one-line "subject/headline" field and a multiline text box (see http://en.wikipedia.org/w/index.php?title=Wikipedia:Sandbox&action=edit§ion=new). Currently, if you hit "Enter" in the subject/headline field, most browsers will treat this as a "submit" request, apparently because this is the only one-line field on the form (Bugzilla:4273). Is there any way to change the table markup so that the form will work the same way, but that browsers won't treat Enter as a "submit" request? From what I can tell, the Summary field is an input field, while the text box is a textarea, but I'm not very good with html forms. -- Creidieki20:08, 14 December 2005 (UTC)[reply]
There's a javascript trick for this. Most browsers seem to treat hitting Enter on a form as a click on the first submit button on that form. Therefore inserting a transparent 1×1 pixel image button at the top of the form and giving it an onclick handler that returns false will prevent hitting Enter from submitting the form. It's a crude hack, I know, but it seems pretty reliable in practice. —Ilmari Karonen (talk) 22:05, 14 December 2005 (UTC)[reply]
I must be knowing any effect or dangers that would be coming if someone (not being me!) were to be ingesting 5 heroin filled game rabbits. please be helping. Should I be going to the hospitle after doing that? This is urgent!
Are we to assume the rabbits have been cooked? And did the rabbits ingest the heroine or were they injected with it? If injection, before or after their death?
my suggestion is
immediately without delay to get the victim to a hospital to have their stomache pumped out.
be prepared to give a statement to the police in which the cross examination may last XXX hours.
Depending on nation state etc. there are often laws requiring medical personnel to inform the police when a person's medical condition implies that some reportable crime may have occurred, such as
As you all know in th uber popular movie return of the sith, they made a clon army that without knowing about it, was programmed to assasinate the good guys in the movie, even though they were trained from birth to be clones? But could or how would this wor in real life? Could it have been done and we might not ven know about it? until late? opinions? science? facts?- anon
Current state of art ... the clone arrives as a fetus, with normal speed development same as an ordinary child.
There was another thread somewhere now in the archives, about risks of science, when commercial interests are more interested in short term profits than safety.
Mad Cow disease is man made accident, that originated with Mad Sheep Scrapie got passed to cattle, then thanks to careless experiments with Deer, it is now in the wild, at least in North America, with most wild animals susceptible, because the food chain that eats the Deer, also gets this. Pigs and other livestock also got it. So this is not because of evil intent, but short cuts thanks to greed.
Toe Jam is a sweet preserve made from toes. First, debone the toes, removing the nails if necessary. Next, chop the toes into small cubes about 5mm x 5mm x 5mm. Put in large pan. Add equal weight of sugar, and enough water to fully dissolve the sugar. Boil until thick. Alternately, a toe jam is when you jam your toe against a wall, thus compressing the bones. --YixilTesiphonSay helloBe shallow22:53, 14 December 2005 (UTC)[reply]
Well, i am doing a website and i want to create a login/sign up but i don't know how to do that. Can you help me?
-Mumai
If all you want is to make some part of your website accessible with a password, you have to configure the webserver so. Read the Apache manual for example: [35], although I guess there may be more comprehensive descriptions too. -- (sorry, it seems I forgot to sign this) B jonas19:25, 15 December 2005 (UTC)[reply]
There are host sites you can buy into, that come almost default that way, such as Weblogger.
Setup the site as restricted, then there is a place you go to define new users and invite them to join, or send them password (like in e-mail which is not exactly secure).
This kind of system is for people who want to be able to use the power of the Internet, without having to learn the programming that is needed to make things work.
They don't mention the depth of coverage for each article so its hard to extrapolate. I assume they picked articles that were similar. If so, looking through that list of errors compared to Britannica, i'd say that wikipedia is in very good shape. David D.(Talk)01:26, 15 December 2005 (UTC)[reply]
Unfortunately the standard deviation for the number of mistakes per article is slightly higher for Wikipedia (3.47) than for Britannica (2.43), suggesting our quality may be more variable. ‣ᓛᖁᑐ03:04, 15 December 2005 (UTC)[reply]
Well no surprise there. Some of the wikipedia science articles are terrible. But they are all a work in progress and will improve eventually. David D.(Talk)04:12, 15 December 2005 (UTC)[reply]
Is there currently a drive or WikiProject to improve the quality of the articles in question, or for that matter, does anyone maintain a list of WP articles mentioned in the media as needing improvement? I would imagine a list of those articles would be good to have, as experts will be attracted to them, and they're also likely vandalism targets, so they should be watched and improved. This is just a suggestion, but if it doesn't exist I'd like to start something like that.
A number of people posted on the village pump that they got responses back from nature saying they are working on publishing the list of errors on their blog, so stay tuned. - TaxmanTalk21:40, 16 December 2005 (UTC)[reply]
The decibel is a commonly used unit of sound loudness. However, according to the article, a decibel is a dimensionless unit.
There are several variations on the decibel listed in the article, but I'm unable to figure out which one is correct.
Which decibel variant is the correct one to use when talking about the subjective loudness of a sound to humans? Or is merely decibel sufficient?
--Cybercobra04:20, 15 December 2005 (UTC)[reply]
A bel is just a factor of 10. A decibel is one tenth of that, so it's a factor of 101/10. The actual unit for measuring sound intensity is the watt per square meter, but it's much more commonly stated as a number of decibels in relation to 10−12 W/m2. For example, 30 dB is 1000 times that intensity, so 10−9 W/m2.
However, sound intensity is not the same as subjective loudness. No matter how loud a sound is at 50 kHz, you won't be able to hear it (but your dog might). Apparently the unit for subjective loudness is the phon. —Keenan Pepper05:49, 15 December 2005 (UTC)[reply]
You're correct about a decibel being dimensionless, so it really just describes ratios. When used in the audio world, it's often used with a specific reference. While people may say "that sound was 85 decibels", they really mean something that should be written as something like 85 dB(SPL), which compares it to a reference level of 20 micropascals. Decibels have many other standard references, such as dBm, dBv, etc... kmccoy(talk)00:50, 22 December 2005 (UTC)[reply]
They both take their name from the Roman "vinegar cup". They are related by appearance (at least in an anatomist's imagination) rather than by volume. - Nunh-huh04:55, 15 December 2005 (UTC)[reply]
Part of the answer to the question is related to the structure of the data, and packing. Data is being transmitted at the speed of light along the cable, right? It is going two ways at the same time. There are multiple parallel data, like in a TV signal, there is both audio and video, in parallel with each other.
Assuming you mean in terms of computer networking cable, thinwire (co-ax ethernet) tops out at 10 MiB per second, and twisted pair goes up to (at Cat 6) 1GiB per second - assuming you have the correct hardware on both ends. Ethernet has more information. I'll note that, in principle, there isn't really a difference between the maximum data throughput of the two cable types, but as twisted pair was a much nicer topology, noone bothered designing and standardising aything faster through co-ax. Syntax02:39, 20 December 2005 (UTC)[reply]
See if you can open the recovery file. (Search Word's help to find out where it is, it's different for different setups and platforms). - Nunh-huh04:52, 15 December 2005 (UTC)[reply]
I hope you haven't closed Word yet - doesn't it delete all the recovered documents from the previous session upon exit? It should also offer you the choice of the file as last saved by you (which I would imagine is good), and the automatically saved versions... Enochlau05:14, 15 December 2005 (UTC)[reply]
With the galaxy, sun and earth all moving, is it possible to stay still in one spot in space?
It depends how many variables you use to define "one spot", if you mean X,Y, and Z coordinates are all kept constant, than sure it's possible-ish, but since the expansion of the universe is modeled in 4D, I'd say that last axis might complicate matters--Aolanonawanabe16:28, 18 December 2005 (UTC)[reply]
By the principle of relativity, you cannot "stand still" in one place. Not moving and moving with a constant velocity look and feel exactly the same. As Michelson and Morley demonstrated with their experiment, there is no absolute frame of reference by which we can measure whether we are "moving" or "staying still" in space. Enochlau05:12, 15 December 2005 (UTC)[reply]
This is a tricky question, and depends on what you mean by "stay still" and "in one spot". Until the acceptance of the heliocentric model, most people would have replied "yes" without second thought (Earth doesn't move, therefore if you stand still, you aren't moving). With the adoption of heliocentricism, the notion of an "absolute center" shifted to the Sun, with various explanations for the motion experienced by everything else (including epicycles). Now special relativity is popular, in which there is neither an absolute center nor an absolute zero speed — but there is a relative zero speed, which is the speed of the observer. So by relativity, you can consider yourself to stay still in the exact location where you are, which of course is practically meaningless. ‣ᓛᖁᑐ05:20, 15 December 2005 (UTC)[reply]
Actually, Eienstein's theory of relativity does not state that everything is relative to everything else, just to certain constants, so yes, it is possible. Max 216.209.153.1514:09, 15 December 2005 (UTC)[reply]
How can i make a radio with household parts, and parts from Old radios, cell phone, and mini tv's?
Building a "crystal set" is suprisingly easy. All you need is a coil of wire, a diode (that's what the crystal was for; now diodes are really tiny and cheap), some earphones, and a capacitor that you can change to tune it to different stations. A crystal set is cool because it doesn't need any power other than the radio waves (but therefore there's no way to turn up the volume). You can probably figure out how to build one just from the Wikipedia article.
Actually, I just read that it is possible to tune in to an FM station with an AM receiver such as a crystal set. It depends on the circuit having a very high Q factor, and of course the quality won't be that great. It works best if you tune to one side of the FM band rather than the center. See [37] —Keenan Pepper07:18, 15 December 2005 (UTC)[reply]
Sun had been radiating enormous amounts of energy since its formation. has it been loosing its mass accordingly?.
If so ;
Can it be quantified?.
What are the effects on planetary orbits , if any?
If not , why so?
sombansil
Yes, it has been 'losing' mass (to be correct, converting mass to energy through nuclear fusion). Yes, this mass loss can be calculated, since we know how much energy is produced by a hydrogen-helium fusion reaction, and how much mass is converted to energy during this reaction. Taking an estimate of the total energy output of the sun over its history, we can estimate how much mass it has 'lost'. However, compared to the total mass of the sun (1.9891 x 1030 kg) the mass decrease is virtually negligible, and certainly not enough to have a visible effect on planetary orbits.
Addendum: it also loses mass through solar wind. From that article:
Approximately 1×109 kg/s of material is lost by the Sun as ejected solar wind, about one-fifth that lost due to fusion, which is equivalent to about 4.5 Tg (4.5×109 kg) of mass converted to energy every second.
Just a quick reminder to do your own homework. "If not, why?" is usually a dead give away that you're doing someone's homework. To the poster, instead of asking a homework question verbatim, just point out where you're having difficulty. --Quasipalm18:22, 15 December 2005 (UTC)[reply]
Is it possible to mix (install together) SATA and PATA hard drives in a single system? If so, how should I do it? Is it a good idea? Thanks in advance. 61.94.149.17710:28, 15 December 2005 (UTC)[reply]
I've got such a setup and it works. The very fact that there are motherboards with both SATA and PATA connectors should be a sufficient indicator that it should work. Since SATA is fairly new there may be some problems with that, but I don't see how the combination could cause any problems. If I'm not mistaken, the access of the drives is the same, irrespective of whether it's a SATA, PATA or SCSI, because the translating is done on the drive/interface itself. (Not sure if I put this right.) DirkvdM11:57, 15 December 2005 (UTC)[reply]
All mobos I've seen that use SATA also have some standard ATA connectors so that you can plug in CD-Rom drives, etc. (AFAIK almost all SATA devices are hard disks). You should be able to add standard ATA HDs to those connectors without any problems. --Bob Mellish16:57, 15 December 2005 (UTC)[reply]
Have there been any crashes of commercial airliners into bodies of water (lakes, oceans...) where (some) people on board have actually survived? I know that there are quite a few land crashes with few or no casualties, but I can't think of any water landings where not everyone was killed... — QuantumEleven | (talk)12:44, 15 December 2005 (UTC)[reply]
After checking out that list, it doesn't seem to me to be that dismal of a figure. Many low-passenger-count flights had 100% survivor rates, and many large-passenger-count flights had minimal fatality rates. I guess it's all about perspective, though.
If you take one cubic metre of stones and crush them in a crusher to produce finer aggregates, what will the volume of resulting aggregates
a)>1 cubic metre
b)=1 cubic metre
c)<1 cubic metre
Thank You
Depends on the size and shape of the original stones, I'd say. For example, if you start with a single cubical stone with one meter edges, the answer would probably be a. If, on the other hand, you start with spherical stones 50 cm across, packed into the same one meter cube (8 will fit exactly), the answer is almost certainly c. And of course, if you only measure the actual volume taken by the stones, not counting the spaces between them, then the answer is always b by definition.
--Ilmari Karonen (talk) 14:21, 15 December 2005 (UTC)[reply]
I'd support (c) too, but I'm not sure. If I'd want to know this, I'd take a vesel with a scale on its side, put some breakfast cereals in it, write up the volume from the scale, crush the cerial to very small bits (this is the difficult part), and see if the result will fill the vessel to a higher or lower level. Of course, stone could behave differently. – B jonas19:11, 15 December 2005 (UTC)[reply]
I would have gone for c) too, but notice that Ilmari has already refuted that. Very clever! (Though the last bit is a bit corny). But I'm sure one could generalise this in a formula. Actually, I believe there is a form of geometry that deals with just this sort of thing, but I can't think of the name. Topology doesn't seem to be it. DirkvdM08:04, 16 December 2005 (UTC)[reply]
...except that this holds only if they are all the same size (the packing generally gets denser if there are stones of various sizes), and ignores possible extra gaps at the edges of the container (which will on average be roughly proportional in volume to the radius of the smallest stones). Not to mention the fact that real stones are rarely spherical, especially not after crushing. And then there's the fact that randomly packed granular materials may not even have a constant volume — they may settle (or expand) when shaken. —Ilmari Karonen (talk) 21:38, 16 December 2005 (UTC)[reply]
I was talking with a teacher and we came across the fact that a green bean could be a vegetable or a fruit and we were wondering which one it is. It is not a root or a leaf however it has beans and that means that they can reproduce and regrow. Therefore i just need to know whether beans are a fruit or a vegetable.
Thank You,
Melinda
So alfalfa is also a fruit? So what is the classification of non-legumes like celery?
No he is refering to the beans themselves being fruit. Alfalfa is eaten as the shoots of the plant not the fruiting body so it is a vegetable, not a fruit. If you read Fruit, it explains a fruit is essentially the part of the plant that grows from a fertilised flower and contains the seeds of the plant. If a vegetable is a pert of a plant that does not contain seeds then it is not a fruit. --Martyman-(talk)22:43, 15 December 2005 (UTC)[reply]
If you use the technical definition of "latex", it's quite possible to make a latex of nylon, by producing very fine particles of it, suspended in water.--Joel13:49, 21 December 2005 (UTC)[reply]
technology developed originally for the military but now used in our homes
I´m a Brazilian journalist, working for a Science and History monthly magazine.
Right now, I´m doing research to write an article to answer the question "Which products originally invented for the military are now used in our homes ?" (For instance: canned food, the internet, etc.)
I would be most grateful if you could send your answers to this question. I also would be grateful if you could provide names and e-mails of specialists (historians, researchers, sociologists, political scientists, etc) who could be interviewed by e-mail about this subject.
You might also find useful info in the History of Space Exploration. Many products and services originally developed for astronauts, such as powdered orange juice, powdered milk, microwaveable instant meals, subsequently found their way into every home. Related to that, look at what has happened with Spy Satelites. Today there are several commercially available views of planet earth connected through the Internet, where anyone can see detail that a few years ago was only available to the military.
Some products and services were invented jointly for the military and for a nation as a whole.
The Internet was created by the military but it was not solely for the military, it was to provide communications with all sectors of government, business, academia, society, and be reistant to disruption in a disaster. We saw this concept fail in the Hurricane Katrina disaster, at least for the people on the ground there.
The US Interstate System had a similar joint purpose. At the time of WW II, many of the roads across the USA were not strong enough for the military to get from one side of nation to the other in a crisis, heavy equipment had to go by Railroad. But with the Interstate System, the National Guard and Reserve could be decentralized in many communities, and rapidly get to where they needed. But the financial success of the system needed it to be used by the mass public. It was not just for the military.
A lot of research into products and services for the military, can be made less expensive per unit person, if the beneficiaries of the work can be extended to the larger population. We see this in protection against various medical risks. The troops need to be vaccinated against a spectrum of diseases and biowarfare risks, then if the threat materializes, populations of whole nations also need protection.
It has been a while since I saw what progress was being made on cloning limbs to repair self. It may be that US politics has shut this down. The theory was that before going into harms way, troops blood samples would be stored some place, then after they exposed to radiation damage, or lose an arm or a leg, the blood samples be used to grow replacement parts for the injured soldiers sailors airmen, and because it was from their blood, their body would not reject the replacement organ.
Have a look at the history of computing: one of the first embedded computers was the guidance computer for the Minuteman missile: later versions, along with the Apollo program, pioneered the use of the integrated circuit. SAGE was one of the first real-time computer applications ever built, and pushed the industry along enormously. Heck, Colossus and ENIAC were both used for military purposes. Another classic example of WWII technology applied to home use is the microwave oven, the core of which was the cavity magnetron used in radar.
Many millioms of people died in WWI and WWII and I would not try and justfie the loss of life but think where we would be now had it not been for their sacrifice. Next time you jet off for a week end holiday just remember it is only just over 100 years ago since the first powered flight. Without those wars it is unlikly that aircraft would have developed passed the wood and string stage at this present time. I would hate to try and work out the percentage of tecnological advances we enjoy today that wern't attributable to our need to kill ourselves or to protect ourselves from being killed by our fellow man. With great regret I say long live testosterone.--Eye16:01, 18 December 2005 (UTC)[reply]
Not exactly used in the home yet, but used all over the place in civilian life, is Radar. Sewe if you can find the book "The Invention that changed the World" about how RADAR was invented, There's fascinating stories in there about how Axis and Allies used different wave lengths, and how they figured that out so they could do jamming. Anyhow, after WW II, RADAR made the Airline industry as we know it today, and great advances in Astronomy, and safer highways. User:AlMac|(talk)07:45, 20 December 2005 (UTC)[reply]
Check out literature on the History of science. I saw on a recent Science TV channel how Leonardo da Vinci was employed in the development of Mathematics to figure out how to get medieval weapons of warfare to send forerunners of artillery shells to the precisely correct targeting. While that math has advanced to more superior weapons, it has also become available to civilians for other purposes. Most all math today came about thanks to either warfare or early business book keeping. User:AlMac|(talk)07:51, 20 December 2005 (UTC)[reply]
One of the first documents published by Galileo was a manual for how to operate what he called a "Military Compass" which was something he made in his workshop that was similar to a calculating instrument called a slide rule, something very popular with engineers prior to major development of personal computing. User:AlMac|(talk)07:55, 20 December 2005 (UTC)[reply]
I am doing a science project on The Effects of Herb Robert on Acne Bacteria. i need more information on Herb Robert. The pigments in the leaf that makes it what it is. i am trying to find out what elements make up Herb Robert.
The wonderful thing about Wikipedia is that you can type in whatever you need information about in the little search box on the left of your screen and hit "go." For example, try typing "Herb Robert." It will take you here. Especially check out this link. I myself know nothing about botany, so that's all I can do. Now to slink back to the Humanities desk... --zenohockey02:18, 16 December 2005 (UTC)[reply]
If you've read E-mail, the basic technique is to write a mail user agent that supplies a forged "from:" header. SMTP is a text-based protocol, and it is quite easy to manually type an entire email message (including whatever "from:" header you'd like) using a raw SMTP connection. The basic insight is that the address information used for the delivery of the message is separate and distinct from any header content you typically see in your mail client. -- Rick Block (talk) 22:57, 15 December 2005 (UTC)[reply]
You should read the RFC about the SMTP protocol there are even some examples in it. The destination mail server can be found if one does a nslookup with type=mx on the destination domain. helohe(talk)09:49, 16 December 2005 (UTC)[reply]
I am curious if anyone has linked having abdominal surgery, specifically tummy tuck with causing headaches. Once the tummy has been cut and sewn tight to reduce the area of tissue the torso is then pulled forward into a forward flexive state. Pulling the torso/thoracic into flexion will pull the head into flexion which then puts so much more pressure on the "righting reflex" which causes the cervical musculature to go into hyperextension, thus creating major tension headaches.
I have been experiencing this since July, 2005.
I would love to speak with anyone on this subject. www.giese@pbcc.edu
what is the meaning of wet wing design in aviation? what r its advantages?
Ok, basically there's two main ways that airplanes store fuel: in tanks or in "wet wings". Most aircraft store fuel in the wings, some simply have tanks in the wings like the gas tank in your car. Other, so-called "wet wing" aircraft, seal the entire wing and use that as a tank. Thus the metal on the outside of the wing that defines the wing is the same metal thats holding the fuel. This is advantageos because it means that you don't have to carry extra metal for a separate tank inside the wing, and you can put fuel into every nook and cranny of the wing which means you can store more. However, wet wings are much more prone to leaking and getting them manufactured right can be really tricky. Thus, they're mostly found on larger commercial aircraft, not general aviation aircraft. -User:Lommer | talk07:50, 16 December 2005 (UTC)[reply]
Yes. I'm not entirely sure where to put it though (i.e. what to call the article). I've written most of Aviation fuel, and it would be closely connected with that. Perhaps I'll write an article on aviation fuel systems? Might be a bit hard to find but with appropriate redirects it could work. -User:Lommer | talk22:48, 16 December 2005 (UTC)[reply]
Something annoying starting to occur on my PC. On my Internet browser, when I click Google search results, the page goes to MorwillSearch.com. This doesn't happen with other links. I go up to the URL, press enter, and can access the page I intended, but this is frustrating. I've run AdAware and Spybot, but to not avail. Advice? Neutralitytalk04:35, 16 December 2005 (UTC)[reply]
Yes. Hijack This will solve this problem. But be careful which lines you delete when you run it, and make sure you save a backup. Usually it's pretty easy to see which lines should be excised. (any containing Morwillsearch.com, for a start) Prototc10:43, 16 December 2005 (UTC)[reply]
Most likely this is a browser helper object (BHO) if you are using Internet Explorer which detects certain URLs and words to redirect you to sponsored links. If any strange toolbars have appeared recently, see if you can uninstall it. Otherwise, take the advice of the others and use HijackThis and delete the appropriate line. This will be labelled 'BHO', but remember Proto's advice! Archer717:52, 18 December 2005 (UTC)[reply]
No, because the engine produces so much waste heat anyway. Usually the radiator pumps the extra heat to the outside of the car; when you turn the heater on some of it is directed inside instead. —Keenan Pepper05:05, 16 December 2005 (UTC)[reply]
Considering how hot it gets in a car when you turn the heating up all the way, I wonder how much energy is lost. The efficiency of getting the heat into the car is probably very low and a car is badly isolated and moving fast, which causes a lot of heat loss. If, despite this, you can still get the interior of a car so hot (with just waste energy!), then the energy consumption of a car is probably way higher than the heating of an average house. Then again, one doesn't drive a car constantly (usually about one hour per day). So I wonder what consumes more energy, driving a car for one hour or heating a house for, say, the equivalent of 8 hours in a temperate climate (no heating in summer and low at night). Is there a good site for energy footprint of not just cars and house heating but also household appliances and such? I can't find one, most things I find are cute little quizzes and no simple info. How hard can this be?
However, my search did teach me this little tidbit: "If everyone in the United States made sure their car tires were adequately inflated (through weekly checks), gasoline use nationwide would come down by 2 percent." And keeping the car tuned in other ways can add another 10% efficiency (for the car that is). Of course, having a car that has an engine that's just big enough for what you need will make the biggest difference - in most cases (especially in the US where huge cars are popular) I assume less than half the 'horsepower' would be sufficient.
One of the best lists I've found so far is this one: [38], although, ironically, it doesn't include the car. Somewhere else I read that a typical electric car uses about 20kWh of energy to drive 100km. Suppose a commuter drives 50 km per day, 20 days per month. That would mean 200kWh per month. The table gives about 1000 kWh per month, which is 5 times as much. But one doesn't normally have all those things and a comparison with an electric car isn't entrirely fair (also because they're usually lighter than 'normal' cars). And I haven't included shopping (the frequent stops in city traffic consume loads of energy), so I suppose that for an average household the car consumes about 1/3 of the energy. No wonder a minor thing like keeping the tires appropriately inflated can make such a big difference. DirkvdM10:10, 16 December 2005 (UTC)[reply]
Me again. Found this (from [39]: In the US, cars and light trucks account for 40 percent of the nation’s oil use.
It depends. In most cars, no. In some (a very small few), yes. In most cars the heat surplus is big enough, but there are some efficient cars where it isn't enough (low-power highefficiency diesels, hybrids etc come to mind) where the heat output, at least in cold conditions, just isn't enough (at least to heat the car rapidly - even though the heat output is sufficiently big to maintain the temperature, it might not be enough to heat the car in less than 100 km...), and an extra, electric, heater also is installed. Using this would of course mean raised fuel usage. TERdON00:20, 19 December 2005 (UTC)[reply]
The other exception is the early Volkswagen Beetle, which has a rear-mounted, air-cooled engine, which made the prospect of piping hot water from it a little too difficult during the first few models. These had a gasoline-powered furnace in the cabin, which (according to some old folks I talked to years ago) ran the risk of explosion if it was turned on without ignition. --Joel14:01, 21 December 2005 (UTC)[reply]
The colors of light reflected from the bottom of a CD are the result of refraction from the closely spaced grooves. The colors of light spanning the sky in a rainbow are the result of diffraction through myriad tiny raindrops. In the first case we see color because different wavelengths are selected by the groove spacing; in the second, because different wavelengths are dispersed to different positions in passing through the water droplets. Both depend on wave mechanics. --KSmrqT12:53, 16 December 2005 (UTC)[reply]
Why does SAS (developed by Jim Goldsmith some thirty years ago and now used practically everywhere) use Midnight on the 1st of January 1960 as their date reference point?
ie that date is defined as zero, dates before are negative (31st december 1959 is -1) and dates after are positive (2nd jan 1960 is 2). it also counts hours and minutes and seconds from midnight on that date. So it must be significant in some way. Any ideas anyone? Cheers. James. --62.49.11.1115:35, 16 December 2005 (UTC)[reply]
You seem to have made a mistake. If 1960-01-01 is day 0, then 1960-01-02 would be day 1 (assuming days are numbered serially). --Juuitchan
Well I'm not sure what SAS is (is that the same as SAS System?) but 1st Jan 1960 was probably an epoch date on the first system it was implimented on (or if not, was chosen as an epoch date by the programmers), in the same way that 1st Jan 1970 is the Unix epoch. Generally epoch dates don't have any special significance - they just a handy date/time to start counting from. --Bob Mellish16:03, 16 December 2005 (UTC)[reply]
In CRT monitors, if we feel 13.75 inches (in a 15 inch monitor) as big, it would be possible to adjust the size to say 13 inches. Will the same be possible in a LCD monitor?
Can we change the viewable area in LCD monitors and laptops?
(The original asker of the question)
Do you mean that it is not possible to reduce the size?
Just another query, Is it possible to do that in windows if not in the monitor?
In principle, sort of. It depends on the electronics that are attached to the screen - these are required in a CRT, and not in an LCD, so probably not. On the other hand, a software appraoch would work for an LCD - where you define the outer (say) 100 pixels to be black, and tell the OS not to use them. The only OS I know that supports that kind of wacky configuration is the GNU Hurd - which is very much not a 'suitably for general use' OS. Syntax02:48, 20 December 2005 (UTC)[reply]
I tried to find the answer on google by typing in the definition, but that didn't get me anywhere. I also tried dictionary websites, but I could't find one that would let me find a word by giving the definition.
The lens is made–mostly–of crystallins. (There are three families of crystallins: the alpha-, beta-, and gamma-crystallins.) I couldn't tell you refractive indices off the top of my head, however. TenOfAllTrades(talk) 22:04, 16 December 2005 (UTC)[reply]
The eye's lens varies from n=1.406 in the centre to n=1.386 at the edges; as well as its lens shape, it also focuses light by being a GRIN lens. The aqueous humor is n=1.336 and the viterous humor n=1.337. The cornea has n=1.376. All values from Chapter 5 of Hecht's Optics. --Bob Mellish01:18, 17 December 2005 (UTC)[reply]
Wow! Gradient index optics! I had never even heard of that. And I guess it makes sense that the two humors have the same index of refraction as water, because they're mostly water. Thanks for the great answers! —Keenan Pepper03:18, 17 December 2005 (UTC)[reply]
I read somewhere that the basic building blocks of matter where photons at rest, and i think that's kind of silly, but i'm no physcist nor mathematician so i dunno...
but it sounds like new age BS.
Btw, how is that theory called that tries to describe everything (including matter, etc..) only as a fraction in multidimensional space-time? (based on the Kaluza-Klein theory if I remember). helohe(talk)23:36, 16 December 2005 (UTC)[reply]
This is as much a scientific question as it is a philisophical one, but I was hoping that you could help me find info on something. I read that a long time ago, Chinese monks used to practice the art of walking through walls. I knwo this sounds crazy, but if you have any knowledge of quantum physics then you may be able to grasp this theory. I believe it was once on an old Discovery Channel show, so if you could maybe find an archive of that. I would greatly appreciate any help you could give me on this! Thanks!
I believe the quantum mechanical concept you are thinking of is quantum tunneling. When you're done reading that look up classical mechanics. The only forces you or I will ever experience are those which obey the laws of classical mechanics. The wierdness of Quantum mechanics can only work for individual atoms or subatomic particles. Electrons can tunnel inexplicably, people cannot. Its still fun stuff though, read up :) Jasongetsdown02:56, 17 December 2005 (UTC)[reply]
Point: Old Chinese monks could most certainly not walk through walls, contrary to the legends. Quantum mechanics suggests that there is a tiny, tiny, tiny chance that such a thing could happen, but beyond that one gets into the fuzzy realm of religion. Which I leave up to you. --George08:19, 17 December 2005 (UTC)[reply]
To combine the above with what Jasongetsdown said. In dividual particles may move through a wall (then again, what is a wall at that scale?). And people are made up of particles. But they'd have to all do this at exactly the right moment for a something a s big as a human to move through something as thick as a wall. I've heard of an exam question being to do the maths on this. So there is a chance that that could happen but it's immensely small. So I suggest you don't start trying. (Hmmm, didn't I give a similar response earlier somewhere?). DirkvdM10:43, 17 December 2005 (UTC)[reply]
It's cute to conflate the mystical-seeming logical contradictions of ancient Eastern philosophy with the logical contradictions of modern quantum physics, but the truth is that most feats attributed to ninjas and sects of monks were either feats of strength or slight of hand, which seemed magical to an observer who could not imagine the amount of lifelong training these experts endured. If a monk appeared to walk through a wall, it was probably a feat of misdirection or 'stage magic' on a level probably exceeding David Copperfield or David Blaine, which was put on for the purpose of inspiring the religious faith of observers or else to inspire donations to the temple. -72.144.236.15006:00, 20 December 2005 (UTC)[reply]
Hi, I was wondering if anyone could recommend some books or web sites that could get me into computer programming, on a very, very basic level. It looks very interesting and I'd like to look into it, but the sections in all the bookstores look very daunting; I wouldn't know where to begin. I'd appreciate your help, thanks. --03:00, 17 December 2005 (UTC)
Pick something that interests you and keeps your interest. You might want to go for languages with visual interfaces so that you can see your results quickly. --HappyCamper03:02, 17 December 2005 (UTC)[reply]
Step 1) Pick a language to learn. Scripting languages, such as Python, Ruby and Perl, to name three prominent examples, are especially good for novice programmers. I can personally recommend Python, but Ruby has some momentum behind it, and Perl is an old hacker favourite.
Step 2) Find resources on your language. There will usually be a resource page on the language's website (look for anything labelled 'beginners' or 'tutorial' or similar), and googling will definetly result in a few good hits.
Step 2.5) There will be at least one mailing list for newbies. Sign up, try and understand the discussions, and if you get seriously stuck on something, ask a question on there.
Setp 3) Play around! Nothing beats some practical experience when learning to program. Do any examples in the tutorials you read, try out any little snippets in there, and try and extend them to do more useful stuff. You know all those irritating little tasks that only take about 30 seconds but you have to do constantly? Automate them in your language - you'll be rewarded with valuable experience, and cut those 30 seconds to 5. (Of course, if you're a hardcore MUDder/gamer/sysadmin/etc like my friend here A Lee-Yas, this is probably why you wanted to learn a programming language in the first place :))
If you are interested in making simple programs as a hobby for Windows, I recommend the Microsoft Visual Studio Express Editions. At the moment they're free and there's lots of help on getting started on MSDN. However, Python, Ruby and Perl may be better for contributing to open-source projects and more complicated applications.
How to people such as David Blain and Criss Angels float in the air???
It's really simple. They just stand on the edge of one foot, at a certain angle to the camera (or live audience) so you can't see the edge that's touching the ground. The hard part is getting the angle just right, and acting up a storm to distract people from your feet. —Keenan Pepper04:44, 17 December 2005 (UTC)[reply]
It was the third film, where Indy must make a "leap of faith" and step into what appears to be nothingness above a huge chasm. But he does step, and when he does finds himself on a bridge painted or carved of stone to look like a cliffside on the other side of the gorge. --Articuno101:23, 18 December 2005 (UTC)[reply]
Mind you, the Balducci levitation is just one of the methods magicians can float. David Blaine used a combination of Balducci and standard wire suspension. I'm not familiar with Chris Angel(s). But there's also someone (I believe it was Corey King) who has a method to float which can be viewed from both the front and the back. The best thing to find these things out is to surf the net and forums where people discuss magic or simply visit your nearest magic shop and actually buy the effect (what most people refer to as the "trick"). Also, remember that magic is not just knowing the method behind the "trick", you also need to know how to present it in a way that entertains your audience. - Mgm|(talk)10:28, 18 December 2005 (UTC)[reply]
Hello, this is KeeganB. What would be the danger of going on a diet restricted to vitamin pills and the occasional bit of solid food?
Possibly bad for the stomach, depending on how much solid food you ingest. This was discovered when a low-weight diet was sought for astronauts. Your tummy needs something to chew on, so to say. Also, vitamins aren't quite the only thing the body needs, so it again depends on the solid food; how much and what does it contain. My advise: stick to a well balanced diet of solid food and throw the vitamins out the window. Along with any other pills, unless you've got some 'disorder'. What is the reason for the question? DirkvdM10:50, 17 December 2005 (UTC)[reply]
That would depend on just how occasional that "occasional" bit of solid food is, and what it consists of; you would also need to consume water to offset the water lost in urine, perspiration, feces, and expired air. A normal diet consists of much more than vitamins; it consists of minerals, protein, fat, and carbohydrate, as well as vitamins. You need to consume enough calories to maintain your basal metabolic processes, enough of the essential amino acids in protein to maintain lean body mass, enough minerals to maintain skeletal bone density and electrolyte balance. There are also presumably many unknown chemical constituents in normal food that contribute to health. You'd be better off consulting with a dietitian than relying on propaganda from the nutritional supplements industry.-- Mark Bornfeld DDS Brooklyn, NY 16:08, 17 December 2005 (UTC)
I deliberately didn't mention specific nutrients because the list would be endless, and as Mark says, there are probably also lots of chemicals we need but don't know about yet. Have any experiments been done with people or animals getting a diet of just he things you mention? Of course, this has been done to some extent with astronauts (though so strictly?), but a lack of trace elements and such will probably only have an effect over a longer period of time. I know the Soviet Union did lots of such experiments because they focused on long term stays in space (as a result of which Russia is now considered the expert country for this sort of thing). But did they take it this far (meaning consumption of nothing but water, assorted vitamins, minerals, carbohydrates etc)? DirkvdM08:51, 18 December 2005 (UTC)[reply]
I agree with the previous comments and would add a few pts:
Many synthetic vitamins are in forms which are difficult to absorb or use and may actually be of little practical value. For obvious reasons, they don't starve people and just give them vitamin pills to test how effective the vitamin pills really are.
The full digestive tract needs to be exercised to continue to work properly. Fiber, for example, is important for colon health.
I have heard that some animals, apart from human, do kill themselves.
I want to know
1.It is ture?
2.Why are they doing this?
3.Can you give me an example animal name?
Thanks
Hmmm, that's going to get quite philosophical. Many social insects readily sacrifice themselves to defend their hive; other social animals will do the same on occasion. Is this suicide? What about salmon, who die after travelling upstream to breed? The example of "animal suicide" you're probably thinking of is the lemming; this myth was apparently spread by a Walt Disney wildlife film.
Salmon have little choice, I believe. The change happens to them irrespective of what they do (not sure, though). But soldier ants indeed sacrifice themselves for the hive. And some mothers let their kids eat them (again, more common with little critters than mammals). And the reason for that would be (as always) evolution. If one mother had a genetic 'abnormality' that made her let her kids eat her and the kids thus had a better chance of survival, that genetic 'abnormality' might spread and become 'normal' (whatever that is). Of course, if the mother would otherwise have had many more offspring (in other words if other mothers did that and thus got more offspring) then it might not work. DirkvdM10:58, 17 December 2005 (UTC)[reply]
Whale beaching behaviour may also be suicide, especially since the same whales have been observed to beach themselves repeatedly after being carried back to deep water. For complex creatures, like whales, they may suffer from "brain malfunctions", like we do, that cause human suicides. An evolutionary exlanation is also possible. Old, sick or weak whales, which can't reproduce or contribute to the pod, may kill themselves to avoid consuming food others could eat. Thus, they are helping their genetic relatives pass on their genes more than they could if they continued to live. This may be a concious decision, or they may just have an instinct to swim toward to beach when they feel old, sick, or weak. For most animals, this isn't necessary, as predators or others of their own species will kill off the old, sick, and weak. Sharks might do this, for example. If this theory holds, then suicidal behaviour would be most common in "gentle" animals at the top of the food chain, like whales amd humans (OK, semi-gentle). StuRat12:47, 22 December 2005 (UTC)[reply]
I believe the beaching is (always?) done by whole groups of whales, not by individuals. So that would invalidate your reasoning. Even if the entire group were weak, they'd be helping other groups, not their relatives. DirkvdM13:20, 23 December 2005 (UTC)[reply]
Designing an experiment to show that an increase in temperature infuences the release of red pigment from beetroot. Any ideas???
Seems like a fairly simple homework question. Put some beetroot in cold water and at the same time put some beetroot very hot water and watch to see what happens. --hydnjotalk14:51, 17 December 2005 (UTC)[reply]
Hello. I was reading biodiesel where I saw "E. Duffy". Does someone know for what does the "E." stand for ? I think that Duffy should not be a redirect but rather a disambiguation page, do you agree ? Thanks in advance--Youssef11:32, 17 December 2005 (UTC)[reply]
I tried Wikiwax (typed in "Duffy" and waited) and although Wikipedia has two articles on E. Duffy's, neither of them had anything to do with biodiesel. I don't think a disambiguation page should be created, disambiguation pages are not search tools - they exist to navigate between articles that would otherwise share the same title. Ideally we could use the List of people by name, but it needs lots of updating--Commander Keane11:58, 17 December 2005 (UTC)[reply]
Do any one of you use 15" LCD monitor?
I just want to know what is the resolution you use.
Do you use 1024 x 768?
Is it comfortable?
And, what is the distance between your eyes and the monitor in the case of a 15" LCD monitor?
One of the terms you want to look for when picking out an LCD monitor is Native_resolution. This is the resolution that each pixel on the LCD represents one pixel being sent to it by the video card/motherboard. This and many other answers can be found at Liquid_crystal_display. A04:36, 18 December 2005 (UTC)[reply]
Clarifying the answer above — an LCD monitor is designed to run at one specific resolution (you can read all about it at Native resolution, and unless you have a very good reason you shouldn't run it at any other resolution. For most 15" monitors, the native resolution is 1024x768, however you will definitely want to check your monitor's documentation.
