Wikipedia:Reference desk/Archives/Science/2008 November 10

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November 10

physics

what is meant by magnetic flux and magnetic meridean? —Preceding unsigned comment added by Kunal pdj (talk • contribs) 07:15, 10 November 2008 (UTC)

Have you read magnetic flux? Can't help with the meridean I'm afraid. Feel free to come back if you have more questions. —Cyclonenim (talk · contribs · email) 07:25, 10 November 2008 (UTC)

I'm just speculating here but perhaps the magnetic meridian is like a line of longitude for the Earth's magnetic field, like a line that goes through the north and south magnetic poles. This is just a guess, though. --WikiSlasher (talk) 07:56, 10 November 2008 (UTC)

correct [[1]]. I'm adding it to the meridian article, so magnetic meridian should now give an explanation EverGreg (talk) 09:22, 10 November 2008 (UTC)

scientific names

Hi all,

What are the scientific names of the two macroscopic invertebrae phylum with hard parts which have successfully invaded and thrive in all three major habitat: marine, freshwater and terrestrial.

Thanks —Preceding unsigned comment added by 122.108.248.74 (talk) 08:50, 10 November 2008 (UTC)

"The reference desk is not a service that will do homework for others." Otolemur crassicaudatus (talk) 11:01, 10 November 2008 (UTC)

Indeed. But you could start with our invertebrate article, which has a list of the 9 invertebrate phyla with examples of members of each one. Gandalf61 (talk) 11:29, 10 November 2008 (UTC)

Putting things up your ass

Please don't be put off by the title- it's a serious question!

Am I right in thinking that when you put a drug up your ass, that works by going into the bloodstream. And yet if you put, say, an apple in your ass, you probably wouldn't absorb the apple into your bloodstream - it would just sit there?

If you put a load of sugar up your ass, say in cube form - would that just stay there, or would it absorb into your bloodstream? And would it make you fat? Or energised? Given that it never gets into the stomach.Jacobsen's Ladder (talk) 11:37, 10 November 2008 (UTC)

You can, indeed, absorb things through the rectum and colon. See Enema. I expect you are correct that an apple would not be absorbed, at least not quickly (and if it stayed there too long it would probably do serious harm, see Bowel obstruction). Sugar should be pretty easily absorbed, since it will dissolve in the natural moisture present in the colon and be absorbed into the bloodstream. There should be no difference between absorbing sugar that way and eating it, you would gain the calories and you can either use them or store them as fat. --Tango (talk) 12:10, 10 November 2008 (UTC)

Glucose (also known as dextrose) can be absorbed rectally[2]. Glucose is often used in energy drinks etc because it can be absorbed directly through the intestinal wall when swallowed. Sucrose is the form of sugar in table sugar, and when eaten is broken down into simpler sugars (glucose and fructose) by enzymes in the intestines before being absorbed. Some sucrose would be broken down by enzymes in the lower intestine if administered rectally, but I'm not sure how effective this would be (a quick search doesn't show up any relevant research, though a lot of people are doing funny things to locust rectums[3]). So, glucose administered anally would work, but sucrose would be less well absorbed. The above mainly refers to sugar solutions. If administered in cube form, you would have to wait for it to dissolve, which would slow the process. --Maltelauridsbrigge (talk) 12:13, 10 November 2008 (UTC)

these people did the experiment, though I am not sure that their results are reproducable... --Jayron32.talk.contribs 14:58, 10

November 2008 (UTC)

The rectum is a well accepted route for the administration of both hydrating fluids and drugs. Where drugs are not tolerated orally by the patient or where an infusion by needle is inappropriate then the rectal route serves. Generally the substance needs to be in solution as the interior of the rectum is only moist and a dry substance may not be easily absorbed or it may irritate the mucosa. The glucose, fructose or whatever is not likely to have any greater energising effect than that taken orally. Energy is largely (though not exclusively) a psychogenic phenomenon. Taking lots of sugars or other carbs won't necessarily give you boundless energy. Richard Avery (talk) 16:19, 10 November 2008 (UTC)

I have heard from an unreliable source that you can put cocaine up your ass and it will have the same effect. The advantage will be that you won't destroy your nose or vein due to your addiction. The hole history sounds plausible to me, but I don't know if some people do it actually. 80.58.205.37 (talk) 16:15, 10 November 2008 (UTC)

It wasn't that long ago that the blogs were quickly copying the story of a wife who killed her husband with a 3L sherry enema. You can also find many sources that explain how to use a tampon and alcohol to get drunk without drinking - for those days when you apparently want to get drunk but don't want to hold a glass or can or bottle or box... 16:24, 10 November 2008 (UTC)

I don't think the wife was responsible (although she probably should have stopped him). The man won a Darwin Award, I think. --Tango (talk) 16:37, 10 November 2008 (UTC)

Delivering analgesics by suppository has the advantage of avoiding first pass metabolism. (No puns intended.) Axl ¤ [Talk] 19:04, 10 November 2008 (UTC)

Anyway: the reference desk will not do your homework for you :) --PMajer (talk) 20:32, 11 November 2008 (UTC)

electricity

how many watts is mesaraed as units in india —Preceding unsigned comment added by 118.95.124.242 (talk) 12:56, 10 November 2008 (UTC)

Ministry of Power at this site can be useful for answering your question [[4]]Hope this helps User:Maheshkale

Asperger's and phone conversation - is it talking or just calling?

