Wikipedia:Reference desk/Archives/Science/2011 October 11

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October 11

Neutrino

Einstein has always maintained that speed of light was calculated for an electromagnetic wave.Holding that neutrino travels faster than it seems unrealistic considering it is not an EM wave.But should we consider that Theory Of Relativity for a non EM wave particle?Bdaysuneet (talk) 07:26, 11 October 2011 (UTC)

Should we consider that the theory of relativity for a non EM-wave particle is what? You have half a sentence there. Plasmic Physics (talk) 08:37, 11 October 2011 (UTC)

There's a fair bit of investigation to go through before assuming that. Some neutrinos were detected at the same time as a supernova explosion was seen recently which indicates they don't go faster than light. If there isn't some silly mistake and the results are confirmed there will be quite some job trying to reconcile it with that result. Dmcq (talk) 09:40, 11 October 2011 (UTC)

We should wait until we have evidence that there are neutrinos that travel faster than light rather than ill-informed reporters misrepresenting a story on a topic of which they have very little understanding. -- kainaw™ 14:42, 11 October 2011 --(UTC)

may i say something regarding on weather travelling faster than speed of light is possible or not? for as much as einstein seems to insist according to his formula of E=MC2 showing the reason why it is impossible for anything to travel faster than light, I on the other hand have been working on this for sometime and have found that due to four errors weather made by science or einstein for not spoting it where ENERGY-MASS-MATTER-E=MC2 and the big bang is of concern I have found what I belive enough evidence within those i have just mentioned, where it has given me a 70% probability that travelling faster than speed of light is possible, although saying that I have always belived that there are certain particles not yet found that are travelling faster than speed of light, the first particles to come out of the big bang and the last particles at the end of the impact that created our universe, I am know as a historian science/physic researcher and thearist analist--188.28.166.239 (talk) 00:29, 12 October 2011 (UTC) (UTC). carlos portela

If you have real evidence to counter the vast amount of research that confirms Einstein's claims, then now would be an excellent time to publish a paper in a respected journal, but, if you write your paper in English, do get someone to proof-read it first. Dbfirs 08:30, 12 October 2011 (UTC)

first i like to say that everytime i log in once i try to go anywhere it logs me out for some reason, so regarding what you have said..if you could help me in how or where i can really send my valuation regarding what i have written,, not that i want to discredit any one in science or einstein for that matter..is just until it gets read by a real proffesional scientist or someone in astrophysics.. i really don't know how much i got it right, although saying that my explenation according to those i have explained to..being friends..they find it it makes sence, i have send a report to metro news paper within hours of hearing about the atom smasher lab in europe claiming they might have successfuly recorded one of their particles going faster than light..i have even send them an email aswell which i got it from their own website..but up to now no reply..i seem to be finding a big problem in anyone considering in hearing me out..it may be all hot air and nothing..but what if i am right and got something?/ ... for if i got something it would also mean that man made machine with todays technology, within five years a spaceship could be build where it could travel more than 100,000 miles an hour..without hurting the pilots inside..i just need someone honest within the science field or media who can give me a chance to read my report and take me a little serious..i have proff that i been on to this project since last year.. but was not ready to make it public or say anything as it is kinder unfinished yet..but since hearing the news i felt i had to try and get my word out. any ideas?? who i could get in touch with, where they will reply back with their comment??.. any ideas... mfe_science/sittos_science: carlos portela — Preceding unsigned comment added by 188.28.11.17 (talk) 22:21, 12 October 2011 (UTC)

It is unlikely that you will easily find anyone who will take you seriously because 99.999% of theories that contradict both established beliefs and substantial evidence turn out to be total balderdash. Einstein was an exception! Take a careful look at your work and decide whether it is worth writing it up carefully in your own language (Dutch?) with as much actual evidence as you can provide, then take it to someone at the University of Amsterdam (if you live somewhere near), where you will possibly find a research student who might look over your paper and tell you whether you are writing anything that makes scientific sense. Dbfirs 06:23, 13 October 2011 (UTC)

well thanks for that..although i am not dutch i know my spellings are not corect but that is becaous my keyboard is crap working..lol.. i am spanish living in london and my best language to write it on would be english since been living here to long.. one question..would i be violating any legal system if i was to send an article to all news papers at same time?/ rather that one at a time wating for each to see if they respond or not before moving on to send it to another news paper, i mean is not as if i want any payment for it..anyway thank you for responding to my writing sorry if it annoy you the spellings..maybe i am missing something, just is to logical i guess specially when if the big bang is to be true within that theary. there is enough evidence or argument to verify that there was at least at one time in the life of the universe where some particles did travel faster than speed of light.. what annoys me is that einstein insisted that nothing travels faster than light according to his equation and everyone just seem to accepted it.. anyway thanks again for your kind replies..shall not bother you no more..lol and what is wrong with wikipedia that when i come here it logs me out automatic,grrr soo annoying,,mfe_science/sittos_science188.28.242.170 (talk) 11:34, 13 October 2011 (UTC): carlos portela