And as for the distance, that varies from person to person, on how long you use it every day, how good your eyesight is... try and do what feels most comfortable for you, view it at a distance where you can read anything on the screen without straining your eyes or squinting. — QuantumEleven | (talk)10:21, 19 December 2005 (UTC)[reply]
I'm using a 17 in LCD monitor, but I thought I'd still answer this question.
LCD monitors have a maximal resolution, on which they can be used optimally. Lower resolutions than this are still readable but don't look nice enough; higher resolutions shouldn't be used. For my monitor, it's 1280x1024 (as this is an 5:4 shaped one), but this wasn't easy to find out. In fact, I looked through the documentation distributed with it a few times, and it definitely wasn't there. (I suppose they think it's enough if the Windows driver they include on the cd knows about it.) The only place this number is written are the advertising documents which lists all properties of the monitor – I had these because I've chosen the type of monitor to buy from them.
Also note that to get a good image on a TFT monitor, you may have to press the AUTO button of the monitor. I've found that this is only neccessary when I use a certain video mode the first time with the monitor, but pressing again can never hurt. Without using this button, the image can appear sort of unfocused, or some sides of the image can be invisible.
So, I use 1280x1024 with a 17" monitor and it is very comfortable. The distance to my eyes is usually between 60 cm and 90 cm. Note that there are a few other factors that can affect the comfortability a great deal, like the tilt angle of the monitor; how high you put it (relative to where your head is), the brightness, contrast, and other controlls; and most importantly the lighting conditions of the room (the room should be lit well but you shouldn't see reflections of the lamps or the sun on the monitor). I have strong myopia which is probably why I'm more sensitive to these conditions than most others. – B jonas13:44, 20 December 2005 (UTC)[reply]
can you tell me the method used to separate a mixture of 2 miscible liquids, water and propanone (acetone). The boiling point of propanone being 56 degrees celcius.
I have broken my Galileo Thermometer but still have the glass spheres.
I have tried just putting the spheres in a glass of water but they
all just float at the top of the glass, even if i change the temperature
of the water. Can anyone tell me what i should use instead of ordinary water
and if the glass container should be sealed?
Thanks
David Spooner.
I would like to open a door latching device by using speach recognition.
Any ideas how i can achieve this?--172.201.249.205
I have actually built one before - albeit a very crude one. Take a recording of your voice, find the Fourier transform of it, and figure out all the unique characteristics of your voice. Then, buy a programmable digital signal processing unit, program it, and attach an output to the door. Takes about 3-4 months to figure out everything if you do this by yourself. --HappyCamper19:04, 17 December 2005 (UTC)[reply]
Suppose there is a spacecraft traveling in space at near the speed of light. On it a person is traveling toward the direction that the spacecraft is moving in. If the combined speed of the person traveling relative to the spacecraft, and the actual speed of the spacecraft is greater then the speed of light, what would happen?
I'm no expert, but I would guess that all that would happen is that the collision would be equal to the collision of an object travelling at the combined speed of the two spacecraft and a solid object. --Think Fast18:58, 17 December 2005 (UTC)[reply]
Speeds don't add that way. If the spaceship is moving at speed A relative to Earth, and the person is moving at speed B relative to the spaceship in the same direction, then the person is not moving at speed A + B relative to the Earth. The person is moving at speed where c is the speed of light. If one spaceship is moving at c/2 away from the Earth in one direction, and another is moving at c/2 in the opposite direction, then the speed of the two ships relative to each other is 4c/5, not c. —Keenan Pepper19:20, 17 December 2005 (UTC)[reply]
Plus the mass of the person would be so great the person would no longer be a person and the spacecraft would have been long since crushed. Hypothetically. Halcatalyst05:30, 19 December 2005 (UTC)[reply]
Um, no? That contradicts the basic principle of relativity. You wouldn't notice anything different inside the spacecraft, no matter how fast it was moving. —Keenan Pepper23:44, 19 December 2005 (UTC)[reply]
In human terms, I don't think there would be any "You" in a spacecraft moving near the speed of light. If there had been one when the spacecraft started off, s/he would have suffered the physical effects predicted by relativity theory, which as I recall would include fatal compression on the axis of the direction of travel. But I yield to those who know more than I (a lot of people!). BTW, I was trying to be funny above by injecting a practical objection into a theoretical discussion. Halcatalyst01:32, 20 December 2005 (UTC)[reply]
I think, actually, that the force you would experience on your body would only be as a result of accelaration, not velocity. If you tried to quickly get to the speed of light, you might crush yourself, but if you're in a closed ship and not subject to air drag, I should think that no matter your velocity, you would be fine. It's just a matter of accelerating at a safe pace. --ParkerHiggins | Talk01:53, 20 December 2005 (UTC)[reply]
Exactly. You would not be crushed or feel anything different in a ship going near the speed of light, because the basic principle of relativity is that you can't tell how fast you're going. —Keenan Pepper06:05, 20 December 2005 (UTC)[reply]
Is it possible to have a gas with 50% bosons, and 50% fermions, where Fermi-Dirac and Bose-Einstein statistics are simultaneously observed? --HappyCamper19:08, 17 December 2005 (UTC)[reply]
This would only be of observable magnitude with Helium, where Helium-3 (a rare isotope) is effectivly a fermion (as the nucelus has a odd number of fermions), and helium-4 (the common isotope) is effectivly a boson.
This is, indeed observable, and is what lead to the discovery of He-3. It's noticable as a difference in boiling points. Something's tugging at my breain about miscability too, but I can't rightly recall. Syntax03:03, 20 December 2005 (UTC)[reply]
i guess it has to do with conditioned stimulous and response, like in pavlov's experiment's.
like , when you urinate, you hear the sound, so you asociate both, and then, when you only hear the water, you asociate it again and the physiological response is triggered.
ps. sorry for my spelling, english is not my 1st language.
Perhaps they think they're wetting the bed? Have you tried this with a representative sample of your sleeping partners, or is it just hearsay? --Shantavira09:08, 18 December 2005 (UTC)[reply]
The urban legend in the US (re: hand in warm water) is that it makes the person talk in their sleep thus revealing some secrets. ;-) --hydnjotalk12:50, 18 December 2005 (UTC)[reply]
No, I've never tried it, myself. :) It's something you see all the time in movies and TV shows where teenaged boys are congregated together in sleeping arrangements -- summer camp, school dormitories, etc. User:Zoe|(talk)00:02, 19 December 2005 (UTC)[reply]
That person will feel very relaxed and so the urge to urinate comes. 165.21.83.230Naruto90
I think the theory on the hand in warm water is that it causes the person to think they are back in the womb, where they urinated freely into the amniotic fluid. StuRat13:04, 22 December 2005 (UTC)[reply]
1) In very cold regions, how to very small rodents survive the winter? Do they group together and hibernate? The page on Mice is lacking quite a bit of information.
2a) What is heat? Why do particles move faster or slower depending on heat? Why do photons emit heat on impact with other particles? Why does mass shrink or expand depending on heat? (On an atomic level, what is happening when heat is flowing into the system to cause these things to happen?)
2b) Since heat is energy, why must energy be expended to cool matter, as opposed to removing energy from the matter? I'm sure that other people have thought of this before -- what is it called? --Demonesque20:50, 17 December 2005 (UTC)[reply]
1) No idea, but I guess they hide in burrows, which keeps them warm and safe enough for hibernation.
It's hard for rodents and other small mammals to survive in very cold (polar) regions because their bodies dissipate too much heat. Larger animals have an advantage and that's why they're there and the rodents aren't. Natural selection. The permafrost is too close to the surface for burrows. Halcatalyst05:23, 19 December 2005 (UTC)[reply]
There are plenty of arctic rodents, mostly lemmings and various voles. They survive the winter by tunnelling through the snow cover at ground level; the thick layer of snow protects them from the extreme cold (snow is a very good insulator). The results of the tunnelling are often very conspicuous when the snow thaws in spring, with the tunnels visible from the vegetation having been eaten away - MPF23:54, 19 December 2005 (UTC)[reply]
2a) Heat is essentially just kinetic energy. Particles moving faster or slower isn't an effect of heat - that's what heat is. This also explains matter's expansion. Photons cause heat because radiation contains energy, and that energy has to go somewhere.
2b) What do you mean by 'energy expended'? After all, you can't use up energy. You can't create or destroy it. The concept that is instead important here is entropy. In particularly, the famous second law of thermodynamics, which states that in general, the entropy of a closed system increases. Entropy is in many ways a measure of how close the system is to equilibrium, so if you want to decrease entropy locally by moving a system out of balance - e.g. making one part cooler than another, you have to increase entropy elsewhere. (This is also why there it's comparatively easy to cool down an object that is hot relative to its surroundings.--Fangz22:28, 17 December 2005 (UTC)[reply]
Who said it did? I didn't say question one and two were related. Anyway, thanks for the answers. Still not sure about a lot of it, though. I am familiar with the conservation of energy. What I mean is what is happening with heat that particles become "Excited." Why does it expand? Most importantly, though, I'll rephrase my last question. Why does a refrigerator have to be plugged into a wall? Heat is energy, so why must more energy be used in some form to cool the area inside of the 'fridge? Electricity or flame must be used to cool things. This seems counter-intuitive, as the air already has energy in it. Why aren't we working on a way to tap into that energy? If we are, what is it called? --Demonesque23:34, 17 December 2005 (UTC)[reply]
Gases expand when heated because the excitation of the molecules "pushes" other molecules away. Imagine a group of close packed people, if they start suddenly moving from side to side in a quick manner, the the spaces between the people will increase, I hope that makes sense. As to why we need power to run a fridge, this is because a fridge makes use of a heat pump to cool the air inside it. This means what it is actually doing is taking heat from inside the fridge and putting it outside, thus cooling the air inside. To do this requires a compressor, which needs energy to run. - Akamad23:54, 17 December 2005 (UTC)[reply]
To expand on what I wrote. In a fridge, we are moving heat from a low temperature area to a high temperature area, since the air inside is cooler than the air outside. This will always require an energy input. Since the natural thermodynamic order of things is for heat to travel from high to low temperatures. As to why we can't use the energy in the air in the fridge: there certainly is energy there (since it is above absolute zero). However, to make use of that energy, we require an even colder reservoir for which the heat in the fridge would want to flow into. Have a look at the Carnot efficiency article. - Akamad00:07, 18 December 2005 (UTC)[reply]
Thank you for your answers and your time. I guess I'm not articulate enough to ask what I want to ask here. I know how refrigerators work and that molecules become "excited." I just don't know WHY they become excited. Maybe no one does?
There are some very smart people here at Wikipedia. There are also some very articulate people here. You need combination of people who know the answer to the question, can explain it well, and happen to see the question at this place.
There's a lot of stuff we are able to observe happening in nature. Some can be explained as a general rule "That's how a class of objects function under those conditions." which may or may not be an acceptable answer to "Why?"
To explain why the energy in heat can't be used unless there is a temperature differential, let's look at a potential energy analogy. If you had a weight at the top of a 1000 meter cliff, you could push it over with a rope attached, and use the pull on the rope to power a dynamo during the fall, to get some electricity. Now, if the weight is still at an elevation of 1000 meters, but the ground is uniformally 1000 meters above sea level, with no cliffs, there is no way to turn this weight into energy, even though it still has the same amount of potential energy as in the first example. You could move the weight to a place where there is an elevation difference, but you would likely use more energy moving it there than you would get back, unless a cliff was quite close. Similarly, you need a steep temperature differential where the two temperature regions are quite close to each other to extract more energy than is used up. StuRat09:45, 22 December 2005 (UTC)[reply]
Do any of you know if the 'paranormal phenomena' issue has been settled? I mean, has anyone proven them to exist or not? The reason I ask is that there are a lot of companys and individuals out there that make a buisness out of this. They are all seem to be doing good buisness, so I wonder if there's any truth to these things. (unsigned by User:201.230.73.118 )
Hard question to answer. Who "proves" these things? Who "proves" that faith in God is not a waste of time, or is? "Paranormal" covers a lot of ground, and includes phenomena, or alleged phenomena, that science cannot explain. Science has dismissed a lot of so-called evidence as flawed, hence does not admit that such phenomena have occurred to begin with. I think you need to examine each phenomenon individually and ask questions about it, rather than lumping all paranormal stuff into one basket and asking whether it's true or not. JackofOz21:59, 17 December 2005 (UTC)[reply]
The question is somewhat tautological. If a paranormal event gets proven, it instantly becomes just a normal part of science. --Fangz22:17, 17 December 2005 (UTC)[reply]
It is usually impossible to prove a negative, to prove that there is no such thing. I cannot disprove the existence of the tooth fairy even though I strongly suspect she doesnt exist. Clearly no one has proven that what you probably mean by "paranormal phenomena" exist. I can imagine lots of ways to prove the existence, but I confess I cannot think of a way to disprove the whole category. What do think such a proof would be like? alteripse00:01, 18 December 2005 (UTC)[reply]
I believe that in order to call something a theory it has to make predictions. So 'if this is true, then under these conditions such and such must happen'. And if it isn't even a theory then science can't do anything with it. Also, an experiment has to be described in such a way that other scientists can repeat it completely separately. Now 'paranormal' can mean loads of things, but let's take a psychic who conjures up spirits or whatever. Then scientists at the other end of the globe have to be able to do exactly the same experiment. But for that they'd need the original psychic, which would mean it's not an independent experiment. DirkvdM09:17, 18 December 2005 (UTC)[reply]
That sounds like a scientist's way of saying that this particular experiment is inherently unprovable. But at least that's not as extreme as saying that such a phenomenon does not exist because science has not given its imprimatur for it to exist. A T Mann, at p.63 of "The Divine Plot" says: "... scientists assume that 2 experiments can produce the same quantitative results, but they cannot, because the circumstances can never be exactly reproduced, nor can external influences be eliminated. The earth moves hundreds of thousands of miles through space and time every day in the movement of the solar system through time. Reproducability is a central fallacy of modern science ...". Science is one way of considering and explaining the universe. It is not the only way. Seems that paranormal stuff like ESP is regularly debunked by the Randis of the world, on the basis that nobody has proven scientifically that it is real. But maybe that's the point. Maybe it's simply outside what science can grapple with, but is nonetheless very real. By staring at the back of a stranger's head, I can make them aware that I'm looking, or at least feel uncomfortable. I have done it at various times in public transport just to prove to myself that it happens, not because I'm some sort of malicious weirdo. Science would say there is nothing connecting me with that person, but I would say that I know and the other person knows there is. Science could never prove this to the satisfaction of its internal criteria. It occurs nonetheless. JackofOz08:56, 19 December 2005 (UTC)[reply]
Rubbish. Science doesn't make any such assertion about whether or not your 'effect' is real. Science demands that before you claim it is real, you put this ability to a rigorous test. For example, the following experiment would easily net you the 1 million dollar prize:
Get a group of students. Don't tell them why they are there. Randomly select 2 groups of around 20 each. Now, sit them in a two rooms watching a movie. Now, in one room, have an experimentalist sit behind the students, staring at the back of their heads. In another, have you staring at the back of their heads. Have them write down their feelings afterwards. If a significantly higher number record feelings of being watched, then you get the money. Otherwise, it's just aphonenia. If you demand a 1-to-1 relationship, then have them watch movies 1-by-1. If you think the process is affected by stellar position, or whatever, then do it as the times you usually use the bus. If you think the bus angle is important, have them watch movies of a bus journey, or get questionaires done after they get off buses, and compare with a control set. And so on. The fact that you have 'done it at various times' is a claim of reproducibility, and it puts you into the firing range of scientific methods.
If Mann is at all right about his assertion, then he would disprove Relativity and create a huge number of paradoxes. If an effect is that sensitive to 'external events', then science wouldn't be alone in not detecting it. After all, science is just an analytical system. If it happens often enough to be noticeable in the first place, then science will certain work with that degree of reproducibility.--Fangz12:10, 19 December 2005 (UTC)[reply]
You said: "Science doesn't make any such assertion about whether or not your 'effect' is real. Science demands that before you claim it is real, you put this ability to a rigorous test." Doesn't the 2nd sentence negate the 1st? Isn't the 2nd sentence saying that science only accepts as real those things that have been proven to be real using scientifically rigorous tests? This supports the point I was making. I am not a critic of science, but neither do I reject paranormal claims out of hand. If some phenomenon currently considered "paranormal" were to become scientifically proven, then it would no longer be called "paranormal" and its reality would no longer be questioned. But just because science has not yet proven a particular phenomenon is real, does not necessarily mean that it is not real already. Science is not the final arbiter of reality. Hamlet had it right, I think: "There are more things between heaven and earth, Horatio, than are dreamt of in your philosophy". (Philosophy here referring to knowledge, or science) JackofOz01:52, 20 December 2005 (UTC)[reply]
Part of the definition of Science is that some experiment or process can be written up in detail, then some totally independent group of people repeat the experiment and get the identical results.
With paranormal phenomena, it would appear that some people have some abilities, from whatever sources, perhaps genetic, such that they do something, and no matter how their actions are documented, other people who lack that genetic ability are not going to be able to duplicate the process.
Further, the alleged phenomena is something that cannot be explained by the people observing it. It is not that they used scientific method working with some theory and experiments to polish an understanding. Rather, something weird happens, like in a dream we see something, and we think it is just a dream fantasy, then later we see same thing happen in reality. Well was the dream some kind of clairvoyance? How can we tell when a dream fantasy is a prediction, and when just a fantasy? This sort of thing is just one person's word and interpretations, like sighting a UFO or having a religious experience, far too subjective to be called Science. User:AlMac|(talk)08:17, 20 December 2005 (UTC)[reply]
There's still this hang up with what science has to say about paranormal phenomena. You're all talking as if science were the only paradigm that could ever possibly be relevant. The original question was not whether paranormal phenomena have been proven scientifically, but whether they have been proven. OK, that kind of begs the question, how is something "proven" if not using a scientific method? Fair question, and not one I can answer. Paranormal phenemona by their very nature are, or can be, extra-scientific, so we need a "bigger picture" frame of reference here. My original rhetorical comment was about faith in God and who could ever "prove" this was justified. Science could never in a billion years settle that question one way or another, but there are billions of people for whom there is no possible doubt about faith in a supreme being, and for whom no "proof" will ever be necessary. The effects of prayer and faith have been voluminously documented over many millennia. Witness the 70-odd miraculous cures with the water from the spring at the grotto of Lourdes, which have been rigorously and exhaustively documented and subjected to the most extreme scientific and medical scrutiny. Science can't explain how these cures occur, which puts them into the category of paranormal. But there's no possible doubt as to their veracity. JackofOz11:19, 20 December 2005 (UTC)[reply]
Question "How is something "proven" if not using a scientific method?"
Answer = One way things can be "proven" outside of a scientific method, is through the court system, provided someone brings a case, and it is not thrown out by a judge.
All sorts of people make claims, such as commercial claims about cosmetics, faith healing, spiritualism, and all sorts of people complain that those claims are bogus. User:AlMac|(talk)02:15, 21 December 2005 (UTC)[reply]
Court "proof" is a really low standard, as it comes down to whatever a judge and/or jury, a small number of often not-too-bright people, believe. Court verdicts are often wrong as a result. Note that the existence of God could easily be proven by a personal appearance, or even a few of the Biblical miracles, like the parting of the Red Sea on a holy man's command, would be sufficient to convince most of us. The lack of such levels of proof since the dawn of science seems mighty coincidental to me. As for sudden cures, there are many explanations:
1) Many diseases do go away, or at least go into remission, spontaneously, both for those who believe in miracles and those who don't. I used to have plantars warts (on the feet), then they went away. Had I been a religious fanatic, I could have said the chicken whose head I bit off was what cured me.
2) Many diseases are subject to the "placebo effect". Arthritis, for example, is measured primarily by the amount of pain reported. If someone thinks they are cured, either by visiting Lourdes or by biting the head off a chicken, they may convince themselves the pain level is reduced or eliminated.
3) There are also shills who are willing to pretend they were sick and then cured, either for money or just for fame.
4) Then there is just the gap in media coverage. The millions of people who visit Lourdes and don't have any "miraculous cure" rarely get much press. This makes it seem that the few who do report a cure are 100% of the people who went, because we never hear about the rest.
I believe many of the paranormal claims have been disproven. For example, the "cold reading" methods used to convince people a particular "pyschic" has a connection with the dead can be easily replicated by anyone who spends a few hours studying the technique. For example, when someone points to a part of the audience and says "I'm seeing someone over here whose name starts with a J"...the chances that one of the 100 people in that general area will have a first, middle, or last name starting with J, or have some dead relative with a first, middle, or last name that starts with J, is probably in the 99.999% range. Yet, when somebody says "that's me !" they are absolutely sure the "pyschic" has proven his "gift" and are ready to hand over their life savings to them. It's hard to believe that the dead person is only able to tell the pyschic the first letter, and not the whole name. It also seems odd that no dead person ever tells the pyschic his name starts with a rarely used letter. Dead Quincy, Xavier, and Zachary apparently lack the ability to communicate with pyschics, LOL. StuRat09:06, 22 December 2005 (UTC)[reply]
... Ms. Fogle is broke, ... she had no sooner filed for bankruptcy, ... than [sic] she was hit with a flurry of solicitations from major banks. ... "Every day, I get at least two or three new credit card offers ... at pretty high interest rates,"
...Credit card companies have long solicited bankrupt people, on a calculated risk that income from the higher interest rates and late fees paid by those who are trying to get their credit back will outweigh the losses from those who fail to make payments altogether.
What? Is this the whole story? Where do the late fees and interests go? Do they become a part of the banker's profit immediately? Or are they used to write-off the debt as well? I think most, if not all, late fees and interests go to the banks. Am I right?
Let's say there are two banks, each lends the same money to customers at the same interest rate.
Bank A: Reliable customers. They pay back the debts on time. And they come back again when they need money.
Bank B: Unreliable customers. Most of them pay the minimum. Some pay old debts with new debts. Some go bankrupt.
Because the interest rates are the same. You can say they make roughly the same money each year if the interests directly go to the bankers. Only Bank B has a much lower turnover rate.
In theory, the bank's money comes from depositors. The depositor shall get the money back. So the bank needs to collect the profit and the seed money as well. However, ...
Bank A: The bank makes easy money. Its depositors are safe.
Bank B: The bank makes easy money. Its depositors are taking all the risks.
It seems to me in the case of Bank B, the bank takes almost all the profits and very little risk. The risk goes to the depositors. If the bank goes bankrupt in a decade, that's not today's managers' problem. They'll be retired by then. Am I right? Is my theory applicable to the fact? -- Toytoy04:55, 18 December 2005 (UTC)[reply]
This is in no way a problem limited to the banking industry. Making short-sighted decisions designed to increase quarterly profits at the expense of the long-term health of a company would seem to be in the interest of many CEOs. For example, selling off the most profitable divisions for immediate profits, leaving the company saddled with unprofitable divisions, would serve a CEO who has a bonus structure based on current profits only. The only limiting factor is that SOME shareholders do have the long-term interest of the company in mind, especially employee shareholders. If they can manage a majority, they can fire such a CEO before he does too much damage to the company. Of course, if they again offer pay based strictly on short-term performance to the next CEO, they are likely to get the same result. StuRat08:27, 22 December 2005 (UTC)[reply]
So a couple nights ago, after playing Wave Race 64 for what must have been 5 or 6 hours almost nonstop, I went to bed. However, the patterns of the waves in that game, rapidly undulating up and down, would keep "playing" in my mind, like an uncontrollable looping video, making it hard to sleep.
First off, does this phenomenon have a name? Second, is it related at all to how when you hear a catchy tune, for whatever reason it keeps playing in your mind even when you try to think about something else (damn you, Pink Floyd!) and it effectively messes up your concentration or sleep also? --I am not good at running07:42, 18 December 2005 (UTC)[reply]
Hypnagogia is a bit much for this, don't you think? This appears to be a common case of overstimulated nerves. It is like riding on a motorcycle all day and feeling the rumble of it all night or wearing a hat for hours and then feeling it on your head long after it has been removed. Some nerves are very sensitive to overstimulation - especially the cones in the eye. After being stimulated, they continue react when the stimulus is removed. The brain just responds to the nerves. So, after stimulating various nerves in the body all day and then removing the stimulus, the nerves continue to react and signal the brain. If you want to get really scientific about it - the nerves are actually having a negative reaction. They are sending a signal that the stimulus is not there. But, for something like motion, moving left right left feels about the same as moving right left right. --Kainaw(talk)16:58, 18 December 2005 (UTC)[reply]
Correct. Afterimage occurs in the optic nerves. They are easily stimulated and quickly get over it. Nerves that are harder to stimulate will have the afterimage effect much longer. --Kainaw(talk)13:49, 19 December 2005 (UTC)[reply]
I've noticed that some time after cross country skiing, my walking motion is more like skiing. It takes a while to "switch back" to normal walking. StuRat08:07, 22 December 2005 (UTC)[reply]
Coffee#Brewing says that coffee should ideally be made with water at 93 C. I use the first method under 'boiling'; I put the ground coffee in a cup and pour boiling water on it. Now boiling water is 100 C. But I assume that during the pouring the water will cool down fast. But it would have to 'loose 8 C' over a distance of about 10 cm. Of course this is more complicated, because the cup will cool it down even faster, but then the ground coffee will have already been in contact with hotter water and I don't know how how bad that is. But could someone with a good thermometer test this? Pour boiling water and measure the temperature at various distances? And, alternatively, pour the water in a cup and measure the change in temperature. Of course this would require a very fast-acting thermometer, and preferably an electronic one. But I believe those exist (well, I know they do, but are they fast enough?). DirkvdM09:35, 18 December 2005 (UTC)[reply]
This does not a question make. Seriously, it's difficult to figure out what your asking. Are you worried that coffee prepared in a cup will cool faster than in a pot? In any event it is not a concern, I know that pouring water in a cup to prepare something, say ramen noodles doesn't cool until some time after they are ingested.--Ridge Racer15:06, 18 December 2005 (UTC)[reply]
I thought the question was quite clear. I want to know at what temperature the water is when it hits the ground coffee, because ideally it should be 93 C. How to measure that is the problem. Especially if you don't have the right thermometer, so that's why I made that bold. Just a simple experiment for someone with the right equipment. DirkvdM08:11, 19 December 2005 (UTC)[reply]
The water should not be at 93 degrees. Water that hot will burn the coffee. That is why professional baristas use thermometers when thay make coffee. Especially, if you are making a latte, cappucino, or flat white, the milk should not be heated above 65 to 70 degrees before it is poured into the espresso. Milk protein scalds at around 70 degrees. Many people like their coffee to be very hot. In that case the cup can be preheated with 90 degree (or so) water. A digital thermometer is pretty inexpensive, about $15, and will give you a nearly instant read ---Rupee
I just hoped domeone would have such a thermometer ready. It would have to be very instant, though, giving the right temperature in a fraction of a second. But are you saying the coffee article is wrong? At what temperature should the water be then? And does it depend on the roast and grainsize? Never mind the milk because I drink my coffee straight. DirkvdM13:26, 23 December 2005 (UTC)[reply]
I would argue with the term "premature greying". We have this concept that people, especially women, don't get grey hair until they are elderly. This misconception is reinforced by the media and the extensive use of hair dye, when, in reality, middle age is when most people start to grey, and many start earlier on. I had my first grey hair at 18 (right after I started drinking cofee, I wonder if there is a relationship). StuRat13:09, 22 December 2005 (UTC)[reply]
1. What is good (accurate, easily obtainable) indicator of processor performance (speed), today?
Until some time ago, we used CPU clock rate ("megahertz") to gauge processor performance (speed), and it seemed pretty accurate too. However, I think gauging CPU performance solely based on its clock doesn't seem to be relevant today, as most processor manufacturers starting to remove CPU clock (at least from product names), and I heard many benchmarks resulting in CPU with lower clock rate outperforming CPU with higher clock rate.
A clock tick tells the computer to start changing to the next stable state. Put more clearly, one instruction is performed per clock cycle. But that leaves the question how big an instruction is. Because different architectures (with different size instructions) started to compete on the market, the clock rate was no longer a good indication (walking for ten minutes doesn't get you further than running for five minutes, so to say). Anyway, the processor speed (however measured) is overrated. It's a good rough indication, but other parts of the computer can matter a lot too, depending on what kind of work you want it to do. Fort example, if you need to do a lot of graphical work (like movie editing) then a graphical card that takes some load off the CPU's back will help more than a faster CPU (being a fast runner doesn't help a lot if you need to cross water (unless you're a jezus christ lizard - or indeed the guy himself :) )). But there are many more aspects, indeed too many to mention here. DirkvdM08:49, 19 December 2005 (UTC)[reply]
A combination of physics and economics; notably, as I understand it the speed of light is becoming an issue. Say your processor is running at 3.2 GHz. That means one cycle takes seconds. Light (and no signal can be transmitted across the chip faster than light, generally electric currents are significantly slower) travels at approximately metres per second. That means that in one clock cycle, light can only travel a bit under 10 centimetres, and electric currents a bit less than that again.
But as processes continue to shrink, you've got all that extra space on your CPU die; how do you take advantage of it? Well, what AMD and Intel have done is whack a second CPU inside the one physical chip; it's the easiest way to take advantage of the space, and seems to improve performance a lot more than using the space for more cache would. --Robert Merkel11:10, 18 December 2005 (UTC)[reply]
So in order to increase speed you need to make the CPU smaller, but now the limits of the present technology (the materials used) are approaching the limits (although that has been said before and workarounds like Robert mentions have circumvented the problem). The size of the conduits are approaching molecular levels. So different materials and signal carriers (like light) are being researched. I can't find an article on this, though. Surely there must be one (a technical subject (computer related even) that is not covered by Wikipedia? Impossible! Right?). DirkvdM08:49, 19 December 2005 (UTC)[reply]
As well, CPU's are burning up as all those moving electrons get packed into a small space. Intel is dying with this right now. AMD and Sun are trying other methods to increase memory throughput. --Zeizmic15:23, 21 December 2005 (UTC)[reply]
Most PCs have two IDE connectors. The Operating system usually looks for the first harddrive on the first IDE connector. What is not explained in the question is: Are they IDE drives? Are they using the same cable? Have the jumpers for Master/Slave/CS been changed? Is the new harddrive formatted? If so, is it a format readable by the OS?
In writing a chapter in an ongoing fantasy story, I've come across an interesting opportunity to link a present event to a future character (an alchemist, among other occupations) that will eventually make an appearance.
But in order to avoid a too-obvious deus ex machina, I'd prefer using an actual substance that can be isolated solely through repeated distillation or other relatively simple chemical processes, which has incapacitating properties more-or-less identical to that of chloroform as it is commonly (and inaccurately) portrayed on network television shows.
Pretty damn close to unconsciousness, for what it's worth. But what about ether? Easy enough to make (distill ethanol and sulfuric acid). General anaesthetic. --jpgordon∇∆∇∆18:15, 18 December 2005 (UTC)[reply]
Does anybody else think it's a bad idea to assemble a list of easy to purify, volitile solvents, that could be used to render someone unconscious? (: Oh and ether would boil away too fast I think--Aolanonawanabe19:42, 18 December 2005 (UTC)[reply]
You mean a list like that on wikipedia? Sounds cool to me, but reminds me of The Manual of Crime over at wikibooks, which sadly was deleted.--Ridge Racer20:49, 18 December 2005 (UTC)[reply]
That was simply a loaded question. Realistically, any content on Wikipedia can be construed as "dangerous". The mind is abstract enough to do this if it wanted to. --HappyCamper23:06, 18 December 2005 (UTC)[reply]
Nope, ether works just fine and in fact used to be kept in little bottles in doctors kits for the express purpose of being an easy-to-administer general anasthetic (just put it on a rag and inhale it). -User:Lommer | talk23:51, 18 December 2005 (UTC)[reply]
Tube lights typically have very narrow spectral bands rather than a gradation of light throughout all frequencies. In other words they are not like sunlight. So the question is what is ordinary? In fact there are many different tube lights that have different light qualities. Some are more red, others more blue and others a mix of all colors, so called full spectrum. Check out this page for some typical spectra. David D.(Talk)19:52, 18 December 2005 (UTC)[reply]
how to burn a cd of 700 mb with more than 1 gb to 5 gb fo data in it. i saw a cd windows 2003 pirated 10 in 1 with 4.7 gb of data in it....
The maximum raw capacity of a CD-ROM varies; some can actually store up to about 912 megabytes of data. Data compression can allow data to be "squeezed" into a smaller amount of data, and expanded to its original format when desire. However, in most cases, data distributed on CD's is already distributed in compressed form. I suspect what you actually saw was a DVD-ROM. DVD-ROM is so cheap and ubiquitous nowadays you wouldn't bother trying anything else.--Robert Merkel21:42, 18 December 2005 (UTC)[reply]
Of course, a DVD with hacked software would probably not be a DVD-RAM, but a writeable DVD, but it redirects, so above link still works. DirkvdM08:54, 19 December 2005 (UTC)[reply]
I was hoping to build this circuit of an analog synth. It's very simple, I understand, but I haven't done much building in my career. I have a question with the inverter number CD40106, and it's location on the circuit. Part UI-A (which I think is two of the prongs on the 14 prong inverter) appears to have four connections to it. It looks like two go off to resistors, and one goes to a power, and the other goes to a ground. I don't know how that works, or how to wire that.
I have a picture of the part of the schematic in question, but I'm not sure if I can upload it for copyright reasons. I'd be perfectly happy to provide any more information if it would help! --ParkerHiggins | Talk22:25, 18 December 2005 (UTC)[reply]
That is the standard way to draw the power connections to an IC that contains multiple logic gates. U1 is a hex inverter, and all six inverters in the package share the same two power pins on the IC - pins 7 and 14. (Note: 'pins', not 'prongs'.) To save space, we always draw five of the inverters without any power connections, and one with them. In this case, they have drawn the power pins attached to the inverter with its input on pin 1 and its output on pin 2. All you have to do is wire up pin 14 to the positive supply and pin 7 to the ground, and all six inverters will then work. --Heron23:01, 18 December 2005 (UTC)[reply]
Good answer Heron, looks like I shouldn't have taken so long to answer the question after starting the edit. A23:13, 18 December 2005 (UTC)[reply]
You are right, U1-A is part of the same chip as U1-B and U1-C. The extra conections you see in U1-A that are absent from the others are for power (pin 14) and ground (pin 7). Common convention states that you should include these pins on one of the device elements, U1-A in this example, as they do need to be connected for the chip to work, but not all of them. A23:11, 18 December 2005 (UTC)[reply]
Oh man, you guys are lifesavers! Just to clarify, there is no distinction as to which two pins are 7 and 14, right? I mean, they're on one end, but doesn it matter which end, or is there any way for me to tell which end? Thanks! --ParkerHiggins | Talk23:56, 18 December 2005 (UTC)[reply]
To rephrase that question, is there a standard system of pin numbering? For example, it seems reasonable to me that U1-A, for example, would refer to a set of pins opposite each other, as would the power pins, 7 and 14. Shouldn't the connections from U1-A be labeled 1 and 8, then, not 1 and 2? Also, is there any distinction between pins 1 and 8 and pins 7 and 14? If I flip the inverter over, there's no telling which is which! If it would help answer this question (I know I'm throwing a lot of arbitrary numbers around) I can photograph the component itself. --ParkerHiggins | Talk07:42, 19 December 2005 (UTC)[reply]
If it's the usual sort of DIP package, one end will be marked with a U-shaped notch or depression. Since it's got 14 pins, holding the notch uppermost and looking at the labelled side, the pin numbers will run 1-7 down the left side, then 8-14 up the right side. Thus the power pins will be the bottom-left and top-right pins. If there's no notch, usually pin 1 is marked with a dot.
For example, our picture at Image:DIL14 IC HCF4093.jpg is a 14-pin DIP. You can see the notch at the top left. The pins we can see will number 1 to 7 from the left to the right. The pins we can't see from this angle with run 8 to 14 from the right to the left. --Bob Mellish15:33, 19 December 2005 (UTC)[reply]
If you are ever in doubt about the pin numbering of a common device like a 40106, just go to the website of a mail order electronic components company like http://www.maplin.co.uk. They have a page of information called a data sheet on every device they sell, including the 40106 (PDF here), that includes a picture of the gates with pin numbers. Happy constructing! (And no, I don't work for Maplin.) --Heron20:42, 19 December 2005 (UTC)[reply]
I was wondering if anyone could answer the question of wheather the "See Clearly Method" works. The "See Clearly Method" has been advertised as being able to correct a person's vision naturally without the use of a new perscription for ones eyeware. I was also wondering how it actually works? If it does what are its limits, etc?
Pure bullshit. Anyone can become a doctor and advertise as such these days. Generally speaking it lists treatment as eye exercise, diet/nutrition, and a low stress lifestyle. This might help slightly blurry vision if you have malnutrition or stress, but trust me, if your eyesight requires prescription glasses, you can't fix them for $9.95. Also, quoted from the site, * This self-assessment should not be used as a substitute for the medical diagnosis and treatment of your vision, nor should the See Clearly Method be a substitute for diagnosis or treatment by an optometrist or ophthalmologist. Before using the See Clearly Method, you should consult with an optometrist or ophthalmologist to determine if any eye disease or other condition requiring specialized treatment is present.--Ridge Racer03:05, 19 December 2005 (UTC)[reply]
Perhaps it could help you see clearer when the correction needed is very little (less than minus 1). Anything higher is not going to be correctable with mere excercize. Making your eyes strain to see properly is more likely to tire them than anything else. - 131.211.210.1008:33, 19 December 2005 (UTC)[reply]
The ciliary muscles do not dilate the pupils, they change the shape of the lens to focus on near or distant objects. (The other muscles are called, logically enough, iris dilator muscles.) I can voluntarily make my eyes go in and out of focus, which seems like I'm voluntarily contracting and relaxing my ciliary muscles, but I could be wrong. —Keenan Pepper21:14, 19 December 2005 (UTC)[reply]
I've heard that there are six kingoms of living things in the world: animals, plants, fungi, protists,eubacteria and archaebacteria.But what about microbes?I've about heard that apart from animals and plants the other type of living thing that exists is microbes.So why haven't biologists classified microbes as a single group of living things?
Believe it or not there is more genetic diversity among microbes than there is among plants and animals. The eubacteria and archaebacteria are the current kingdoms that describe prokaryotic microbes. I guess protists could be described as microbes (assuminjg you are using the general definition of small) but they are definitely eucaryotes and so are not grouped with the prokaryotes. Not all fungi are microbes. Some fungi are the largest organisms on earth. You can't see them as they are in the soil but they can be as large as 15km2 in area. David D.(Talk)04:24, 19 December 2005 (UTC)[reply]
In other words, the term microbe is about size, it is not a taxonomy classification. And the number of kingdoms is also reason for dispute. A logical ordering wqould seem animals, plants, fungi and bacteria. But that's anthropomorphic. Along the lines of what David said, there is more variation among bacteria than among the other classes, so those should be grouped together, as Woese does, who introduces a third 'class', Archaea, based not on looks but on genetics (which makes more sense). Archae would by looks be classified as bacteria, so basically there's bacteria, bacteria and Eukaryotes, which include animals. We animals are just a speck in the variation of life. Actually, there's even dispute about the classification into Kingdoms, with Domains being an alternative higher 'order' (hard to find the right word here because 'order' and 'class' are themselves terms in the classification). DirkvdM09:24, 19 December 2005 (UTC)[reply]
Hi, this is a question related to Wikipedia. I recently re-installed windows and now I seem to have lost my japanese fonts. I can't edit japanese content anymore because everything shows up as question marks in Firefox and IE. Where do I download japanese fonts for windows so I can edit again? I've had no luck googling for the answer. Thanks --Quasipalm05:30, 19 December 2005 (UTC)[reply]
Thanks, but I checked that early on and Firefox recognizes the page as Japanese or UTF-8 as the case may be, but it simply doesn't show correctly. This lead me to believe that the fonts on my system don't have glyphs for Japanese, but I'm clueless how to find fonts that do that I can install. Thanks for the follow up though, I should have added that to begin with. --Quasipalm17:16, 19 December 2005 (UTC)[reply]
On a related note, doesn't wikipedia have a page where you could test this stuff out and then gave instructions on how to get the fonts? I could swear I came across something like that while reading the Unicode article.--Ridge Racer06:16, 19 December 2005 (UTC)[reply]
If you go to the Microsoft website, you can download Japanese at [43]. That's what I did, but it doesn't work with all versions of Windows, and you might need Office XP. smurrayinchester(User), (Ho Ho Ho!)18:58, 19 December 2005 (UTC)[reply]
I think people are often a little too keen to download things which they already have. Windows 2000 and XP come with all the Japanese fonts and stuff you need, you just have to install them. This is an indirect process: basically you tell Windows you want to support a language (and this involves more than installing the font) and Windows will do what is required (have the Windows CD handy). Start at the Regional/International control panel. Notinasnaid18:04, 22 December 2005 (UTC)[reply]
plane of voltage generation in piezoelectric crystals.
sir,
Is the plane of application of stress and plane of voltage generation same in the case of piezoelecric crystals(both 2d and 3d)??.if no how do they vary? 07:48, 19 December 2005 (UTC)
I'll hazard a take at this question. In order for an undeveloped country to become successful in the global economy several things must happen:
External factors
Developed nations must be willing to trade with your country on a level playing field. This includes no tariffs, quotas, or other trade restrictions, and no subsidies for competing products from their end. Current WTO trade negotiations are moving in this direction, but we are not there yet.