I red that those with Asperger's Syndrome have anxiety about talking on the phone. I was wondering, is that really right? Or is it just making the call they have problems with?

It seems more intuitive that - if a person has a condition wherein they need things in fixed patterns, need to plan out how things will go if they go out, etc. - that the mere calling of someone on the phone would be the biggest problem, not talking in and of itself. There is actually a lot less nonverbal communication to take into account, and therefore less stuff they have to sort through mentally, when talking on the phone. But, with calling someone, you never know if the person will be there, whether you are interrupting, what their mood will be, etc.. Similar, if someone calls, you don't know who it will be (unless you have Caller ID, what they want, and so on.

So, is it just talking on the phone, or is it instead the anticipation of receiving/making a call that troubles those with Asperger's?209.244.187.155 (talk) 14:45, 10 November 2008 (UTC)

Where did you read that??? No, anxiety about talking on the phone is not one of the symptoms for Asperger's syndrome, and not even a common characteristic. However, somebody with Asperger's could have trouble understanding the "unwritten rules" of talking on the phone, and develop an anxiety. Lova Falk (talk) 15:10, 10 November 2008 (UTC)

Aspergers (and it's big brother: Autism) is a 'spectrum' condition. There are people to be found on all points along the line between normality and autism. Hence, people (such as myself) with Aspergers have a reasonably wide range of issues and it's impossible to speak for everyone who is on that spectrum.

But we can make some generalizations: Interpersonal communication of all kinds is more difficult for aspies than for normal people. Picking up non-verbal cues is the hardest thing for all of us. Hence, on the telephone we are at least on an equal footing to other people - which means that for some of us, using the phone is easier than face-to-face - and using things like eMail and IRC is yet easier (because even tricky things like comprehending the tone of voice is eliminated). However, some Asperger's (myself included) find phone conversations more stressful than face-to-face. In my case, this is because I still don't have an innate mental model of what the other person is feeling or thinking - and the few tricks I've been taught about body posture and facial cues are useless too. So I dislike phone conversations slightly more than I dislike face-to-face conversations - but both are basically unpleasant. Email/forums/IRC is easiest for me. SteveBaker (talk) 16:46, 10 November 2008 (UTC)

Is this compound acidic or basic?

A student has asked me whether acetylcholine is acidic or basic. Acetylcholine is a quaternary ammonium cation, and as such, has a permanent + charge on the N. So I believe this means that it won't gain or lose a proton, regardless of the pH of its environment, and consequently is neither acidic nor basic. But this sort of thing has always confused me, so please let me know if this is wrong before I give out bad information. ike9898 (talk) 14:52, 10 November 2008 (UTC)

Things can be acidic in ways other than the Brønsted–Lowry acid-base theory ("acid is something that loses H+"). If you put this N+ thing in water, how might it interact (remember water exists partially as a mixture of "H+ and OH-")? If you change the balance of H+ and OH-, you're changing the pH of the solution. DMacks (talk) 17:52, 10 November 2008 (UTC)

I suppose it will either remove some free OH- from solution, consequently increasing the ratio of H+ in solution and lowering pH, or it will have no effect at all. How would you describe acidity/basicity of this molecule, short of being quantitative about it? Would you simply call it a weak acid, or it there something more precise you can say? ike9898 (talk) 18:06, 10 November 2008 (UTC)

Asuming that the -NH₃⁺ bit is the most acidic bit, it will have some measurable pKa value. Any solution that has a pH above this number will result in deprotonation of the molecule. According to this page, the Ka of acetylcholine is 1.8e-5, which means the pKa is 4.74. So any solution of a pH greater than 4.74 will deprotonate the -NH₃⁺. In other words, in a pure water solution (pH = 7.00) acetylcholine will be acidic. Cheers. --Jayron32.talk.contribs 17:59, 10 November 2008 (UTC)

The N doesn't have a proton to lose. It has 4 substituets. ike9898 (talk) 18:06, 10 November 2008 (UTC)

You're right. I misread the article. But the pKa of the molecule is measured, so it really is a weak acid. It doesn't matter WHERE the proton comes from. Looking at the structure, the base form of Acetylcholine is likely to be a zwitterion of the form CH3COOCH^-CH2N⁺(CH3)3 or maybe on the next carbon to the right... --Jayron32.talk.contribs 18:13, 10 November 2008 (UTC)

What about the effect cited by DMacks above? Is the + charge going to pull OH- ions out of solution? ike9898 (talk) 18:19, 10 November 2008 (UTC)