Apologies for the incorrect assumption. My dodgy internet connection somehow suggested that your IP address located to the Netherlands, but now it suggests Maidenhead (UK). I wondered if you were Spanish but living in Holland. I strongly recommend that you write up your paper in Spanish, or that you get someone to proof-read your English. Before wasting your time, you might like to read our article on Inflation (cosmology) where your "evidence for faster-than-light travel is explained by Metric expansion of space (not the same as travel through space). Why not create an account to avoid being logged out? Dbfirs 08:33, 14 October 2011 (UTC)

What is the function of the long carbon tail of Chlorophyll a(and b,d also)?

I guess that it might affect the absorption of sunlight, and may distract free radicals that may cause harm to the structure. Is it right?--202.153.93.50 (talk) 09:54, 11 October 2011 (UTC)

No. It's a water-insoluble anchoring structure. It's discussed in Chlorophyll a.-- Obsidi♠n Soul 14:04, 11 October 2011 (UTC)

The article (which is itself not a reliable source) does not contradict the IP OP's speculation. I'd be surprised to learn that the tail doesn't affect the absorbativity, if that is a word. The rule in biology is multiple overlapping functions. His questions seem quite fertile, actually.μηδείς (talk) 21:22, 11 October 2011 (UTC)

Woodward's rules are a good guide to determining what (if any) effect various groups have on the frequency of uv/vis absorption of an organic structure. For chlorophyll a, the long chain is fairly decoupled from the chromophore (the central ring structure with magnesium) so the fact that it's a "long chain" probably has little to no effect. Alkyl groups in general do not have any noticeable uv/vis activity (usually need pi bonds for that), and even an isolated pi bond such as the alkene in the chain only absorbs deep in the uv. This is all in contrast to alkyl groups directly attached to the chromophore (see discussion in the article). The electron pathways and regions of excitation in the various photosystems seem pretty well studied, and I don't see any claims that the long chain is involved. The idea of being not involved in the light-harvesting and energy-transfer processes is actually a pretty important possibility (vs "probably some effect, even if we don't know it"). Any light absorbed by the anchor or any additional steps in the transfer pathways represents a loss of efficiency, so it's not a bad idea to have an anchor that doesn't do any photosynthetic-pathway activity. On the other hand, it could be a structural element that helps stabilize a certain excited state or something like that...probably could look at a 3D structure of the molecule as bound in its larger complex to see exactly where the chain is. One of the cool things about biochemistry is that the structures have actual shapes and each atom is in a certain place (and therefore can only react with other things nearby)...my bio students often have trouble seeing beyond "there's this amorphous black-box thing called chlorophyll", words written on reaction-arrows. DMacks (talk) 21:54, 11 October 2011 (UTC)

Er... its function as an anchoring structure is well known enough that calling Wikipedia an 'unreliable source' in this case is pretty unwarranted. They do help keep the chlorophyll molecules arranged neatly in thylakoids, maximizing the surface area and thus efficiency in gathering light. That can be considered as 'affecting the absorption of sunlight', though that's reaching. Defusing damage from free radicals is accomplished by accessory pigments as well - carotenoids (which do have overlapping functions) - not the tails.-- Obsidi♠n Soul 23:37, 11 October 2011 (UTC)

I am sure I said overlapping function, not wrongly attributed function. Indeed, "contradict" means to negate, not just to give an alternative. For example, the fact that jawbones are jaw bones does not contradict their use in hearing. And saying the article is not a reliable source in no way implies it is known to hold false information. Now, I am not saying either that the long chain has indeed been shown to serve the OP's proposed purposes. And I don't have sources. (My focus of study in biology was above the organismic level.) And indeed the anchoring function is clear. But larger molecules do have broader spectra and lipid chains do bond free radicals. The hypotheses are not uneducated. See subcontraries.μηδείς (talk) 00:45, 12 October 2011 (UTC)

That tail is a saturated hydrocarbon, so I really doubt it's going to help much with absorbing sunlight, nor interacting with free radicals. Compare Geranylgeranyl pyrophosphate. Wnt (talk) 03:15, 12 October 2011 (UTC)

A speed debugger?