Internal factors
Transportation infrastructure; such as roads, railroads, seaports, and airports; must be developed.
Communications infrastructure; such as telephone lines, cell phone towers, satellite phone access, and internet access; must be developed.
Energy infrastructure; such as electricity, natural gas, and gasoline; must be made available.
Other infrastructure; such as drinkable water, sewage and garbage disposal; is also needed.
Educated workers are needed which are willing to work and reliable. Typically, in the early stages it is necessary to import large numbers of highly educated workers. Later, as more natives become well educated in production techniques, they can take over many of the technical jobs.
Modern housing is needed, with heat, air conditioning, indoor plumbing, etc.
Security is needed. That is, workers and executives must feel reasonably safe from war, ethnic conflicts, terrorism, and hostage taking attempts. Ideally, these things can be eliminated entirely. If that is not possible nationwide, creation of a "safe zone" with heavy security, may be the only immediate solution.
Stable government is needed. In particular, a peaceful method of succession is needed for transitions in government. The threat of coups or other political instability will drive off investments.
Honest government officials are needed. Those which require bribes to do their jobs scare off investment, not so much due to the money itself, but rather due to the unpredictability of not knowing what level of bribes are required by each official.
Honest government leaders are needed. Those which steal all the nation's resources leave little for infrastructure development. Democracy is typically necessary, but not sufficient, to get honest leaders. Voters must also put a higher priority on honesty than other factors, such as whether a candidate is of the same religion, ethnicity, or tribe as the voter.
You've got that right. From square waves, not the common and easy other way around. I don't have a particular reason to want this right now, but looking at the samples of a sine wave on a sound file I got... well, inspired.
Anyway, after thinking about it a little I found out that this sum, (the fundamental is positive, though), leads to a somewhat "good" approximation of it:
As you can see, the values tend to expand indefinitely on the zero crossings of the 3rd harmonic, and the overall shape is not smooth but it is stable. Now, my questions:
Is this the best method to approximate the sine curve?
What could I use here to at least stop the indefinite growth at the zero crossings?
If this was a signal, what could be used to smooth it? (a filter of some sort, perhaps?)
I'm no expert on the subject (or any subject for that matter), but as a square wave can be made by adding up the odd numbered harmonics of a tone, the opposite could be done by substracting them. Right? Maybe that's what Subtractive synthesis does. DirkvdM09:47, 19 December 2005 (UTC)[reply]
Not really. Check square wave. The result of the additive synthesis using sine waves is imperfect. All these are really approximations. Also, the above sine approach was done by continually subtracting square waves of the fundamental wave. ☢ Ҡieff⌇↯10:42, 19 December 2005 (UTC)[reply]
No, this is not the best basis for approximating sine curves. the best basis is obviously the sine curves themselves, wherein every Fourier series has only 1 term. Any basis that is "close" to sines will do better than square waves. I'll wager you'd do quite well with sn x for small elliptic modulus.
Well, I meant with square waves, really. If I could afford anything else for the experiment involved here this wouldn't be a challenge, would it? Also, elliptic functions are far mor complex than a square wave function. ☢ Ҡieff⌇↯11:42, 19 December 2005 (UTC)[reply]
Oh, I see. Well in general, Fourier series are unique. So if you've found the right Fourier series for sine in terms of square waves (I haven't checked it), then not only is it the "best" approximation; it's the only approximation. As far as elliptic functions being complex... well I just thought you were looking for any mathematical functions that could approximate sine curves, and from a mathematical standpoint, the elliptic functions are far more simple than square waves, among periodic functions. But I guess I misunderstood the question.
How can you ask that, after having just done a Fourier series with square waves? No, you can do Fourier analysis in any orthonormal basis. -lethetalk16:13, 21 December 2005 (UTC)[reply]
The growth that you see at the zeros should probably not be unbounded; it should stop at some finite limit. This is known as the Gibbs phenomenon, and is well known when approximating jump discontinuities with smooth functions. I've never seen it mentioned when it comes to approximating smooth functions by discontinuous ones, but it doesn't surprise me at all that they exist, and I expect similar methods to fix them would work.
Actually, if you look at the signal function, they shouldn't be, since , and you're always dividing this value to the odd number of harmonic and adding that to the point near the node. I can't really explain this mathematically because I don't know the english terms, but the points near zero will always have something added/subtracted. ☢ Ҡieff⌇↯21:41, 21 December 2005 (UTC)[reply]
Yep. Tried the lowpass filter with only 10 harmonics and I got an excellent approximation. :D Still, I wonder if there is a filterless method. ☢ Ҡieff⌇↯02:12, 20 December 2005 (UTC)[reply]
AC (= sine curve) currents arise naturally ought of electric generators. I'm not sure how to turn a square wave into an AC wave. You could maybe get some nice approximations by combining some filters. Maybe an electrical engineer will happen by.
Yes, AC = sine, but what about generating a sine curve from DC? I suppose you could play with some capacitors and diodes approximating a triangle wave signal, but that wouldn't be all that accurate either. ☢ Ҡieff⌇↯11:42, 19 December 2005 (UTC)[reply]
The more I think about it, the more I think you probably cannot do this with simple analog circuitry. All circuit elements I know turn DC currents into at worst exponential decays. The only way to introduce sinusoids is with other sinusoids. So I'm thinking hook the square wave into an on/off switch for a generator.
thinking even more: using resonance, you can get filters that select a narrow frequency band. Pass a square wave through that filter with the right band, and it should select only a single harmonic, which will be sinusoidal (to a great approximation).
DC is turned into AC because you know exactly what youre trying to make (60hz pure sine) and the circuit is designed to pulse at a high frequency to 'build' the sine wave as it goes up and down, the current is then filtered via a coil into a near-perfect wave which then actually feeds back and modulates the PWM input to ensure the sine tracks properly at a varying load. This is 'easy' since there is a sine already present. Transistor audio amplifiers work the same way, except they use a variable input as the tracking source. Working from an unknown square wave is tough since you can't see the future to know when the pulse will end.
Easier way to do this without anything fancy. Integrate the square wave, using a wide band integrator with a low frequency dump, you will get a good triangle wave. The triangle has much lower harmonic content, every other odd harmonic with flipped phases every other odd harmonic. Synthesize a sine from that. Another approach would be to filter the tringle wave, with a low pass filter. You would be able to use a simpler LPF.Dominick(TALK)16:17, 19 December 2005 (UTC)[reply]
Hello my name is Keith, I'm a steel worker I have just started working with aluminium and myths are floating in the air and i'm looking for some help, I was just wondering if you were to grind on mild steel and the red hot sparks are shooting off and hitting "In Contact" the Aluminium what would happen? would it be contaminated, corroded, oxidized??? please help.
Hi Keith. I'm not an expert on this, but as I understand it the red hot sparks from a grinding wheel are pretty small and cool down very quickly (something I've confirmed by being hit by them as they come flying off my Dad's angle grinder). I would think that they'd generally just hit the aluminium and bounce off. I'd be more worried about the abrasive effect of the bits of steel flung at the aluminium damaging that lovely shiny aluminium finish more than anything.
If a piece of steel did somehow manage to embed itself in the aluminium, the steel would almost certainly corrode first.
Nope. Not in this situation...remember, those sparks are caused by friction, and are just hot shavings of metal. They are rather small, and by the time they hit the aluminum, I would expect them to be relatively cool, and not do much damage to the aluminum. It would not initiate any significant chemical reaction. Well, I suppose you can stretch this a bit, and say that the shavings might scratch the surface, which causes it to oxidise, but this is a good thing - when aluminium oxidises, the coating is actually a protective one - it is not like iron where the oxide (rust) falls off and causes structural damage. --HappyCamper04:12, 22 December 2005 (UTC)[reply]
Except that most people find the white aluminum oxide ugly as compared with shiny polished aluminum, especially when it appears as spots, making the aluminum look like it has a disease. StuRat23:54, 22 December 2005 (UTC)[reply]
I could beef that article up (whoops I was thinking of accelerograph), but it's more oriented towards seismic accelerometers. (There are many types that all work differently.) In general it is difficult to get a good accelerometer up and working. There are some lab demo kits for the 'cheap & cheerful'. Most accelerometers just output a voltage; then you need a data acquisition card and software to analyze the results. For seismic work, I always wanted a small laptop kit for measuring equipment resonance, but everything is very expensive. --Zeizmic14:59, 21 December 2005 (UTC)[reply]
I climb eight flights of stairs several times a day to my office. Which would give me the most benefits of exercise, taking them singely or two-at-a-time? (Using any definition of "benefits of exercise" you think fit).
Well, I don't if anyone could really give a factual answer to this, but I think it goes like this. When you take two stairs at a time it equates to taking a larger stride, but one stair at a time would turn out to a longer distance. So, I would say taking one stair gives you more than or equal to the amount of exercise that you would get from taking two stairs at a time.--Ridge Racer18:30, 19 December 2005 (UTC)[reply]
This is practically equivalent to "should I life small weights for many reps or large weights for a few reps?" The answer depends on your goal. Do you want to build endurance or strength? Longer strides will build strength and more short strides will build endurance. As for the excercise of stair-stepping, I am influenced by the hypertension studies all around me in the hospital where I work. If your heartrate is not elevated for 20 minutes, it is not effective cardiovascular excercise. Then, a joke made by a doctor at a conference I attended where a similar question was asked: "Why not bunny hop each step? That will be a workout you won't forget." Just to note, I work on the 12th floor and the doctors try to force us to use the stairs. I usually cheat and ride the elevator up to the 11th floor and then walk up the last one. --Kainaw(talk)23:52, 19 December 2005 (UTC)[reply]
Doesn't it look suspicious when you arrive fit? Normal people would be panting after climbing 12 floors. Anyway, it's indeed the amount of effort you put into it. I once walked a marathon. I even carried a daypack and it was up and downhill over fairly uneven tracks. This took me over 10 hours. But I'm confident I couldn't run a marathon. So faster means more exercise. DirkvdM08:57, 20 December 2005 (UTC)[reply]
Are you positive? Because I'm on the verge of buying the XP SP2 CD on eBay, and I wouldn't want to waste my money...--Archducky Duck
If you have the software and the licence, there shouldn't be a problem. Mind though that the system requirements for windows XP may give you some problems. See [44]. -- Ec561819:02, 19 December 2005 (UTC)[reply]
It is not necessary to reformat the hard drive in order to upgrade Windows ME to Windows XP. In the process of updating, setup determines whether the file system should be changed from FAT32 to NTFS, based on some criteria I am unaware of-- perhaps compatibility with programs already installed. (After the upgrade, it is possible to change the file system once from FAT32 to NTFS; this has some benefit as regards resistance to file corruption, and will permit native file encryption if you're upgrading to Windows XP Pro rather than XP Home). Some old programs that directly access the hard disk may not work if you change to NTFS. Also, as Ec5618 mentioned, there are many hardware issues, and much legacy hardware that would otherwise be compatible with XP does not have approved XP drivers available. There is an XP upgrade advisor wizard that runs automatically during XP setup which can point out these issues before you make the upgrade. Alternatively, you can run the wizard as a standalone program. see: Windows XP Upgrade Advisor-- Mark Bornfeld DDS Brooklyn, NY 21:11, 19 December 2005 (UTC)
What would happen on earth if an asteroid or meteor strike knocked the moon out of its normal orbit?
There would be a huge distruption of the tides, possibly causing tsunamis and other such events. If the knock was big enough, it might distrupt the Earth's orbit. I guess the moon could also crash into the Earth if the blow knowcked it inwards or slowed it down. — Asbestos | Talk (RFC)
What would happen if the Moon did impact the Earth? Would gravity immediately crush the Earth+Moon combination into a sphere, or would it stay funny-shaped for some time? I'm guessing there would be a pretty major impact winter regardless... —Keenan Pepper21:06, 19 December 2005 (UTC)[reply]
No, that would depend on the structural integrity of the moon. The Roche limit refers to bodies held together only by gravity. The moon's material strength and resistence to tensile stress would keep it intact inside it's Roche limit. I don't know how strong the moon is, but I would assume it could make it all the way to impact before it broke apart. - TaxmanTalk16:27, 20 December 2005 (UTC)[reply]
I was thinking that too. The roche limit isn't all that far from the Earth's surface anyway (about 1.5 times the radius). So, how long would it take Earth+Moon to be crushed into a sphere? Would the pressure make the rock flow as a liquid? —Keenan Pepper19:32, 20 December 2005 (UTC)[reply]
Yes, the Earth/Moon combo would become molten, with all the oceans vaporized, and would quickly settle back into a slightly larger sphere and then cool in that shape, with a thin solid crust containing new continents and oceans. The collision might also send out several large clumps of materials that would form a series of smaller moons. StuRat03:50, 22 December 2005 (UTC)[reply]
In the original question, "knocked the Moon out of its normal orbit"
is rather nonspecific. If the Moon was deflected by a small amount,
that'd be "out of its normal orbit", but there wouldn't be any major
effects on the Earth. The biggest effect would probably be cultural:
the length of the lunar month would change, and all cultures using a
lunar calendar (such as Islam) would need to
deal with that. Also, solar eclipse fans, who might already have
trips planned to see eclipses over the next few years, could find
their schedules all wrong.
If the Moon was deflected into a more eccentric
orbit without much change to its period (the lunar month), that would
mean that it would be closer when at perigee and farther when at
apogee. Even a small change might noticeably affect the tides,
since tidal force varies as the inverse cube of the distance. Sometimes
when a coastal region is threatened by flooding, a higher-than-usual
tide can cause the flood to happen; the perigee change might make that
a more common occurrence. Apogee and perigee changes could also give
some solar eclipses a noticeably different appearance than now.
But I suspect the intention was to imagine a more violent disruption,
one that deflects the Moon into a grossly different orbit. In that
case we wouldn't be worrying about tides -- the energy relase from the
impact itself would be, well, astronomical. The Moon's kinetic energy,
if I calculate correctly, is about 4 x 10^28 joules. If just 10%
of that energy went into heat, that would be equivalent to a
trillion-megaton explosion. And don't forget that the
impacting body will contribute kinetic energy of its own that will
also turn into heat. I don't know how to calculate it, but I would
guess an impact that size would be enough to cause significant radiant
heating on the Earth. Not to mention fragments splashing out, large
enough that some of them could cause damaging meteorite impacts on
the Earth, maybe even global-disaster-level effects.
--Anonymous, 07:40 UTC, December 20, 2005
There is a 50% chance the collision would be on the far side of the moon, in which case the radiation wouldn't be a problem for us. (The chance might be less than 50%, if the Earth provides some shielding of the near side.) Large meteors resulting from the collision might still hit the Earth, though, even if the impact was on the far side. StuRat04:04, 22 December 2005 (UTC)[reply]
That clearly leaves us with only one option... Eliminate the moon before it eliminates us!!! But seriously, are there even any known asteroids with near enough mass to disturb the moon that greatly, if they were to hit it?
I was curious about this, so I fed the problem to the Impact Effects Calculator. Assuming the Moon were to simply halt in its orbit, dropping straight down onto Earth and colliding after 2.5 hours, the energy of its impact would be 2.92x1032J, just exceeding the combined gravitational binding energy of both objects (2.285×1032 J). This seems to be reflected in the calculator's estimate that the crater diameter would be 11,300 km. At least someone on the far side of Earth should have twenty minutes of relative safety. ‣ᓛᖁᑐ16:58, 22 December 2005 (UTC)[reply]
And that calculator probably assumes that the crust would not be ruptured. When it does, the effect would be even more dramatic. StuRat23:46, 22 December 2005 (UTC)[reply]
Many years ago when I was taking lower division physics my professor remarked that every equation used in physics can be derived from one of eight fundamental equations, one of which was F=ma (the only one I remember). What might the others be?
But F=ma would be pretty helpful for lots of stuff, and there are seven more. That being said, I couldn't begin to guess which eight he might've meant. Some important ones are:
I think the non-logged in user above means that F=ma is wrong, while, say, F=dp/dt is equivalent classically, but is also correct in modern physics sense. --Ornil04:28, 20 December 2005 (UTC)[reply]
I remember hearing something similar. Also, Hawking wants to describe everything with one superformula. So how may are there now? Or what if we limit it to 'traditional physics'? The SI base units are mass (m, kg), time (t, s), length (l, m), electrical current (I, A), temperature (T, K), quantity of matter (n, mol) and luminous intensity (I, cd). How do they relate? The SI derived units give relations. Which of these are basic? Of course Hertz doesn't count because it is only expressed in one unit (the second). Then there's
Force: F = ma
Energy: E = mv²
Power doesn't qualify either because it's expressed in terms of energy and time, which we already have. Same for many others. But then there's
Electric charge: V = It
Confusingly, 'I' can mean two things. Are there no unambiguous symbols? (I looked these up in a science table book. Shouldn't those be given in those articles?). Anyway, on I go:
Magnetic flux: how do you write that?
Oh dear, this is too long ago. I think the principle of what I mean is clear. But someone more knowledgeable could do this much more easily. DirkvdM09:56, 20 December 2005 (UTC)[reply]
The best answer is probably that what your professor told you is inaccurate, if not downright wrong. If you're looking for important formulas in classical physics, then you should definately mention Maxwell's equations and the laws of thermodynamics. It would make more sense to say that all measurable quantities can be measured in units derived from 7 fundamental units, as indicated above. Hope this helps. Siebren12:57, 20 December 2005 (UTC)[reply]
...is three too many. Dell Inspiron 5100, 384MB, XP. It seems to happen after I go away for a few hours, leaving the laptop on, with the lid closed. The blue screen has no useful information, only hex addresses. Windows keeps a data log which I've forwarded to the Microsoft web site; but the automated analysis there simply says the problem was caused by an (unknown) driver. I haven't installed any drivers for a very long time. I did perform two system restores, the first to the day previous and the second to two weeks earlier. A non-Dell tech suggested it might be a memory problem, citing a previous case with the same computer. He said I had 256K and 128K memory chips and that if one of them wasn't working it could cause a pointer error, corrupting memory and causing the crash. Is this reasonable? What should I do? Thanks, Halcatalyst01:52, 20 December 2005 (UTC)[reply]
Well, to test if the memory is bad, use Memtest86. It takes awhile to run but is pretty good in seeing if that's the source of the problem. If is, you figure out which RAM card is bad and replace it, not very hard. If it isn't RAM, then you have to try other things. --Fastfission03:05, 20 December 2005 (UTC)[reply]
It lost me when it asked me to enter the disk image source file name. I'm afraid I don't have nearly enough technical expertise to use the tool. Thanks anyway, Fastfission. Halcatalyst03:24, 20 December 2005 (UTC)[reply]
I had almost the same thing with an older Gateway. Turned out the heatsink on the CPU had become loose. Put on some lithium grease (better to use thermal if you have any) and tightened (but laptops are tricky beasts to take apart and put together). Now it can run forever, compiling Linux kernels. --Zeizmic23:14, 20 December 2005 (UTC)[reply]
Your computer has determined that you are damaging your health by spending too much time online viewing porn (if that's actually possible), and decided to shut down to protect you. StuRat07:40, 22 December 2005 (UTC)[reply]
Why do we see our breath on a cold day but not on a warm day?
Our cells produce water when they undergo cellular respiration to produce energy. Glucose, processed from our food, is broken down into pyruvate in the cytoplasm, protons (positive hydrogen ions) and electrons extracted from it, which is then oxidised with oxygen to yield water. This produces water in our breath when we exhale. Heat, due to entropy in cellular respiration, makes this water particularly warm. This allows more water to be dissolved into the air. On a warm day, our breath isn't much hotter than the surroundings, and it loses very little heat, thus keeping most of the water dissolved (transparent/hidden). On a cold day, the saturation capacity of our breath decreases immensely as it loses heat to the cold air, making the water in our breath condense. Thus the water particles originally produced in our mitochrondria become visible. -- Natalinasmpf02:24, 20 December 2005 (UTC)[reply]
An incredibly complex answer is given above, but the basic point is indeed that the water vapour is usually free to remain an invisible gas, but on cold days it condenses to tiny (visible) droplets of water. Notice how the steam from a kettle is invisible until it's a few centimetres away from the nozzle — the water cools and condenses. -- Ec561812:02, 20 December 2005 (UTC)[reply]
I'd also note that the incredibly complex answer above is trying to be too clever for its own good. Most of the water we exhale isn't the product of cellular respiration; it's the same stuff we consumed as part of the food and beverages in our diet. It makes its way through the body–as a component of blood plasma, lymph, or miscellaneous interstitial fluid–and some eventually ends up coating the surface of the lungs. (From there, it readily evaporates as described.) TenOfAllTrades(talk) 16:49, 21 December 2005 (UTC)[reply]
The sources of heat and moisture in one's breath are completely irrelevant to the question and should be a "given" unless the questioner asks for more detail. StuRat03:06, 22 December 2005 (UTC)[reply]
Ok, we can forgive you then. I am looking forward to your recipe for lemonaide that starts with the mitosis cycle for cellular reproduction in the lemon tree. Don't forget to list the number of chromosmes ! LOL. StuRat07:33, 22 December 2005 (UTC)[reply]
On a side note, this is the same effect which causes jets to leave a white trail in the sky.
Welcome to Wikipedia. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. Anyhow, see aurora borealis. -- Natalinasmpf02:52, 20 December 2005 (UTC)[reply]
I know I know, I ought to just figure this stuff out already, right? Well, until I do, here goes:
On the CD40106 DIP I mentioned above, the schematic calls to connect components to pins 1-6, in 2 pin pairs. Is it kosher to connect the parts that were supposed to go to pins 3 and 4 instead to pins, say, 10 and 11? It would make layout of my board much easier, because as it stands, all my parts are on one half of the board.
Oh, and if any of you have any good reference to websites or books that have instruction on basic circuitry, I think we all would appreciate that :). I find a lot of stuff on basic electronics, but it's largely theorhetical and doesn't really help me once I start to build. Thanks! --ParkerHiggins | Talk04:03, 20 December 2005 (UTC)[reply]
Yes, since that IC has six identical copies of the same gate, you can swap any gates over as long as you follow the correct pinout, e.g. instead of pins 3 & 4, use pins 11 & 10. Note you have to make sure you get the input and output in the right order.
Absolutely the best electronics book for beginners, IMO, is this one: [45]. Seems not to be in print anymore (you used to be able to buy it from Tandy/Radio Shack), but it covers everything you need to know with a strong emphasis on practical rather than theoretical. --Bob Mellish04:32, 20 December 2005 (UTC)[reply]
If I add some ice (0 degree celcius) to hot water of 40 degree celcius, after 5 minutes, lets say that the hot water became 38 degree celcius, what would the temperature of the ice be? Would it remain 0 degree celcius or the temperature of the ice increases? --165.21.83.24007:20, 20 December 2005 (UTC)Naruto90[reply]
(My answer was longer, and had formatting issues, but, pretty much the same thing):
The ice would melt, and become water, 40oC is certianly hot enough to change it all the way to liquid phase, thermodynamically though, you're right, ice melting in hot water could be broken down into
Water(solid,0oC)-->Water(liquid,0oC)
&
Water(liquid,0oC)-->Water(liquid,near40oC
seperating out the phase change, and the temperature change, while remaining energetically equivalent to the origional reaction,
Depends. No quantities are given. Suppose you threw an iceberg 'into' a puddle of warm water? :) But couldn't the relative quantities be calculated based on the water temp dropping from 40 C to 38 C in 5 mins? Anyway, the answer stays the same. The ice (if any, but the question implies there is some, unless it's a trick question) will be at 0 C. DirkvdM10:06, 20 December 2005 (UTC)[reply]
To answer the literal question, if any ice remains, it would be at 0 °C. At equilibrium, the whole system will be at the same temperature. As explained above, what happens depends on the relative amounts of ice and warm water. If there is only a small amount of water, it be sufficient to melt only part of the ice before it was cooled to 0 °C; you would end up with an ice-water mixture at 0 °C. If there is sufficient water, the ice will all melt and the result will be all water at some temperature between 0 °C and just below 40 °C (of course, depending on the relative amounts). — Knowledge Seekerদ02:12, 21 December 2005 (UTC)[reply]
If you take a look at Lorentz transformations you will see that, if v comes greater than c, the square root becomes imaginary. Therefore, nothing can move faster than speed of light (just by mathematical reasoning). GTubio16:27, 24 December 2005 (UTC)[reply]
Things can appear to move faster than the speed of light in vacuum (c), but no matter or information can actually travel faster than c. According to special relativity, anything that appears to be moving faster than light to some observers will appear to be going backwards in time to other observers. In other words, faster-than-light travel is equivalent to time travel. —Keenan Pepper07:37, 20 December 2005 (UTC)[reply]
Nothing can move faster than the speed of light in a vacuum. But things can move faster than the slower speed of light in non-vacuum situations. When a fast-moving atomic particle exceeds the speed of light in air or in water, it produces a shock wave (a bit like a sonic boom). For more details, see Cherenkov radiation. - MPF11:31, 20 December 2005 (UTC)[reply]
Speed is a relative concept. I could be moving at 0.5 lightspeed (as measured from Earth), drop a buoy, and fire my boosters to accelerate to another 0.5 lightspeed (as measured from the frame of reference of the buoy). Oddly, to observers on Earth I will not be moving at the speed of light, and since time moves differently for me, They will see me moving at about 0.7 lightspeed. I could drop another buoy and accelerate again (instinctively one would say I was moving at 1.5 lighspeed, but to observers on Earth I will be moving at about 0.8 lightspeed). In my frame of reference, things would be different.
Consider that speed is distance times time, and that time is a relative concept.
Light, in my understanding, is a somewhat timeless concept. It moves at the maximum speed in our frame of reference, but from the point of view of the photons themselves they reaches their destination at the moment they are created. -- Ec561811:58, 20 December 2005 (UTC)[reply]
Why do we have prefixes like kilo- and mega- when they mean exactly the same as 'thousand' and 'million'? The overview at SI prefix shows there is such an equivalent for each prefix. So what is the use of using different names than the ones already generally known? Well, one reason might be the ambiguity of a word like 'billion', according to culture. But is that the only reason? DirkvdM10:22, 20 December 2005 (UTC)[reply]
Of course centi for hundreth. my guess is that the prefis are easier to work with and have unique 1 letter codes that are unambiguous. Thousand, ten, thousandth all start with a T. i emphasise this is a guess. David D.(Talk)10:31, 20 December 2005 (UTC)[reply]
Well, believe it or not, there was a time when English wasn't "already generally known" and ancient Greek, like Latin, provided an acceptably neutral core for a non-nationalist scientific language in the 18th and 19th centuries. The prefixes are part of the metric system, which dates to the early 19th century and has lots of advantages. alteripse10:35, 20 December 2005 (UTC)[reply]
Another minor advantage of the prefixes is that they are shorter when written out. Per alterprise, cultural neutrality probably played a big role. Note that the metric system was a French development; if we were to use the vernacular we would have millemetres, centmetres, and dixmetres—not thousandmeters, hundredmeters, and tenmeters.
Meanwhile, you can see the potential for trouble if each region were to use its own language in the units. The British wouldn't have been willing to adopt a system that used French prefixes, so going back and forth from the Continent would have required replacing all those thousandmeters (tm?) with millemetres (mm?). Using the Greek-derived prefixes cuts down on the confusion; everyone can unambiguously use kilometers (km). TenOfAllTrades(talk) 12:24, 20 December 2005 (UTC)[reply]
To see an illustration of potential difficulties, look at the early history of railroading where different nations had different widths between the tracks, meaning a lack of global standards, so trains were designed to run in a particular nation. I have heard it tell that this was done deliberately because some leaders were sufficiently farsighted and paranoid to realize that an army traveling by train could get into their nation pretty fast and economically if their trains required same width between wheels as everyone else. I never learned whether that was ancient history urban legend or not. User:AlMac|(talk)21:46, 20 December 2005 (UTC)[reply]
That problem certainly occurred in Australia when it was a bunch of separate British colonies and not a unified nation (1901). Most of the colonies had unique rail gauges. Travellers between Sydney and Melbourne, the capitals of New South Wales and Victoria, had to change trains at Albury. The problem was not finally fixed till the 1960s, believe it or not. That's why Albury had one of the world's longest railway platforms. JackofOz22:42, 20 December 2005 (UTC)[reply]
From Track gauge, In the nineteenth century, Russia chose a broader gauge. It is widely believed that the choice was made for military reasons, to prevent potential invaders from using the Russian rail system.Shimgray | talk | 20:02, 21 December 2005 (UTC)[reply]
And in Spain the gauge was also wider, for the same military reasons. Only after Franco did they start to change to the European standard gauge and I'm not sure if that job has been finished yet. Well into the 1980's one still had to swap trains at the border. DirkvdM12:31, 23 December 2005 (UTC)[reply]
Is it true that on passenger airplanes it is impossible to open the door mid-flight due to the differential in air pressure between the inside and outside of an airplane cabin?
Regards, Gallaghp
There's probably safety locks on those doors preventing them from opening but I think it's relatively easy to do so if that wasn't the case. Airplane cabins are pressurized to approximately the same pressure as people feel on the ground, which would be higher than the low pressure of the air outside. High pressure inside versus low outside, would make opening a door relatively easy. It's the exact opposite of trying to open a door underwater at the bottom of the sea. The pressure there is a lot higher than on ground level because there's a lot more air (and water) above you applying pressure. So underwater, the pressure outside is high enough to keep you from opening the door. - Mgm|(talk)12:35, 20 December 2005 (UTC)[reply]
Mgm, that would depend on your definition of the phrase "same pressure as people feel on the ground". Commercial jets are not pressurized to pressures one might feel at, for instance, sea level. The pressure within the airplane would be equal to that of a few thousand feet above sea level. See Cabin pressurization for more info. Dismas|(talk)13:35, 20 December 2005 (UTC)[reply]
Boeing's answer on the matter is that the door cannot be opened during pressurised flight. Their website (at least that part) doesn't explain why, but my guess is that the door has a plug design. When the lever is pulled, a plug action is observed where the cabin pressure makes it impossible to push the lever back. You will notice that I have completely avoided disucssing the design of this system, becuase I have no idea how it works.--Commander Keane14:10, 20 December 2005 (UTC)[reply]
Mgm, I'm pretty sure that the doors on (most, if not all) commercial airliners open inward; consequently you would need to pull the door open against the air pressure difference. (They're plug-type doors; they are larger than the opening in the cabin that they seal.) At altitude, the pressure difference between the cabin and the surrounding air is about 8 psi (55 kPa), which works out to aboute ten tons of force on a typical cabin door. TenOfAllTrades(talk) 14:34, 20 December 2005 (UTC)[reply]
I have never come across a commercial aeroplane where the door opens inwards. All Boeings and Airbuses I have traveled on open outwards. Lack of interior space is one reason why this is so. -- SGBailey00:50, 29 December 2005 (UTC)[reply]
Dismas is correct, but the pressure difference between the inside and outside of the plane is still substantial, up to about 1/2 atmosphere, which means that the force on a normal-size door is something like 20,000 pounds (10,000 kilograms-force or 100,000 newtons).
What Mgm is missing is that airliner passenger doors are normally designed to open inward, and so the answer to the question is yes. This design means the latch only has to be strong enough to keep them from coming open due to wind, vibration, and so on when the aircraft is near the ground; it doesn't have to resist the huge force created by the pressure difference. I think I've heard of a model of airliner that does have outward-opening doors, but it would certainly be the exception.
In some cases cargo doors don't have space to open inward, in which case they do require latches that strong. Consequently, the failure of a cargo door can be disastrous. But with the mechanism normally locked, it would still be impossible to open it deliberately in flight because the pressure would keep the bolts from sliding.
--Anonymous, 14:30 UTC, December 20, 2005
You should watch a program about how a boeing door locks failed and the parents of a New Zealander who died in the crash, who pushed and pushed and pushed and pushed and came up with the truth.
He was an aeronautical engineer or something similar.
I might I add that it wasn't easily accepted by the air transport authorities, the door locks were made from very, very lightweight aluminium that was known to be and previously ordered to be changed, by boeing, so that it wouldn't fail.
Very interesting
Not all airplane doors open inwards, however, the ones that open outwards have a double action mechanism whereby they cant inwards before swinging out (the MD-80 is an example). Also, Anonymous is correct about cargo doors. The A320 series is an example of cargo doors that swing outwards, but their cargo doors are so heavy that they're only articulated by a motor, not by hand. I'm not sure if the emergency exit doors on commercial airliners can be opened in flight, I doubt they'd want any mechanism that would impede their opening at all. IIRC, some 60's-era aircraft even had explosive bolts for the emergency exits. -User:Lommer | talk02:03, 22 December 2005 (UTC)[reply]
I would guess that those airplanes with cargo doors that open outward do not have pressurized cargo compartments. Otherwise, the huge forces acting on the cargo doors would be difficult to control with any latch mechanism. StuRat02:37, 22 December 2005 (UTC)[reply]
Pressurizing the cargo compartment allows the pressure hull to be more or less a cylinder, which is a strong shape. If the cabin floor was part of the pressure hull, it would need reinforcement all along the edges where it meets the walls. Also, an unopressurized cargo compartment could not be accessed in flight even if some emergency made it desirable. These issues are more important than the cost of a strong latch on the door. --Anonymous, 10:50 UTC, December 22
A "strong latch" does not begin to describe it. If there was only a 1 psi difference in pressure from the interior to the exterior of a large, 120x150 in cargo door (say on a C-130), the force on the door during flight would be 9 tons ! StuRat23:38, 22 December 2005 (UTC)[reply]
And yet if you search on c-130 and "pressurized", you will find, for example,
this page that confirms that the C-130's cargo compartment is indeed pressurized. --Anon, 02:35 UTC, December 23
Indeed, I have flown on a B-727-200F. I was seated in a jumpseat in a small area just aft of the cockpit, separated from the cargo by a divider, but this was not an airtight divider (I could look around its edges and see the cargo.) The 727's cargo door is the type that opens outward under the control of a motor, and it's something like 140" x 88". kmccoy(talk)15:03, 23 December 2005 (UTC)[reply]
You didn't say under what conditions this occurs, but my guess is that should practice the "stop and go method" of masturbation to teach your body to hold out and not ejaculate too soon. - Mgm|(talk)20:47, 20 December 2005 (UTC)[reply]
I recently heard a lecture about Herbert ?-Stewart or Stuart, I forget his mothers name, however I can easily get it again though it's too late tonight.
I was stunned, bemused, absolutely enthralled.
It seems that he patented the fuel oil compression engine specifics in 18??, in England, this being on the record.
Why then is Rudolf Diesel credited with the "INVENTION" when he patented his specifics two years later?
I will put the entire lecture that I heard on this page
I understand that there have been many Herbert ?-Stewart or Stuart lectures over the subsequent years however it seems that the community has seen fit to believe the promotion put forward by Rudolf Diesel that he alone was responsible for the invention of the 'fuel oil compression engine'.
It is common for multiple persons to be developing technology at the same time however it has been the accepted practice that the first patent is credited with the invention of the device.
It is a matter of record that Herbert ?-Stewart or Stuart, did build a working engine however it is not known, at least by me, at what point that the good professor Diesel built an engine.
The working fuel oil compression engines that were built in Englang subsequent to Herberts patent were not named as Diesel engines. They were given other more generic or builder specific names.
I hope that there are others that can elaborate upon this as the inventor died a bitter and disappointed man subsequent to the media picking up upon the very public, well funded campaign by Professor Rudolf Diesel.
I have no malice towards Professor Diesel however it is well observed that the German aristocracy was very adept at using the media to put their ideas forward.
Me personally, well, I think that the media has always allowed itself to be used and melded by people who understand how powerful it is, though not everyone who understands its power wants to exploit it.
Herbert Akroyd Stuart is the person you're after. This sort of thing is hardly unusual - who invented what, and who made the most significant advance is often convoluted by claim and counter-claim, and sometimes the "winner" (in terms of who gets the credit) isn't necessarily the strongest candidate. The Wheatstone bridge wasn't invented by Wheatstone, and Snell was 637 years late when he discovered Snell's law. The invention of the laser is a more modern example. See James Burke's old book/TV series "Connections" for a look at a bunch more. --Bob Mellish17:05, 20 December 2005 (UTC)[reply]
What is the difference in applications between wet and dry cutting? Such as a wet tile saw, wet concrete saw- when is a wet saw preferable and why is it used? 83.5.231.6614:16, 20 December 2005 (UTC)[reply]
The water removes the substrate that is cut to get it out of the way and typically works as a coolant for the saw blade. So I guess it's going to be used for cutting harder materials. I'm no saw expert, this is just what I recall from watching This Old House or whatever. - TaxmanTalk16:14, 20 December 2005 (UTC)[reply]
Water or some other liquid is also so used in drilling, where the buildup of material and heat in a deep hole can cause the drill bit and/or the material to fail. Lubricants are fequently used, as they also have the desirable effect of reducing friction. StuRat02:25, 22 December 2005 (UTC)[reply]
Sugar soap is a chemical used for cleaning. I had never heard of it when I lived in the United States, but then when I moved to Australia I found that its is very commonly available here. Its main use, apparently, is for washing walls, but I wonder about other applications. Perhaps in America it has another name with which I am familiar. Is it dangerous? Are there other cleaners with which it can be mixed, such as ammonia? And, especially, I just gotta know about the name; Why is it called "sugar soap"?
I found Wikipedia about three weeks ago, and now I visit this site more often than google. This is a fantastic, in-depth, resource, and totally uncluttered with capitalistic interests.
Thanks to whoever answers my question.
We have it in the UK, too. It's a caustic substance, but I can't find its composition. Assume it's sodium hydroxide or something similar. Here's a data sheet (PDF). It's so named because, in its dry form, it looks like granulated white sugar. Chemically, it has nothing to do with sugar. --Heron19:23, 20 December 2005 (UTC)[reply]
Ah, there seems to be some confusion. The 'sugar soap' that the submitter is asking about is apparently an abrasive and caustic powder used for cleaning walls. However, the term 'sugar soap' has also been appropriated by various other manufacturers of 'girly' bath and body products—these ones contain moisturizers, vanilla, and other floofy, frilly ingredients.
The potent, wall-scrubbing 'sugar soap' seems to vary a little bit by manufacturer. (See, for example, powder [47] and liquid [48] formulations.) The important bits seem to be sodium carbonate and sometimes sodium phosphate (caustics), and sometimes sodium silicate (an abrasive); there's also some additional non-hazardous salts that probably are mildly abrasive and/or filler. To find the (hazardous) ingredients in a product, try searching for the product name plus the acronym MSDS. TenOfAllTrades(talk) 19:50, 20 December 2005 (UTC)[reply]
What are the physical features at the ocean shore?