I don't see why that would work. After all, Na⁺ ions aren't acidic in any way; they don't "pull" OH^- ions out of water at all... --Jayron32.talk.contribs 18:25, 10 November 2008 (UTC)

Wrong on both counts. That paper is talking about the dissociation constant of a complex with a receptor, not a pKa. Na+ is indeed acidic, although very weak. Acetylcholine is also a very weak acid; you can deprotonate a carbon next to the nitrogen to form a nitrogen ylide, or the carbon next to the ester carbonyl to form an enolate. But both pKa's are greater than 14, which means that the deprotonation will be largely negligible in water. Acetylcholine could also act as a Lewis acid and react with water as RNMe3+ + H2O -> RNMe2 + MeOH + H+, but that's probably not what the OP had in mind because it "destroys" the molecule rather than simply deprotonating it. --Itub (talk) 20:22, 10 November 2008 (UTC)

Good call, Itub. Yes, I was lazy in not fully reading the article. After looking over the structure, there's no reason to assume that ANY of the C-H bonds is particulatly acidic; they certainly don't look much more acidic than, say, the C-H bonds in acetylacetone, which, while being more acidic than alkyl C-H bonds, really doesn't compare to classically defined "acids". --Jayron32.talk.contribs 21:13, 10 November 2008 (UTC)

Bodily fluids in the wash

If i put something in the washing machine with some sort of bodily fluid on it, it feel like im just making a solution of bodily fluids and soaking my clothes in them and this will then rub off on things - i guess my question is to what extent is the true. thanks. 143karbkaz (talk) 15:10, 10 November 2008 (UTC)

143karbkaz, I think we already answered this question here when originally asked by zakbrak341. I like how your user name is the just the reverse of the original. Laenir (talk) 15:44, 10 November 2008 (UTC)

I forget the password for that account, and its a different question - the question for that was do the enzymes in detergent break down the protiens in semen. This is a different question :( 143karbkaz (talk) 15:56, 10 November 2008 (UTC)

When something with stains from bodily fluids is put into a washing machine (note that name - bit of a clue there!) the washing powder will break down the protein of the stain and allow it to become a suspension in the water. Now here comes the cunning bit, the machine then empties all that water away and rinses the clothes twice more so ensuring that no stains or particulate matter is left in the clothes or linen. Semen, saliva and urine are particularly easy stains to remove and in theory the washing machine does make a 'soup' of bodily fluids but it then proceeds to flush it all away and rinse out the clothes thoroughly. I would bet a wad of cash that it would not be possible to detect semen, saliva or urine in washing after a full hot cycle. This is the same system they use in modern hospitals to clean linen. Dang, this modern technology is good! 86.4.187.55 (talk) 16:09, 10 November 2008 (UTC)

I suppose its probably possible to work it out, such a tiny amount and thats dissolved in what 40L of water, work out the concentration of that, then work out how much water the clothes hold after they have been spun, then work out how much solute would be in that, then when thats all dissolved in the next rinse cycle ect. it would be pretty small. But do you think the solute would rub off on things once its dried? —Preceding unsigned comment added by 143karbkaz (talk • contribs) 16:18, 10 November 2008 (UTC)

It's just as well I don't believe in homeopathy...all of that dilution making things more powerful...Urgh! SteveBaker (talk) 16:48, 10 November 2008 (UTC)

I just knew when I saw your name and "dilution" in the edit summary that you were going to make a comment about homeopathy... you're getting predictable! --Tango (talk) 16:56, 10 November 2008 (UTC)

OK. For the sake of thoroughness, lets ACTUALLY see how much spooge is left on your clothes after your last nocturnal emission and if you wash it in a typical washing machine. Lets make some spherical cow-type assumptions. Lets say that the ejaculate is completely and evenly dissolved in the wash water each time the washing machine fills, and lets assume that you do the "double rinse" option on your washing machine. According to Ejaculation, the average event produces 1.5 - 5.0 mL of spunk. Lets just take the high end of that volume. According to this page, a modern "energy star" compliant washer uses 18-25 gallons per load. Doing a quick conversion, and this time lets use the smaller end, so we can maximize the amount of jizz in the washing machine, for our "worst case scenario" wash, we get a metric volume of 68 liters, or 68,000 mL. 5/68,000 means that after the wash cycle, we have .000735 % of our cum left in the wash. After one rinse cycle this reduces to .000000108 % left, and after 2 rinse cycles, that leaves us with .000000000000159 % of our original stain left in the machine. Considering that the average ejaculation features, according to our article on Semen analysis, 60,000,000 sperm per milliliter, or 300,000,000 sperm in our 5 mL test case. Multiplying this by our dilution factor gives us .0000047; which means that there is a 1 in 200,000 (roughly) chance that a single sperm is left in your washing machine after a standard wash cycle, with the double rinse option. And this is ignoring any effect that soap may have on denaturing or destroying the components of the semen. I don't think you have anything to worry about. --Jayron32.talk.contribs 17:50, 10 November 2008 (UTC)