Let's say you're a really really great speed reader and an equally good computer programmer.

Can your expertise in speed reading help you debug computer language codes? -- Toytoy (talk) 14:07, 11 October 2011 (UTC)

Programming languages are not exactly prose.-- Obsidi♠n Soul 14:25, 11 October 2011 (UTC)

Not sure about reading, but I've seen a speed typist at a little better than 100 words per minute who was a really impressive programmer provided the algorithms were simple enough that they didn't require much thought. A lot can be accomplished with just minor variations on stock solutions for basic data structures and algorithms, and this guy would just burn through those. Dragons flight (talk) 14:43, 11 October 2011 (UTC)

It is possible to pick out certain types of errors in "speed" mode. For example, one of the most common errors in C coding is to write = where == is needed -- I can generally spot that error in a quick scan, if the code is formatted properly. More subtle errors require thought to detect. (Note: I don't believe there is really such a thing as a speed reader. The faster you go through the text, the less thought you can give to what you are reading.) Looie496 (talk) 15:46, 11 October 2011 (UTC)

If you scan code for errors a lot, you get better at it. I grade programming homework. So, every week, I have to scan a few hundred programs for errors. The result is that I can quickly scan my own code for errors - most of the time. Sometimes, the error is very hard to find and it takes forever. The true end result is that I am a rather fast programmer. I've gone to programming competitions in the past and done very well based on experience and speed. -- kainaw™ 15:51, 11 October 2011 (UTC)

Some time ago, there was a spectacularly esoteric C program with a bug, posted on the reference desk. Not to boast - but I solved the problem within six minutes after it was posted. I had been working at a small silicon vendor company, and my job regularly entailed reading awful awful uncommented C++ code for embedded systems; I had taken a momentary break to "refresh" myself by reading the Reference Desk; and this "obfuscated C code" question seemed like a cool breeze. I agree with Kainaw - if you spend a lot of hours each week staring at program code, you adapt your thought processes and start thinking like a compiler. Anecdotally, I have found that during weeks when I am most proficient at speaking with humans, I am less efficient at communicating with computers, and vice-versa. Program-code syntax is quite different from human language syntax, and if you spend forty or eighty hours in a week thinking in C, it does become difficult to switch back to English. Nimur (talk) 16:11, 11 October 2011 (UTC)

"Speed reading" is mostly a joke, anyway. It's not really much different than "skimming". Some people can read faster than others, but those people you saw on TV back in the 80s turning the page every second weren't really absorbing much of the text they were looking at. Here's a good article. APL (talk) 17:23, 11 October 2011 (UTC)

I would be fascinated to see some solid psychological research literature exploring the upper bounds of the "words per minute" rate of reading. Mostly, I think I am interested to see how the measurements would even be formulated. It appears that Cecil Adams used comprehension-testing, after the reading tests, to determine "effectiveness" of reading at various words-per-minute rates. Who are the preeminent experts in this sort of quantitative psychology research, and what books or journal articles have they published? Nimur (talk) 17:30, 11 October 2011 (UTC)

Much depends on what level of "comprehension" is required. I think of skimming as being monitored by some "dashboard instruments" - for example, how interesting the text is (which is evaluated long before understanding it), and front and center the ever-important bullshit-O-meter. Wnt (talk) 19:51, 11 October 2011 (UTC)

The cognitive skills involved in debugging are wide and varied, overlapping with reading and programming, but are subject to the power law of practice, and debugging skill will vary by individual more than by previous skill acquisition. So I would guess that speed reading will not have a large impact but programming skill certainly will. 67.6.175.132 (talk) 20:17, 11 October 2011 (UTC)

My experience is that you won't find the hard bugs when speed reading code. But it's easy to spot code made by beginners that needs extra attention. For instance, code that is copy-pasted or reversely a ridiculous use of inheritance introducing just one or a few methods at a time (Class names with "base" or "context" in it are a sure spell). And it's very easy to find places where errors will occur. In our 50 man year project almost every single line that used Cultures directly or was depending on it in any way introduced a bug. Using regular expressions is not "almost" but "each and every single line". See also Anti-pattern. Joepnl (talk) 01:53, 12 October 2011 (UTC)

Fanning and temperature

Why, when fanning oneself with some sort of object (sheet of paper, for example) or with a fan, the air feels cold? By this I mean, when we fan ourselves, we're rapidly moving the air particles around us; rapidly moving particles tend to move faster than those moving at slower speeds, so why is this moving air not warm? 64.229.153.152 (talk) 20:03, 11 October 2011 (UTC)