How do we know what the speed of light in a vacuum is if we can't even create a perfect vacuum? Would it be possible for a molecule a fair distance away to affect light electromagnetically, or does it physically need to get in the way? Thanks, Zhatt22:39, 20 December 2005 (UTC)[reply]
While it's not easy to create good vacuum in laboratory conditions (i.e. on the Earth), the speed of light is much easier to measure using astrological measurements than in a laboratory, and in the space there's already pretty much a vacuum. —Preceding unsigned comment added by B jonas (talk • contribs)
That's not true. It's actually much easier to measure the speed of light in the laboratory. Furthermore, it's possible to create vacuums in the laboratory comparable to interstellar vacuum. However, a perfect vaccum doesn't exist, therefore a perfect measurement of the speed of light doesn't exist either. This isn't much cause for concern, because no measurement anywhere is perfect. The precision of measurements is constrained, even in principle. Finally, with the modern units, the speed of light is a defined exact number, so if you're using the modern units, you're measuring your meterstick, not the speed of light, no matter what experiment you're doing. -lethetalk12:15, 21 December 2005 (UTC)[reply]
"the speed of light is much easier to measure using astrological measurements than in a laboratory" - no, the only thing you can measure with astrological measures, is the speed of dark (i.e., how long it takes the world to return to the dark ages) - MPF15:42, 21 December 2005 (UTC)[reply]
If we assume the speed varies at a predictable rate relative to the purity of the vacuum, we could look at the speed of light in a 90% vacuum, a 99% vacuum, a 99.9% vacuum, etc., and extrapolate the theoretical speed at a 100% vacuum. This does assume, however, that nothing "strange" happens near a 100% vacuum. For example, there could be an as yet undiscovered "supervelocity" where the speed of light goes to infinity at a 100% vacuum, similar to superconductivity near absolute zero on the temperature scale. While there is no evidence that such an effect will occur, and no such effect has been measured even in the sparsely populated intergalactic spaces, and no current theory predicts it, anything is possible. Thus, testing with progressively purer vacuums (as we are able to produce them) would eventually enable us to find any such effect, if it exists. StuRat02:04, 22 December 2005 (UTC)[reply]
Also, don't forget that we know that the speed of light is exactly 299,792,458 meters per second because the definition of the meter is the distance light travels in a vacuum in exactly 299792458-1 second. — Knowledge Seekerদ03:55, 22 December 2005 (UTC)[reply]
Nothing weird would happen in a 100% vacuum because the only reason a 100% vacuum is needed is so the photons won't crash into anything. The light "thinks" it's in a 100% vacuum all the time - until it crashes. Max 216.209.153.7914:21, 22 December 2005 (UTC)[reply]
How much Zinc Oxide should be used in a 4-oz. bottle of body lotion?
From Google it looks like sunblock usually has between 2% and 10% zinc oxide, so a 4 ounce bottle could have anywhere from 2 to 10 grams. —Keenan Pepper20:36, 21 December 2005 (UTC)[reply]
Would you like to inform me when a subject tree is pruned, it produces significantly low fruit formation in subsequent crop/years. Why? Pl. inform me and oblige. Thanks.
The Chikoo is an evergreen, and thus pruning is not efficient. You should however remove sick or dead parts of the tree. Pruning of buds will for most plants increase yields if done in moderation the next season since the plant will not waste energy on unhealthy or unsuccessfull buds. Overpruning is none to reduce the ammount of fruit and its quality in all plants. Since the Chikoo produces two crops per year and flowers year round pruning saves little energy for the plant.
--Sreyan13:01, 21 December 2005 (UTC)[reply]
I need a Windows/DOS software tool that allows me to batch convert text files (Unicode, ASCII, DOS/MacOS/Unix line breaks). Thanks! -- Toytoy07:06, 21 December 2005 (UTC)[reply]
Well, this isn't a science question, but: The ultimate tool for batch-converting text files between different encodings such as Unicode and ISO-8859-1 is iconv. It's a Unix tool, and the only way I'm aware of to install it is to download Cygwin, a rather large (but free) system that gives you access to thousands of Unix tools from Windows. It almost certainly includes iconv. Another alternative appears to be http://www.iconv.com/ - which lets you convert online by uploading files. Changing line endings is relatively easy in comparison; dozens of tools can do this. Try http://versiontracker.com/ or any of a dozen other Windows shareware sites for a tool that can convert between Windows, Mac, and Unix line breaks.
Dmazzoni10:34, 26 December 2005 (UTC)[reply]
If we know the local ground floor pressure and the pressure at a certain level in a building,how do we calculate the altitude by using the pressure?Is there any practical or empirical equation to calculate the altitude precisely?
The obvious answer is 'yes they do, if all the windows are open'. If it's a closed environment, then things are different, and probably depends on what setting the air conditioning happens to be on that day. Prototc09:55, 21 December 2005 (UTC)[reply]
Note that this method isn't terribly accurate, as local pressure variations due to winds, solar heating, etc. could throw off the results. This method is fine for airplanes, which only need to stay at a certain altitude with a + or -500 foot variation, but there are other far more accurate ways to measure the height of various floors in a building. StuRat01:50, 22 December 2005 (UTC)[reply]
In one episode of rough science, someone measured the size of a mountain fairly accurately by measuring the air pressure at the foot and then at the top. This would of course have to be done with as small a time interval as possible to avoid the influence of any change in weather. But we're talking about quite a height difference here, so, as with the airplanes, any deviations will be relatively less important than with the height of a building. Also, with a building you have to take care that the inside conditions are the same as outside, and heating might increase it. And in a previous question I pointed out that if any openings are only on the windward side that will increase the air pressure (and even more so vice versa because the any wind might suck out air). DirkvdM13:38, 23 December 2005 (UTC)[reply]
Hi. I am trying to convert a word document to a pdf. I can get it working with a normal white background. However, when I tried adding a background effect and converting, the background effect is lost on the pdf, in otherwords the pdf still has the normal white background. Does anyone know how to fix this? I am using Word 2003, and PDF Maker 7. Thanks. - Akamad10:17, 21 December 2005 (UTC)[reply]
As far as I know, the Background Effects in Word only works in the Online View. In my version anyway, if you apply a background colour or texture, the view changes to Online View, and if you change it back to Normal View, the effect disappears. The only way to save the file as a PDF is to save the file as an HTML document (File > Save as Web Page), open the result in Internet Explorer or another browser, and then print the "web page" to the PDF Maker. I think you'll be pleasantly disappointed with the results, it looks awful, but that's Microsoft for you... --Canley12:01, 21 December 2005 (UTC)[reply]
In that case you could try this. Instead of adding a background effect, draw a rectangle over the whole page and add a background image or fill effect to it. Format the rectangle as "behind the text" So that you can read the document then convert to pdf - it might work. Theresa Knott | Taste the Korn16:36, 21 December 2005 (UTC)[reply]
Thanks all for your responses. The method I ended up using was similar to Theresa Knott. Except I didn't know how to fill in a rectangle with a background effect. So I created a blank page with the effect, print screened it, and copy and pasted it in from paint. Once again, thanks. - User:AkamadMerry Christmas to all!07:10, 22 December 2005 (UTC)[reply]
are the artificial flavors added in food items like potato chips harmful to our health?if so how?thanks
That depends on how you define "harmful". Cigarettes are sold to millions (billions?) of people every day and they are considered harmful. Many countries have a governing organization that determines what companies can put into food products. In the United States this is handled by the United States Food and Drug Administration. Also see Food coloring. Dismas|(talk)13:16, 21 December 2005 (UTC)[reply]
It's unknown; some people can develop nasty allergies to flavours/colours such as Tartrazine, Monosodium Glutamate and Aspartame, and no-one knows whether these also affect healthy people. Ironically, the healthier foods, notably 'diet' drinks, can be highest in these chemicals (Aspartame is common replacement for sugar). As to crisps/potato chips however, I'm not sure. smurrayinchester(User), (Ho Ho Ho!)14:11, 21 December 2005 (UTC)[reply]
This is a topic of hot controversey between folks like the Food and Drug Administration (and, at the risk of sounding biased, nearly all mainstream scientists) on the one hand and various health food advocates and others on the other. Some of our articles, like that on MSG, talk about the controversey. If you're really worried, I'd talk to a local nutritionist; be very wary of what you find on the web, as a lot of the information is put out by people who want to sell (ostensibly) healthier products. --George
If you are concerned, one option is to use foods with natural flavorings. Many people prefer the taste, anyway. Some artificial flavors, like artificial grape, are nothing like the real flavor, while others, like artificial banana, are quite close. The main reason for artificial flavors is that they are cheaper. However, food is so inexpensive these days relative to it's historic cost that the extra money spent on natural flavors isn't a very significant portion of most families' income these days. StuRat01:44, 22 December 2005 (UTC)[reply]
You might want to have a look at E number. That's quite an impressive list and most additives are linked, so look up anything that's in the food you eat if there are any warnings about them. That is, if you're from Europe. Elsewhere, I don't know how it works, but you might also look at List of food additives. And to add to the open door that Dismas kicked in. Cars are sold by the billions and have so far killed 25 million people. That's world war scale. And that's not counting the effect of bad air, which one inhales day and night with every breath one takes. I'm not saying you're barking up the wrong tree here, just that there are many more trees and some might be dropping on you much harder (so to say...). :) DirkvdM13:50, 23 December 2005 (UTC)[reply]
Hello, I am a student in PA who is currently trying to determine for a paper whether or not arthritis can be caused or helped along by the cracking of knuckles and such during adolescence and younger years. I understand that not all types of arthritis are subject to this kind of damage. I was just wondering if there were any articles that could be sent to me in a link that may help me along. I have been researching this for quite some time and there are so many differing opinions that it is hard to conclude. And since I do not have the resources to conduct an in depth experiment, I am having a difficult time making my paper solid. I believe myself that it is helped along and caused by the cracking of knuckles and cartilage intentionally when younger. However, there are scientists who both agree with me completely or they are completely against the idea and believe it to be preposterous. Any help would be much appreciated! Thank you!--- Chloe
If I may offer an anecdotal observation.
In my life, I have only observed a subset of adolescent boys who engage in the knuckle cracking pastime. Perhaps some survey could be conducted to find out what proportion of populations admit to having done this at all, and how heavily.
Seems to me, arthritis hits men and women equally heavily. I imagine there may be medical statistics out there on proportions of population suffering at what ages.
Acording to the Wiki article "the disease affects about twice as many women as men". This would lead me to suspect that there may be a relationship with how much milk (calcium) is consumed early in life, since women are susceptible to that bone disease that leads to elderly shoulder problems in later years.
It sounds like you already have found some papers on the topic. Use the references in those papers, and if they are not recent, ask a medical or university librarian (like at a local hospital or university) to help you find more recent papers that have cited the papers you already found. alteripse00:34, 22 December 2005 (UTC)[reply]
Pretty much any computer security protocol can be implemented with pen and paper using postal mail as a very slow (in comparison to computer networks) transport mechanism. For something practical, that real people could use, you should probably think about what kind of security you're interested in (authentication, protection against eavesdropping, ...). -- Rick Block (talk) 17:12, 21 December 2005 (UTC)[reply]
I am looking for a Kerberos-like protocol in which:
Computations can be completed in a few minutes on pen and paper
The process can be completed in a few minutes over telephone
Our new office building is driving us nuts with banging bolts [49]
I only could find a couple of references, but as an engineer I found that there were different ideas on how to prevent it. This would be important for psychiatric hospitals! Is it worth doing an article? Does anybody have any more info? --Zeizmic17:16, 21 December 2005 (UTC)[reply]
Even a short article with that covers the points in the source you provided would be a good thing. I'd never heard of banging bolts but was very interested to read about it. -User:Lommer | talk18:29, 21 December 2005 (UTC)[reply]
Our article mentions that it's not agreed how to eliminate the problem. Aren't friction grip bolts an effective alternative, or is the cost to high? For a hostpital the added deflection performance could be handy.--Commander Keane03:03, 22 December 2005 (UTC)[reply]
One obvious solution is to leave the building unoccupied for a while after it's completed. This would also allow toxins in the new carpet, new paint, new furniture, etc., to vent off before occupants must breathe them, provided these are also put into place as soon as the building is completed. If the expense of an empty building is too much, adding lubricants to the bolt threads to allow them to seat more quickly and quietly might be in order. Some type of oil, which would eventually evaporate and make the bolts "tighter" would be preferable to a graphite lubricant which would leave them loose forever. StuRat07:20, 22 December 2005 (UTC)[reply]
I really believe this could be the beginning of an adverse trend. Maybe the article could invoke some research, such as a civil lab setup, or post-construction seismic monitoring. I agree that some small modification on the bolts (teflon?) could be the answer. --Zeizmic12:57, 22 December 2005 (UTC)[reply]
I would think Teflon, like graphite, would leave the bolts permanently loose as a result of the reduced friction, allowing them to potentially vibrate off over time. StuRat01:40, 23 December 2005 (UTC)[reply]
How bad is a CRT monitor for our eyes and our health? Should we avoid CRTs or is it not that bad? What kind of trouble does that exactly give to our eyes and our health generally? Does keeping our eyes closer to CRTs create more problems than seeing from normal distance? Is there any time limit per day we may follow for being before a CRTs?
A lot of the effect of CRTs on eyes is unknown. These questions may never be fully answered, as CRTs are rapidly becoming obsolete, being one of the few remaining vacuum tube technologies. I suspect that in another decade they will have been fully replaced by LCD and plasma flat screen technology. The only thing preventing a quicker change is the cost of the newer technologies, but those will drop rapidly with mass production. StuRat01:30, 22 December 2005 (UTC)[reply]
Many people have some legitimate ergonomics concerns, like is heavy mouse use (like in computer game playing) more likely to cause carpal tunnel syndrome at a younger age? I work in the profession of lots of people in business sitting most of day in front of work stations, and I have looked into some health issues. I agree that over time this is a moving target.
Do you have fluorescent lights in the ceiling? Many offices have that. The direction of the lamps in the ceiling relative to the placement of the monitors can have a mutual flicker rate interference that is bad on the eyes ... you better off sitting where those lights are from front to back relative to direction you sitting, not side to side, and not directly overhead, but to your sides, overhead. I not have comparable data on other kinds of lighting such as halogen, but at home I use hallogen pointed up to bounce off white ceiling, so the light is diffused.
Do you have to wear glasses, or other vision correction? Did you know that just as your glasses cam be set to be the right length when driving, or reading, or whatever, they can also be set for the optimal distance your eyes from the screen?
There is a science to color contrasts. It is no coincidence that the Telephone Directory uses Yellow Pages (black print on yellow background). Scientific study has shown that, all other things being equal, the easiest on the eyes is black print on yellow background. But this also depends on other stuff around. What color are the walls around the computer monitor you use? Because of this, at home I have a white background text monitor, when I using monochrome stuff (you can manipulate this on your computer settings), and I have light colored walls bahind, above, around my monitor.
Are you working at a "computer desk?" Traditional desks are designed to be comfortable altitude for you to work with papers and writing on them, but keyboard is somewhat elevated above that, so "computer desks" deliberately have lowered placement for the keyboard, so no strain on user.
Is your seating comfortable to see the screen and use the keyboard, and get at other papers, or do you end up working hunched over?
Not really. For one, the units are meter and the like, not the prefixes you're mentioning. For two, c is not itself a unit (to which such prefixes are generally applied) but rather a constant rate. For three, the prefix doesn't have any real meaning that I can see when applied to a rate -- what, exactly, is a "nano c"? c/(10^9) lacks this ambiguity. While examples like Kbps exist, it's debateable whether it's K(bps) or (Kb)ps, and the clear physical meaning is present either way. — Lomn | Talk / RfC19:03, 21 December 2005 (UTC)[reply]
What's the difference between K(bps) or (Kb)ps? I mean, I understand the difference in grouping, but why does it matter—is there any physical or other significance? — Knowledge Seekerদ22:59, 21 December 2005 (UTC)[reply]
I don't see how µc (or, for that matter, kb/s) would be any more "ambiguous" than perfectly ordinary prefixed speed units line, say, km/h. Certainly you can parse that as either k(m/h) or (km)/h, but it's the same unit either way. SI prefixes are applied to derived units, including units of speed, all the time. Applying them to nonstandard units like c is no more silly than using units such as attoparsecs. —Ilmari Karonen (talk) 19:13, 21 December 2005 (UTC)[reply]
I'll cite from your linked article: bits of dry humor combined with putative practical convenience. If that's a rationale for feasibility, then by all means, proceed. — Lomn | Talk / RfC19:48, 21 December 2005 (UTC)[reply]
I can see it having some practical convenience. When talking about astrophysics and the like, I offten hear the phrase a fraction of c come up. Instead of saying zero-point-zero-zero-one cee, or a thousandth of a cee why not just say mili-cee? Zhatt20:05, 21 December 2005 (UTC)[reply]
I think I erred in using "rate" as the example when I referred to c as a "constant rate"; my personal objection derives from c as a constant. I find the thought of a decapi equally silly, despite the fact that such a number does exist and could be referred to. — Lomn | Talk / RfC22:03, 21 December 2005 (UTC)[reply]
It's not like you can't take a multiple of a rate, I mean you could take a µδ(fn)/δt (a 'micro' derivative if you will) but all you'd be doing is multiplying an ordinary differential, by a constant µ, hence µ x δ(fn)/δt, which is, kind of silly--Aolanonawanabe22:12, 21 December 2005 (UTC)[reply]
I've been thinking about this for a while and I wasn't really convinced by the explanations above. I'd have to say that there is no inherent reason that one couldn't combine a prefix with a rate and so on. I think Lomn is on to something: we think of c as a constant and it does seem odd to use the prefix. The π example is telling as well. You're right that since we often specify speeds that are fractions of the speed of light, the prefixes might be useful. But even if there were some geometric situation in which one-tenth of π were used frequently, I'd probably still want to use 0.1π rather than dπ. It somehow feels different with constants or measurements compared to units of measurement. But I think the main obstacle for me, surprisingly, is pronunciation. Perhaps it's just the way I think, but when I see "5.5 mm" I hear "millimeter" in my head, not "em em". I hear "microliter" instead of "mu ell" (although I've occasionally said "kay gee" for "kilogram". But the point is, I wouldn't know how to read μc. Certainly not "mu see". "Micro see"? "See" is the name of the symbol, not the unit. And of course "micro the speed of light" is ridiculous. I'd probably read it as "one hundredth the speed of light" or "point one see" and therefore I write it "0.1c". Now if a unit of velocity were defined such that one unit was equal to c, the speed of light in a vacuum, that would be a different story. The distinction is subtle, but significant. For instance, regarding the atomic mass unit, written "amu" or now "u", I would never think to write "k·amu" or "ku" even if the abbreviation "u" for "atomic mass unit" were more prevalent. However, I routinely use "kDa" (kilodaltons), where one dalton is equal to one mass unit. Not sure if this helps, but this I think is why the idea doesn't sit well with me. — Knowledge Seekerদ10:29, 22 December 2005 (UTC)[reply]
I understand now. At the start I thought that c or constant would be a bad term to use. Like you said, we need to somehow make up a unit for the speed of light in a vacuum. lv? Two µlv = 599.6 m/s? Needs work, but thanks. Zhatt18:34, 22 December 2005 (UTC)[reply]
It's perfectly acceptable to have a unit defined in terms of a constant. That is, after all, what a light year is. Astronauts frequently speak of milli-g gravity, which means one one thousandth of the constant g. No reason why one couldn't also speak of µc, millionths of the speed of light. -lethetalk21:51, 22 December 2005 (UTC)[reply]
How much do celestial objects affect gravity on earth?
Because we have the moon, sun, and planets, each with their own gravity, and these objects move in relation to the earth, one would expect "down" as given by a plumb bob to vary. How much does this "down" vary? One would also expect the weight of an object with given mass (but kept in a constant location on earth) to vary. How much would it vary? --Juuitchan
The effect is quite minimal, and is only obvious in the case of tides because the total amount of water in the oceans is so vast. It's like we are zoomed in on the very top of a bar graph which has a microscopic sinusoidal change in height. Other forces which affect little g, the acceleration due to gravitiy on Earth, (such as the elevation, centripetal force, and local variations in density) can have more effect than the tides. StuRat01:24, 22 December 2005 (UTC)[reply]
There are only two celestial bodies that could have any effect. The gravitational effect decreases with mass linearly and with distance by the third power. The Moon has only 1/100 the mass of the Earth (didn't know it was so little) and 380.000 km away, which is 1/50 of our surface distance to the centre of the Earth (the centre of gravity). That to the power 3 and divided by 100 is about one ten millionth of the Earth's gravity. So that's negligible. The Sun is 150 million km away, which is 1/20.000 of the 8.000 km from the surface to the centre of the Earth. To the power three is about 1/(10^13). Its mass may be 330.000 times that of the Earth, but that isn't sufficient compensation. The effect is still only about 3/(10^8) of Earth's gravity, so even less than the effect of the Moon. Anyway, which way it works depends on the relative position of the bodies to where you are. During the day the Sun would pull you up, but during the day it would pull you down. Based on these results you might think that such a small relative attraction could hardly cause tides, but then They're only a few metres high at most (how much is that really?), which is less than one millionth of the 8.000 km Earth radius. DirkvdM14:53, 23 December 2005 (UTC)[reply]
Im trying to find info about Very Extensive Non-Unicast Service ?
I see it come up on Comptia test questions at times.. But trying to learn what VENUS is..
Is not easy. Thanks
A "VENUS Domain" is defined as the set of hosts from two or more participating Logical IP Subnets (LISs). A multicast shortcut connection is a point to multipoint SVC whose leaf nodes are scattered around the VENUS Domain.
As the article says, an industrial process is used to convert most of the starch and glucose into fructose, which is much sweeter. They are substantially different products. —Keenan Pepper05:49, 22 December 2005 (UTC)[reply]
Are there any household chemicals whose reactions with other household chemicals would be examples of exponential growth? (This is a homework question, but I have to do experiments and stuff after I figure out which chemicals will do this, and figuring out the chemicals on my own was not a requirement, because the point was the exponential growth, because it's math homework.) 216.174.52.18422:50, 21 December 2005 (UTC)[reply]
Exothermic chemical reactions are not so much exponential than a feedback loop (ie. due to Brownian motion there is a tad of uncertainty in predicting the rate of reaction), since regular combustion is at a steady rate, not an exponential consumption of fuel. Perhaps nuclear fission is a better alternative? :D -- Natalinasmpf01:31, 22 December 2005 (UTC)[reply]
I think the nuclear fission example is quite similar. That is, in both cases, energy from the earlier reactions drives the future reactions, at an ever increasing rate, until the energy is dissipated or the fuel is used up. StuRat03:24, 22 December 2005 (UTC)[reply]
I really meant the exponential reaction in an atomic bomb, not a nuclear reactor, which is not exponential. In both a nuclear reactor and controlled combustion (ie. a fireplace), the rate of energy being released is linear, not exponential. Perhaps a forest fire, on the other hand... -- Natalinasmpf10:54, 22 December 2005 (UTC)[reply]
In both the cases of spontaneous combustion of a pile of rags and a nuclear weapon, energy feedback is important in creating exponential growth. In the case of the rag pile, the outer rags insulate the inner rags, and prevent thermal energy from leaving the system. Thus, this thermal energy becomes feedback into the system and increases the rate of combustion, thus releasing more thermal energy, which in turn causes faster combustion, and so on, until the pile bursts into flames and is able to vent heat normally. At this point the growth is no longer exponential. StuRat22:34, 22 December 2005 (UTC)[reply]
Agreed. That's why I suggested the spontaneous combustion of oil and gasoline soaked rags. These are household chemicals, or at least, garage chemicals. The safety issue could be handled by putting the rags in an outside fire pit or barbeque grill, attaching a digital thermometer to the center, and monitoring the temp continuously until the maximum temp is reached. Note that whether it bursts into flames is dependent on many factors, such as the ratio of oil to gasoline, the level of ventilation allowing oxygen from the air into the combustion area, and the outside temperature. Hopefully some rise over the ambint temp can be observed, although it will only actually burst into flames under ideal conditions. The growth of bacteria in a plate of apple juice would be more reliable, but is moving into the area of biology (in addition to chemistry, not in place of it) and is more difficult to measure. StuRat22:47, 22 December 2005 (UTC)[reply]
In some US households there is exponential growth of debt. Did you know the US national average saving rate was negative? That means foreign investors are keeping the US economy afloat. User:AlMac|(talk)05:58, 23 December 2005 (UTC)[reply]
Any acidbase neutralization reaction (e.g. vinegar and baking soda) will most likely follow second order kinetics, and thus an exponential growth in the concentration of the products over time. See rate law. In fact, most ordinary chemical reactions will result in exponential growth/decay of reactants or products. Pharmacomancer19:18, 26 December 2005 (UTC)Pharmacomancer[reply]
What are the odds of a woman that recently gone off birth control would get pregnant if they recently had sex?
It depends on age of the woman, fertility before use of birth control, type of birth control used, time since it was discontinued, number and regularity of menstrual periods since discontinuing it, how many times since then she has had sex, when in relation to the last menstrual period she has had sex, and the fertility of the male(s). If you supply those factors we might might be able to guess odds. alteripse00:30, 22 December 2005 (UTC)[reply]
Describe the steps in the synthesis of a polypeptide?
If you don't realize that DNA is not a polypeptide, we need to start with some real basics, don't we? DNA is a polynucleotide, a chain of nucleotides. A polypeptide, a chain of amino acids, and the most important natural polypeptides are proteins. The sequence of nucleotide bases in the DNA of a gene carries the information for making one protein (one polypeptide). When something activates the specific gene, the DNA base sequence is transcribed to RNA, which is a one-stranded polynucleotide. RNA moves out of the nucleus, into the cytoplasm of the cell, and attaches to a ribosome, which is like a tiny machine that translate the RNA into a polypeptide by joining amino acids together into a chain. For a bit more detail, see protein biosynthesis. alteripse00:26, 22 December 2005 (UTC)[reply]
What property in zinc causes it to make you ill if you take zinc lozenges on an empty stomach? I had a cough and took a zinc lozenge (the instructions on the package say to take them with a meal), and went to make breakfast, but found I didn't have any milk, so I drove to work to pick something up at the cafeteria at work, but by the time I got to work, my stomach was cramping up and I was sick to my stomach. Zoe (216.234.130.13000:45, 22 December 2005 (UTC))[reply]
The active ingredient of zinc lozenges is usually zinc gluconate, with a little glycine added. I am not sure how to answer your question of "what property" can nauseate you. I am reminded of Moliere's doctor who answered a similar inquiry into how a sleeping medicine makes you sleepy with "by its dormitive property". So the answer would be, zinc gluconate made you sick at the stomach by its nauseant tendency. Hope you're feeling better soon. alteripse01:14, 22 December 2005 (UTC)[reply]
I suppose there is an answer, but it might not be known. For example, it may act as a catalyst in a reaction which leads to a chemical product which blocks a nueroreceptor responsible for limiting the secretion of hydrochloric acid, thereby changing the pH of the stomache beyond it's "comfort range". I made that all up, just to show what the chain of events might look like, if it was known. StuRat03:17, 22 December 2005 (UTC)[reply]
There was a simple 2-D computer game I used to play in the mid-90s that involved redirecting a laser light around various obstacles using mirrors, so that the light hit a target. It was kind of like the Incredible Machine, because first you set up the configuration, and then you pressed the "run" button to see if it would work. Does anyone remember the name of the game, and perhaps where I could find it? -Jian
If we are talking about an adult elephant, then definitely the elephant. Lions don't mess with them. One stomp or goring with a tusk could kill a lion instantly. A lion's method of killing, breaking the neck of the prey, would be completely ineffective against an elephant. It couldn't reach an elephant's neck, and even if it could, it couldn't get it's jaws around it, and if it could, it still couldn't break it. StuRat03:12, 22 December 2005 (UTC)[reply]
From what I remember, before a lion can brake somethings neck, it first must trip it while its running away. I doubt a lion would be able to trip an elephant, running our not. Zhatt06:21, 22 December 2005 (UTC)[reply]
Yes, the lion must brake (stop) them, before it can break (fracture) them. And how is an lion going to stop an adult elephant going at breakneck speeds ? StuRat07:02, 22 December 2005 (UTC)[reply]
It is also true that lions (and tigers in Asia) will take baby elephants - still not an easy task, as they have to make sure the adult elephants are not too close by MPF11:02, 22 December 2005 (UTC)[reply]
This is quite risky to the cats, as elephants, unlike most herd animals, will attack the cats who are attacking the baby elephant. They also will form a defensive circle around the baby elephants, if they perceive a danger to them. A lost baby elephant, however, might fall prey to the big cats. StuRat22:26, 22 December 2005 (UTC)[reply]
The lion has no chance, and he knows it, that's why he runs away. Loxodonta africana > all, only an adult rhinoceros can injure a full-grown elephant. --GTubio17:37, 25 December 2005 (UTC)[reply]
I can't help notice from time to time when I load a page I wind up getting <div id="fundraising" class="plainlinks" style="margin-top:5px; text-align: c, instead of actual content, not terribly important, but is this some kind of glitch in the scripting for the banner?--Aolanonawanabe03:18, 22 December 2005 (UTC)[reply]
how come we have found the cure for other viral diseases but not AIDS?
And what exactly happens when HIV is injected into a person?thanks
It's only been around for 20 some years, which isn't much time. Most diseases were studied far longer than that before a cure was found. Also, some viruses seem to mutate more than others, making cures harder to find. On the conspiracy theory side of things, one could argue that pharmacuetical companies aren't interested in investing billions of dollars in finding cures, which would be unlikely to offer a return on investment. A treatment that keeps people with AIDS alive, but requires expensive meds for the rest of their life, is far more likely to be profitable. Thus, the big drug companies invest their money there. StuRat05:39, 22 December 2005 (UTC)[reply]
Conspiracy theories aside, keep in mind that we don't actually have a cure for many viruses, including (notoriously) the common cold. Usually the immune system kills the virus on its own, but HIV attacks the immune system itself. If HIV destroys your immune system then you have nothing with which to fight back. —Keenan Pepper05:42, 22 December 2005 (UTC)[reply]
I agree that once any disease, such as AIDS or leukemia, has completely destroyed the immune system, there is not currently much hope, short of a transplant of portions of the immune system (like bone marrow or stem cells) from compatible healthy individuals. However, it takes years for AIDS to completely destroy the immune system, and this point may never come for many on the latest drug "cocktail" treatments. This would allow ample time for a cure to be administered, if one existed. StuRat06:57, 22 December 2005 (UTC)[reply]
In chemical engineering when referring to chemical reactors, "space time" can refer to the mean residence times of molecules entering the reactor. There should be a disambiguation in the Space-time article for this. Maybe I'll put it in some day. When I did a search of "space time" on the net, I came across far more entries referring to the physics concept than the chem. reactor concept. H Padleckas20:56, 26 December 2005 (UTC)[reply]
How is it that when we apply brakes to a car only the upper portion of our body moves forward whereas our legs remain in the same position?
Due to inertia, all parts of our body actually want to move forward. However, our legs while sitting are in contact with the chair, and there is friction between the legs and the chair that stop that part sliding forward. However, there's nothing to stop the top part of your body from moving forward (except for the seat belt but there's a bit of slack in that). enochlau (talk) 05:51, 22 December 2005 (UTC)[reply]
That's a very good question. I agree with the above users. I'd guess that it's a combination of three factors. One, you'll automatically brace yourself with your feet against the floor, which will hold back your whole body but won't stop you from bending at the waist. Especially because much of this force is directed along the axis of your leg, it doesn't require as much effort and is less noticeable. Secondly, the friction of your body against the seat also makes it harder to move, although again it doesn't stop you from bending at the waist. Third, the lap belt over your waist will do the same. To hold your upper torso in place are a couple factors. One, you tighten your abdominal muscles but since this is not an action you do routinely (like stabilizing with your legs), it is more noticeable. Also, wearing a shoulder belt will help hold you in place, but as Enochlau noted, shoulder belts usually give slack unless they are tightened sharply. Finally, you may brace yourself with your arms if you are being driven by a particularly reckless driver. — Knowledge Seekerদ07:33, 22 December 2005 (UTC)[reply]
I would like to know what is the difference between Electrical and Electronic Devices?
Plz Answer the question in simple words without using too much of scientific terms!!
An electrical device is any device that uses electricity. A hair dryer, a washing machine, an electric fire, a torch and so on.
An electronic device uses transistors and other electronic components. They are complicated and small and usually low voltage. Electronic devices are obviously electrical devices. A computer, a radio, a mobile phone, a digital clock are all electronic devices. It's a matter of complexity really. Theresa Knott | Taste the Korn08:08, 22 December 2005 (UTC)[reply]
Basically, electronic means it uses small amounts of electricity to carry information; electric (or electrical) means it uses electricity in larger amounts as a power source. This is a simplification, but you wanted simple. It's like the difference between putting a bit of black ink on a page to write a message, and painting a window black to shut out the daylight. --Anonymous, 11:00 UTC, December 22
Physical and biochemical effects of being reversed
Many years ago, I read an entertaining science fiction short story by my favorite author, Isaac Asimov. In it, a character is removed from our three-dimensional universe into a fourth one; he is later returned. It is easy to prove his journey to a skeptic: when he was returned, he was returned in the opposite orientation. His heart now beats towards the right, his appendectomy scar is now on the left, and so on (I don't remember the details, but you get the idea). I find this quite plausible; I have no difficulty imagining a two-dimensional being (such as a Van Gogh's Starry Night) being removed from a two-dimensional universe into our three-dimensional one, then being returned "upside down" so that it would seem to be mirror-reversed to the other 2-D inhabitants.
I wonder, though, if there would be any other effects. It seems obvious to me that our traveler would be aware of the change, as he would now see everything flipped. That is to say, he would have no difficulty navigating his world, but writing would now be flipped, his house would have the living room on the left instead of the right, and so on—it would be as if someone had mirror-imaged his entire universe. There are two issues I'm less sure about. One, would there be effects related to physics? I seem to recall that some particles or laws of nature are not equivalent when reversed in a mirror. I lack the knowledge to understand or grasp this, and perhaps it is not yet possible to guess at the nature of the effect on our friend.
My bigger question is wondering about the biochemical effects. While stereoisomers have no effect in basic chemical reactions, the enzymes in our bodies are stereospecific. For the most part, we use D-sugars and L-amino acids. Our friend's sugars, amino acids, and enzymes would all be flipped. The enzymes would have no trouble metabolizing the molecules already present in his body. Oxygen and water are symmetric and would pose no problem. But how about something like glucose? The glucose in his body would be L-glucose, right? If he were to ingest D-glucose, it would look like L-glucose to him. Would his enzymes be able to use it in reactions? Would they be able to break down a peptide bond between two "D"-amino acids? In short, would he be able to derive energy and raw materials from food? He may have some enymes able to react with a couple molecules but I can't imagine it would be sufficient. It seems to me that such a reversed person would slowly starve to death, unless some dedicated person worked to
synthesize the appropriate nutrition. Apologies for the long post. Am I way off? Anyone have any idea? — Knowledge Seekerদ10:54, 22 December 2005 (UTC)[reply]
I wonder if this story wasn't actually The Reversed Man, also titled Technical Error, by Arthur C. Clarke... in which the reversed man finds himself slowly starving for exactly the reason described. --Anonymous, 11:05 UTC, December 22
Thinking about this some more, he'd better stay away from glucose entirely, which may be very difficult. After returning to 3D, all of his bacteria will be reversed, but it won't take long for him to pick up fresh colonies of normal bacteria. Presumably he'll be very safe from infection while the old bacteria starve and the new bacteria try to settle in, but undigested sugar will probably make him seriously ill once the latter are established. ‣ᓛᖁᑐ18:50, 22 December 2005 (UTC)[reply]
That's an interesting point, actually. Having a gut full of starving intestinal flora probably isn't good for you either. The loss of all those symbiotic bacteria isn't going to protect him from infection; it's going to make him more vulnerable—unfriendly, opportunistic infections won't face the usual competition. TenOfAllTrades(talk) 18:59, 22 December 2005 (UTC)[reply]
Yes, he may need to be very careful to prevent normal bacteria from outcompeting his gut bacteria. Oughtn't it be very difficult for normal bacteria to infect reversed tissue, though? ‣ᓛᖁᑐ19:38, 22 December 2005 (UTC)[reply]
From a purely physical standpoint, only the weak nuclear force violates parity. I don't think the weak force is important to the functioning of the human body, so he should be okay if he can just find stuff to eat. —Keenan Pepper17:06, 22 December 2005 (UTC)[reply]
By the way, it might not be necessary to flip yourself through some four-dimensional space to achieve reversal. It may turn out that our universe is non-orientable, in which case you would just have to make a very long journey along an orientation-reversing path. Dmharvey19:07, 22 December 2005 (UTC)[reply]
Maybe. I don't know enough physics. I didn't realise that basic physical laws were as orientation-dependent as that article seems to imply. Dmharvey01:51, 23 December 2005 (UTC)[reply]
Note that there is a condition where a person is born with all their organs mirrored just as described. However, molecules are not reversed. This condition does not seem to be harmful, although doctors using a stethoscope or performing surgery on such a person must be aware of it so they can find the organs in the proper place. If someone knows the name of this condition, I would like to know it. I would also like to know the cause of this condition, if known. StuRat22:15, 22 December 2005 (UTC)[reply]
"Writing would now be flipped" : his, or what he sees ? Gardner wrote a book about parity, The Ambidextrous Universe: Mirror Asymmetry and Time-Reversed Worlds. A baby does not care if it is a left or right breast ; the brain can learn and it is more and more difficult to learn something contrary. See for yourself ... Harvestman22:35, 22 December 2005 (UTC)[reply]
Both. His writing would look normal to him, but be backwards for everyone else; while everyone else's writing would look normal to them, but backwards to him. StuRat01:27, 23 December 2005 (UTC)[reply]
Reptiles are called cold-blooded because they produce very little body heat; their metabolism relies mainly on the temperature of their environment. They do have some control over their body temperatures, though, including:
The distance varies a bit over it's orbit, since the orbit is elliptical, not circular. See the Earth article for the details, particularly noting the info in the template on the right side of the article. StuRat11:27, 22 December 2005 (UTC)[reply]
HELLO AM NARESH
AM A MEDICO IN OSMANIA MED COLLEGE
I HAVE A SEMINAR ON "USAGE OF SAFE AND PROPER DRUGS"
PLEASE HELP ME IN GIVING SOM POINTS
THANK U
Basics of drug use:
1. Right drug
2. Right dose
3. Right time
4. Right patient
These are obvious basics but failure to deliberately ensure each of these points leads to most medication errors and most injuries of people by their medical care. alteripse12:15, 22 December 2005 (UTC)[reply]
I would add:
5. Right combination with other drugs the patient is taking (no negative interactions).
6. Right delivery method (time-release or immediate acting, pill vs. injection, intramuscular injection vs. intravenous injection, etc.).
7. Ramp it up. Unless a specific dosage is needed to treat a crisis, start with a low dosage to check for side effects, allergic reactions, etc., then gradually increase the dosage until the minimal level is found which is safe and effective.
I listed an exception for a crisis situation. Do you know of any other exceptions where starting with a low dosage and ramping it up is not indicated ? A good example of a drug to ramp up is a pain reliever, where the absolute minimum needed to manage pain should be given, in order to limit side effects and avoid dependency. StuRat00:10, 23 December 2005 (UTC)[reply]
How about hormone replacements, antibiotics, anti-arrhythmics, anti-thyroid drugs, anti-inflammatorys, chemotherapy, etc, etc including virtually everything? Even for analgesics, most people would prefer to be given the most probably effective dose first, and then to try reducing it when some relief has been obtained. Go to medical school before you argue about medicine. alteripse11:57, 23 December 2005 (UTC)[reply]
Also, some common sense is needed. Waking patients to give them a sleeping pill makes no sense, for example. Neither does giving insulin to a diabetic who currently has a low blood sugar level. StuRat13:27, 22 December 2005 (UTC)[reply]
Add ... have a human in the technology loop. There have been several cases of hospital medication administered according to computerized arrangements which had software bugs, patients died, physicians ended up in jail, because they had a responsibility that they could not delegate to computers. User:AlMac|(talk)06:07, 23 December 2005 (UTC)[reply]
Don't you think Naresh is really a third world doc asking the anonymous doctors and "doctors" (Hi, I'm not really a doctor but I play one on Wikipedia...) here for help with his residency homework? alteripse06:42, 24 December 2005 (UTC)[reply]
No. It's a plasma, which is a distinct state, not usually considered to be a solid, liquid, or a gas. Although, if you had to choose between them, it is closer to a gas than the other two. StuRat13:12, 22 December 2005 (UTC)[reply]
If flame were made of plasma, wouldn't it be affected by a magnetic field? I just held a fairly strong permanent magnet near the flame of a lighter and nothing happened. —Keenan Pepper16:20, 22 December 2005 (UTC)[reply]
The Straight Dope is that ordinary fire isn't plasma.