That's got to win some kind of award for the largest quantity of synonyms for sperm used in one paragraph. —Cyclonenim (talk · contribs · email) 18:08, 10 November 2008 (UTC)

I don't follow your calculations. You seem to be assuming that there will be 5ml of liquid left in the washing machine after it drains each time, I expect it is considerably higher. --Tango (talk) 18:10, 10 November 2008 (UTC)

Hense the spherical cow reference. OK. Lets assume that there is really 500 mL of water left after each wash, so I was off by a factor of 10,000. That's still a 1 in 20 chance of finding a single spermatazoa in the wash. I am not concerned... --Jayron32.talk.contribs 18:19, 10 November 2008 (UTC)

There are 3 drainings, so wouldn't you be off by a factor of 1,000,000? That would give an expectation of 5 sperm after the wash. I think your cow is a little too spherical. I think the fact that any sperm would almost certainly be killed by the heat (and perhaps the soap) is more important than the dilution (which is far too difficult to calculate reliably). --Tango (talk) 19:14, 10 November 2008 (UTC)

Actually, the three dilutions I did would be the 5/68,000 500/68,000 500/68,000, to get the 1/20 number. --Jayron32.talk.contribs 19:19, 10 November 2008 (UTC)

What if the machine does not have a special spunk cycle? Edison (talk) 19:59, 10 November 2008 (UTC)

The point of the calculations is to show the rediculousness of the premise of the original question. The idea that when you wash and entire washload of clothes, some of which has a trivial amount of semen on it, that that semen could somehow cover all of the clothes in the wash, "contaminating" them. The idea that you could somehow "coat" an entire washload of clothes with semen (well, using a washing machine. If you and a bunch of friends were REALLY dedicated...) by simply washing clothes is just silly. --Jayron32.talk.contribs 20:39, 10 November 2008 (UTC)

Well, yeah, but our concepts of filth aren't necessarily dictated by logic. Here's a little experiment my roommate showed me back in uni: take a small cup of water, like the little Dixie cup you use at the dentist. Drink a little of the water. Everything okay? Now spit into the cup, as much as you can without actually horking up anything nasty. No need for phlegm, just mouth saliva. See if you can refill the cup to replace what you drank. Okay, now drink the spit water. You know the water is okay because you just drank it and you know the spit is okay because it's yours and it just came from your mouth, yet most people have a very hard time gulping down the mixture and even many that can do it, can only do it as a "dare" type thing. There's nothing in the cup that wouldn't be in your mouth the second you take a swig, but one is filthy while the other is not. No logic there. Matt Deres (talk) 17:45, 11 November 2008 (UTC)

VCR tape to DVD

How do I copy one to the other please?--212.139.78.231 (talk) 17:48, 10 November 2008 (UTC)

Probably better suited for the computing reference desk, but here's a little article which gives you some hints at how to do it. Basically, it requires hardware: Linky —Cyclonenim (talk · contribs · email) 18:05, 10 November 2008 (UTC)

Buy a DVD recorder. My computer came with one installed. --Jayron32.talk.contribs 18:06, 10 November 2008 (UTC)

Do you have a DVD player for your TV that can burn DVDs? If so, just connect your VCR player to the DVD player's input and follow the instructions for burning DVDs. If you don't, and want to use a computer DVD burner you will need a TV tuner card to connect the VCR player into. If you want more details, there are loads of tutorials online, try google. --Tango (talk) 18:07, 10 November 2008 (UTC)

Don't use a standalone DVD recorder. They usually make proprietary discs that are not readable by other machines. I've had two and neither made DVDs that any other machine could view, even the DVD-ROM on my 'puter. Matt Deres (talk) 17:47, 11 November 2008 (UTC)

I agree with Matt..I purchased a standalone and was quite upset to find out the discs would not work in any other player. cheers, 10draftsdeep (talk) 18:26, 11 November 2008 (UTC)

You have a few options here, you can use a dedicated vhs dvd combo recorder, you can connect a player and a dvd recorder, you can buy an external device (pinnacle supply a few) or you can get an internal video capture card and the related software. First is the easiest but least flexible, the last is the hardest but gives you all the options. Alternatively, you can use a specialist company who can either put the video onto DVDs for you or provide as video files and help you edit them. One such Company is Vinyl to Digital and they can convert vhs to dvd or to any other format and provide help and support for whatever you want to do. 17:35, 26 May 2009 (GMT)

water clock from 2008

http://www.alibaba.com/showroom/Water_Clock/------------15--------------.html

Where would I find an explanation on how these work? —Preceding unsigned comment added by 12.213.224.56 (talk) 18:21, 10 November 2008 (UTC)

Maybe in the article Water clock? --Jayron32.talk.contribs 19:14, 10 November 2008 (UTC)