Because the movement you induce on the air molecules is miniscule compared to the speed those molecules were already moving. Googlemeister (talk) 20:13, 11 October 2011 (UTC)

Please see perspiration. 67.6.175.132 (talk) 20:18, 11 October 2011 (UTC)

Have a gander at Wind chill old bean. Quintessential British Gentleman (talk) 20:56, 11 October 2011 (UTC)

Indeed, turning on a fan in a closed room will increase the air temperature ever so slightly (due to the energy you are imparting into the air). However, as Quintessential British Gentleman's link points out, the reason you feel cold is due to the increased convective heat losses that occur due to the high wind speeds. - Akamad (talk) 21:17, 11 October 2011 (UTC)

If I remember the results of the calculation correctly from studying the gas laws in high school chemistry, individual air molecules average a speed of about 1,000 miles per hour, but in random directions, at room temperature. Fanning adds a very small coherent velocity change on top of this. μηδείς (talk) 02:30, 12 October 2011 (UTC)

In addition to the increased convective heat loss mentioned above, it will aid evaporative cooling if you are sweating and the humidity is not too high. -- 49.229.25.26 (talk) 02:51, 12 October 2011 (UTC)

(ec)If the air is above 37 C, the convective effect on heat transfer is no longer beneficial, but then it should help sweat evaporate faster. I wonder if there is some situation in a hot desert where sweat already evaporates instantly, where fanning does no good for either purpose and makes a person feel hotter. But such a circumstance is surely dangerous at best. Wnt (talk) 02:51, 12 October 2011 (UTC)

If the air is still then, even in a desert, the humidity of the air within a couple of milimetres of your skin will still be quite high, prevently the rapid evaporation of sweat. A fan mixes the air so you get dry air next to your skin and you get faster evaporation. That should mean that fans are more effective in a desert, not less. --Tango (talk) 12:04, 12 October 2011 (UTC)

Magnesium based leavening?

Are there any possible leavening agents with magnesium? Would magnesium oxide leaven bread? Magnesium carbonate? I have a feeling there may be only one way to find out. 67.6.175.132 (talk) 22:54, 11 October 2011 (UTC)

I don't think so, what gas are they going to give off when cooked. Magnesium bicarbonate is not stable as a solid to be useful. Graeme Bartlett (talk) 00:03, 12 October 2011 (UTC)

The logical choice would be magnesium carbonate, which is very stable. Dominus Vobisdu (talk) 09:33, 12 October 2011 (UTC)

Sure, Magnesium is essential for any type of life, including Brewer's yeast. See Magnesium in biology. On a serious note, magnesium carbonate would probably leaven bread in sufficiently acidic recipes. However, as the article notes, it may work as a laxative in high concentrations. Experiment at your own risk. Buddy431 (talk) 03:38, 12 October 2011 (UTC)

Yes, magnesium carbonate would work just fine if paired with an acid like cream of tartar. Besides the laxative effect, the taste would probably be horrible, too, as magnesium salts generally have a very unpleasant bitter taste. Dominus Vobisdu (talk) 09:31, 12 October 2011 (UTC)

Are there any magnesium compounds which taste good? Dualus (talk) 17:51, 12 October 2011 (UTC)

I eat a little Epsom salt every now and then for energy, and what's odd is, usually it tastes very bitter, but sometimes it is tasteless or even very sweet. I really wonder what determines the taste of it on a given day. Wnt (talk) 21:24, 13 October 2011 (UTC)

Without further study, I tend to assume these things vary with ones nutritional needs and health. I know that during my period, super-sweet things, and water, and salt, taste delicious and wonderful. If I haven't eaten all my very dark chocolate in the first few days of my period, it will sit untouched until the next. But I have to season food based on carefully measuring the spices for a few days, because my ability to taste them is diminished and I risk cooking something inedible for everyone else! And vegetables become unpleasant and unappetising, for the same time. Weird, but not medical advice, I personally have had much contact with doctors about this general area, and they are unconcerned with my eating patterns, but everyone should, of course, have their own individual case examined by a professional, but much like dehydrated people not tasting the salt in oral rehydration therapy. 86.163.1.168 (talk) 22:04, 13 October 2011 (UTC)

Wnt: what do you mean you eat epsom salt for energy? Epsom salt does not have any kilojoules (or calories.) Unless you have some kind of magnesium defficiency in your diet, or you have some kind of genetic deffect limiting your ability to absorb magnesium, it has no effect on you energy-wise. If it does, I suspect that it is a placebo effect. Plasmic Physics (talk) 00:18, 16 October 2011 (UTC)