I would say fire refers to the whole process of combustion, as Max said, and flame refers to the body of incandescent gas (with only very few charged particles, not enough to qualify as plasma). —Keenan Pepper16:32, 22 December 2005 (UTC)[reply]
I use "fire" and "flame" synonymously, with "combustion" used for the more general case of any oxidation. This avoids having to say that digestion, which involves oxidation of food, is a "fire in your digestive system", which just sounds wrong.
I stand by my assertion that it's a plasma, although a weak one, as does our plasma article. One test is that it's more electrically conductive than normal, non-ionized gases. I would also think that a powerful enough magnet would affect it. You might need one on the order of strength used in particle accelerators to see the effect, however.
Specifically, it's a type of cold plasma, which have a low percentage of ionized atoms. The word "cold" is a bit misleading, as it's only cold relative to a hot plasma, like that in the Sun. Warm plasma would have been a better term, since ultra-cold plasma could then be simply called cold plasma, but we are stuck with the terms we have. StuRat21:39, 22 December 2005 (UTC)[reply]
Fire can be considered to be a very low temperature partial plasma, or a type of cold plasma. ( What a sad state science education is in the United states ). It is a chemical reacation ( exotmermic ), where plasma is a ionization property of matter. See Plasma
hello
my friend has breast cancer.she has been under treatment for the past 2 weeks.she doesnt tell me how serious it is.can you tell me what the chances that she will live?thank you
It depends on the type of breast cancer and how far it has spread. If it has metasticized to the lymph nodes and several other organs, it's a virtual death sentence. If it is contained to one small lump, near the surface, it may be very treatable. StuRat13:20, 22 December 2005 (UTC)[reply]
Fortunately, the survival rate for breast cancer is quite high compared to other cancers. In the U.S., the five-year survival rate is 86% -- a number that jumps to 96% when the cancer has not spread to other parts of the body. If the cancer has spread, the survival rate is 21%. This is why breast exams are so important -- so they can catch cancer in the early stages. -- Mwalcoff04:58, 23 December 2005 (UTC)[reply]
It's because those animals couldn't make it there on their own. I'll give you two good examples to think about: rabbits in Australia and rats in Hawaii. These animals were only brought there fairly recently due to human exploration, but they absolutely took over. The simple reason they weren't already native to those islands is because they couldn't get there until we (unknowingly) took them there in our boats. --Cyde Weystalkcontribs15:59, 22 December 2005 (UTC)[reply]
Also note that many oceanic islands are rather new (compared to the age of the continents). So, it isn't like an island full of animals drifted away from the coast. The island built up from the ocean floor and eventually broke through the surface of the ocean. --Kainaw(talk)19:14, 22 December 2005 (UTC)[reply]
This is true for volcanic islands, which are the vast majority of islands. Note that islands are also sparsely populated with other animals, like reptiles. Unless creatures can swim or fly, they rarely could arrive on the island on their own. Amazingly, some land animals do seem to have somehow arrived, possibly a pregnant female on driftwood after a hurricane. Darwin particularly studied how the few varieties that arrived on the Galapagos Islands evolved to fill all the ecological niches in the island, which were left vacant by absent species. This is also true of the largest island continent, Australia. There marsupials evolved to fill the gaps left by the absence of placental mammals. StuRat21:07, 22 December 2005 (UTC)[reply]
True. there are also earthly planets without placenta mammals because we did not get there yet. --Harvestman
How can you know, considering we haven't gotten there yet? :) Actually, that could be a serious question. Could something that we would classify as a mammal evolve on another planet? The chances of that happening on one planet are minimal, but the amount of planets is probably immense. DirkvdM15:11, 23 December 2005 (UTC)[reply]
The concept of "minimal chance" is relative. Consider something easy to think about - flight. What is the chance that a lifeform will evolve flight? Most people say it is very unlikely. But, if you think about it, many insects developed flight. Reptiles can glide over great distances and are closely related to birds (most of which can fly). Mammals also gained flight (the bat). There are even fish who can glide for long distances above the water. Considering all of that, flight isn't really so improbable. So, if flight isn't really improbable, what is the improbability of a living species evolving a mammory gland?
I haven't used SQL for awhile and I'm a bit rusty. Here's the problem I'm trying to figure out the best way to solve:
I have a table of data (tbl_data) and a table of keywords (tbl_keywords) which are connected to each other through a joining table which keeps all of their one-to-many links straight (join_data_keywords). This all works fine.
What I want to do is filter the results in the data table by keywords. I can get it to do this very easily using an OR operator (for example, I can have it SELECT entries which have either or both keywords A and B associated with them), but I cannot seem to figure out the best way to do this with an AND operator (i.e., SELECT only entries which have both keywords A and B associated with them, but not just one or the other).
I've figured out a way to do this with DCount function calls (this is in MS Access), but it is very slow and not very elegant. I thought UNION might help but it also seems to use OR rather than AND as its method. I suppose I could join a number of IN with additional statements inside them -- but is there a better way to do this? Hopefully the above will be somewhat comprehensible to someone who knows about SQL... --Fastfission18:38, 22 December 2005 (UTC)[reply]
Assuming your mapping table has a unique key on data/keyword combinations, you can count the number of rows matching your 'or' comparison. For example: "select count(*) as cnt from join_data_keywords where keyword='keyword 1' or keyword='keyword 2'" If cnt is 2, you got 2 hits (one for each word). If you had 3 keywords you were checking for, you'd want a return of 3. Some SQL databases will let you get it all in one query as "select *, count(*) as cnt from join_data_keywords where (keyword='key1' or keyword='key2') and cnt=2" --Kainaw(talk)19:12, 22 December 2005 (UTC)[reply]
Glancing at this again, I realize that I didn't group by the data field. It should be apparent that you will group the data fields and get 0, 1, or 2 hits per data field. Of course, the exact syntax depends on the database. --Kainaw(talk)01:55, 23 December 2005 (UTC)[reply]
I recently read a book on the history of electicity. In the explanation of electons, they are described as spinning about the nucleus of the atom. So my question is: why aren't electons stationary about the nucleus of the atom? What gives them the forward momentum to zoom arond the nucleus?
Eletrons have spin. This spin ultimately arises from group theory - remember, that "spinning electrons" should not be taken so literally -- it only describes a particular aspect of an electron, and at best, only a particular mathematical description of it. --HappyCamper01:18, 23 December 2005 (UTC)[reply]
Electron spin Electrons lining up in a field would have a property related to angular momentum, but like Happy Camper says, not a physical spinning particle, at this point is is more like a wave with a macro-world property. If it gets confusing don't feel bad. You just have to ignore reality a bit! 12:41, 23 December 2005 (UTC)
I have a wool, polypropelene blend Navy watchcap. It's warm, but it itches like a bitch. Why is this so? I've heard it's some kind of allergic reaction. Jasongetsdown20:58, 22 December 2005 (UTC)[reply]
There are two ways a material could cause a skin reaction:
A physical irritant. A material can have sharp or rough features which abrade or puncture the skin. Fiberglass is an example of this type of irritant.
A chemical irritant. A chemical present in the wool, such as lanolin, could react with the skin to cause an allergic reaction.
I don't know the specifics with wool, so will let someone else answer that. One suggestion, don't wear wool directly against the skin, to avoid the reaction. For example, if you have a wool sweater, make sure you wear a shirt with long sleeves and collar which you can fold back over the edges of the sweater to keep it from rubbing on your skin. Alternative man-made fibers are also available which are just as warm and hypo-allergenic, so you might consider those. Wool also has many other negative qualities, like it's expense, the need to dry clean it to avoid shrinkage, it's tendency to absorb water and mildew after rain, and it's attraction to moths. Warm synthetics exist with none of these problems. StuRat21:21, 22 December 2005 (UTC)[reply]
6th grade science project-"what age group has the best memory"
I have search the Internet for what age group has the best memory. I found one & only one web site with my exact question,but unfortunally that site was no longer available. I'm at my wits end. PLEASE can you direct me to a site that I can find this information.
It may be a good idea to test the memory of young kids versus adults. I've heard in some science show with a British geneticist that young children have better memories that slowly deteriorate as they get older. That's why young kids are so good at memory and that's why one should learn a second language as early as possible. - 131.211.210.1108:31, 23 December 2005 (UTC)[reply]
Note that "memory" could mean different things. If you mean the ability to see something once and then remember it, that ability is probably best in young children, who are good at FORMING memories. On the other hand, if you mean the total amount of things that are stored in a person's brain, then middle aged people probably have that claim to fame. How quickly people can access memories might be another way to measure it. The type of memories you are interested in, like word meanings, phone numbers, people's faces, etc., might also change the age advantages. StuRat18:18, 23 December 2005 (UTC)[reply]
Okay. Here's my question. What is the origin of the rather graphic euphemism "purple-headed yogurt slinger"? Granted, the yogurt slinger part is pretty self explanatory, but the purple-headed...? I don't know if I've ever seen a purple penis, and I have to say I would wonder about the health of the person who had it. (This was prompted by an episode of Extras on HBO in which Kate Winslet refers to a "purple-headed womb ferret." I just thought I'd ask about the more common one, that I had at least heard.) Dlayiga00:00, 23 December 2005 (UTC)[reply]
i'm actually not sure,because I'm not a boy, and I am a virgin, but I think that a pennis turns purple when the guy is arroused, or something... —Preceding unsigned comment added by 201.230.135.234 (talk • contribs)
That was uncalled for. I have a fair knowledge about and opinions on war, yet am not a veteran. Do you think only participants are allowed to have opinions on any particular subject ? StuRat01:16, 23 December 2005 (UTC)[reply]
I'm sorry if my comment caused offence. That was not my intention; I expressed myself poorly. I was just very curious as to why the anonymous user bothered to spend her time saying anything at all, given her own statements that she knows nothing whatever about the subject. I'm at a loss to know what anybody was supposed to do with the "information" she contributed. This was an extreme example of an increasingly common occurrence on Reference desk pages. Many answers these days are prefaced with words like "I don't really know but ..", or "I guess ..", or similar things that tell us the person is having a stab in the dark. That's not to say the information is worthless in every case, but I really wonder sometimes about the value of these contributions, and what is their motivation for speaking up in the first place. I have another issue with editors who criticise questioners for asking homework questions, but then proceed to provide detailed answers anyway. Sometimes egos are a little unrestrained around here. (I include myself in that last remark, BTW). Yuletide felicitations JackofOz00:37, 24 December 2005 (UTC)[reply]
If enough blood is forced into any part of the body, it will turn purple. When I was a kid, I could pinch my shoulders together and my face would swell and turn purple. Now it just gives me a terrible headache. You can try it with something safer though. Put a rubberband around a finger and watch it turn purple. I would not suggest trying it around your penis. Rings for that normally have snaps so they can be removed. --Kainaw(talk)03:05, 23 December 2005 (UTC)[reply]
hahaha! very funny, of course it is because of the blood, I knew it! that's why I answered what I answered and jackofoz said my answer sucked bassicly. but it is obvious, like when i was a kid i used to suck on my arm until that spot turned red or purple just for the fun of it.
well i know something about purple blood. the blood without oxygen turns purple. or some regard it as blue, thats why when one's skin get hit , blood jams in there, any loses oxygen gradually and turns blue/purple. so you figure the remainig meaning of purple headed thingy !
--Muhammad Hamza20:50, 26 December 2005 (UTC)[reply]
I think the original poster (indeed, the euphemisms) refer to the color of the glans in general, even in the flaccid state. If it were strictly related to increased blood flow, such as is necessary to produce an erection, it stands to reason the "purple-ness" would subside or disappear completely when the male is not aroused. Similarly, applying suction such as Kainaw suggests would result in this type of color change being signifcantly more noticeable as the result of oral sex. Given this, it is much more likely it is simply a result of pigmentation, much the same way a male's genitalia can/will turn darker or redder in puberty. TopCat9922:55, 26 December 2005 (UTC)[reply]
I think, out of common sense, that the people who think that QM is affected by consciousness or observation are fooling themselves, HOWEVER I have an open mind and I know one of the interpretations requires consciousness in the picture,so it might as well be true, but actually, I think that's rubbish... and I think what actually affects the outcome of these experiments are the methods used themselves, and not the scientist's consciousnes nor god's nor anything! anyway, what do you guys think? —Preceding unsigned comment added by 201.230.135.234 (talk • contribs)
thank you,I knew that, but I mean,can't that be because of the devices used? why does it have to include consciousness in the picture? i think seriously that it is new age BS and it should betaken lightly
No it is because any test introduces an element to the system. This is when I get to the quantum view. Unlike much "new age" science these can be reproduced, and is repeatable everywhere. An observer does not have to understand the measurement for it to work. Dominick(TALK)00:15, 23 December 2005 (UTC)[reply]
There is a simple resolution to all this - remember that quantum mechanics is a theory which is intended to be used for microscopic systems, not for macroscopic systems. If consciousness is in the realm of the macroscopic, then any attempt at extending quantum mechanical results to that is simply false. Well, strictly speaking, not quite - you could in principle try to describe a macroscopic system with quantum mechanics, but you would get nowhere. Other theories exist to deal with that, like statistical mechanics - a wonderful subject, but I have yet to see anyone attempt to explain consciousness with that yet! --HappyCamper01:04, 23 December 2005 (UTC)[reply]
One more thing: Lots of theories which try to link consciousness and quantum mechanics do so via the ever expansive wavefunction - yes, mathematically speaking, these functions extend everywhere to infinity - but remeber that they also drop off extremely rapidly, and are localized to an extremely small section of space - an attempt to manipulate a specific wavefunction at the macroscopic level, is well, essentially impossible. If we could do this, we would have massive benefits to society such as quantum computers already. --HappyCamper01:07, 23 December 2005 (UTC)[reply]
Happy Camper is quite wrong; QM does apply to macroscopic systems. Now, for lots of sorts of macroscopic systems, the quantum effects tend to cancel out rather than reinforcing, so you don't see them. But it can very easily happen the other way too. I suspect that many naturally-occurring chaotic macroscopic systems (such as weather) exhibit quantum indeterminacy. (I'm not a physicist or meteorologist so I can't be 100% sure about the weather example, but the claim that QM applies only to microscopic systems is plain nonsense; take, for example, a computer linked to a Geiger counter, programmed to do different things depending on how many hits it gets). --Trovatore06:56, 23 December 2005 (UTC)[reply]
That's not what HappyCamper was talking about. Of course you can hook a Geiger counter up to whatever you want but that's not interesting. The interesting quantum weirdness happens when the complex probability waves interfere, before they are manifested as real probabilities. That is what we can't hook up to macroscopic phenomena yet. If we could we'd have a quantum computer. —Keenan Pepper07:23, 23 December 2005 (UTC)[reply]
But the discussion wasn't about quantum computers; it was about consciousness. The claim that consciousness is related to QM--whatever its other merits or demerits--is not refuted simply by noting that consciousness appears to have consequences in macroscopic systems. --Trovatore07:31, 23 December 2005 (UTC)[reply]
oh, so is the quantum computer thing impossible at the moment? or maybe for ever? and also, I think that it's not our consciousness that is in the QM level, I think maybe it's something else's consciousness.
Not quite...we do have some very primitive quantum computers already, but certainly nothing as substantial as something to support something like an operating system. The implementation for quantum computing is still very much in its infancy. I don't really know what consciousness is, but I can tell you that if you ever studied quantum mechanics in all its glory and abstraction, you will find it extremely beautiful. It is mysterious, powerful, sublime...words just cannot describe it. Anyway, I digress :D -HappyCamper02:34, 23 December 2005 (UTC)[reply]
how so? i'd love to, really, but I'm not good at all with numbers :( I do better with humanities than with sciences but i LOVE science, i think it's one of the best things that has happened to humanity and to me :)
Question: Is my first question not a Scientific Question?
Question: Does my first question exhibit the common fallacy, “begging the question” (petitio principii), and does it employs the term “creation” ambiguously?
Evolution is a very recent field of study, while creation myths probably go back all the way to prehistory. Additionally, any act of creation must have occurred before evolution could take place.
This is a question about history, not science. History is inherently unknowable without direct observation and reliable records.
It's the fallacy of many questions, not begging the question (it presupposes creation and evolution occurred). Creation is also an ambiguous term — there are very many beliefs about what creation might have been, and they basically all contradict each other.
Creationism is the believe that some higher being (often God) created the earth and the universe and all animals in it. Evolution is the belief that present-day animals have evolved from prehistoric animals. Personally, I think that if you take creationism a little less strict, both could be true. God created the prehistoric animals from which other things evolved through evolution. Evolution is backed up by fossils and other archeological evidence, but what exactly can be derived from that evidence is a point of debate. Creationism is mainly based on creation myths like Genesis in the bible. It's not really a question what came first. (The earth had to be created at some point for animals to evolve from a primal soup) The question you need to ask is what you believe in. - 131.211.210.1108:37, 23 December 2005 (UTC)[reply]
If you are asking which claims the earliest point of origin for the current species on the Earth, then evolutionary theory says early life started to evolve soon after the Earth's formation, some 4.3 billion years ago, whereas the Christian Creationism myth puts it around a few thousand years ago. Other religions put it at various ages, but few go back 4.3 billion years. StuRat10:06, 23 December 2005 (UTC)[reply]
Its not a scientific question. Many believe that God created to world through Evolutionary processes. The two terms need not be opposed. I would saw the fallicy is a false dichotomy. Dominick(TALK)15:10, 23 December 2005 (UTC)[reply]
The question of all men. Does someone else exist and why does he exist? Tied into the definition of the omnipotent and infinite would be the eternal, so the answer would be nobody, if he exists separate from the created being. We are on a tangent I fear. Dominick(TALK)19:51, 23 December 2005 (UTC)[reply]
Just because some of the versions of the evolutionary theory state that evolution has been around for billions of years dosn't make the concept that old --Shanedidona03:33, 24 December 2005 (UTC)[reply]
Well, so far we've seen creation, evolution and evolution created by God. Which leaves one more permutation: God created by evolution. That's just as valid as the one but last option, which happens to be supported by a whole bunch of weaklings looking for a politically correct way out (my God, I'm unforgiving this morning :) ). DirkvdM09:07, 24 December 2005 (UTC)[reply]
Sorry, I forgot one permutation: neither. In the sense of 'no theory' it's rather unacceptable, so is there a third option? Evolution, creation or .... ? DirkvdM11:06, 24 December 2005 (UTC)[reply]
So you're saying that there are philosophical foundations for saying that 'no theory' is actually a third option. True. I've been down that road and it drove me nuts. Try taking the notion that nothing is certain to its logical conclusion - philosophy is a serious potential mental health hazard! But then I accepted that and now try to make sense of the world I think I perceive. What else can one do? So in that perceived reality (which must have something in common with your perceived reality, whether youre a figment of my imagination or not) what could be a third option? DirkvdM15:57, 24 December 2005 (UTC)[reply]
No, we are, most likely, not living in a steady-state universe, nor an oscillating one. Big-bang theory is all but established as fact; the generally accepted scientific theorem is that the universe (small u) came into being in an explosive event Big_Bang between 13-15 billion years ago, give or take a few.
Of course, even 15 (17?) billion years doesn't allow time enough to evolve complex life forms, or most likely, any life-forms at all, as some have suggested that it did. A rational explanation is difficult to accomplish, and accounts for a good deal of the current 'controversy'; it would seem as though there are both evolutionary and creative forces behind the natural world, and it takes a lot of good science to gain good evidence. To top it off, since it's an emotionally charged issue, you don't necessarily stand to gain the public's affection from your research. Renaissongsman03:08, 11 May 2006 (UTC)[reply]
Way off topic, I was pointing out science and Faith are not diametrically opposed. All too often thats what this argument devolves into. (pun intended) Dominick(TALK)13:46, 24 December 2005 (UTC)[reply]
I think that even if creationism was right (which I don't think it is) it would be like a pun made by god to us, so we don't have any obligation in believing in creationism and we are being true to ourselves if we opt for believing in evolution, no matter if fossils are some god's joke to test our faith or whatever. I think that even if fundamentalists are right in every silly thing they say (which may be true because we don't know if the universe is logical) even if that happens, we have sufficient reason to cling to science and dispise religion, even if it is true, because we have never gotten anything good out of it.
If you laugh really hard for a long time that's cardiovascular exercise, so I guess you could call laughter a treatment for obesity, atherosclerosis, etc. Obviously, other kinds of exercise are more effective...
Actually, it's both physiological and psychological. Laughter (and good moode) changes some aspects of human metabolism, somewhat like a placebo, so it can help the body healing itself and improving overall health. I'm not familiar with the technical terms so I cannot direct you to a good article on the subject. ☢ Ҡieff⌇↯06:17, 23 December 2005 (UTC)[reply]
You probably need to consider when the idiom/proverb appeared. Back then, before antibiotics, painkillers, when 'medicine' included leeches and ground up jewels, laughter was probably indeed the greatest medicine. At least it didn't make you worse.--84.64.57.24213:10, 24 December 2005 (UTC)[reply]
I just saw the third episode of the BBC documentary series 'time machine' in which they stated that to live long you should be happy and eat your veggies. A happy attitude (staying young at heart) can apparently increase your life expectancy by 20 years. And free radicals, which get into your body through sunlight and the oxygen you breathe in and have a devastating effect on cells, are eliminated by eating vegetables. Or so the documentary said. Probably oversimplified. DirkvdM14:04, 24 December 2005 (UTC)[reply]
Are you sure about that? The theory I heard about it is that this was an evolutionary left-over from our crawling days, as some intrinsic means of syncing arm and leg movements.--Fangz14:58, 23 December 2005 (UTC)[reply]
That sounds like BS to me. A leftover with a significant energy cost, like swinging the arms while walking, would have evolved out long ago. The balance answer makes much more sense. Try walking without swinging your arms to see how hard it is to balance that way. StuRat18:06, 23 December 2005 (UTC)[reply]
Agreed, it is about maintaining balance. Walking without swimging your arms isn't hard though ... now sprinting, on the other hand, is. Go try that and you'll get a real appreciation for how necessary movement of arms is during movement of legs. --Cyde Weysvotetalk18:28, 23 December 2005 (UTC)[reply]
What medicine(s) is most commonly prescribed to treat depression in paediatric cases? (either/or by percentage of pediatric cases, or percentage of relevant cases to the number of prescriptions given) Are there any medicines used more frequently on kids than on adults? -Tim Rhymeless (Er...let's shimmy)07:39, 23 December 2005 (UTC)[reply]
The only psychotropic meds for which prescriptions for children outnumber prescriptions for adults are the stimulants like Ritalin for ADHD. The bulk of prescriptions for all antidepressants are for adults. In the US, only a few of the antidepressants have actually been approved by the FDA for use in children and antidepressant use in children has been the subject of public controversy in recent years. Probably the most commonly prescribed antidepressant in children in the US in the last decade has been fluoxetine but many others have been used.
[54]alteripse08:13, 23 December 2005 (UTC)[reply]
I would say not intentionally. Of course, if the flower has malformed flowers the bee may not find it, and if the pollen is too loose it will have blown off in the wind before the bee arrives and if the pollen is stuck to the flower too well, it won't come off on the bee. If the nectar is unpleasant, bees will avoid that flower from then on. If the tunnel for the bee to get to the nectar is too tight, they will go elsewhere. So, bees can have many unintended effects on flower evolution. StuRat09:58, 23 December 2005 (UTC)[reply]
More specifically, eugenics is selective breeding applied to humans.
The bees might indeed miss a malformed flower. And if one doesn't contain much nectar they might not stay long enough for pollination and maybe skip all the other flowers (it makes more sense to speak of the plant being less healthy). And of course if a plant is sick it will more likely be less fit. And this could in some way be related to its genetic makeup, so yes, there will then be selection and thus evolution in the sense of pruning the weakest. But what is 'healthy'? One could define that as most fitting the given situation (the fittest). But a flower might also deviate in a way that attracts more bees. One might see a deviation as less 'healthy', but by this definition it is more healthy. And then you get evolution in the sense of creating more variation. Which will also work the other way around. Hummingbirds perform the same function as bees. Some developed longer beaks, thus only pollinating long flowers. So the flowers got longer and then the beaks got longer etc... DirkvdM19:18, 23 December 2005 (UTC)[reply]
It's a ligated cation, so it should behave mostly like a salt, it dissociates to some degree and the anionic portion probably has some detergent activity, but in water, it just dissociates, see solubility or freezing point depression, or ionic equilibria, also from the article Solubility:5.1 g/100 ml (@ T=293.15 K), with the standard heat of formation (ΔformHo) for the hydrate being −3276.75 kJ mol-1, to calculate the extent of the dissociation--Aolanonawanabe18:35, 23 December 2005 (UTC)[reply]
Hello ladies and gents. I'm thinking about learning XML, because if I can be halfway decent at it, I can apply for a job that I know is going to be coming up in a few months and earn about another £5,000 a year, but don't really know much about it (I know what it is, because I read the article, but I'm more interested in knowing how long would it take to pick up the basics, how I could use it to put together forms from an SQL database, how long and how tricky it would be to learn all that. Also if there's any decent learning tools around (preferably for free, which is my favourite number). My current level of programming knowledge is restricted to some very simple C and Java, and HTML, up to around the level of putting tables together and things like that. Thanks. Prototc11:47, 23 December 2005 (UTC)[reply]
You know HTML and you want to learn XML? Congratulations. You already know XML.
Well, as long as all the tags are lowercase, and opened and closed in a proper tree structure (e.g. <b><i></i></b> instead of <b><i></i></b>), then most HTML is also XML.
XML is used for so many different things though. You can't really "learn XML" because the basic concepts are so simple, but there are so many ways to process it (SAX, DOM, XSLT...). Be more specific. —Keenan Pepper02:18, 24 December 2005 (UTC)[reply]
While some oceans (like the Atlantic) are expanding due to plate tectonics, other oceans (like the Pacific) are contracting for the same reason. The melting of the glaciers and the Artctic and Antarctic ice caps due to global warming is the only cause I know for the expansion of all oceans, caused by a rising water level. StuRat17:58, 23 December 2005 (UTC)[reply]
Actually, to my surprise I recently learned that global warming also causes the oceans to heat up, which causes the water to expand and the sea levels to rise. But that won't be at a rate of 2,5 cm per year, so that's probably not what you're talking about (we'd be getting wet feet a lot faster here in the Netherlands, so maybe this is also a bit of wishful thinking :) ). DirkvdM19:23, 23 December 2005 (UTC)[reply]
But what will happen to the condition of islands if this continues?
I have never seen pigeons land in trees.I've seen them on wires,buildings,on the ground and on billboards but never in trees..Can someone tell me why they don't land in trees?
I'm guessing you live in a city, so the pigeon you are most likely to see is the Rock Dove. These birds used to live on cliffs on the coast, so they find a building with a sheer drop more reassuring than a tree. They will stay in trees occasionally, but if the opportunity for a building is there, they will take it. smurrayinchester(User), (Ho Ho Ho!)17:43, 23 December 2005 (UTC)[reply]
Every year in August and September the tree outside my front window bears fruit, and is full of pigeons climbing and resting on gthe branches. Also, I found some pictures:
I just want to be completely sure about something I recently read, it is: We have A and B, at both A and B something explodes. I (the observer) am at exactly the same distance from A than B when the explosions (events) happen, but I am running at a relativistic speed (wow) towards B. Because light travels at a universal constant, c, both events will appear to me simulatenous, right?
Well, something exploded at A and B at the same time... relative to whom? If an observer stationary relative to A and B observes them to explode at the same time, he would see that the light pulses did not arrive to you at the same time - because you will have moved in the intervening time towards one of the explosions. You as the moving observer would also observe that the two pulses arrive at different times, but you will deduce that this is because the two explosions were not simultaneous. SR tells us that both views are in fact equally valid.--84.67.129.21019:33, 23 December 2005 (UTC)[reply]
I made such a stupid mistake, I meant exploded at the same time relative to a stationary observer being the distance A-observer and B-observer the same. What I don't get is how can the moving observer (in relation to the stationary observer in relation to A and B) conclude the events weren't simultaneous, if light is a constant for him, no velocities should be added... so A-mid = mid-B both rays travelling at c-> simultaneous. Of course, in the stationary observer's (again in relation to A, B) frame c remains the same, so (in this frame) both rays won't arrive to the moving observer at the same time, right?
If you're moving towards B (and presumably, away from A) then no, the light from A & B won't reach you simultanously (you are moving towards B, therefore light had to travel less distance). And if you calculate when the events happened (knowing your speed, the elapsed times, and your distance from A & B), then you will conclude that the event at B happened before the event at A, in your frame. Try giving each event an (x,t) coordinate in the stationary frame, and using the Lorentz transforms to calculate what happens in moving frame. --Bob Mellish22:09, 23 December 2005 (UTC)[reply]
By the way, if c wasn't a universal constant for every frame, time dilation would occur too, but in a different matter. The lack of distance that light has to travel from B would have to be considered along with the addition of velocities (v + c), isn't it? --85.50.5.18712:26, 24 December 2005 (UTC)[reply]
What is a safe amount of ice on a pond for ice hockey?
8-10 cm is a bit creaky, I'd prefer 15 cm for walking on, on my own. For active sport with several people, like ice hockey, I'd want it a lot thicker, say 30 cm - MPF22:54, 23 December 2005 (UTC)[reply]
I don't understand your question. Do you have a local network you want to divide into subnets? See subnetwork for some basic background information, first, then if it doesn't answer your question, can you rephrase it so we can understand it? -- Natalinasmpf13:05, 24 December 2005 (UTC)[reply]
You need a router or bridge. You need to program this to partition traffic, and build routing tables upon your subnets. Check out the TCP/IP article.
Hello This is KeeganB. Does Marijuana interact with Lamictil? I'm having trouble finding out. By the way, I'm not a pothead. I just recently tried MJ for the first time and I wasn't very impressed.
Just a suggestion; in many places in the world marijuana possession and use are illegal. Admitting to criminal activity on a very public website like Wikipedia isn't a great idea (unlikely as it is that, in this case, anybody would bother to follow up on what is generally viewed as a relatively minor offence). For future RD users, I'd suggest you phrase your questions in such a way that *doesn't* imply any illegal activity. --Robert Merkel08:44, 24 December 2005 (UTC)[reply]
So if one wants to ask a question about jaywalking then it should be carefully phrased? Depending on where one is from (say, Singapore). DirkvdM09:23, 24 December 2005 (UTC)[reply]
Chewing gum also gets you in trouble there. Seriously, if you are taking mood stabilizers, watch out for other mood drugs such as alcohol and mj. Most likely you will find they just start to give you a big headache. If you take both in large amounts (and you are bipolar), you are dancing on the edge of sanity. --Zeizmic16:07, 24 December 2005 (UTC)[reply]
Maybe I should have mentioned that I didn't and don't have MJ in my possession. It was someone else's weed. --KeeganB--
Btw.: Erowid has some very comprehensive information about drugs. And because of a drug being illegal this dos not imply that the drug has bad impact on you. That are just government laws and they are mostly only money-oriented and have no other sense. helohe(talk)02:56, 25 December 2005 (UTC)[reply]
I feel somewhat daft asking this question, but here goes - I have a computer with Windows XP (Home Edition) on it, and it's getting time for it to be reinstalled. I still have the "rescue disk" that came with the machine, which I presume I can use to reinstall the OS. My question is, is this rescue disk equivalent to a Windows XP CD if I bought it singly? I would presume not - if not, is there a danger that if I wipe out too much of my PC during the reinstall (eg do a complete hard drive format, instead of just running the reinstall from an existing installation which would then be overwritten) that the rescue disk will no longer be able to install Windows? I was thinking that the rescue CD might need some things left on the hard disk in order to work properly - is this true?
Ancillary question: not being a huge fan of repackaged software where I don't know what I'm getting (see my snide comments about rescue CDs), I was thinking of getting a 'full' copy of XP (eg from Amazon, so not an OEM version) so that I knew I'd be able to reinstall fully even if I changed my hard disk, wiped it completely, whatever. Would this give me any advantages versus just sticking with the rescue disk? Or does that vary from PC manufacturer to PC manufacturer, since they put different amounts of stuff on their rescue disks?
And, final question - commercial copies of XP come in two flavours, "full" and "upgrade". Do I understand it correctly that, in order to use the "upgrade" version I need to run the installer on an existing installation of a previous version of Windows (2K, ME, 98...), whilst I can install the "full" version on a completely blank HD? Does that not make the "upgrade" version an enormous pain if you wish to reinstall the OS every 6 to 12 months (something I've always found was a good idea with most versions of Windows)? Or am I missing something here?
Not sure about rescue disks, etc., since I've never used them. But "upgrade" version of XP just require you stick in the CD of a previous version of windows during the XP install. It doesn't actually require you to have that version of windows installed already. --Bob Mellish22:22, 23 December 2005 (UTC)[reply]
It's probably not a "rescue disk", formally, as that's a floppy with some really basic tools on it. I'm guessing your PC was made by a large manufacturer like Dell, and it's really a reinstallation disk (although they may call it a rescue disk). If that's the case, then no, it most certainly isn't the same as a proper retail XP install disk. It's a hardware-specific (and rather brain-damaged) thing. Depending on the manufacturer, it's one of these:
A cut-down install disk, with all the necessary drivers present and all the unnecessary ones absent, and various install scripts configured to bring your system back to factory condition.
A compressed install image, a freeze-dried version of the system in its initial state.
Both will work essentially only on this exact model of the machine (or, in the first case, sometimes on very closely related versions). Creating these simplifies support headaches for the manufacturer, and it gets them a (significant) break on the price from Microsoft. This (and the yet more pernicious practice of not giving you a disk at all, just putting the reinstall image on a separate partition on the drive) is, IMHO, a royal screw-job, as it utterly prevents you from using a piece of software you own on any later (or replacement) PC you own.
As to whether it will wipe your entire disk, I don't know (it depends on how the specific manufacturer set things up). Even if it doesn't, you shouldn't trust it to preserve your valuable data, and a backup of that is vital. As to programs, it'll probably annihilate the windows registry, which will make every program you've installed essentially vanish (their directories may, or may not, still exist in "program files", but many will be unservicable).
Bob entirely correct about the difference between a full install and an upgrade. I've no idea whether an upgrade version will consider your reinstall disk to be something it's willing to allow an upgrade for, but if you have an old ME or NT disk lying around then it should accept that.
Note that you'll need to download the drivers for your system sepately (from the site of Dell or whoever). You should certainly make sure you have the drivers you need to get online (modem/ethernet/whatever drivers, depending on your means of accessing the net) pre-downloaded (and stored on a cd or floppy or whatever) - otherwise you risk getting into a chicken-and-egg scenario, where you need a modem driver but can't get online to download one because you don't have a modem driver. -- Finlay McWalter | Talk22:51, 23 December 2005 (UTC)[reply]
Can someone provide some introductory text / information about consciousness, particulary from the perspective of science rather than philosophy? A friend of mine mentioned Roger Penrose, and more interestingly, the concept that the Universe (as we know it) could be 'conscious' in some respect. I'm at a bit of a loss where to start, so a gentle introduction would be nice. It has always intrigued me how subjects like Cosmology are actually supportive of the idea that there is a higher being.
Nobody knows the answer, but that doesn't stop them from writing books. Susan Blackmore wrote an intro text on consciousness, might be good. She claims to explicate all theories, even ones she doesn;t believe. If you want physics, look at quantum mind. 14 theories, only one, at most, which is right. Penrose wrote 3 books on the topic, he has his point of view, as do David Bohm; and Frank Tipler "THe Physics of Immortality". There's plenty to read, just don't believe everything. Just dive in. try http://consciousness.arizona.edu/GangofOne12:09, 3 January 2006 (UTC)[reply]
Are structural formulae eligible for copyright? I ask because while working to fill in drugboxes for Wikiproject Drugs, I've come across a wide variety of copyright labels attached to images of them, including {{PD-ineligible}}. If the latter is correct, it'd make things a bunch easier when I find images without any license at all. GeeJo(t)(c)00:29, 24 December 2005 (UTC)[reply]
I am not a legal expert, but I am 95% sure yes, just as long no creativity in portraying the structure (color coding, additional wordings, etc.) is used. For example, if someone had created Image:O-TableImage.png and not released it under a free license, and had asserted copyrights over it, it would of course, not in the public domain, whereas if someone had made a diagram of the electronic configuration for oxygen, not released it under a free license, even so, it would be PD. -- Natalinasmpf02:48, 24 December 2005 (UTC)[reply]
I'm not 100% sure either. But based on all the structural formulas I've seen in the past 6 years, I honestly can't think of one I consider to be copyrightable in anyway. It would defeat the purpose of having it anyway. Structural formulas are supposed to be pictures shared among scientists so they can see what structure a molecule is supposed to have. Unless, as Natalinasmpf stated, some creative work was involved, I would NOT call them copyrightable. - Mgm|(talk)20:26, 24 December 2005 (UTC)[reply]
Again, IANAL, but I am quite sure that they are ineligable unless there has been some creative modification. One way to think of them is as a unique language meant for conveying one kind of data. -User:Lommer | talk16:22, 25 December 2005 (UTC)[reply]
In a standard form they are no more copyrightable than equations or the phone book. They are simply "facts" and the only copyrightable aspect of them (depiction of facts in such a way) is well past any copyright expiration. I'm not even sure Feynman diagrams, which as a form of nomenclature more recent than the structural formula, are copyrightable. --Fastfission00:54, 26 December 2005 (UTC)[reply]
Structural formulas of larger compounds are simplified Lewis structures that show bonds as lines instead pairs of dots. If there are any people with any claim to all structural formulas ever drawn, that would be Gilbert N. Lewis and whoemever else helped with the development of this system. Personally, I variously upload images of structural formulas as GFDL or PD. -- Rune Welsh | ταλκ | Esperanza04:32, 26 December 2005 (UTC)[reply]
Thanks for the answers. Now at least I at least feel justified in adding the pd-ineligible tag to any no-license structural diagrams I come across - provided they're of a decent enough size/quality to keep in the articles. GeeJo(t)(c)18:26, 26 December 2005 (UTC)[reply]
My Windows XP Pro computer hangs on startup on the logo screen with the moving blue loading bar. I can load windows without hanging only into safe mode, however.
I have tried: (Not in order)
1. clearing up Hard Drive space on the drive with the operating system
2. minimizing startup items and services
3. Loading Fail-Safe defaults on BIOS
(While in Safe Mode) go to Start and Run "CHKDSK /V"——It may or may not show/fix something(s). Then attempt "CHKDSK /R": It will say that it can do it the next time you boot-up——choose "yes" and reboot (it may take an hour or so to complete). This is XP's version of "ScanDisk": See MS XP CHecK DiSk. ~Kaimbridge~22:26, 24 December 2005 (UTC)[reply]
There should be a way to find out what causes the hang. I haven't had to diagnose such a problem in Windows XP - in Win98 you have to choose "Boot with logging" from the menu you get by pressing F8 during the boot. Try looking at the system logs anyway after first booting normally with hang, then booting into safe mode. You can see logs by right-clicking My-Computer and choosing Manage. If you can identify which driver is causing problems, then you have a choice of disabling that single driver, replacing that hardware component, updating that driver to a later version, or rolling it back to an earlier one.-gadfium00:45, 25 December 2005 (UTC)[reply]
Is Yellow #5 a naturally occuring dye? If so, where does it come from? Why does nearly everything in my kitchen have Yellow #5 listed in the ingredients? Is it poisonous? Does it cause cancer?