That article is about old-fashioned mechanical clocks, with gravity driven water as the power source. This questioner is asking about electrically powered digital clocks that use an open container of water as a primitive cell. Possibly a Daniell cell, but I'm not sure. APL (talk) 19:48, 10 November 2008 (UTC)

They run on saltwater batteries. Digital clocks require so little energy that even a "homemade" battery can work. You may also be interested in two potato clocks The Amazing Two Potato Clock. See the brief paragraph here : List_of_battery_types#Homemade_cells. APL (talk) 19:13, 10 November 2008 (UTC)

Please note - the power doesn't come from the water - it comes from the dissimilar metals in the two electrodes reacting with each other via the water. Hence the claims for "potato powered clock" or "lemon powered clock" or (god forbid) "water powered clock" are all just a tad inaccurate. SteveBaker (talk) 21:30, 10 November 2008 (UTC)

Indeed, as Steve notes, the power provided is from the difference in reduction potential between the two dissimilar metals. These set ups are functionally equivalent to ANY other battery, like good old double-a cells, and the salt water/lemon/potato provides NO electromotive force themselves; they only provide the medium in which the required spontaneous chemical reactions happen. --Jayron32.talk.contribs 22:12, 10 November 2008 (UTC)

Galaxy flow

If the galaxies are moving in the same direction, isn't that the same as saying they aren't moving at all? If there was a supermassive object beyond the visible universe, wouldn't it be impossible to receive any effects from it, including gravity? Before any of you mention it: xkcd. — DanielLC 18:23, 10 November 2008 (UTC)

If it were due to a massive object then the galaxies nearer it would presumably be moving faster than those further away, that difference would be meaningful value (as you say, the actual movement of a given galaxy is meaningless since there is no universal frame of reference - in fact, it's the tidal force that has the measurable effect rather than the gravitational force itself). As for it being beyond the observable universe, I agree, if we're observing its gravitational effects then we are observing it so it must be within the observable universe. It could be something more fundamental than just a lot of matter, though, perhaps something to do with the global structure of spacetime? I think we're probably in the unfortunately common situation of a journalist not knowing what they're talking about (New Scientist is generally better than mainstream journalism, but it's far from perfect).--Tango (talk) 18:31, 10 November 2008 (UTC)

The cosmic microwave background defines a privileged state of motion everywhere in the universe, called the Hubble flow: it's only if you're moving with the Hubble flow that the CMB is isotropic. The large-scale net movement (which may not be real) is with respect to that. The part about its being a pull from beyond the observable universe is just speculation (only circumstantially supported by the data), but it makes sense once you understand the ambiguity in the definition of "observable universe". The part of the universe we can actually observe with telescopes is limited to a past light cone extending back to 400,000 (0.0004 billion) years "after the big bang", which is when the primordial soup cooled down enough to become transparent. (See Age of the universe#Explanation for what "after the big bang" means.) If you extend the light cone another 400,000 years back in a naive way, assuming matter/radiation dominance, then the size is not much different—either way you get about 46 billion light years (comoving) in every direction, which is the value in our observable universe article. But most cosmologists think that there was an inflationary epoch a small fraction of a second "after the big bang" during which the growth was dominated not by matter or radiation but by a cosmological-constant-like quantum field and the universe expanded by a factor of 10^{something large} in a very short time. If you extend the past light cone through that, it covers an enormously larger (comoving) area. So the idea is that the net motion is due to something from the pre-inflationary era which is inside our past light cone but well outside the part of the universe that we can actually see. -- BenRG (talk) 20:51, 10 November 2008 (UTC)

I've never heard of "observable universe" being used to mean anything other than the light cone going all the way back to t=0, is it common to define it to stop at the moment of last scattering? --Tango (talk) 21:58, 10 November 2008 (UTC)

It is fairly common, if somewhat inaccurate, to use "observable universe" to mean "visible universe" (i.e. the universe as probed by light). Dragons flight (talk) 22:12, 10 November 2008 (UTC)

I noticed that too.. if we're seeing the gravitational effects of an object, we must be seeing the object itself. Unless, as said above, it's some weird phenomenon independent from the laws of physics as we know them. which is a pretty unreasonable assumption. 72.236.192.238 (talk) 22:34, 11 November 2008 (UTC)

is my scientific methodology sound?

i'd like to test whether a wikipedia article is being suppressed.

my methodology is:

1. identify a control page that
   1. is approximately the same length as the test article
   2. has an inadequate lead section
2. the test article is international law and the arab-israeli conflict, which has an inadequate lead section
3. my hypothesis is that the reason it doesn't meet our wikipedia:lead_section guideline is it's being suppressed
4. to make the test blind, i will pay a paper mill to read both articles and produce a lead section for each that
   1. meets the guidelines of wikipedia:lead_section
   2. incorporate as much of the current lead as possible (to minimize the chances of reversion)
   3. is in line with lead sections of good articles of the same length
5. from two different net cafes i will
   1. create a new wikipedia account
   2. from each account change one of the page's intro to the intro produced by the paper mill
6. if the improved control intro is not reverted/obfuscated but the improved test intro is, i will conclude that the wikipedia article is being suppressed

what do you think of my scientific methodology —Preceding unsigned comment added by 82.124.214.224 (talk) 19:30, 10 November 2008 (UTC)