I don't really know anything about this, but judging from the article I'd say from the perspective of the Planck Units the SI Units have the disadvantage that they're anthropomorphic. To humans, however, that's the advantage because we're the anthropos. But ‣ᓛᖁᑐ already said that in different words. But the fundamental constants no longer equalling 1 puzzles me, because they're not anthropomorphic, are they? DirkvdM09:37, 24 December 2005 (UTC)[reply]
It might be very helpful for quantum physics, but for for anything bigger than atoms, it's a bit useless. For example, a metre stick, measured in planck lengths would be 6.18719992 × 1034 lengths long. Even using a massive prefix (yotta, or 1024), that comes to 6.18719992 × 1010 or about sixty one billion yotta-planck lengths. smurrayinchesterMerry Christmas!(User), (Go Carolling)10:45, 24 December 2005 (UTC)[reply]
What I'm getting at is, our derived practical units would all be on different scales. A practical unit of time (T) would be 1043T; length might be 1034L; mass could be from 105M to 108M; temperature would be 10-32Θ. The speed of light would then be 109L/T, while the gravitational constant would be 10-11L³/(MT²), and so on. Our practical units would lose the special meaning that the Planck units have (but at least they do give the constants easy values). ‣ᓛᖁᑐ14:50, 24 December 2005 (UTC)[reply]
After two edit conflicts....
On second thought, that isn't really a problem. Just come up with a new word for 1034, say 'googa', and a 'googaplanck' would be about 18 cm long. We'd get used to that just as easily as we're used to kilogram. Nobody uses 'gram' to measure, say, one's weight because it's too small. And that's no problem, is it? DirkvdM15:00, 24 December 2005 (UTC)[reply]
And in reaction to ‣ᓛᖁᑐ (after the edit conflict). You've got a point. We'd need words for all sorts of prefixes and the relation between them would be lost because 'normal' people can't handle orders of magnitude of over 1010. An advantage of the system we have now is that one can use 'kilo' as a prefix for both metres and grams. But then, 'ordinary' people don't use them in that way. Actually, in Dutch (I don't know about English) 'kilo' is uswed for 'kilogram' and 'kilometre' is used for km/h. And in English, the common pronunciation of 'kilometre' shows that people haven't a clue that there's a prefix there. So 'normal' people use the units as completely separate entities. The science community will have a harder time because it has to deal with larger orders of magnitude, but astronomers manage that too, by introducing stuff like the Astronomical Unit. Not ideal, I admit, but not a major problem either. So the pros and cons have to be weighed and what are the pros of using Planck Units? Saying just that they're less anthropomorphic is just being politically correct and therefore a load of crap. But the equations are simpler, aren't they? And that would be a real major advantage. After all, a major goal of science is to get the formulas simpler, right? DirkvdM15:23, 24 December 2005 (UTC)[reply]
It's possible the objects observed to be dense enough to be black holes are actually not gravitational singularities (or Kerr rings), but the theories about what else they could be (e.g.gravastars) are not widely accepted. ‣ᓛᖁᑐ05:14, 24 December 2005 (UTC)[reply]
Two recent eprints which should be readable by laypersons willing to skip over some math are:
The first is more theoretically oriented and the second more observationally oriented, so they complement each other well. ---CH17:13, 24 December 2005 (UTC)[reply]
ive always wanted to know this.ive broken a dozen glass tumblers.why does this happen when i put ice in glass tumblers??.but if i put ice in plastic cups nothing happens to them.how is this possible?
When you put ice in a glass tumbler, some parts of the glass cool down more quickly than others. The parts that get cold shrink a tiny bit (see thermal expansion) and put stress on the glass. If there's too much stress, the glass breaks because it is brittle. Plastic, on the other hand, will bend much more before it breaks, because it is more flexible. —Keenan Pepper05:10, 24 December 2005 (UTC)[reply]
Well, there are many different types of plastic, but glass is probably indeed always less flexible. Also, it probably always has a higher Thermal conductivity, meaning that a sudden local change in temperature will more easily happen. DirkvdM09:45, 24 December 2005 (UTC)[reply]
Hello there, and thank you in advance for taking the time to look over my question. I have been experimenting with yeast lately, and I've run into troubles in two ways: first of all, I cannot easily distinguish between live and dead yeast, and secondly, I cannot find a method to make them reproduce and increase in number.
For the first problem, I am currently using Congo red dye to stain the yeast, and then examining the yeast through a microscope. My logic is that the dead yeast will be dyed, and easily visible, whereas the living yeast will remain colourless after being given enough time. The problem is, even with yeast that is probably dead (activated, then immersed in water for two days without light or food), a good portion will remain colorless. Boiled yeast, on the other hand, all become coloured.
Could there be a reason for the dead yeast to expel dye, or could the yeast be alive after all?
As for the second problem, I have tried the potato dextrose broth solution to make the yeast reproduce, but with no apparant result. Is there some special method with which I use the broth? Currently, I am using the broth in place of water with a bit of sugar when activating yeast. Once again, I thank you for reading my questions. --Borbrav06:55, 24 December 2005 (UTC)[reply]
I've once made a little distillery (horrible results, by the way) and the method I used to create the alcoholic 'beverage' to distill was to put yeast in water with loads of sugar (not just a bit). But do you mean to say you don't want to do that? DirkvdM09:49, 24 December 2005 (UTC)[reply]
I'd doubt that "activated, then immersed in water for two days without light or food" is enough to kill yeast - once some die, the rest can use the dead yeast as a food resource. Maybe try something more potent to kill them, such as brine or sugar syrup (so long as they don't affect other aspects of the experiments). To make the live yeast reproduce, try some suitable nutrients, such as a beer starter kit or some bread dough. - MPF13:47, 24 December 2005 (UTC)[reply]
Most of the pages here will include that information, and will also have one as a redirect to the other. If there are any that fail to do so, note them here, or better at Wikipedia talk:WikiProject Tree of Life, and someone will get round to adding the required information - MPF13:39, 24 December 2005 (UTC)[reply]
-A rather vague question there, how long is a piece of string? (Uncyclopedia says it's 18.29 metres). Games by a single developer can cost nothing (except time and a lot of skill) to create, while big companies like EA will have budgets spanning millions of £/$. Try looking at Computer Game or look up your favourite game developer/game for the sort of budgets envolved. -Benbread13:02, 24 December 2005 (UTC)[reply]
And time is money and if you translate the time spent (wasted) on games into money that will probably be much more than the money spent (wasted) on buying the game. It's like with a car. Buying it may seem expensive, but that's probably about 20% or 30% of the total cost, which includes driving and maintenance. And that's not even counting the time you could have spent in a more useful manner if you used public transportation. But I digress. DirkvdM14:46, 24 December 2005 (UTC)[reply]
Well, vote for a party that wants to improve that. I know, now you're going to ask me "what if you live in a country where such a party is non-existent?" I don't know. Emigrate to a democracy? DirkvdM09:16, 25 December 2005 (UTC)[reply]
Thanks for noticing this article and posting a question about it here. "Bovasial contex" means nothing; the article was a "joke". --JWSchmidt03:07, 25 December 2005 (UTC)[reply]
December 23, 2005, I asked 3 questions about Creation & Evolution and had very mixed reviews. So, I’ll ask again. Which came first “Creation or Evolution”?
Note: Creation, is not to be misunderstood for “Creationism” but, rather to the point of origin.
Did Evolution come before Creation or Creation come before Evolution?
Well, sure then. Something alive appeared, and then it started evolving. So evolution came after. Obvious enough, isn't it? ☢ Ҡieff⌇↯03:25, 25 December 2005 (UTC)[reply]
A major flaw in your question is that it contains an assumption, namely that there is something like creation (in this sense). Do that and you're instantly in the realm of theology. So I refer you to Wikipedia:Reference desk/Theology. Well, ok any other ref desk then, not science, because you've intrinsically left the scientific realm. DirkvdM09:25, 25 December 2005 (UTC)[reply]
However, if you believe the universe was created, evolution had to happen by its sheer definition. You need to have something to let it evolve. - Mgm|(talk)11:07, 25 December 2005 (UTC)[reply]
If we assume evolution is a natural process (as scientists generally do), then the question becomes about as nonsensical as asking "What came first, the universe or the second law of thermodynamics?" The latter is a property of the former -- a condition or a process, really -- and so asking whether it "came" afterwards doesn't really get straight the relationship between the two. Evolution is a process, not a "thing". --Fastfission16:58, 25 December 2005 (UTC)[reply]
Somehow, whenever I open up windows task manager, the window is too big. It takes up the whole screen and I can't get the rest of the options. Is there anyway to make task manager open up small?
What you've probably done is maximised it and then hidden the menus. To fix it up, double click the grey area to bring back the menu bars. Then double click the title bar to restore the window to normal size. enochlau (talk) 04:24, 25 December 2005 (UTC)[reply]
You can also right click on the title bar, and type 'S' for size. ( Actually that does not work. You must use the restore option first... )67.161.14.10422:54, 25 December 2005 (UTC)--[reply]
Reading your question above, I feel that the only simply and direct answer came from Kainaw. He stated that something must be created before it can evolve. Is your question scientific? I went to Science and it states that science is a system of aquiring knowledge. Is your question part of a system of aquiring knowledge?
Ok. Which ever came first will not make a diffrence. Flat earth came first, before round earth. Newtonian Physics before Einstienian, and Greek atomic model before Bohr. And now onto the epistomonological question:
Creation dates to the earliest writings of the old testment,
Which dates to about the time of Moses, but this is subject to controversy. P.J. Wiseman has a theory that Moses didnt write Genesis but rather translated them from cunieform script, which would have been written from eyewitnesses. ( Yea right. Anyone around for the creation of the universe, plese comment on my talk page )
Evloutionary theory was first published on October 24, 1859 The_Origin_of_Species, althoght some argue that he was merely collecting the scientific evidence for a idea floating around in british intellectual circles, while the french were busy making wine.
Note: Genesis is a Jewish/Christial religious text based upon faith.
If the question is about time scales and processes, then sure, it can be a scientific question. That is to say, if I had a real sure sense about what you were asking, it might be possible to tailor it in a scientific way (i.e., "Did biological evolution happen only after matter existed?" is surely answerable as "yes". However asking "Do the underlying principles of biological evolution rely on matter existing?" might be "no", depending on what one views a "principle" to be, though whether this would be "scientific" or "philosophical" depends on how much of a border one sees between the two approaches). --Fastfission17:03, 25 December 2005 (UTC)[reply]
ok. I am going to answer your question as literally as possible. Creation began as an act of God, it was the essential, primal and atomic origon. Evolution began with the Big Bang. Creationists believe date the Creation somwhere around 6,000 years ago, and theories date the Big Bang at 13,700,000,000 years ago. Acording to Creationists, Evolution does not occur. Before you can compare which came first, you need to answer the question: Which is the most likely to reflect the reality of the past, and where is your faith? 67.161.14.10411:25, 26 December 2005 (UTC)--[reply]
I read the articles on the Pokemon gene and Sonic hedgehog and with Google I've confirmed that scientists have named a gene the cappuccino gene. These are all examples of scientists giving facetious, pop-culture–inspired names to genes. I've also heard it reported that there are Star Trek references in the names of some genes. Does anyone know what they are? I'm curious!
Of course the cheapest (though stiil astronomically expensive) and most humanitarian (though still environmentally disastrous) method is to landfill the Strait of Malacca, which would forever destroy the island of Sumatra, making it instead a peninsula of continental Asia. One would, though, want to dig the Thai Canal first, as the consequences for international shipping would also be pretty serious.--Pharos07:42, 25 December 2005 (UTC)[reply]
You need a secret base hidden in a hollow volcano, loyal henchstaff, and a hugeass laser weapon. And most important: pump a dozen bullets into the hero first, and only then expound your diabolical plans at great length to his still-warm twitching corpse. -- Curps08:02, 25 December 2005 (UTC)[reply]
You don't seem to understand how this works. Any continuation of a discussion should be at the original thread (as you can see others do). You keep on starting new ones, which makes it difficult to follow the discussion. DirkvdM09:37, 25 December 2005 (UTC)[reply]
It might not have been you, but I also seen almost this same identical collection of questions asked at other WP:RD. So there are questions and anwers all over the place on this one related thread. I suggest you create a section on your personal talk page, copy & paste all the pieces of the discussion to there, since they are doomed to disappear into the archives any day now, then invite people to continue the discussion there. User:AlMac|(talk)21:56, 25 December 2005 (UTC)[reply]
why do we feel a burning sensation when someone pokes out eye?and why is it advisable to apply ice to the wounded eye?
Your eyes are sensitive to make sure you protect them. If you are asking why the specific combination of unpleasant and painful sensations feels somewhat different to you than the same injury applied elsewhere, one can guess that it has to do with greatly increased density of nerve endings in the area compared with most other parts of the body. The 3 reasons I can think of to apply ice to an eye injury are (1) it distracts your brain from some of your pain signals and reduces their intensity; (2) it gives you something to do rather than howl about the pain or do something damaging, and (3) ice temporarily reduces blood flow and and interstitial fluid accumulation in a local area, with the effect that there is less swelling around your eye after you have been hit. I can't think of any advantage of ice for any other type of eye injury. alteripse11:59, 25 December 2005 (UTC)[reply]
What is the technical name of a long [longitudinal] projection or a long wedged ridge-type projection or bar of concrete under the deck of the bridge? OR please tell me a general [technical] term for a long [longitudinal] strip-type projection on any flat surface of a material; e.g. long [longitudinal] strips / projected bars on the deck of a mechanical jig.
I look forward to have a positive response and thanking you in anticipation.
Does wifi have any advantage over wimax?
If wimax has more coverage and higher speeds, why are towns choosing wifi over wimax?
And why has google chosen wifi instead of wimax?
Which is the cost effective of the two? which is more economical?
wimax is technically superior to wifi in most ways, but it is relatively new, expensive, and poorly supported, while millions of computers already support wifi and support comes preinstalled on a good fraction of new compueres. The answer to most of your questions is that wimax may well be a great solution for the future, but wifi is the most useful for the greatest number of people right now.
OK, assuming that the global warming hypothesis is correct, two effects (at least) will come into play with regards to the oceans:
1. More evaporation, precipitation and snowing in Antarctica (ie less water in the oceans)
2. The water in the oceans will expand due to increase in temperatures (ie more volume of water in the oceans)
Excluding external factors like comets bringing in more water, will the oceans, as a result of the above two effects, increase in depth or decrease? (and are the above two the only/the most important?)
Uhh...if the temperture is warmer, then less of the precipitation on Antartica will freeze, and more of the current frozen precipitation ( snow and glaicers ) will be joining its physical partners in raising the ocean level. Comets acculmilation of water is neglegible, and has not been figured into ANY climatic models in current literature. ( see American Geophysical Letters, 1957 ~ 2005 )
I think the most critical effects of global warming:
Mankind thinking THEY are primarily responsible for what is a "season" of the planet that lasts hundreds of years, and taking efforts to try to mitigate the next global warming season, which could have the effect of making the global cooling season after that much worse ... another Ice Age can be more serious than anything that global warming can do to us.
Oceans will rise several feet over several decades ... today New Orleans in trouble because just a few feet below sea level, when hit by a nasty storm. In 50 years or so, hundreds or perhaps thousands of coastal cities will be in the same boat.
The disaster in New Orleans had little to do with either the storm, or the rising seas. There is photographic evidence that the flooding was NOT due to the storm, but the mismanagment both of the maintenence of the dikes, and the emergency relief effort. Holland is in a worse situation, both in terms of weather and depth, BUT seem to manage much better.
There is a season to hurricanes that is not as long as the season of global warming and cooling. This hurricane season lasts 30-50 years, in which the USA is in the early stages of one that will get much worse in the next decade or two. This will acelerate US politics to take global warming seriously, and so lay the seeds to make the next global cooling season a total catastrophe.
We can look at the history of past seasons of global warming and oooling to see its impact upon what crops can grow where. This may not be the place to discuss this in detail, but there was a relationship between rapid climate change in the middle ages, and the onset of some of the worst Plagues in history.
Firstly, Artoftransformation, I did look on the Global Warming page. Unfortunately, there is nothing there. You actually meant the Sea level rise article. And you meant "it's", not "its". Were I am newbie, I meant have taken some offense to your somewhat biting sarcastic comment. Please do not do this again; there are many people on this page that have never used Wikipedia before and your tone will only put them off.
I disagree: "Presently, the IPCC predicts sea level rise of less than 1 meter through 2100," was in the article on Global Warming. Althought I disagree both with the reporting and the findings, I will not argue using my primary research.
Secondly, on the Sea level rise page, it states that thermal expansion WILL be a significant factor.
Again, NASA Goddard, and the IIPC disagree with the content and facts of that article, personally I put more belief and interest in primary scientific sources.
Try this: Put an ice cube in water. It Floats. Its less dense, then water, hence when the north pole melts, the density increases, displacing less water. I will find a link to the denisty of sea water vs tempreture and post it.
Actually, I am not so clever. Since I have interviewed both scientists who disented on the IIPC First Assessment report, and corraspond with the head of global climatic modeling at NASA Goddard ( your tax dollars at work ), I personally know both the direction and strength of current aod future research. See you at the next Panel Discussion. ( Last month it was rather tame, and next year it looks like the same )...See Refrences:
It would seem as they are at least 6 to 7 years behind current research, and that current research will not likely be published for a few more years to come. None of this is based upon origional research. 67.161.14.10410:32, 26 December 2005 (UTC)--[reply]
as told above, its an illusion. to be concise, in evenings, when the sun is near horizon, things on horizon are far smaller than sun, which makes sun seem relatively bigger
AlMac, I'm confused. Are you saying that not warming the Earth up now will cause a worse glacial period than there would have been had there not been any humans? By the way, you seem to be confusing ice ages with glacial periods, but that's a common misconception. Indeed we are in an interglacial period now, but the warming up is going rather faster than one would expect from that. And anyway, increasing the CO2 content of the atmospere is bound to have some effect, the net fresult of which is more likely than not going to be negative (as for any change). In other words, we're performing a global (meaning no escape) experiment without having a decent clue about the possible outcomes. DirkvdM13:29, 27 December 2005 (UTC)[reply]
Global Warming is usually painted as a one time planetary disaster, that human activity on the planet is responsible for, leading to efforts to get a political partisan consensus of multiple nations to combat that which is believed to be causing it.
I believe that Global Warming, and Global Cooling, are part of a cycle both of which have occurred many times in history.
Consider that where the Titanic was struck by an Iceberg was about the same distance from the equator as where the Vikings crossed to North America. My understanding is that the Vikings did not have any Iceberg trouble because they crossed at a time of Global Warming, while the Titanic was in a time of Global Cooling.
So we have this cycle. Human action can have many impacts. To the extent that human actions are intended to push the planet in the opposite direction from Global Warming, it would stand to reason that they might have the effect, in the next Global Cooling cycle, of making that worse. User:AlMac|(talk)16:32, 27 December 2005 (UTC)[reply]
Once again, you have this the wrong way around. Human activity is pushingt the climate towards warming (not cooling). The intended counteraction is to stop doing that, thus taking away the effect. Oh dear, what am I saying, the intention is to reduce the effect. Tokyo was about making a first start with that. Just a first start. And even that is not coming off the ground. Don't worry, we'll be getting nice and hot in a few decades because the effect is coming on top of the interglacial we're in the middle of now (and maybe a bit colder in a few hundred years). By the way, serious changes have happened in Earth's past, for sure. And, depending on the seriousness, more or less species died off as a result. That it happened before doesn't mean we shouldn't worry about the results. And it's happening a lot faster now than ever before, I believe (a matter of decades), which by itself could give the experiment some 'interresting' side-effects. I don't fancy being a guinea pig. DirkvdM14:24, 28 December 2005 (UTC)[reply]
According to http://www.thewolfeclinic.com/acidalkfoods.html, grapefruit, lemon, and apple cider vinegar are "alkalizing foods". I always thought these were some of the most acidic foods. Is this just blatantly wrong or is there something I'm missing here? Does alkalizing mean something different from alkaline? Where can I get a correct table of the pH values of foods? —Keenan Pepper22:40, 25 December 2005 (UTC)[reply]
I just found Alkaline-forming foods. I have honestly never heard of this before so I don't know whether it's pseudoscience. Is there any evidence to support this or is it just a scheme to sell health food products to people ignorant of chemistry? —Keenan Pepper22:59, 25 December 2005 (UTC)[reply]
I dimly remember that there was a medical theory that stated that there were two kinds of stomach juice - acidic and alkaline. Proteins would be digested under acidic conditions, and carbohydrates in alkaline conditions. If you mixed those two in a meal Bad Things would happen. It's of course Complete Bollocks, as the stomach juice is strongly acidic always. Pilatus02:21, 26 December 2005 (UTC)[reply]
Some guy who decided to blame a shitty ecomony on a minority group from the middle east, invaded his neighbors to secure fuel and such, blamed the removal of civil rights on socialists, jews and other "subversives" in the german government--205.188.117.7102:28, 26 December 2005 (UTC)[reply]
World War II's origins are from Adolf Hitler and his National Socialist (Nazi) Party took control of Germany and Japan, and the invasion of Poland, and the attack on Pearl Harbour.
Exactly, and they took power by complaining about religous minorities from the middle east, and socialists, both of which were probably ruining their perfectly nice countries, "national socialist" is probably one of the worst hack translation jobs in the history of language, but go with that if you want to, some day maybe you too can too can root out the commies and the middle eastern immigrants from your country in the name of national security--63.22.29.25316:06, 26 December 2005 (UTC)[reply]
I think, primarily, the biggest issue here is that no person can write a law, in the sense of scientific laws. You can write a hypothesis, which, if repeatedly demonstrated to be true can be deemed a theorem, but I think the ascent into law doesn't usually happen within a lifetime. Think about Einstein's theory of relativity, right? But if your new hypotheses are accurate and actually new, I don't think your level of education would get in the way of their legitimacy. --ParkerHiggins ( talkcontribs ) 07:36, 26 December 2005 (UTC)[reply]
PhD, just means Piled higher and DEEPER. Publish your theory, and look for expermentalists to verify them. Send papers to refereed journals, and ask your local physics professor for a review first, and DO explain a bit more about them here. Artoftransformation09:02, 26 December 2005 (UTC)--[reply]
And we mean HERE in THIS thread ... Please do not start a new sub-topic like you did with the chicken & egg question about creation and evolution.
What I mean by chicken & egg is that when species-A evolves into species-B we have creation of species-B at the SAME identical time as the evolution of species-A, which is a slightly different answer than some other people gave to that series of thread installments. User:AlMac|(talk)10:03, 26 December 2005 (UTC)[reply]
havent u guys seen the pic of the spinning jenny ,in that pic ive made a box on certain areas could u tell me what it is and what it is made up of --- the preceding unsigned comment is by 212.72.30.135
Pictures with my digital Sony DSCW1 are often blurred when
the motive i moving. How to get sharp pictures?
You need to decrease the exposure time. This is often possible to either do using a mode on the camera (something for rapid motion), or manually (by setting the settings manually). If the subject is well-lighted (i.e. outdoors) i will be much easier to have a small exposure time as well. --Borbrav17:11, 26 December 2005 (UTC)[reply]
Cant believe that I found an answer on this. Most point and shoot cameras have immediate sharpen filters. Try loading it into a photo-editing program and use the sharpen filter. Artoftransformation07:43, 27 December 2005 (UTC)--[reply]
No no, that's patching things up a little. Best to get the pic right in the first place, and shortening the exposure time is indeed the most logical one. This will, however, make the photo darker. You could increase the ambient light or else open the shutter wider (aperture), but that last option means the image will be sharp in a narrower depth range. Sorry I can't find the right words to explain this in a simple way right now. But if you're a newbie to photography you cou,d probably use some dedicated presets in your camera (if it's a fairly recent digital one anyway).
A last option (when it's a constant motion like someone running) would be to follow the moving object, but then the background will be blurred. DirkvdM13:41, 27 December 2005 (UTC)[reply]
I agree with DirkvdM, use a shorter shutter speed (1/120 - 1/500) depending on light and speed of subject. If you require more light increase the size of your aperture (low numbers eg. 2.8) and/or raise the ISO of your sensor (should have an option in your menu, try 400). Probably best use the "sports" scene though.--Doc0tis22:19, 29 December 2005 (UTC)[reply]
Its common knowledge that a gust of wind can put out say a candle or a matchstick. But doesnt the wind contain oxygen a supporter of combustion? Why,then do the flames go out in the presence of a gust of air?
A large enough flame won't go out, as the gust of wind rapidly cools down the fuel source below the point at which it will burn. --Borbrav17:07, 26 December 2005 (UTC)[reply]
Yes the incoming oxygen comes at great expense of the flame at being cooling oxygen if the flame is small. If the flame is large, then there is enough heat that oxygen can be provided while reducing temperature insignicantly, unless you get a tornado or a hurricane, that is. -- Natalinasmpf17:17, 26 December 2005 (UTC)[reply]
The best way to visualize this is that for fire to exist, there must be three elements: fuel, an oxidiser, and heat. If you remove any one element, that will put out the fire. A lot of people say that only fuel and oxygen is needed for fire, but this is obviously quite silly as that would mean that the wooden desk I'm sitting at right now would be on fire (it's not). Heat is just as important as the other two elements. -User:Lommer | talk02:25, 27 December 2005 (UTC)[reply]
And to continue the previous explanation, wind will disperse the heat and may bring it below the threshold of heat needed for the fuel/oxygen combo to ignite. I'm still dissatisfied with this answer, though, because to get glowing embers to ignite it helps to blow on them. And from experience I know that you can blow pretty hard without blowing them out. Blowing hard is generally even a good thing. DirkvdM13:47, 27 December 2005 (UTC)[reply]
Blowing on embers is probably only cooling the surface, not the heat inside. While allowing oxygen to reach the glowing parts, which by then can resurge, reheat the surface and reignite. Blowing on a piece of slightly glowing paper for example, would be likely to extinguish it immediately, due to lack of depth. -- Natalinasmpf17:05, 27 December 2005 (UTC)[reply]
This is because the heat of the flame evaporates the fuel, which then burns. If the wind blows faster than the flame can grow towards the source of fuel it will starve. Pilatus02:20, 1 January 2006 (UTC)[reply]
Hi, I [understand that wikipedia is not a medical expert source so don't bother me with the whole disclaimer please] have been experiencing a spasm-like problem in my arms, however it is not accompanied by pain. My upper arm muscles suddenly contract once and then stop, and I barely even feel it. If I think about it long enough I can keep them from happening, but on the most part it seems to be involuntary. What might this be? — Ilγαηερ(Tαlκ)16:51, 26 December 2005 (UTC)[reply]
It could also be carpal tunnel syndrome, a kind of repetitive stress syndrome that office workers and computer addicts suffer from and have to watch out for. Therapy and, eventually, surgery are the only known cures for repetitive stress syndromes. Or maybe multiple sclerosis. [I'm not a medical genius so don't bother me with the "no, that's how the sickness is" thing please] Or it could be your unconscious telling you to Wikibreak. ;) Igor the Lion(Roar!)18:52, 26 December 2005 (UTC)[reply]
I like to introduce my two new laws of physics for review. This law’s of mine are from years of research.
Below are my two new laws of physics I called: “Law of Time, Energy And Motion” and “Law of Origin”.
Law of Time, Energy And Motion states:
Time, records the beginning and the end of any and all historical events, regardless of its insignificance. Energy, used to cause an explosion which sets a body into motion. Motion, caused by the force from the strength, of the explosion, when energy is applied.
Law of Origin states:
1. “A body set in motion, from a point of origin, will come to rest”.
2. “A body can not be in motion without a point of origin”.
3. “A body can not come to rest without a point of origin”.
4. “A body can not exist without a point of origin”.
Hate to say it, but somebody might have beaten you to your discoveries by a few centuries. These laws of yours look like variants of Newton's laws of motion (especially the first one), albeit veiled in terms like "origin", "time", and "energy". Newton's first law states that an object at rest or in motion stays in that state unless acted upon by an external force. The origin-destination part is already superfluous. Time is also necessary for these events to happen, hence it's not being necessary. Igor the Lion(Roar!)18:57, 26 December 2005 (UTC)[reply]
Wikipedia is not a place for original research, or for formal peer review of such research. To get your theories accepted as scientific, you would need to write up a formal paper, including the experiments you have done to demonstrate your hypothesis, and submit it to a reputable scientific journal. However, they would clearly reject it because your "laws" make no sense. I doubt this is the kind of comment you were welcoming, but there you go. rspeer / ɹəədsɹ 19:03, 26 December 2005 (UTC)[reply]
On your first law, I would say that according to Quantium Electro Dynamics, (QED) the simultainous creation and destruction of an anit-proton violates this law. The creation time and destruction time are identical so the magnitude of duration is zero. It would be of great service to you to read the Feynman Red Books.
On your first part of your second law. If the amount of dark matter in the universe is not enough to collape the universe, then if you mark a point of the center of mass of the universe, and draw a straight line to the furthest point(s) of expansion, then if the universe is open, then these distances will increase eternally, and will never come to rest.
What is the probability of two people having same fingreprints?
though no case is not yet known of same finger prints but still please dont say that fingerprints are absolutely unique. i read the figure a long long time ago in some book but forgot
There are about one billion possible minutiae combinations on a fingerprint; since there are about 5 billion people inhabiting the Earth, and each has ten fingers, this means that statistically it is likely that fifty people on Earth share a fingerprint
I would suggest that the 50 billion fingerprints are all unique, but the limitations of our technology are such that we can discriminate only to a certain level. In the future, this may be different. JackofOz20:51, 26 December 2005 (UTC)[reply]
As I recall, the probability of two people having the same fingerprint is about one in 20 million. The probability of two fingerprints being mistaken as being the same is currently about one in a hundred. GeeJo(t)(c)21:12, 26 December 2005 (UTC)[reply]
I don't at all remember where I saw this, but I read an article on the probablilty of people sharing half- or quarter-prints, which is probably much more likely, and may be what actually happens. The difference in the prints is in the position of the minutae, such as ridge endings and bifurcations. Even if people have the same print, there probably are a enough minutae o make it a difference. The likelihood of people sharing the same fingerprint when there are so many options is even lower than 50 people out of everyone on earth. 152.163.101.1223:49, 30 December 2005 (UTC)[reply]
Water tends to minimize its surface area. If a drop is falling through the air it forms a sphere because there are no other forces acting on it (besides negligible friction with the air). If the drop is resting on a flat surface, there are two forces competing with each other: gravity and surface tension. Surface tension tends to form it into a sphere; gravity tends to flatten it as low as possible. The result is a kind of squashed dome shape. It also depends on the chemical properties of the surface: water on a waxy surface will bead up more than on glass. —Keenan Pepper21:59, 26 December 2005 (UTC)[reply]
Hydrogen bonding is the most significant of the forces in surface tension for water, IIRC. This is a rather weak bond compared with other bonds, but raises the forces between molecules significantly, and competes with gravity in order to maintain connected other water molecules. -- Natalinasmpf06:50, 27 December 2005 (UTC)[reply]
well natalina i knew that .. but never knew that it was impact on water's shape.. thank you keenan and natalina and obvioulsy bob for the earliest reply !
Greetings,
I've been researching a product called "ThreeLac", on the Internet. It's a treatment, originally from Japan, for candida (yeast infection)-type infections. I've been trying to find out if the three main ingredients it lists are safe to ingest. They are: 1. Bacillus Coagulans 2. Bacillus Subtilis and 3. Enterococcus Faecalis.
In Wikipedia I found them, and, as suspected, they can cause serious diseases. I'd like to find out (from a reliable source) if this is safe to take as a treatment.
If you want medical advice from a reliable source, you really shouldn't be asking on Wikipedia. Not to disparage Wikipedia or yourself, but medical advice should only come from medical professionals. Ask your doctor or specialist. --Canley03:43, 27 December 2005 (UTC)[reply]
The product is appropriate for the alternative medicine type of candidiasis (i.e.,, the yeast connection type where the diagnosis is based on a vague symptom list or fraudulent tests from quack lab), not the kind of candidiasis where someone can actually culture or see the organisms microscopically in any part of your body. If you find this confusing, you can thank the quacks for one more dishonest and misleading appropriation of medical word usage for purposes of fraud and confusion. Unfortunately, if you have a serious candidal infection and you use this, you may not survive, but for the culture-bound syndrome type, it might work. alteripse17:34, 27 December 2005 (UTC)[reply]
I read the article, but I didn't get any clossure, nor peace of mind, haha..does anyone have anything to say about this? ( about the moon landing hoax that is)
I have seen both the Apollo rockets, have worked for someone in the NASA program, and have touched a moon rock, and have looked at one under a microscope. The texture of the lava flows must have been formed in low gravity. so...unless there is a source of molten rock in orbit, it would have been a lot cheaper to make the road trip then to burn the rock. Artoftransformation07:32, 27 December 2005 (UTC)--[reply]
Check Nazi moon base, they were there first! As far as it being a hoax, that would be tough given the state of the art in special effects in 1969, and the state of the art in 2005 in examining footage. Someone would have found something by now if it was a hoax. Dominick(TALK)13:36, 28 December 2005 (UTC)[reply]
So dominick,do you mean, none of those was actually a hoax? I mean, nor the apollo one, nor the nazi one?because I speak spanish and I don't get you, sorry:)
Es muy improbable que el Apollo aterrizaje (?) fuera falso. Ningunos astrónomos (ni científicos en general) dudan la veracidad de la misión. Dominick dice que como efectos especiales en 1969 no fueron muy avanzados, y hoy tenemos tecnología tan poderoso, debemos poder encontrar pistas en los vídeos si serían falsos. Por otra parte, es improbable que los Nazis salieran de la Tierra. No hay ninguna evidencia que viajeron a la luna; es un mito viejo en cual solamente muy pocos personas creían. (¿Entiende mi español? Hace muchos años...) — Knowledge Seekerদ23:39, 28 December 2005 (UTC)[reply]
Thank you so much!!! :) I understood it all! that was so cute! thanx!!!:)
If you observe the newsreel images of American astronauts hoisting the "star spangled banner" on the moon you will see that the flag is fluttering-as flags do on Earth on windy days.But if the moon has no atmosphere then how does the American flag move in the wind?Isnt it impossible?
Did you know that the moon is subject to frequent moonquakes? From all those mertorite impacts. Im suprised that one hasnt hit the flag while it was standing.
Actually there are no moonquakes (of tectonic origin). The moon has a solid, non-liquid core. It is tectonically and geologically dead. And meteorite impacts don't really happen anymore. At least, we haven't yet observed a single big meteorite impact since the discovery of the telescope. And it would take a big impact to cause a moonquake. Remember, Luna is billions of years old, and it has accumulated those craters in a very long period of time. Also, most of the craters were created near the beginning of its lifetime. The solar system has been relatively weeded out of possible big impactors over all of those billions of years. --Cyde Weysvotetalk18:26, 27 December 2005 (UTC)[reply]
Of course the flag moves about while it's being hoisted. It's not a rigid object, is it? (18:14 UTC, December 27)
Well, depending on how you define "big", we actually observed a 12cm meteorite impacting just a few days ago [61]. Also, when it comes to moonquakes, I suspect that what the Artoftransformation was referring to is the fact that the moon is still oscillating because of vibrations from ancient imapcts. I can't remember where I read this, I can't seem to find the source again, but the gist of it is that we've used the Lunar Laser Ranging Experiment to determine that the moon is gently oscillating about two axes. This is hypothesized to be because a large meteor would compress the moon along the axis parallel to its trajectory, and the moon sort of squishes out like a rubber ball. After the impact the moon continues to oscillate back and forth for a long time, and this small vibration (measured in centimeters and with a period of days IIRC) is measurable. -User:Lommer | talk21:48, 27 December 2005 (UTC)[reply]
Well, I wouldn't consider that big. It only created a crater "about 3 meters wide and 0.4 meters deep" (from your source). And it wouldn't cause moonquakes. As for what you said about Luna still oscillating from ancient impacts ... I am highly doubting that. I'd like a reference to a scientific journal article. Everything I know about astronomy is telling me this just doesn't feel right. --Cyde Weysvotetalk21:59, 27 December 2005 (UTC)[reply]
The stick held out the flag, and the momentum gained while being waved about by the astronauts kept it flapping for a while. If you went to the moon today, the flag would be completely still, but in a waving position. smurrayinchester(User), (Talk)16:01, 28 December 2005 (UTC)[reply]
I'm a nurse working in a hospital. We have a policy at the hospital that intravenous synthroid are only to be given by MD's, not RN's. However, no one I work with seem to have any idea why there is such a policy. Anyone have any suggestion? Perhaps IV synthroid can lead some kind of acute adverse effect?
Hi there. Wikipedia's article on Levothyroxine is rather short. This site seems to have fairly comprehensive information on the drug and appears comprehensive, but I'm not competent to judge its accuracy. From my layperson's reading there doesn't appear to be anything there to explain your hospital's policy, but perhaps there's something there that makes more sense to you than to me. You might also do a search on PubMed, a search engine for medical journals, to see if anything relevant turns up. Oh, and it's possible one of the medical professionals who reads this site might have a better answer than I (whose only skill in this area is being better than average at using search engines) can provide. --Robert Merkel12:47, 27 December 2005 (UTC)[reply]
There are hospitals that have safety policies about a physician or an RN being required to give any drug by iv push that is ordered. IV thyroxine is very safe but is quite expensive and in my experience over half of the times I have seen it used was used unnecessarily. I suspect either that the policy default is to include all drugs except common ones specifically excepted or if it was specifically designed for IV thyroxine, was based more on economics than safety. Check with your pharmacy; they should be able to tell you why. alteripse14:01, 27 December 2005 (UTC)[reply]
Evaporation of Water below 100c, at atmospheric pressure
Why is it so that when, for example, water is spilled on a day whose average temperature is say 25 degree celsius, evaporate or diminishes after some time? Evaporation temperature is 100 degree celsius at 1bar pressure, then why does water evaporate at such a lower temperature? —Preceding unsigned comment added by NIKHIL SHARMA (talk • contribs)
Boiling is different from evaporation. Evaporation often means interaction with an open system, hence, there can be fluctuations on a molecular scale (heat, Brownian motion, etc.) that causes molecules to escape into the air, molecule by molecule through diffusion et al, due to differences in gradient. This process can repeat itself because the concentration drops again, restoring the gradient difference (ie. if there's wind) for more molecules to escape. Basically, molecules just simply need to gain a small amount of energy to escape, surface by surface. In contrast boiling happens not only in the surface. Air pressure also affects diffusion, as well as generating a vacuum, which is why it affects these processes. Anyhow, boiling per se allows the entire liquid in bulk to change phase and break intermolecular bonds (hence one sees bubbles), whereas evaporation only happens at the surface. -- Natalinasmpf06:37, 27 December 2005 (UTC)[reply]
(N.B. This is a variant of your question, I noticed too late) At high altitudes, water boils at low temperatures, too. Tibetans are actually able to make boiling tea that is not hot. This is because of the lower atmospheric pressure at the higher altitudes. Water requires (if I remember correctly) a certain atmospheric pressure and needs to be in a certain temperature range to remain liquid. Remove the pressure or change the temperature and *poof* - there goes your water. This is also one of the arguments that some NASA scientists use to disprove the existence of liquid water on Mars (i.e. the water would evaporate due to low atmospheric pressure). Igor the Lion(Roar!) 19:34, 27 December 2005
(UTC)
"Boiling tea that is not hot". That's nonsense. At 8000 m the boiling point of water is still around 75 oC which is still considerably hot, for my tongue at least. -- Rune Welsh | ταλκ | Esperanza15:47, 29 December 2005 (UTC)[reply]
While it's probably still hot for drinking, I've heared that it can pose problems because cooking food can take much more time at that temperature. In fact, that's true on 100°C too, which is why we use pressure cookers.
What is the code for opening .jpg files using c-programming. Secondly, how can 256 color .jpg files be opened without losing their original colors.Thank You.
It appears that he is asking how to open a JPEG without color loss. If any compression was used, you cannot get the original image back. JPEG is a lossy format, which means that is loses information when it is created. I'm sure there are algorithms to try and get back to the original image, but they exist mostly in Hollywood - where they can re-create a clear license plate with just three gray pixels. --Kainaw(talk)15:42, 27 December 2005 (UTC)[reply]
I especially like the ones where they can recreate a scene by looking at the reflection from somebody's eyeball (consisting of said 3 pixels in the original picture). CSI is particularly fond of that one. To the original poster: you may be better off using Java, which has built-in JPEG capabilities. --Bob Mellish16:16, 27 December 2005 (UTC)[reply]
I was wondering if someone could post information on the metric of color distance in particular the NORMALIZED COLOR DISTANCE(NCD) and how to find it for an image,I am not able to find it anywhere on net!!