If you're serious about the scientific aspect, some obvious problems are that two data points don't mean much, and that two encyclopedia articles are different enough that one is not a good control for the other. If you're more interested in improving article content, forget this science experiment and just bring up your concerns on the talk page. There's no need to resort to sockpuppetry or subterfuge- in fact you'll find that doing so makes your work here more difficult rather than easier. Friday (talk) 19:52, 10 November 2008 (UTC)

I'm not interested in doing work here, and I'm not interested in the article I linked -- that's why I've never made an edit. I am interested in (knowing--not changing) whether Wikipedia articles are suppressed! That is useful and good information to know... I'll think about your specific concerns, but please tell me if you have an easy way to improve my test algorithm. —Preceding unsigned comment added by 82.124.214.224 (talk) 20:14, 10 November 2008 (UTC)

Actually: do you have an easy way for me to divine whether Wikipedia articles (such as the one I linked) are being linked, and in a way that is scientific? I don't understand your point that two Wikipedia articles are "different enough" that if the intro paragraph of one is reverted to two short sentences (the latter of which doesn't even make sense) and the control articles aren't, it wouldn't imply that the control article was being suppressed?? The only reason for the control, is to show that reverting a good, obvious improvement doesn't normally go on. How would you feel if the control group were, say, twenty articles?

You haven't defined what suppression is. You're experiment wouldn't prove suppression in any way, because that would mean reading the intent of people who are removing information from the article. There are many good faith reasons to remove text from an article, or to prevent new text from being added, and not all of them imply "preventing people from hearing the TRUTH!". --Jayron32.talk.contribs 21:08, 10 November 2008 (UTC)

Nice attempt to paint me as a conspiracy nut ("the TRUTH"). How about you read what I wrote and come up with a single good faith reason to remove the lead the paper mill would produce from the article itself and based directly on our lead guideline? —Preceding unsigned comment added by 82.124.214.224 (talk) 21:41, 10 November 2008 (UTC)

The use of the word "suppression" is itself perjorative, and implies a deliberate attempt to deceive. I see no evidence of that here, and I also see no evidence that the methodology would test for that. --Jayron32.talk.contribs 22:09, 10 November 2008 (UTC)

Who said anything about deception? I mentioned suppression. If you don't think there's any reason to even suspect it, why don't you take 30 seconds and change the lead paragraph to something sensible, after reading the rest of the article. I am genuinely interested in whether your good-faith attempt will get reverted, and I don't know if it will. Try it! If it does get reverted, we can discuss why, if you still won't think it's suppression...

Removal != suppression. There are many reasons to remove verbage from an article, and suppressing it, which is basically the intentional act of preventing information from becoming public knowledge, is only one of them... --Jayron32.talk.contribs 23:52, 10 November 2008 (UTC)

What is suppression? When one viewpoint surpasses another and thus oppresses the lesser? Wikipedia is built on this. It's the collective ideology of capitalism, the industrial revolution, and Web 2.0: Putting something out there for others to shamelessly improve on. Mac Davis (talk) 23:12, 10 November 2008 (UTC)

No, I mean suppression literally: pushing things down into the bucket. I would like to test whether the mentioned article does this by not having a lead paragraph.

"Pushing things down into the bucket?" As I understood what you meant, I would say the same thing Jayron32 did. Often elimination of words is the best writing technique. Mac Davis (talk) 23:26, 10 November 2008 (UTC)

You're normally absolutely right, and the first thing I do after typing something is cut, cut, cut. In this case however the lead paragraph hasn't just been pruned -- it doesn't exist at all! Look at the "introduction" to international_law_and_the_Arab–Israeli_conflict and you'll see the lead paragraph doesn't exist. For comparison you can read our guideline, and then read the intro section of some good or featured articles. Now do you see why I am interested in whether the missing lead is an act of suppression or not, and would like to test it? I'm not saying it is, or isn't -- here at the reference desk, my question is about the methodology for testing this.... If you'd like to be my volunteer, please, make some improvements to the lead section so I can see if they'll be reverted. To make the study blind, I don't want to make changes myself... —Preceding unsigned comment added by 82.124.214.224 (talk) 23:49, 10 November 2008 (UTC)

How do you intend to control for the different levels of attention the two articles receive? I suspect that any article relating to conflicts in the Middle East will have a large number of unique editors, a large number of edits per day, and appear on a large number of editors' watchlists compared to the typical Wikipedia article. Edits to sensitive topics are also often more successful if they are discussed in advance on the article talk page — a precaution that is often unnecessary for less contentious areas.