Thank you,
Hari Puvvadi
First, drop normalized for now and focus on color distance. There are multiple ways of calculating color distance. Some get the average absolute difference between the red/green/blue tones of all neighboring pixels. Some average the difference of every pixel to every other pixel. Some are not pixel-based at all and use an analog histogram. So, unless you know what kind of color distance you want, you are stuck. As for normalizing it, you are referring to comparing color distances between multiple images. Assume you have three images with shades of red. One has a min red tone of 10 and a max of 20. Another has a min of 1 and a max of 50. The third has a min of 90 and a max of 100. By normalizing, you adjust the differences so that each image is working off the same scale. So, you would adjust each image so the min is something like 1 and the max is something like 100. Then, get the color distance. --Kainaw(talk)01:47, 28 December 2005 (UTC)[reply]
Alphabet contains 26 letters (don't forget punctuation: ! ? , ; - " ) é à : ), printing machines date back to 1440, and at that time, around 1000 books were printed each year (nowadays it is around 700000).
Could you tell me when all possibilities of variations will be exhausted ?
When will literature be redundant? —Preceding unsigned comment added by 82.125.117.98 (talk • contribs)
Only if you consider a rigid limit for size for the texts (which is silly) and consider valid 99% of the other possibilities are pure garbage, a bunch of nonsense characters, I'd say the answer is way too much to worry about. But seriously, considering the fact a book could be written to be indefinitely long, the answer is never. ☢ Ҡieff⌇↯09:26, 27 December 2005 (UTC)[reply]
Some rough calculations give around (30^500000) years, given some assumptions and approximations. The is weeeelll past the expected life expectancy of the universe.--84.64.190.112:18, 27 December 2005 (UTC)[reply]
There are an infinite number of variations. Jorge Luis Borges toyed with this idea in his short story "The Library of Babel", in which a library contains every possible 410-page book. This library turned out to be the size of one whole universe, so I guess that has to be quite a lot of books. And if you expand that to a library containing every possible n-page book, I guess it will have to be infinitely big.... In the story, most of the books contained nonsense, too, such that the librarians would rejoice when they found a single meaningful page or even a word. Igor the Lion(Roar!)19:27, 27 December 2005 (UTC)[reply]
Aw, man. I thought I was going to get to bring up The Library of Babel but I see I was beaten to it soundly! Also -- there is probably not an infinite number of variations in the strict sense, but from a human point of view the difference is unappreciable. --Fastfission15:53, 28 December 2005 (UTC)[reply]
Also remember, that even if you totally exhaust the latin alphabet and all its variations, you still wouldn't have filled your library. You would be able to make the same exercise with the cyrillic alphabet aswell. And the greek. And hieroglyphs. And indian scripts. And the chinese, japanese (all three (?) of them!) and korean writing systems as well. And the ones of native americans. And runes. And scientific and mathematical special signs. And then we have combinations of them (especially in multilingual books or science books...) TERdON15:37, 30 December 2005 (UTC)[reply]
What is the name of the usually black and white board shown at the beginning of a film clip (with Scene, take, film, etc) - I've heard it called "Marker", "Slate" etc, but cannot find a wikipedia article on it, nor a generic name? Can anyone help me out? Thanks :) -Benbread23:30, 27 December 2005 (UTC)[reply]
Can anyone help me find the specific heat of lemon juice and the specific heat of milk? If anyone can figure out what it is please list them in joules/grams degrees celsius. thank you. Evan cold
Both lemon juice and milk are mostly water, so if you can't find a more accurate answer you should be okay using the specific heat of water, 4.185 J/(g °C). —Keenan Pepper02:40, 28 December 2005 (UTC)[reply]
A Google search reveals that the specific heat of milk is .92 BTU per pound degree Fahrenheit, which converts to about 3.851856 joules per gram degree celsius. I couldn't find the specific heat of lemon juice, only one question that makes students assume it's the same as water. --AySz88^-^02:47, 28 December 2005 (UTC)[reply]
You need to remember that milk is a combination of different substances. Specific heat is a quantity that can only be attributed to a pure substance (one type of molecules). Besides, there's loads of different types and brands of milk, each of which could have a different specific heat. - Mgm|(talk)22:48, 28 December 2005 (UTC)[reply]
Actually, the specific heat of a mixture seems to be the sum of the specific heats of its pure parts in proportion to how much of it is in the mixture (by mass). [63] --AySz88^-^22:57, 28 December 2005 (UTC)[reply]
The specific heat of milk depends on its fat content - the water component has high specific heat, the fat, low. So skimmed milk has a high specific heat (nearly the same as water), while full cream milk (3-4% fat) is lower, and full cream Jersey cattle milk (4-6% fat) even lower - MPF23:22, 28 December 2005 (UTC)[reply]
I am a middle school student, and I would like to know how to calculate the specific heat of certain liquids. Can some someone please explain how to do this and give an example.
My doctor has been doing extensive testing and has recently come to the knowledge that I have torn the cartilage in my chest that connects to the breastbone, in both sides of my chest.
He is now talking about operating to repair it, and, as he stated it, "cut the nerve that is causing the pain".
My question is, is the brestbone, or the cartilage, or even the nerve, located in any way behind the sternum ?
I am seriously contemplating going through with this surgery, but I am curious to know if the sternum will have to be broken during the surgery if I do it.
Thanks,
Katie Jackson
Ms. Jackson, you should really be talking with your physician about this matter. Or ideally, the surgeon who will be performing the procedure. That's part of her job. The breastbone is the common name for the sternum. The cartilage that connects it to the ribs connects to the side of the sternum. However, I don't know the details of the surgery; by far the best person to discuss this with is the physician who will be performing the surgery (or else the one recommending it). — Knowledge Seekerদ06:33, 28 December 2005 (UTC)[reply]
I do not know how old you are nor the details of your symptoms. Episodic chest wall pain is extremely common in adolescents and young adults. It can be sharp and brief, or dull and vague and prolonged. We usually call it costochondritis and describe as a strain or inflammation or tear in the cartilage, tendons, muscles or connective tissue joining the ribs and sternum. Perhaps because people this age do not commonly have much experience of serious disease it often seems excessively frightening or disturbing to them. It is a "clinical diagnosis", and cannot be confirmed by testing or imaging. The most effective treatment is usually description and reassurance of transience and non-seriousness. If they fall into the hands of a doctor who is well-intentioned but does not know the enormous differences in disease probabilities by age, or how to deal with teenagers effectively, the result may be too much testing and consultations performed in ways that intensify the anxiety rather than allay it. At worst it produces what used to be quaintly called a cardiac neurosis. I have trouble imagining a cause of chest pain warranting surgery but IANYourD and you will have to decide whether these generalizations apply to you and whether you need another opinion. alteripse13:16, 28 December 2005 (UTC)[reply]
I don't think that's it at all. The electron gun has to focus the beam of electrons onto the screen, so all the parts of the screen have to be the same distance from the electron gun, hence spherical curvature. It has nothing to do with the strength of the glass. —Keenan Pepper19:52, 28 December 2005 (UTC)[reply]
i have a 'PS2' mouse attached to my pc the problem is that sometimes it appears to have a life of its own because it begins to move randomly in evry direction although i was not even touching it mouse nor was it shaking only the pointer kept on moving here and there do u guys have any remedies for this
I suspect demon infestation. It's a common problem with mice, as compared to other peripherals such as keyboards, which are rarely possessed by forces of evil. To solve your problem, I suggest trying a partial exorcism.
Step 1) Acquire some holy water (also known as soapy water) and a cloth.
Step 2) Open the bottom of the mouse, and remove the ball.
Step 3) Using the holy water, wash the ball and dry.
Step 4) Remove any fluff or dirt from the mouse's innards. Remember, cleanliness is next to Godlines, so by cleaning it out you're repelling any demons.
Step 5) Replace ball, and close the mouse up again.
Step 6) (Optional) Pray to any deity/ies of your choosing that your mouse stays free of Beelzebub's clutches, and repent from any sinful behaviour.
NB: This exorcism will not cure any problems with mouse daemons, such as point32. If these daemons are demonically infested, you will have to call in a professional exorcist. --Sam Pointon11:59, 28 December 2005 (UTC)[reply]
I've observed a similar effect whenever my mobile phone goes off near the mouse. I can only assume that the RF shielding in the mouse is less than milspec. Ilmari Karonen (talk) 13:09, 28 December 2005 (UTC)[reply]
If it is not a wireless mouse, you may have a bad cable. Look carefully for any indications that the cable was physically damaged (pinched, crimped, twisted). The damage might be right where the cable connects to the mouse. --JWSchmidt16:16, 28 December 2005 (UTC)[reply]
If it is a wireless mouse, it's possible that another source could be interfering with the signal, such as cordless phones or other wireless equipment. smurrayinchester(User), (Talk)16:20, 28 December 2005 (UTC)[reply]
thanx alot guys ill clean its'ball'
by the way what is point 32
Because the actual ocean is a barren wasteland. Organisms live where the water interacts with other stuff: on the ocean floor (with ocean vents), on the coast (with land), and on the top of the ocean throughout (with air). The "middle" of the ocean, like say a few hundred miles off shore and a couple miles deep, is pretty much absolutely barren. There's no source of oxygen and no source of light energy to drive photosynthetic life processes. Your question is basically similar to asking why most organisms tend to live in forests rather than deserts. It's simple, there's a better ecosystem in the forest, but us being landlubbers, we don't exactly see this at first when we look at the ocean because we think it's all just seawater. --Cyde Weysvotetalk14:06, 28 December 2005 (UTC) by FINLAY JOHN JACK[reply]
How to rename a folder with ASCII characters using DOS prompt in Ms-windows
How do you draw unwaranted attention to yourself without using all capital letters? Right, you use bold type. IMHO you do not deserve to get an answer. DirkvdM14:12, 28 December 2005 (UTC)[reply]
Dont be so rude! Of course he deserves an answer. I'm not sure what the anon is asking but to rename a file in DOS I think you jus type rename oldname newname at the command prompt (oldname shjould be replaced by the actual old name of the file newname should be replaced by the actual newname you want) Theresa Knott | Taste the Korn14:27, 28 December 2005 (UTC)[reply]
I think the person is having trouble with filenames that use ASCII characters that are not typeable (such as character 7, the bell). I don't know the answer, but maybe someone does with a clearer question. --Kainaw(talk)14:41, 28 December 2005 (UTC)[reply]
That makes sense. To type a character that isn't present on the keyboard you hold down the alt key and use the numeric keypad to put the ASCII numerical code in. Well from memory I think that's what you do - it doesn't work in linux. Let me boot to windows and I'll try it out. Theresa Knott | Taste the Korn14:49, 28 December 2005 (UTC)[reply]
You can set up a compose key with X. It's easy to do in GNOME. I use Ubuntu and I just go to System->Preferences->Keyboard and select Layout Options. I have mine set to the left alt key but you can also make it the windows key or the menu key or some other things. —Keenan Pepper15:39, 28 December 2005 (UTC)[reply]
Go to its parent directory so that when you type dir it is listed, then type ren oldname newname. If the problem is that you can't access the name because it has spaces or odd characters, use dir >dir.txt and edit dir.txt to be ren oldname newname keeping the oldname from the dir command. If it has spaces in you will need to put it in "". The rename dir.txt as mycmd.bat and type mycmd. -- SGBailey00:39, 29 December 2005 (UTC)[reply]
If you had an IBM Keyboard, that's what the HEX key is for, to make it rapid for programmers to incorporate weird characters in their programs, either ASCII or EBCDIC or HEXADECIMAL or some other such code. Check the archives of the discussion for Reference Desk ... there's some places in the world where they only communicate using upper case ... some kind of cultural thing. User:AlMac|(talk)07:01, 29 December 2005 (UTC)[reply]
how do ballerinas spin so fast plenty of times without feeling dizzy?
thanks
Watch the ballerina's head as she spins - although her body is spinning at a uniform speed, her head isn't. Instead, she looks at a fixed point in the distance, and keeps her head pointed straight at it. When her shoulders have spun round so far that her neck is twisting too much, she quickly snaps her head around through 180 degrees to fix on another point, roughly opposite the first. Then, as she continues to spin, she snaps her head around to the first point (and continues like this). I just tried that now, and it still makes me dizzy (but less so than just keeping my head at a fixed angle to my shoulders). I guess they practice this too. -- Finlay McWalter | Talk12:55, 28 December 2005 (UTC)[reply]
However, figure skaters can't do that, because they spin too fast. They just have to get used to the motion with practice. --Anonymous, 08:00 UTC, December 29
how can we find if water is mixed in the milk we consume?
What do you mean? Cow's milk (straight from the cow) is mostly water. Human's milk is mostly water. Goat's milk is mostly water. What milk are you consuming that isn't mostly water when the animal is milked? --Kainaw(talk)14:39, 28 December 2005 (UTC)[reply]
The simplest way might be to get a couple of whole milk samples from a couple of other sources and subject the 3 samples to some simple physical tests: evaporate equal amounts and see if you have equal amounts of solids left, or do successive dilutions until the milk is non-opaque and see if your suspected sample looks translucent first. The detection advantage you have is that the only reason to dilute milk with water is to increase the volume, and there is no reason to do that by just a couple percent or it's taking a legal risk for minimal gain. Besides, if it is only be a tiny amount, what do you care?
Note that we are not talking about fat content, but total solids. Make sure your samples have the same fat content. Also, make sure your samples do not come from the same dairy under different labels.
There have been different milk purity issues in different times and places:
Dilution with water because milk is sold by volume
Deliberate fraudulent addition of substances to make milk look more saleable
i need some help with coding for a web site i want to make. i read that i can use a input tag for buttons instead of the normal button tag but i am unable to understand how to use the input tag. i am able to display the button i want but i dont know where to place the link. i have been tought how to use notepad for making webpages but i want to use macromedia-dreamweaver coz i feel it is much easier and takes less time. if any one knows any good site that i can refer to or if they can help me out then please mail me at (removed)
Try <input type='submit'> - an input tag that looks like a button. You can use Dreamweaver, but it is not easier. You are making a choice between learning HTML or learning all the menu items and tools of Dreamweaver. --Kainaw(talk)17:38, 28 December 2005 (UTC)[reply]
Gluons contain supposedly the strongest binding energy in the universe. They hold together quarks, which hold together protons, neutrons, muons, etc., which hold together atoms, and so on. Now, here is my question: can this process be reversed; as in, can there always be something made of something else in both ways? In mathematical terms:
According to the Standard Model, gluons mediate the strong force, which binds quarks together into protons and neutrons. The muon is not made of quarks. It is a fundamental particle which has no internal structure. Quarks themselves are also fundamental particles.
Of course, the Standard Model might be wrong, and quarks might be made of smaller particles after all. That's pure speculation, though, until there is experimental evidence for it. The Standard Model agrees very well with current experimental data. —Keenan Pepper19:43, 28 December 2005 (UTC)[reply]
My Wireless network is becoming retardedly slow. Sometimes it's fast, sometimes slower than dial-up on a cable connection! It never goes up to our max cable speed (about 3-4 mbps) even though it says very good signal strength (max I've ever gotten on my PC is 1.5 mbps). What could be causing this intermittent slowdown? This is getting really annoying. —Ilyanep(Editorials)17:43, 28 December 2005 (UTC)[reply]
How do you know that your wireless is the problem? As far as I know, that's just how cable modem networks work. They are shared, so if a lot of people on your shared segment are using their cable and internet service, your performance suffers. That's all in that article btw :) - TaxmanTalk18:39, 28 December 2005 (UTC)[reply]
I agree that the cable modem can crawl, but there are lots of reasons for slowness (I've had them all!). The router could choke because of trojans on your PC, opening up too many IP connections. Getting rid of spyware is a great performance booster! As well, wireless does not like microwaves or wireless phones. If they are running, your throughput again crawls. --Zeizmic14:00, 29 December 2005 (UTC)[reply]
"It then decodes the satellites’ locations from their radio signals and an internal database"
The "internal database" must be unique to the GPS system, and you will need one for the Galileo system. Therefore, it looks like you will need to buy a new dual mode receiver.--Commander Keane19:16, 28 December 2005 (UTC)[reply]
Although the radio signals themselves will not be different, according to today's Dagens Nyheter (available online in Swedish here). The article states that this will create a market for receivers that can handle both systems. As Commander Keane points out, however, I think it's likely that receivers designed with only GPS in mind will not be able to use Galileo. 217.208.26.17712:45, 29 December 2005 (UTC)[reply]
I am in Ferndown, Dorset and using BT Broadband Basic.
Is this Broadband over PPPoE ?
'Broadband' has become a somewhat ambigious term, extensivly used in marketing. The service you're talking about is ADSL, which is PPPoE over ATM. Therefore, essentially, yes. Syntax00:34, 30 December 2005 (UTC)[reply]
will we never ever ever be able to determine what triggered the big bang? I read that all our scientific understanding breaks down at that point and that all scientists agree,hmmmm.. is that true? haha
...is my question dumb? :(
Our scientific understanding currently breaks down at 10^-43 seconds after the Big Bang has already begun. Whether we will be able to ever go earlier than that is fairly uncertain, and there seem to be no promising reasons to believe we will ever be able to coherently ask what happened before the Big Bang in scientific terms. This might be one of those times to say, "Looks like there will always be some mystery in the world!" but in reality there is always and likely will always be a lot of mystery left in science, and this is just one of the more obvious instances of that. --Fastfission22:52, 28 December 2005 (UTC)[reply]
There is no before the Big Bang, if we accept that the Big Bang is when the idea of before started to make sense.--Fangz23:17, 28 December 2005 (UTC)[reply]
of course there is no before but something has to have triggered it! c'mon, I think we as humans cannot give up! no matter how misterious something looks! :)
Why must something have triggered it. Take radioactivity as a counter example. An individual radioactive atom can decay now or in a thousand years. There is no trigger. it's random - determined only by probability - no cause and effect. Theresa Knott | Taste the Korn01:55, 29 December 2005 (UTC)[reply]
Many find the idea of something being totally random unacceptable. I, for one, am convinced that this is based on a lack of knowledge (our present framework of laws can't predict it, but these will chage over time as they always have). But another comparison is with matter. Where did that come from? What 'triggered' the coming into existence of matter? That's a bit of a silly question (or is it? - it's similar to asking what happened before the big bang)). Is it acceptable that matter has always existed? Is it then acceptable that the big bang has always been as a fixed point at the start of the universe's existence? DirkvdM12:44, 29 December 2005 (UTC)[reply]
Maybe, I think that concerns theology, from that point on...but it's like, we will never extinguish our desire for knowledge and understanding...and I have faith that in the future, maybe us or maybe some better versions of us, will indeed be able to gain such knowledge, and I believe, like einstein did that 'God doesn't play dice' ...I mean, it might as well seem random to us! but who knows if there's something quite rational behind that aparently random thing that triggered it, and we can not know, since we are 'inside' the...let's put it this way videogame.
I know! QM is unpredictable and so on...I knew that, but what I mean is, not that we can predict things, maybe god does play dice at the QM level, but that doesn't say that beyond that qm level, there may be something that has those propabilities already determined, and the people inside the 'videogame' (that's us) can not know the outcome,and thus , think it's totally random, but! the people outside the videogame,know the outcome, but only, they don't let us know they know it.
I don't know if I'm making myself clear, sorry.
ps. by people outside I mean God or whatever multidimensional thing you want to imagine.
But that is exactly what a hidden variable is. The idea is - the world isn't really random, it's completely deterministic. Unfortunately the variables that do the determining are hidden from us. It's an attractive idea, but attractive /= correct.
Yes exactly that, I'm sorry for not understanding your answer about the hidden variables, well I believe there are indeed hidden variables that do the determining, but did you say that experiments prooved that those don't exist and that random is in fact random? or is there still room for a hidden variable to be 'guiding' the randomness from 'within' or from 'below' or 'underneath' or whatever...haha
There have been quite a few experiments done see Bell test experiments. All the experiments carried out so far point to their being no hidden variables. However critics have argued that there are ways round it, the experiments haven't tested the idea fully. New experiments are being planned (I got that from the article) So my best answer to you is - I don't know for sure but watch this space! Theresa Knott | Taste the Korn08:40, 30 December 2005 (UTC)[reply]
Thanx, you rock :) , hey by the way! do you believe in 'god' or something?
There is a theory which states that if anyone ever discovers exactly what the universe is all about, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states this has already happened.
How do they deal with itches? Obviously, they might have a device to move over the area, to scratch it, but I'd probably scratch myself ~100 times a day. Do amputees naturally suppress the urge to scratch? Mjm196421:49, 28 December 2005 (UTC)[reply]
Well, first off I would think that it would depend on what limb in particular had been amputated. Although I'd imagine that if they couldn't reach an itch, they would do the same thing that non-amputees do, use a stationary object such as a chair or corner of a wall to reach the itch. Dismas|(talk)22:08, 28 December 2005 (UTC)[reply]
I don't know, but the worst is dealing with phantom itching in the amputated part (yes, it does happen) - how does one scratch a leg that isn't there? - MPF23:07, 28 December 2005 (UTC)[reply]
is it backed by science at all? does the white race have anything better than, say, latin american women? I mean, there is always this steriotype that white men are the smartest creature on earth while women are less and most of all if they aren't white women.
and, did the germans have any 'contact with subterranean alien races' or whatever? if it is not so, why do some german scholars think so? I'm confussed...
Also! what about the german moon base? wow... there's some crazy theories out there! darn! haha
There is a difference in how different races perform in IQ tests. Of course IQ tests are very good a decided how well you perform in IQ tests but are they good in deciding intelligence? I don't believe that there is any reason to believe that differences between races and sexes are at all significant compared to differences between individuals. There are some very smart people about and some very stupid ones.
The Germans belief in their own superiority has a lot to do with wishful thinking. Times were hard then, they'd lost the first world war and had crippling debts and inflation. They needed to feel good about themselves. As for German moon base? Are you kidding? Theresa Knott | Taste the Korn01:52, 29 December 2005 (UTC)[reply]
Actually I'm not... I just read it today here..just some questions up this one,
and also... well a race that has to invent something to feel superior without having facts to do so, doesn't sound that superior to me... and also, I read somewhere that men are 5 points smarter than women as a general rule, and I ... just looking at the world myself, can see that it's usually white people who are the most creative and who have made the most acomplishments that we have thanks to them... I'm not white by the way, I'm latin american, and I don't mean to offend other races by this statement, it's just that, I entretain that possibility in my mind... that somehow white people are smarter and more creative.
Hmm language - probably black
Art -great art has been invented by all cultures and all races
Mathermatics again all races but the indians, chinese, greeks and arabs are particlualy famous.
Music - all races
Literature - all cultures
Science - here whites do have a temporary advantage, but there is no reason to assume that advantage will last.
As for men being 5 points smarter than women - who designed the IQ test a man or a woman. Do you see what I am getting at ? Bias is difficult to eliminate. If you set score by these somewhat crappy tests I believe Asians come out top. Theresa Knott | Taste the Korn02:18, 29 December 2005 (UTC)[reply]
Men and women, on average, do have some difference in ability—each gender is a little better at certain things but there is a lot of variation within gender so it would be very difficult to draw a broad conclusion in most cases. If you picked a random man and woman you couldn't be sure at all that one would be better at creative expression or the other one at visualizing in three dimensions (although you could more confidently predict that one would be stronger or one would live longer). Part of this is cultural, but much is genetic too. Regarding races, it's much more difficult for many reasons, not the least of which is it's hard to come up with a good scientific definition of "race" (even though it would be useful in some areas, like medicine). Nevertheless, it is often possible to draw some very broad but limited conclusions—still, much of this is culturual rather than genetic. For instance, people growing up in a country where English is spoken who then move to an English-speaking country may pursue different jobs than one who learned English in school before immigrating. However, it cannot be denied that Europeans (including their former colonies in the Americas) are dominant in the world today. Why that is has been a matter of much speculation. You may find Jared Diamond's Guns, Germs, and Steel interesting, as it tackles this very question in far more detail than could be done here, and with evidence and reasoning. I've only just started reading it (yesterday!) so perhaps it will not end up being a good book, but it is thought-provoking so far (which is the purpose of a good book). Consider checking it out from your library. — Knowledge Seekerদ03:07, 29 December 2005 (UTC)[reply]
Awesome, I will try to find it, but I think it will be hard since I live in South America.
I think maybe many factors intervined, but I also read somewhere that back in hindu history, they considered white people, gods, so ideas like this are not this recent...also the legend about the Teuton women that killed themselves in a 'heroic' manner, I think in ancient greek times or something and they considered them goddesses, so maybe there's a little truth in the speculation of their superiority, who knows.
Perhaps an online bookseller would be helpful? Regarding gods, I think you may be referring to some of the encounters Native Americans had with European explorers, although perhaps those tales are apocryphal. — Knowledge Seekerদ22:43, 29 December 2005 (UTC)[reply]
I've been noticing this world development too, and I almost have a conclusion that white people are (until now) the people who change much the course of the world. If we take look at ancient world, they have great kingdom like Egypt, Greek, and Rome. But in Asia here, we do have China. But it seem that European kingdom keep growing in science, mathematics, architecture. While China stagnate, until recently. Asia also has Japan, the most advance country in Asia. roscoe_x03:07, 30 December 2005 (UTC)[reply]
actually, I'm getting to the conclusion that it depends upon each single person and not a race to be 'better', and also, maybe white people had the advantage of the cold weather, since they had to build better shelters than,say, africans.
"As for men being 5 points smarter than women " Not true. The average man IQ == average woman IQ. However, the width of the bell curve is wider for men than women, thus there are more men at the extremes, ie more male geniuses and more male idiots. According to what I read. GangofOne11:06, 2 January 2006 (UTC)[reply]
You know what, your analysis is completely messed up! If you analyse very carefully in terms of actual contribution, there are three races that stand out immediately : chinese, caucasian(white) and indian. Every major discovery, invention etc can be attributed in part to these. I have no idea how you say that caucasians have a distinct advantage in science, seeing as science in modern context, of empirical conquest of knowledge, is an arabic concept.
Also i do not see how you say that the "black" race is the foremost contributor to language, when it was the Indo-European language group that is responsible for over 80% of languages spoken today. (cf Latin, sanskrit, all european langauges etc.
Conclusion : There are differences between the races, but you cannot generalise to say that all members of a certain race will be good at certain things. For example, the nazis claimed that the jewish race was the lowest form of human life, when in fact there have been brilliant jewish scientists such as Nikola Tesla and Albert Einstein to name a few.
I am trying to play a dvd using quicktime, but the dvd keeps playing throught windows media player. Does anyone know how to fix that so that Quicktime will be the default video player for a dvd? Also, is there any solution to converting home videos into a format playable on the new video ipod without purchasing quicktime plus? If anyone knows the answer please list them! thanks, stephanie wells
Although I would personally prefer to use wmp, you should be able to use quicktime as your default player by following these steps. Please note that while this probably will work, I don't have quicktime myself, and these instructions are just based on some quick research.
1. In wmp, open 'options'
2. Select the 'file types' tab.
3. Deselect all the boxes.
4. Close wmp, and then open quicktime.
5. Choose 'preferences' from the edit menu, then 'quicktime preferences'.
I have one question. Most of the bacteria die if the meat is cooked properly. If I keep a piece of meat outside in Sun light, and keep it for a few days then cook it, I am sure that people get sick after eating that. But the bacteria should die after eating. So my question is that why people get sick.
BR,
Ram
The problem is that some of the organisms that colonise your beef also secrete toxic chemicals which survive the cooking process. Even though the bacteria are killed, the toxins are left behind. The canonical example is botulism. The bacterium Clostridium botulinum produces a potent neurotoxin: botulin toxin. (C. botulinum is an anaerobic bacterium that sometimes shows up in improperly handled canned goods.) Cooking the food kills the bacteria quite readily, but the botulin toxin remains to cause disease.
Note that not all bacteria generate such toxins—at least, not in such great quantity or potency. Meat products contaminated by Salmonella bacteria, for instance, can be safely consumed after cooking. TenOfAllTrades(talk) 03:49, 29 December 2005 (UTC)[reply]
Lots of peoples in various cultures and circumstances dry meat in the sun. One of the memorable sights in a Mediterranean harbor is the racks of drying octopi. Some types of drying preserve the meat better than others, but I suspect thin strips of muscle or game meat in hot sun would often desiccate rather than rot. alteripse11:39, 29 December 2005 (UTC)[reply]
I would imagine a certain amount of salt is used and the irradiating effects of sunlight may have an effect too. Though maybe the drying and salting dwarfs that. - TaxmanTalk15:48, 31 December 2005 (UTC)[reply]
The 9000 certainly looks familiar; my boss had one, maybe about 1998. Looked like a very chunky mobile phone, which "split open" like a book, hinged along the left-hand side. The part with the screen has the "front" on the other side. Shimgray | talk | 15:51, 29 December 2005 (UTC)[reply]
You say the part with the screen has the "front" on the other side. — in fact it's not that simple. The communicator has the wierd property that (when closed) the speaker and the microphone are on the opposite side than the display and the keypad. For this reason, most people try to raise it to their ears the wrong way, with the speaker facing outwards. (I don't know if this is the case with all phones of the series btw.) – b_jonas20:02, 30 December 2005 (UTC)[reply]
I think it's rather a Nokia 9210. Nokia's Communicator series now have newer models than the 9000, numbered 9100, 9200(?), 9300, 9500. 9000 had a greyscale display, and two shift keys. – b_jonas23:33, 29 December 2005 (UTC)[reply]
The car is the Bean 14 which was involved in two-record breaking journeys: Darwin-Melbourne in 1926 and London-Melbourne in 1927. The National Museum's website has more information [65]. --Canley12:45, 30 December 2005 (UTC)[reply]
what are the benefits of quitting smokeless tobacco?
Nicotine is a minor carcinogen and can stop the body fighting cancer properly. Also, on a more material point, you will save money and tobacco can dye the mouth yellow-brown. smurrayinchester(User), (Talk)10:47, 29 December 2005 (UTC)[reply]
Smokeless or not, tobacco as its used for smoking contains several harmful and addictive chemicals. Quiting smoking will help you get rid of an addiction and stop you from inhaling tar, nicotine and other crap which in turn will almost certainly improve your health and lengthen your life span. - Mgm|(talk)10:49, 29 December 2005 (UTC)[reply]
Smokeless tobacco is widely perceived as being less harmful than the smoked variety. This is patently false: smokeless tobacco is clearly linked to oral, esophageal, and stomach cancer, as well as oral inflammation, gum disease, gum recession, tooth decay, tooth staining, to say nothing of what it makes your breath smell like. In a world where people watch their diet, spend thousands of dollars going to the gym to be physically fit, buy nutritional supplements to extend their life-- using tobacco products is the antithesis to health and happiness. Quitting smokeless tobacco will do more to improve your life than all the other pro-active healthy lifestyle habits combined-- and you'll save money to boot. This is a no-brainer.-- Mark Bornfeld DDS Brooklyn, NY 19:50, 29 December 2005 (UTC)
Well, my question is how to open and play ".mp3" or ".wav" files using C programming? Thank you.
You can "open" the file using fopen(), but I suspect you want to do more than just open it. There are many C libraries for decoding MP3s, for example libmad. The way to open and play a file will be different depending on which library you choose, so read the documentation and learn how to use the library. RIFFWAV files are much simpler than MP3s. They usually have uncompressed PCM audio with a short header describing the format, sampling rate, and number of channels. —Keenan Pepper14:07, 29 December 2005 (UTC)[reply]
Why is it that telephone lines have four copper wires inside when only two are necessary for voice capabilities (0-4kilohertz)? You may be tempted to answer that the other two wires are perfect for a service such as DSL, but you have to remember, phone lines have had 4 wires since long before DSL, and the person who thought up DSL simply found a use for those other two wires. So why were there four in the first place?
I suspect the initial motivation for using RJ11 was ISDN (which uses four of the eight pins for balanced transmission, and has the other four as no-connects). The cost increment of having two pairs in a cable instead of one is so trivial there's no reason not to do so, and latterly folks use the second pair for a second line (in 2-line phones) or some low-power applications (my neighbour runs his doorbell-extender over the other pair). -- Finlay McWalter | Talk13:13, 29 December 2005 (UTC)[reply]
There were two pairs for two lines. In 99% of all installations (when I was 100lbs younger), telco dediced that four wires was most economical to stock. If there was an issue with the blue pair, the orange pair could be swapped in without pulling a new wire run. Some may recall the old "digital" cable bundles with 20+ pairs, I used to watch for installations so I could get free chunks of bell wire. Dominick(TALK)13:23, 29 December 2005 (UTC)[reply]
Hi! I'm having difficulty finding a definition for Tier 0-4 network support. I've searched your site, Google, ITIL, etc and have found nothing. Please help. Thanks.
First, there is a Tier 0? I've always referred to Tier 1 as the top level.
Second, what do you mean by support? You have a Tier 1 network that you need support for? I certainly hope that isn't the case or there would be a lot of Tier 2 networks in trouble. --Kainaw(talk)20:03, 29 December 2005 (UTC)[reply]
A tier system is often used to describe the people who work in IT support in big companies. Tier 1 support is often the person inside a company one calls when they have an issue with IT. If Tier 1 can't fix it, they elevate it to Tier 2, etc., etc. You'll see "Tier X" used on resumes and job posting boards. This might be what you need to know, but it's hard to be sure out of context. Here's a random example: [66] --Quasipalm20:14, 29 December 2005 (UTC)[reply]
Yes, That's what I mean. I need to define clearly who does which Tier and exactly what they do in each tier, how do we differentiate between the tiers? How do we know when we need to escalate? As far as I have been able to find Tier 0 refers to self-service, things that a customer can do on their own before actually contacting the company.
Trust me, if it were on Wikipedia, I'd most likely have found it by now; most of the pages on Unicode fonts contain little information about how much of the latest Unicode revision the font supports. That's what I'd like to know. ;) Nightstallion(?)05:41, 30 December 2005 (UTC)[reply]
Is it bad to leave a DVD player or Recorder in standby indefinatly?
Only in the sense that it is still connected to the power grid, and thus constantly drawing power and always at risk of being struck with a surge. Tzarius07:10, 30 December 2005 (UTC)[reply]
One machine in standby generally consumes just a few Watts, but it's getting more and more common for every household (in the West at least) to have a whole bunch of machines in standby and together they constitute quite an assault on energy resources and the climate. Then again, a little research for a previous answer taught me that maybe the simplest / most effective way to conserve energy is to keep the tires of your car inflated at the right tension. Better still, stop driving a car and use a bike of public transportation, but your situation may not give you that option (option 3 - vote for a party that would change that, and if that isn't possible, option 4 - migrate to a democracy. But apart from going off topic I'm starting to repeat myself ... :) ). DirkvdM11:42, 2 January 2006 (UTC)[reply]
Does anyone know how a person 91 years of age may be treated for stomach cancer? I have read about general treatments for stomach cancer, including surgery and both chemotherapy and radiation treatment. I was just wondering, if there might be a different approach for a person who is 91, down to 100 pounds in weight, and who already seems to be compromised to a certain extent as far as her health is concerned. Would a physician typically recommend surgery for someone this age?
Thanks for your help.
I would suggest you ask these questions of someone who deals with this frequently, who can confirm that the person actually has stomach cancer, and who can go over all of the choices for treatment. An internist or gastroenterologist can find out if the person actually has stomach cancer. An oncologist would be most familiar with treatment options. alteripse11:23, 30 December 2005 (UTC)[reply]
There is some difference in approach in that at that age you generally don't have to worry about long term (>10 years) consequences or fertility when considering treatment options. --WS18:30, 30 December 2005 (UTC)[reply]
When did VHS tapes start being made with Macrovision anti-copy encoding? Is it still possible to convert my VHS collection and put it on DVD just for myself?
Yes, I read that article before i asked, it only states when the Law was passed, but does not state when Movies started being made with Macrovision. I'd Assume It would have been before, but i'd like to know, how long before.
Hi guys, I saw the question on the 'crazy mouse' and i have a similar problem. My mouse is an IBM mouse and is USB, optical and it has a scroll bar. My problem is when i am using it it often disappears or starts from another place. For example: I am moving my mouse pointer around in the middle of the screen and then the pointer will be exactlty in the top left hand corner. Please help me my patience is wearing thin! --Ali K09:21, 30 December 2005 (UTC)[reply]
Could be the surface you're using it on, or the lens could be dirty. Gentle cleaning with a cotton bud should help in that case. Or it could be that the internal components or wiring are damaged, in which case I recommend getting another mouse. Tzarius11:14, 30 December 2005 (UTC)[reply]
Dell Dimension/Optiplex PCs were shipped the last couple years with an upgrade to an opitcal mouse. However, the Dell mousepad was not optical-mouse-friendly. So, Dell sold alternative mousepads to solve the problem. I saw the problem in action on many desktops. It is exactly as described (the mosue hops around for no reason - usually to the top left corner of the screen). So, as Tzarius said, it is very likely you need a different surface for the mouse. --Kainaw(talk)02:00, 31 December 2005 (UTC)[reply]
Hi, i am 25 yr old(male).My problem is that i am very sensitive to sex subject.Whenever i saw girl , i just think about sex.Its not normal i know but i can't control myself.I masterbate 7-8 times in one day within perion of 15 days.I would like to know that how can i control my emotions and dirty mind? also what should the frequency for my edge for masterbate.I supposed to get married within one yr.Help me.Don't answer general thing.Give specific direction.Thank you.
As with any habit - it is a habit. A stimulus causes an uncontrollable reaction. Why is it hard for alcoholics to stop drinking when they spend every night in a bar? Why is it hard for smokers to stop smoking when they hang out in the smoker's lounge at work? Removing the stimulus helps. Then, there is idle time. What are you going to do to replace the habit? It is very difficult to stop a habit without replacing it with another habit (preferrably a constructive one). If you are really getting married soon, bring up the problem. You do not want to start a marriage with secrets. --Kainaw(talk)14:16, 30 December 2005 (UTC)[reply]
take up some interesting hobbie and start organizing your time so that you focus on a variety of things, and also,go see a psychologyst...and maybe just relax, because compulsive sex happens when you are under too much stress.
Standard compulsive behaviour, on a list of many things, such as pulling out your hair. You need good psychiatric drugs, only available from your doctor. --Zeizmic21:10, 30 December 2005 (UTC)[reply]
I agree it is probably a psychological issue and not a moral or habitual issue. Consider talking to a psychiatrist about it, they will probably have a number of options which will get to the point and not have you worrying about whether what your brain is telling you to do is "wrong". --Fastfission23:43, 30 December 2005 (UTC)[reply]
It seems you want to stop masturbating because you think it's "dirty". Well, it's not, and neither is thinking about sex. It's normal and natural. Don't stop for the wrong reasons. JackofOz00:12, 31 December 2005 (UTC)[reply]
Let me rush to add my voice to JackofOz's comment. I'm 25, and when I see an attractive man (since that's what I like) I think about sex. It's not because there's something wrong with me - it's because I'm a 25 year old guy! It would be much odder if you didn't think of sex when you saw an attractive woman.
As for the masturbation, well, what's too much masturbation? There's a national average, and you're certainly far above that for someone your age and sex, but there's also a national average for piano playing - and if you're far above average for that, good for you. Now, if your masturbation is causing you physical problems or making you stressed out psychologically, you should see a psychologist. Otherwise, you could just be an overly horny young guy. --George00:48, 31 December 2005 (UTC)[reply]
I'd like to comment, carefully.
I feel most of the above responses are fundamentally sound and given in good faith.
I agree that lust, high sex drive, and frequent masturbation are generally the norm for guys in their 20's (and older!)
I think you should consider seeking psychiatric/psychological help only because your compulsive reaction to the stimulus (women) is distressing to you (because its a compulsive habit), not simply because you've got sex on your mind and masturbate a lot.
I agree that you need to talk to your future wife about this. If you keep it secret, you'll run into problems later when (not if) she finds out and/or you end up becoming unfaithful.
I feel that drugs have little or nothing to offer you. If I were you I would be very careful about accepting drugs to treat this.
It may also help to think about how you view women in general. There's plenty written about the objectification of women you may like to read to help you gain another perspective.
Which was the first microprocessor that had instructions which specifically supported stack (like PUSH, POP, CALL, RET etc.)? I wonder, because I program mainframes and System 360 hasn't instructions for stack manipulations, so I guess it came later. Samohyl Jan20:45, 30 December 2005 (UTC)[reply]
There's other names for similar functions. AS/400 is a distant child of the 360 (unless the # 360 has been reassigned decades later to another machine with same #) and I am experienced with many family members in between. As long as I can remember (back to the 1960's) there has been a phenomena of a stack of programs which can communicate with each other (like CALL, MESSAGE, PARAMETERS) etc. The higher programs or sub-programs in the stack, can call the next level down, and pass some values to it. The lower level communicates back whatever results, can end, or go into a wait state, until the higher level calls again. However, this stuff not handled at the microproscessor or CPU level per se, it is an Operating system function. User:AlMac|(talk)21:32, 30 December 2005 (UTC)[reply]
Do you mean "microprocessor" or just "processor"? The 4004 include a JMS (jump to subroutine) instruction and a return that pushed addresses onto a stack. However the stack was only 3 words long and was in register, not in external memory. -- SGBailey23:26, 30 December 2005 (UTC)[reply]
there has been a major dispute about weather or not an air plane can brake in mid air and stay still for a short period of time. When looking up air brakes I have gotten several articles but none really explaining can a 747 stay in mid air without moving? Can you please help to dispute this question. My e mail is <removed to avoid spam - see history> thank you
The short answer is no, because the only way a plane stays up is by moving air over the wings. If the plane stopped in mid air, it would fall like a brick. Air brakes aren't *that* effective, they're used for slowing down when approaching a runway. Tzarius22:07, 30 December 2005 (UTC)[reply]
Fixed wing aircraft can't stay in the air without moving, as airfoils (i.e. wings) only work when there is moving air travelling across their surfaces. In practice if an aircraft were flying and you made it slow down past its stall speed the wings would no longer general lift, and the aircraft would drop. If it was near the ground the aircraft would crash. If not, the fall would make the aircraft gain speed (at the expense of altitude) taking it above the stall speed, and the pilot might be able to regain control. In practice pilots (well, civilian pilots) try very very hard never to stall (as it means losing control) - even when they're gliding, they keep the nose down enough so the plane stays above the stall speed. Even a big tub like a 747 can glide if it has to. I've no real idea what the stall-speed of a 747 is; I'd guess about 100mph. --Finlay McWalter | Talk
Reverse thrust and air brakes are different. Reverse thrust is done by baffels with redirect engine thrust. air brakes are aerodynamic surfaces (on the wings, and occasionally on the fuselage) which stick out and retard airflow. As these aren't very big, the are (as Tzarius says) not terribly effective. -- Finlay McWalter | Talk22:28, 30 December 2005 (UTC)[reply]
Airplanes can indeed stop their forward motion. I've done it, on purpose, several times with both a Cessna 152 and Cessna 172. I've also flown backwards. I've never flown a 747 so I don't know if it's ever been even attempted with such a large aircraft. Yes, it is true that air flowing past an airfoil does indeed create lift and if you take away the lift then the plane stalls and falls. And pilots do indeed get into a stall very often during their training for the purpose of learning what to do in the event of a stall and to become more familiar with what creates a stall. To come to a stop, and even fly backwards, the plane is flown into the wind while in a controlled stall. The power to the engine is reduced so that there is not enough power to keep the aircraft moving forward. Because of Newton's third law when the engine pushes the aircraft forward as hard as the wind pushes it back, it remains still. If the wind is strong enough, it will push the plane backward.
But at airspeeds that low the lift generated by the wing would not be enough to keep the plane up, you would be loosing altidtude, not staying "still". --Martyman-(talk)23:27, 30 December 2005 (UTC)[reply]
Correct, I knew I should have gone into greater detail... At the same time that the plane is slowing down the pilot would put the aircraft into a climb for the wings to generate more lift. At this slow speed with the wings at such an unusual angle, the stall warning horn goes off, and keeps going off, for the duration of the manuever. The plane can sustain it's altitude because the wings are creating just enough lift to keep the plane in the air but not enough to climb. Dismas|(talk)23:32, 30 December 2005 (UTC)[reply]
P.S. From our own article on the Antonov An-2: "This slow stall speed makes it possible for the aircraft to fly backwards (if the aircraft is pointed into a headwind of ,say, 35 MPH, it will travel backwards at 5 MPH whilst under full control)." Dismas|(talk)23:40, 30 December 2005 (UTC)[reply]
Skilled aerobatics pilots in specialised aerobatics planes can hang their planes still and vertical in the air for short periods; their engines produce enough thrust to counteract gravity without any assistance from the wings. They are limited in the amount of time they can do so, though, as they have no control from any of the aerodynamic surfaces in such a position. They can do some other pretty amazing stunts where the wings aren't used for lift; see this photo. That wasn't a momentary thing; the guy flew the length of the runway, level, with the wings held vertical like that. --Robert Merkel00:36, 31 December 2005 (UTC)[reply]
C-130s (and similar prop-driven large cargo aircraft) have the ability to hang. In reality, they are not staying still. They are flying very slowly at an upward angle into high wind. It happens regularly in the coastal winds here (Charleston AFB). For a person on the ground, it looks like the huge plane is just hanging in mid-air. I've sat on the beach and watched them appear to hang in one spot for well over 10 minutes. --Kainaw(talk)01:56, 31 December 2005 (UTC)[reply]
Stalls have been used in manuevering since at least WWI, the original Immelmann turn involved nearly stalling before coming back down in a different direction. Modern fighters like the F-15 have enough thrust that they can essentially stand on their tail. Night Gyr17:00, 2 January 2006 (UTC)[reply]
I have been grabbling with this question for quite some time. I like to know the best way of incorparating the Information Technology in Schools especially in developing countries, with particular reference to the IT and the Student world; IT as a tool to the Principal, IT as a tool to the Teacher etc. How does the IT impact children of such young ages positively and negatively? Is there any particular thing to guard against? How do I retrieve the answers to these questions from the Internet?
Regards
William —Preceding unsigned comment added by 83.229.102.4 (talk • contribs)
A very specific answer to a very general question (I don't know if this is what you were asking for): Linux is for free and when you learn Linux you also learn how a computer works (as opposed to msWindows). The second bit is important for all education and the first bit for education in developing countries. DirkvdM11:50, 2 January 2006 (UTC)[reply]
Is there any correlation between the seemingly intense weather oddities we've seen around the world in 2005 and the report I'd heard that the earth had been slightly jolted on its axis by the quake that set off the post-Christmas tsunami of 2004??? This question has been burning my brain for several months. Have any scientists considered this? Isn't it possible that even the most minute alteration from the earth's normal rotation could shift the patterns of weather?
I've seen no mention of this possibility / theory in any of the media coverage of the weather anomalies for 2005 but surely someone else must have considered this. Can't wait for discussion on this one.
(Ah Haa! So maybe that's what happened to the atmosphere millions of years ago - ending the reign of the dinosaur!)
The exact amount is yet undetermined, but theoretical models suggest the earthquake shortened the length of a day by 2.68 microseconds (2.68 µs) (or about one billionth of the length of a day) [31] due to a decrease in the oblateness of the Earth. It also caused the Earth to minutely "wobble" on its axis by up to 2.5 cm (1 in) in the direction of 145°east longitude [32], [33] or perhaps by up to 5 or 6 cm (2.0 to 2.4 in) [34]. However, due to tidal effects of the Moon, the length of a day increases at an average of 15 µs per year, so any rotational change due to the earthquake will be lost quickly. Similarly, the natural Chandler wobble of the Earth can be up to 15 m (50 ft).
I'd conclude that, since the other things don't really create much of a problem, the changes due to the earthquake didn't do much either. --AySz88^-^23:56, 30 December 2005 (UTC)[reply]
Is it possible, yes. With identical twins, no. With fraternal twins two eggs are released instead of just one. If the woman were to have intercourse with two men in a small enough time period, then it is possible that two sperm from two different men could reach the eggs. The chances aren't very good though. According to our own Twin article: " This can lead to the possibility of a woman carrying fraternal twins with different fathers (that is, half-siblings)." This could also be done with in vitro fertilization, though I doubt any doctor would agree to it. Has it ever happened? I have no idea. Dismas|(talk)23:48, 30 December 2005 (UTC)[reply]
While I don't know if it has occurred, fraternal twins (one light-skinned and one dark-skinned) could conceivably share the same father and mother, although it would be unlikely (more unlikely than fertiliaztion by sperm from separate men? I don't know). It is certainly possible for fraternal twins to have separate fathers. — Knowledge Seekerদ00:24, 31 December 2005 (UTC)[reply]
Right. I should have added, the mother and her husband were both white, and it wasn't because of a skin disease or anything. Needless to say, it was more than a little embarrassing. —Keenan Pepper00:58, 31 December 2005 (UTC)[reply]
It's worth noting that even with that information it's still possible that the fraternal twins were fathered by the same fellow. Depending on the recessive traits carried by mother and father (or mutations in their gametes), it's possible for an apparently Caucasian couple to give birth to an apparently black child. Heck, there was even an episode of Law & Order that described such a case. (Can't beat that for an ironclad proof....) Per the other comments, it is possible to have separate fathers fertilize the twins—though presumably it's quite a rare happening. TenOfAllTrades(talk) 01:11, 31 December 2005 (UTC)[reply]
I doubt that is true, as that would mean we would have one single or very few genes defining skin colour. Or it has to be a child with some rare skin disorder... --WS01:25, 31 December 2005 (UTC)[reply]
Incidentally, in the case of those twins, who are currently about ten years old, they do have different fathers. It was an artificial insemenation process with improperly sterilized equipment that led to one of the boys being fathered by a random black man. --ParkerHiggins ( talkcontribs ) 05:03, 31 December 2005 (UTC)[reply]
All right, it has certainly taken place. First of all, apparently possible but very rarely in humans, a second fetus can form in the uterus while another one is already present; this is called superfetation. If two or more ova from the same cycle are fertilized from different acts of sexual intercourse, it is superfecundation (but note that they may be from the same father, just from two different episodes of intercourse). If they are from different fathers, it is called heteropaternal superfecundation (where "heteropaternal" is from "hetero-" = different and "paternal" obviously from father). These articles, as well as Twin#Unusual Twinnings have more information and some background links. — Knowledge Seekerদ00:43, 31 December 2005 (UTC)[reply]
Citation: "It is suggested that among dizygotic twins born to married white women in the U.S., about one pair in 400 is bipaternal. The incidence may be substantially higher in small selected groups of dizygotic twin maternities, eg. those of women engaged in prostitution."PMID7871943 --WS01:10, 31 December 2005 (UTC)[reply]
If time is how much a can do in correspondence to b. Then grabity should affect time ? right ?
I mean if we are on a planet with 10% more gravity, and it slows down our thoughts(elektrons) and every thing else. Then time will be slower ? will it not ?
Gravity does slow time, but remember gravity is the weakest of the major forces of the universe, so therefore time won't be slower. Please note that gravity doesn't slow down our thoughts (where the heck did you learn that). --hello, i'm a member | talk to me!23:47, 30 December 2005 (UTC)[reply]
But maybe the questioner has a point. Thoughts are not just some ineffable "thing" that have no substance. They are our internal sensory representations of actual movements of elementary particles within our brain. Those particles are subject to the laws of the universe, including gravity. JackofOz00:53, 31 December 2005 (UTC)[reply]
OK, let's get some things straight here. Clocks actually do run faster at higher altitudes, in agreement with the theory of general relativity. This is a measurable effect that GPS satellites must correct for. It has nothing do to with gravity being the weakest "force", because the other forces don't affect the passage of time at all. Gravity is special.
If we assume that thought is a physical process that follows the same laws as everything else (perhaps a big assumption), then it would also be slower in a gravitational field. —Keenan Pepper00:03, 31 December 2005 (UTC)[reply]
Agree with Keenan Pepper. In a stronger gravitational field, it would be expected that all processes run slower compared to a those in a lesser gravitational field, so yes, time should be slower. The biological processes of the inhabitants of such a planet should would be expected to run more slowly as well, so nothing would seem slower to those inhabitants. In the absence of any evidence to the contrary, in the presence of a great deal of evidence of the physical basis of thought, I would assume that thought will obey the same laws (at least until we find out otherwise)—certainly it would be very difficult to imagine thought occurring at the same speed despite neuron depolarization and chemical diffusion and so on being slowed down. — Knowledge Seekerদ00:18, 31 December 2005 (UTC)[reply]
Which makes sense anyway, given that gravity would slow the speed of many proceses and artificial mechanisms even without relativity. (Ie. can you imagine running on Jupiter?) -- Natalinasmpf01:40, 31 December 2005 (UTC)[reply]
Wouldnt a higher gravity environment only change a person's perception of time, without actualy altering time itself? Or is my definition of time flawed? (And no, Natalinasmpf. I cant imagine running in a giant sphere of toxic and corrosive gasses, which is Jupiter.) -JvH 31 December 2005
How do you define time? Relative to an observer in a lower gravitational field, time would appear to run more slowly in a higher gravitational field; that is, objects would move more slowly, molecules would move more slowly, chemical reactions would take place more slowly, radioactive decay would happen more slowly, and so on. The amount of change is a precisely calcuable effect. This effect has been observed, as mentioned above: The atomic clocks aboard GPS satellites do not stay in sync with their counterparts on Earth. It is complicated by several factors, especially that both clocks on Earth and in space are moving through curved paths, but the ones in space are in a lower gravitational field and so would be expected to run faster than their terrestrial counterparts. Software aboard the satellites computes all this and accordingly modifies the time of the atomic clocks. Without relativity, GPS wouldn't work. (I sometimes wonder if Einstein had not come up with relativity, would someone else have thought of it in the last several decades? What if it never occurred to anyone that time could run at different rates for different observers and our first clue was when we launched the GPS satellites and found that the onboard clocks kept running too fast?) — Knowledge Seekerদ02:32, 31 December 2005 (UTC)[reply]
JvH, what I meant is, even without the toxic and corrosive gases, I mean, if we sent a mission to Jupiter, we'd probably find it very slow and exruciating to walk, even with a protection suit because of the immense gravity. Knowledge Seeker - that's a curious thought - I can imagine the hilarity. -- Natalinasmpf04:19, 31 December 2005 (UTC)[reply]
Sorry, I know what u meant. Just making sure you know Jupiter has no surface to walk or run on. -JvH 31 December 2005
Knowledge Seeker- it would work out much the same way it has, but a few decades later. The discovery that led to the theories of relativity was that light travels at the same velocity regardless of the motion of the observer(unless said observer is spinning or accelerating), in celestial and laboratory tests not extremely unlike the satellite idea. The conclusion, eventually, was that time runs differently and space is measured differently by observers that move at different speeds. That was special relativity, from which came general relativity, the thing with gravity. In reference to the earlier posts: as far as I know, which isn't far, since I'm still in high school, a moment in physics is a particular state of a system, and a measurement of time is a standardized measurement of the distance(not physical distance, of course) between one state and another, based on something that changes in a reliable way from one state to another, such as a swinging pendulum(a heavy one, so it stays consistent for a long time), unwinding spring(regulated by a comlplex network of gears) or decomposing atom. If the atom in moment B has half the mass of the atom in moment A, and in moment C it has half the mass it had in moment B, we suppose there must have been an equal amount of 'time' between A and B as between B and C. If there had been twice as much time between B and C as between A and B, and the atom in B still had half the mass of the atom in A, then the atom in C must have one quarter the mass of the atom in B. If in one moment the spring is unwound such that the hands of the watch are all at 12, and in another moment the spring is unwound such that the longest hand has made it to the next mark and the shorter ones are in much the same position as before, we suppose that 1 second has passed. If in another the longest hand has moved all the way to the 2, we would suppose a further 9 seconds have passed. For fractional units of time, similar rules apply, and it all standardizes nicely. So. The universe is a system, made up of many smaller systems that can be observed individually. Due to problems with gravity and so on, as a pendulum gets from one side of its swing to the other in some of the systems, a similar pendulum only gets partway along its swing in others. As the spring unwinds some of the way in some, it unwinds less in others. As the atom decays halfway in some places, it only decays a third in others. In other words, from one moment to another, from one given state of the universal system to another given state of the universal system, a decaying atom in one place might lose half its mass, but an identical atom in another might only lose a third, because gravity causes it to. Thus, by our atomic clock, we say less time has passed in the second place than the first, and so time seems to have slowed down in the second place. All processes slow down in that area, of course, so the interactions between things(such as people's brains and their environments) within the area aren't effected, just how much interacting is done while things in other areas do a certain amount of interacting. Things moving from one area to another, of course, like light, are what cause the confusion. Say you have a light bulb flashing on and off in an area of "slow time". It flashes once per second, at the beginning of the second. In one moment the light is on, a watch shows 12:00:00, in the next, 12:00:01, and so on. Let's say someone in the area of "fast time" sets their watch by the light pulse. When the first pulse reaches them, in the same moment their watch is set to 12:00:00, and then runs normally. Assuming the amount of 'time' the light takes to get from one place to the other(the distance between the moments of departure and arrival) is the same for each pulse, which is a reasonable assumption if the gravitational field isn't changing, the 'distance' between the moments of departure of the first and second pulse will be the same as the 'distance' between the moments of arrival of the first and second pulse, and the person in the area of "fast time" will see a steady beat. However, because his watch unwinds more between one moment(the arrival of a pulse) and the next(the arrival of the next pulse) than the watch of the person in "slow time" does, due to less gravity or whatever, and the chemicals and signals that control his internal clock behave similarly, a second has been and gone before the second pulse arrives, and the third is even farther behind schedule. So, if there is enough light to see by, and by some freak of physics a gravitational field could be set up that would allow someone to see the light without making it too far away to be visible or killing everyone involved, and still cause a significant time difference, all the things happening around the light that take a second or minute or hour in "slow time" are interpreted according to the timekeeping abilities of the people in "fast time", and a great deal can be accomplished while waiting for those slow people to move. BTW, I would like to point out that I know I got many many terms and phrases wrong, and would like to know the correct ones. Also, if I got the concepts wrong, I would like to know that as well. Of course, if I'm right, don't hesitate to tell me so at length. :) Black Carrot06:47, 1 January 2006 (UTC)[reply]
Why does are there so many bogus files on Limewire? As far as I know most of them are bugs. However, being a open source app, these bugs should be fixed by now. Thanks! --hello, i'm a member | talk to me!00:02, 31 December 2005 (UTC)[reply]
What do you mean by "bogus files"? There are a lot of misleadingly named files on the Gnutella network put there by malicious users. They appear using any Gnutella client, not just Limewire. There is no way for Limewire to tell if the contents of a file actually match its filename, so it's not a bug that can be fixed.
I use gtk-gnutella's filtering feature to block IP addresses I get spam from, which reduces the amount that appears in searches and makes legitimate files easier to find. Limewire may have something similar. —Keenan Pepper00:12, 31 December 2005 (UTC)[reply]
This is just the escalating war of file downloads. It can never be perfectly easy for the mass millions because that would mean that an album is released with zero cd sales, or a movie is shown with no theatre audience. And so the copyright cartel fights a rearguard action with paid interference (bogus files) and lawsuits, and sucks out a massive 'tax' on legal file downloads. I would suggest Magnatune for an easy way to get music (and donations to keep the artists fed). Eventually, the distribution cartel will break up and there will be a painless way to get good music and movies, perhaps through fan clubs and direct payments to producers and artists. In the meantime, file downloading is never 'free', you must be in the top 10% of technical expertise to have life easy. Personally, I've given up the race and get really good music from Magnatune. --Zeizmic21:44, 31 December 2005 (UTC)[reply]
Hello. I've looked all over the Net trying to find a way to retrieve an HTML file that's stored in a remote server without having to save it to a local disk. I've gotten the processing of the file once it is saved down, but what I would like to know is: is there a way to save them in memory, instead of the hard drive? Titoxd(?!? - help us)01:42, 31 December 2005 (UTC)[reply]
import java.net.*;
import java.io.*;
public class URLConnectionReader {
public static void main(String[] args) throws Exception {
URL wikiUrl = new URL("http://en.wikipedia.org/");
URLConnection uc= wikiUrl .openConnection();
BufferedReader in = new BufferedReader(
new InputStreamReader(
uc.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
//do something with inputLine; maybe accumulate in a StringBuffer?
}
in.close();
}
}
S.: Imagine an environment without influence of gravity of any kind. Say, somewhere in deep space. (Zero-Gravity)
In one case there is an object with a mass of 1 being propelled with a force of 1 N.
In anonther case there is an object with a mass of 1000 being propelled with the exact same force of 1 N.
Q.: Wich object accelerates faster? Does mass matter in zero grav?
(What does "Mass = Resistance to a force" exactly mean?)
I know Newton says F = M * a , thus mass should matter, but I cant seem to grasp why.
Thanx in advance. An answer to my question cant be too broad or too complex imo. -JvH 31 December 2005
Is the fact that mass matters, in relation to how fast it accelerates when pushed, a consiquence of the gravitational forces of the object upon itself? --JvH 1 January 2006
Hi, I read that 6 beryllium atoms where put in a 'cat state' ... how in the world can that be done with atoms!? doesn't that just happen to quarks and small particles like that?
Is this what you're talking about? Atoms are definitely small enough for quantum effects to play a major role. In fact, quantum states of electrons called atomic orbitals are responsible for the chemical properties of the elements. —Keenan Pepper03:09, 31 December 2005 (UTC)[reply]
so! traditional physics doesn't have that much influence on which element will an atom be? wow I didn't imagine that... but if 6 atoms can be influenced so much by QM can a molecule be?
and I wasn't talking about your link, I was talking about an article read on the NY times online, about 6 beryllium atoms, not 3 beryllium ions, maybe you can find it online.
thank you. Cosmic girl18:42, 31 December 2005 (UTC)[reply]
Quantum mechanics can indeed influence the behaviour of a molecule! In fact, lots of things can be traced back to quantum mechanical effects. Lasers, LEDs, MRI machines are examples...Mercury being a liquid a room temperature is also due to quantum mechanics. Spectroscopy is another rich field where quantum effects are paramount. Even thermodynamics can be linked to quantum mechanics via statistical mechanics and statistical thermodynamics. However, there are also things that quantum mechanics are not so good at describing. Does this help? --HappyCamper18:12, 31 December 2005 (UTC)[reply]
Well, things that are "outside" of the theory...Say, "how to run a successful business", or "fundamentals of chord structure in Bach's violin partitas". These are exaggerated examples, but remeber that QM isn't the answer to "everything" in the universe - but it does do a pretty good job at describing many things very effectively and beautifully. Well, that doesn't mean you couldn't use QM for such things...but if you did, you probably would get much insight from it. Does this help? --HappyCamper18:51, 31 December 2005 (UTC)[reply]
thank you, nice sense of humour :) ...I meant more like, can QM explain things like ... my car? or ... things like speed, motion and those things? --Cosmic girl23:24, 31 December 2005 (UTC)[reply]
Well...yes and no. It depends on what you mean by "explain". QM is sort of like this (in an extremely watered down way) - it says that things ("a system") only exists in certain states. These states have well defined energy values associated with them. And all this is encoded by wavefunctions. You can also represent all these things with matrices. Once you have this matrix (it's easier to work with), you can find out anything you want from the system...the position, angular momentum...all the things you listed above. How do you do this? You apply special operators to this matrix. And what does this operator look like? Well...it's just another matrix. Because matricies are involved, linear algebra is very important in QM too :-)
In theory, you could find a matrix for your car, but because it has a tremendous number of atoms in it, it would be impossible to do so in your lifetime. There are far too many states invovled. Lots of research today goes into finding ways around this problem, by asking the question: "can we find a reasonable approximation which would give us a reasonable picture of what is going on?" - of course, current research isn't so interested in cars and stuff. In principle, you can use QM for "anything", but what is better is choosing the battles that are worth fighting for. For me, I use QM to calculate the spectra of interesting molecules, with at most a handful of atoms. It's in these places where you can use QM to get the most insight - and make very good use of it for society. Does this make sense? Well, don't take too much of the explanations I've put here too literally - it is really watered down...in fact, my colleagues are sort of teasing me as I write this (and they will probably quote this in their lectures) but if anything, I hope this makes you even more interested in QM!! :-) --HappyCamper16:16, 1 January 2006 (UTC)[reply]
Thank you :D, I understood the point,I think QM is cool, and I'm glad I inspired some humour in the world of physics lectures, haha :) --Cosmic girl17:36, 1 January 2006 (UTC)[reply]
Q. Is there a known maximum range to gravity? If so, do objects with a larger mass have a larger gravitational range than objects with a smaller mass? -JvH 31 December 2005
A. As far as we know, there is no such maximum range, nor does any theory that I'm aware of predict a maximum range. Under most circumstances, the strength of the gravitational force between two objects declines with the square of the distance, but never quite reaches zero. See Gravity#Newton's law of universal gravitation. -- SCZenz02:34, 31 December 2005 (UTC)[reply]
A. It is believed that gravity's range is infinite.
Q: I would like to ask that how do we calculate the atomic packing factor(APF) for diamond structure.
A: Okay, this I'm recalling from more than six years ago. Diamond has FCC with alternate tetrahedral interstices filled, so there are 8 atoms per unit cell, each atom having 4 nearest neighbours. Therefore, atoms touch along the body diagonal, giving a = 8*r/sqrt(3), where r is the atomic radius. Now find the total volume of the unit cell (a^3) and the volume occupied by the atoms. 8*4/3*pi*r^3. This will give you APF = 34%. deeptrivia (talk) 04:02, 31 December 2005 (UTC)[reply]
Hello,
My current computer is P4 1.7GHZ, 256 DDR ram, Gforce 4 video card, a 40GB hard drive and a 120GB hard drive, 52X cd rom, 40X12X40 CD/writer. My computer has been getting slower by the day, it is getting old and I really take it to the limit and I have used it for a while. I want to upgrade my computer. What do you think I should get with the upgrade? (note: Please no unrealistic priced products, my budget is up to 800 or maybe 900!!! and also I already am getting a dvd burner)
There's no reason it should get "slower by the day" unless there's something wrong with your software. I'm a card-carrying free software zealot so of course I suggest GNU/Linux, or you could just reinstall Windows or whatever.
Other than that the only thing I would upgrade is the memory. Just plug in another 256Mb stick and you'll be amazed how much faster it goes when you're running a lot of things. —Keenan Pepper04:38, 31 December 2005 (UTC)[reply]
Thanks alot for the advice, I AGREE WITH THE LINUX IDEA 100% but I'm a windows person and the change is gonna be hard. and also I thought about the memory idea, but would a faster CPU help? --(Aytakin) | Talk04:44, 31 December 2005 (UTC)[reply]
Try a Live cd. It will be slow, but I think you'll find it's not that hard to use and it doesn't modify your computer at all unless you choose to install, which also shouldn't be too hard. I've had particularly good experience with Ubuntu Linux. - TaxmanTalk15:33, 31 December 2005 (UTC)[reply]
You've got low RAM, and I agree with Keenan about adding more. However, I wonder if such questions are supposed to be answered here. Maybe you can request/launch another reference desk on Technology related stuff (there's already a wikiproject on technology, so you can ask them.) deeptrivia (talk) 04:46, 31 December 2005 (UTC)[reply]
If your motherboard is a standard sized one you can simply replace it with a new one with a faster processor. The problem is a lot of the major suppliers like Dell do not use standard sized motherboards or do other things with placement inside the box to make it so upgrading is not easy. You can also find your current motherboard manual online and see if it takes a higher processor speed, as some can accomodate a certain level of upgrade. Then Ebay may be a good bet if you know the ins and outs there. But replacing the motherboard, more memory and a new video card may cost you just as much as buying a new computer these days, especially if you bargain hunt. I would certainly second the more memory recommendation before shelling out for a new computer. I found a 512MB stick for $24 after rebates at Circuit City. - TaxmanTalk15:33, 31 December 2005 (UTC)[reply]
Q A wind tunnel uses scale models of planes, etc. Suppose the model is 1/10 scale and you want to simulate a 500 mph wind on the full-sized object. What speed should the wind speed in the wind tunnel be? 50 mph? 500 mph? Other? Bubba73(talk), 05:02, 31 December 2005 (UTC)[reply]
In normal model tests, simply multiplying the scales is often sufficient (i.e. a 50 mph wind speed would be used). However, for many applications, one must take care to use dimensionless quantities and fluids is the most common. The reynolds number is key in making accurate scale models for fluid tests (boats and airplanes are the most common). It's been a while since I've taken fluids, but the upshot of all this is that the math isn't quite as simple as one might be lead to believe, though it has all been figured out and can certainly be looked up. -User:Lommer | talk06:26, 31 December 2005 (UTC)[reply]
By similitude, if your model is 1/10 scale, and you want to simulate 500 mph on the full-sized object, you need 5000 mph in the wind tunnel. That's counterintuitive. So to simulate supersonic flight on a model airplane, the air speed in the wind tunnel is in the thousands of mph. That can be done? Bubba73(talk), 22:08, 31 December 2005 (UTC)[reply]
It's not exactly counterintuitive. The guiding principle here is that the Reynolds number in the two cases must be the same. The Reynolds number involves a product of size and velocity. Therefore if you decrease the size by a factor of N, velocity has to increase by N. Sometimes we have to use supersonic wind tunnels even to simulate subsonic conditions. These wind tunnels are typically small (& transparent), and supersonic conditions are generated only for a short time (fractions of seconds.) deeptrivia (talk) 22:28, 31 December 2005 (UTC)[reply]
Thank you for the information. There is a 2500 foot bridge near here Sidney Lanier Bridge, and it is in an area where hurricanes are possible, so according to [67] they did wind tunnel tests. A 1/250 scale model would seem reasonable, but to test a 100 mph wind on that, the wind tunnel speed would be 25,000 mph. To put it in the 1 foot by 1 foot wind tunnel you linked to, the wind tunnel speed would be 250,000 mph. I may be wrong (I often am), but intuitively I'd expect the actual bridge to withstand a 100 mph wind but a 1 foot model would be blown apart by a 250,000 mph wind. Am I missing something? Bubba73(talk), 00:06, 1 January 2006 (UTC)[reply]
In such a situation, you can always conveniently make use of other parameters involved. For example, take a look at this. Here, they scale the bridge 1:40, the velocity 1:4. At the same time, the mass per unit length is scaled by 1:1600. Finally, they scale their results (frequency) by 10:1. So, there are more parameters apart from L and V to play with, in order to facilitate a reasonable simulation. At the end, you can always scale your model results to get an estimation about the prototype. Bottomline: You will need 5000 mph only if velocity is the only parameter you want to change, and you want the exact same numerical result as for the prototype (not scaled by any factor.) deeptrivia (talk) 01:33, 1 January 2006 (UTC)[reply]
Hello,
I want to know how I can make an icon for my website, and what I mean by icon is the logo that apears at the beginning of the address bar of the browser. For example if you check right now, you'll see the W of wikipedia. My question is what I should do to put a picture as my website's logo. Thanks --(Aytakin) | Talk05:30, 31 December 2005 (UTC)[reply]
A couple of knowledgable friends recently told me that higher quality beer contained a higher quality and/or different kind of alcohol than cheaper beers, therefore producting a different feeling of inebriation. They also contended that a 5.5%abv quality beer will generally get you drunker than a cheap 5.5% beer. Can anybody provide more information on this topic? Thanks!!
If you judge your beers by the alcohol content, it's definitely time for you to try the expensive beers. There's much, much more to beer than the alcohol content; try a real ale or one of the trappist beers in moderation; they're a world away from Budweiser and the other American lagers. You'll drink less, taste more, and feel better the next morning! Keenan is right, by the way, ethanol is ethanol whether you're drinking Grand CruBurgandy or wine coolers.--Robert Merkel06:46, 31 December 2005 (UTC)[reply]
Alcoholic beverages are generally very complex things. For most of them, no one yet has a detailed understanding of what causes each one to taste just as it does and to have just the effect it has on people. There are scads of old wives' tales about which drink or mixture of drinks gets you drunk, makes you violent, or causes a nasty hangover. Most of them haven't been thoroughly tested. For the subtle details, you'd really have to visit a good library. You could do worse than to start with the relevant chapters in Harold McGee's invaluable On Food and Cooking; it also has the advantage of being very famous and therefore probably in your local library.
As for your friend's specific claims: I can see no physiological reason that a given expensive beer will get you drunker than a given cheap beer. Certain chemicals in some particular brand of beer might do something funky, but the generalization is almost certainly false. The part of beer that gets you drunk is the ethanol, and 5.5 is 5.5. --George07:09, 31 December 2005 (UTC)[reply]
Sounds like a great lab experiment! Cheap beer tends to have larger CO2 bubbles, since the gas is just injected. Expensive beer has finer bubbles. This might cause a champagne effect. Ethanol itself does not cause drunken effects, that depends on a complex body reaction with the brain chemicals. Some people can consume large amounts and not show drunkenness. Some people (like me!) can be knocked out with very little.--Zeizmic23:33, 31 December 2005 (UTC)[reply]
Trust me, I just got back from Belgium and am no stranger to a good trappist :-). Thanks a lot for all of the comments, quite interesting.
S.Presume I could somehow stop time.
All motion would cease. Celestial bodies would freeze in space.
Now I would somehow cause time to resume.
Q.When time gets going again, will all inertia be "forgotten" or "remembered"?
Will the Moon come falling to Earth while the Earth decends upon the Sun? Does this prove "stopping time" to be impossible? -JvH 31 December 2005
I would say that "a process stops" means that things do not change with time. In that sense time cannot stop, by definition.--Patrick23:48, 31 December 2005 (UTC)[reply]
Ok, I got an answer for you: The only way to stop it is to travel at light speed. Since only massless particles can do that, there is no inertia to conserve. Time is more or less measured by the change of state of some system or other, so stopping it would by definition prevent any change at all from occurring. If time stopped, laws of physics would indeed be violated. But this situation is devoid of any meaning. Time not stopping IS one of the laws of nature, so it's like asking "If the earth were flat, what would it be sitting on?". Inertia is also resistance to acceleration and its units do not include time—inertia has nothing to do with time. -- Mac Davisญƛ.04:58, 1 January 2006 (UTC)[reply]
I like the 'purging of the cache' analogy. :) But motion is expressed in terms of time, so where there is no time there is no motion and where there is no motion nothing happens. So how could anything have been added to the cache? DirkvdM12:10, 2 January 2006 (UTC)[reply]
This might be the wrong place for this question. If so, I apologize in advance.
I'm using Sam Hocevar's godmode light tool. I'm using a slightly older version than the newest one, because the newest one doesn't work for me at all. However, this older version used to work on both my laptop and my desktop, and then one day stopped working on my desktop. Does anyone either know enough about that script that you could give me a reason why it would stop working on one computer, or, alternatively, is there some kind of reset button I can hit on my desktop to make it work again? A million thanks. --ParkerHiggins ( talkcontribs ) 09:04, 31 December 2005 (UTC)[reply]
Have you already tried clearing your browser cache? Holding down the shift key while clicking the reload button will do the trick in many browsers. If you're using IE, try ctrl+F5 instead. Plain F5 will work in Opera. —Ilmari Karonen (talk) 15:25, 31 December 2005 (UTC)[reply]
Also, please note that old versions of godmode-light.js have a serious bug that can corrupt pages containing HTML entities. Does the version you're using have a line that says: "t.value = l[i].innerHTML;"? If so, you have the bug. A quick fix is to replace "innerHTML" with "value". While you're at it, you might want to try and see if the version at User:Ilmari Karonen/godmode-light.js will work for you. —Ilmari Karonen (talk) 15:34, 31 December 2005 (UTC)[reply]
Is it okay to burn deadly nightshade bushes that have been pulled up & put in a pile. Or will the fumes/smoke be toxic as well? Also, if the plants grow back, how can I kill them & would the method be safe for horses? Or do I need to remove the horses from the field for a period of time & how long would that be? --69.164.248.6012:30, 31 December 2005 (UTC)need2no[reply]
Good question, some toxic plants are safe to burn, some are not.
The plant is also toxic to many domestic animals and livestock; for instance, poisoning can lead to colic, depression, weakness, and lack of coordination in horses, with fatalities reported even for small amounts from 1 to 10 pounds (0.5 to 5 kg).
So, I look at it, and see that a "small amount" for horses would be between 1 pound and 10 pounds. Burning the plant does not release as much of the toxins into the air as consumption. Depending on how small the pile is, and what type of nightshade, you may be able to burn it safely, or may not. -- Mac Davisญƛ.13:31, 31 December 2005 (UTC)[reply]
Why does the jet airplanes leave a trail or a mark when flying at high altitudes. Is it because of the combustion process of jet airplanes or has the type of engines got to do with that
A bit off topic, but after the 2001-09-11 attacks in the US no planes flew for some time and a result was that the amount of sunlight that reached the ground was considerably increased, even to the extent that it affected the weather, I believe. DirkvdM12:13, 2 January 2006 (UTC)[reply]
My understanding of this is hardly complete, but needless to say it's a very difficult question. After all, we don't know how many species there are in the world, we certainly can't go out and count which ones are here today and gone tomorrow, and species long thought to be extinct occasionally show up again. That said, I think you could get a fair overview of two major positions on this by reading chapter 23 of Bjron Lomberg's (extremely controversial) The Skeptical Environmentalist along with this point-by-point critique. I haven't found a document with Lomborg's replies to the critiques, but perhaps someone else can. --George23:41, 31 December 2005 (UTC)[reply]
I'm not sure if this is what the questioneer was thinking of extinction by human causes, but one has to keep in mind that species go extinct all the time. That's how evolution works. So maybe the question should be how many more species go extinct than would have if we weren't here and by what causes. I suppose the biggest blow is yet to come with the increased climate change. And then there is still the question how much of that is caused by human activity (it will certainly play a part, but how much we can't know as long as we don't sufficiently understand how it 'normally' works). DirkvdM12:19, 2 January 2006 (UTC)[reply]
Lets say the New Horizons spacecraft is set to launch January 28. Why would a launch delay of one day (January 29), postpone the pluto arrival of just one year.
I had thought it was set to launch January 17. However, the if the launch were delayed beyond Jan 30, it would mean that the craft could no longer utilise a gravitational slingshot from Jupiter, which the craft is relying on to build up its velocity. Without it, the time to Pluto would increase significantly. GeeJo(t)(c) • 19:35, 31 December 2005 (UTC)[reply]
Think of it like this: Your bus leaves in five minutes. The next bus leaves two hours later. Why would missing your bus by one minute postpone your arrival by two hours? The gravity slingshot works like that, as do launch windows in general. You have to be in the right place at the right time for the slingshot to toss you where you want to go, and if you can't make it there in time, tough. —Ilmari Karonen (talk) 22:37, 31 December 2005 (UTC)[reply]
I was wondering if it is at all possible to build a electrostatic thruster. If it is possible what supplies would I need, do I need any special equipment, and how much is it going to cost? Thank You for helping me, if possible. Patrick Kreidt--67.127.98.13522:14, 31 December 2005 (UTC)[reply]
Surprisngly enough, if all you want is a toy/experiment, you can (or could) buy kits to build your own ion drive. See this document (PDF) for a company selling kits for the purpose. If you want something more powerful I suspect you'll start needing access to things like CNC mills and the like. --Robert Merkel00:48, 1 January 2006 (UTC)[reply]
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ᑐ 00:01, 2 December 2005 (UTC)
ᑐ 10:51, 2 December 2005 (UTC)
ナイトスタリオン ✉ 12:08, 6 December 2005 (UTC)
(talk, contribs) 05:16, 15 December 2005 (UTC)
Please do your own homework.
22:26, 24 December 2005 (UTC)
ᓇᐃᑦᔅᑕᓕᐅᓐ ✉ 22:38, 29 December 2005 (UTC)
Mac Davis ญƛ. 12:30, 31 December 2005 (UTC)
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