In other words, I can think of quite a few confounding factors for your study. Instead of wasting your time and money to generate a meaningless result, perhaps you should try discussing the matter calmly and politely on the relevant talk pages. Accusing editors of 'suppressing' topics (whatever that means) isn't likely to result in the sort of collaborative consensus-building that allows us to create great articles. TenOfAllTrades(talk) 00:01, 11 November 2008 (UTC)

You're right about all that. Let's try it and see how it goes (see my comment below) 82.124.214.224 (talk) 00:23, 11 November 2008 (UTC)

Here's a test: dig into the fossil record and see if there has been any dispute over the contents of the lead. In this case, considering that over the past year there has been only one minor change to that header section, the prior probability of your hypothetical (and amorphous) "suppression" is low. — Scientizzle 00:10, 11 November 2008 (UTC)

I like that test, it proves that no one is digging up the suppressed information. I guess I'll be the first! :) I'm going to do the edit myself and see what happens. I'll post my version here first and you suggest improvement, then I'll post it there. See ya', I'm off to read the article and lead paragraph guideline carefully!—Preceding unsigned comment added by 82.124.214.224 (talk • contribs)

How is something "suppressed" if it's never before been added? The assumption that any reversion of a new addition is an attempt at censorship violates Wikipedia's core behavioral policies, too... If you can improve the article, please do so...but don't disrupt Wikipedia to make a point, okay? — Scientizzle 00:35, 11 November 2008 (UTC)

Okay, I was bold and added this:

The resolutions of major institutions of international law, such as the International Court of Justice, are rejected in the case of the Arab-Israeli conflict by both Israel, the principal state involved in the conflict (there is no Palestinian state), and the United States, another country supporting Israel's decision to do so. This rejection is possible because international laws, unlike the more familiar laws of local and national governments, are neither legislated nor enforced by a sovereign government having jurisdiction and law enforcement powers: there are local and national governments in the world, but no "international government" of the same kind. Instead, countries exercise sovereignty in international affairs, and are bound by the findings of international institutions only insofar as they submit themselves to their authority. At times, nations cooperate easily, and international institutions, as the manifestation of this cooperation, wield considerable power. At other times, such as in the case of the Arab-Israeli conflict, international institutions are less powerful.

with the edit summary "improved lead. Please refer to Wikipedia:Lead_section and make further improvements". We'll see what happens...

Don't post your version here, this is the science ref desk. We're good at science, we're not necessary good with international affairs. The article's talk page is the place to get opinions on changes. Alternatively, you could just update the article and just see if anyone reverts, if they do you can go to the talk page to discuss it then (see WP:BRD). --Tango (talk) 00:42, 11 November 2008 (UTC)

No. I do not think it is sound at all. Not even close.

1. You're going to need to define "suppressed" much better than you've already done.
   1. What does "Suppressed" mean?
   2. Why would this "suppression" manifest itself in the lead of the article?
   3. Are you expecting a particular point of view to be pushed? Or just a general resistance to change?
      1. If the former, which? If the latter why would the Israel article be more susceptible to it?
2. You would need a lot more than two pages to draw any significant conclusions.
3. You would also need your "control" articles to be as heavily watched and edited as your test articles
   1. If the control articles are intended to be non-controversial, this may be very difficult.
   2. How would you measure page watched-ness?
4. You would need your "Essay mill" students to be completely unbiased, and familiar with WP's style.
   1. I bet they'll figure out where you got the articles from.
   2. It would not be a blind study if you copy-edit their leads at all. Even just going through and adding the wikilinking could taint the experiment.
5. You've only described a single-blind experiment. The measurement criteria had better be very well defined ahead of time.
6. You've just now told us, some of the subjects in your experiment, that you intend to run an experiment.

APL (talk) 01:36, 11 November 2008 (UTC)

I was thinking that I shouldn't ask you guys, but I thought it wouldn't really matter, it's a very different circle of people. That's why I didn't ask on the article's talk page though... How important are double-blind studies versus single-blind? Are researchers really that bad when they know what effect they're evaluating?

Yes - in some cases, it makes a big difference. In a drug study where half the people get placebo and the other half get real drugs, it's very hard indeed for the doctor who is handing out the drugs not to say something that will clue the patient in to what's really going on and thereby destroy the placebo effect. Double-blind is the only scientific way to do this kind of study. SteveBaker (talk) 03:26, 11 November 2008 (UTC)

I've made the edit, as you can see. I think it's pretty clear now. Am I wrong to conclude that if it stays (isn't reverted) then the lead had NOT been totally inadequate before my edit BECAUSE of a group of people suppressing the article -- making sure the lead didn't say what's in it -- but for some other reason? Or is this also a wrong conclusion on my part?

The edit in question is here.

So, after discussing your scientific methodology, finding it inadequate, you elect to not even follow your own inadequate procedure? Regardless of what happens here, nothing will be proved, no experiment has been conducted. "Experiment" does not mean "try random stuff and see what happens.".

Incidentally, the lead you added to that article doesn't really seem to be a good summary of the article. It seems more like a brief rant on the implications of the topics of the article, but not really a summary. I don't know enough about the topic to give a fair assessment of that, though. APL (talk) 04:58, 11 November 2008 (UTC)

It would be REALLY tough to suppress an article here on Wikipedia. Remember that all of your changes - and everyone else's are stored in the article's history. If someone "suppressed" something - you can look to your last version - see exactly who changed it, how they changed it and when they changed it. You can go to their Talk: page and ask them why they did that - your question and their answer also remains in the edit history for all eternity. To remove an entire article or do something 'special' to wipe out some editing history would require the decisions of a whole committee of people...fiercely independent people...getting them to agree to suppress something would be all but impossible...and all of those discussions are retained in 'history' pages forever. The paper-trail is very complete and all-but-impossible to alter. Given all of that - it would take a lot of nerve for someone to start methodically suppressing stuff, you could easily create an unbelievable stink (because you can easily prove everything that happened) - and if you're right, people will flock to your side. However, I wish I had a dollar for every time I reverted someone's crappy editing, poor grammar, unreferenced facts, violations of policy/guidelines...and ended up being accused of "suppression". So if you feel something has been inappropriately removed - you've got to go to the talk: page - and ask why. If you disagree with the reasons - then seek to get a consensus of users who agree with your points - if you succeed, you can restore your version and people will defend you if it gets removed again. But if you fail - you'll have a lot of people patiently explaining WHY you're wrong...and you'll simply have to swallow your pride and admit that you're wrong. SteveBaker (talk) 03:26, 11 November 2008 (UTC)

thank you for that... but nothing of mine was removed. can you also explain given that it's not possible to suppress information, why some articles are heinously biased?

Since this whole thing is pretty bankrupt as far as 'science' and experimentation, and, I can't find it right now, but I'm almost positive that there's a WP policy that specifically forbids this sort of experimentation, perhaps this discussion should be brought up in the talk page of the article in question? APL (talk) 05:04, 11 November 2008 (UTC)

(edit conflict) You don't understand NPOV and consider something biased even though it follows it? You're biased and assume anything without the same bias isn't? The articles in question were only written by one or two people and have not been edited for NPOV? The articles in question are the subject of an ongoing edit war and have been locked on The Wrong Version? Making an article NPOV is harder than you think? Making an article NPOV is impossible? There are over a million articles on Wikipedia, so some will be biased? I think people can add to this.

Who said anything about bias? I didn't. Who was that directed to? APL (talk)

APL, I think Wikipedia is only against experimentation that damages it, such as inserting false information. The OP's experiment involves improving Wikipedia. — DanielLC 05:15, 11 November 2008 (UTC)

Fair enough. That may be what I'm thinking of. APL (talk) 05:50, 11 November 2008 (UTC)

Bias (even serious bias) or incompleteness or other defects in a Wikipedia article may be due to the inexperience of the person who created the article, or to "inadequate attention" from other editors, or both. It is not necessarily the result of "suppression". Some articles get little if any attention after they are created. I think a stroll through Wikipedia using the "random article" link will demonstrate that. CBHA (talk) 06:45, 11 November 2008 (UTC)

Bias is a tough thing to judge. What happens is that opinion lies on a line between one extreme and the other - you always regard your own position as being in the middle of the line - so if the article is to the left of where you are - it's biassed. However, for someone who's opinion is to the left of yours - it's balanced. Who's right? Dunno. The solution to bias in Wikipedia is simple - we don't choose the facts - we find references and write what they say in our own words. The opinions of the authors SHOULDN'T matter (although it obviously does sometimes). But if you find an article (especially one with a lot of authors that's been around for a long time) - and you think it's biassed - you should probably take a deep breath and realise that your opinion is not in the center of the spectrum of opinions. For new-ish articles with just a couple of authors - bias can certainly creep in - and it's your responsibility to get in there - talk it out on the discussion page and use FACT with REFERENCES to bring the article into balance and harmony. When you consider the amount of hate and resentment flung around in the articles about John McCain and Barrack Obama - then look at the beautiful pair of articles that were simultaneously brought to featured status in time for the US election day - you've got a pretty good idea of how to do this. You WILL end up agreeing to text that you don't personally approve of - but you'll also have the chance to get the facts in there. Wikipedia is actually a shining beacon of conflict resolution in this regard. SteveBaker (talk) 14:15, 11 November 2008 (UTC)

Speed of Electricity.

http://en.wikipedia.org/wiki/List_of_common_misconceptions states that "Electricity" is fast, but the electrons inside move slow. However I have yet to see an article/document stating the research behind this and blah blah blah. I wanted to know if I could get more accurate sources. I myself have found http://www.eskimo.com/~billb/miscon/speed.html

but I wanted to know if there was a more scientific article on it...

In retrospect the whole list_of_common_misconceptions page has alot of unsourced material but that's not my point. 70.89.49.205 (talk) 19:34, 10 November 2008 (UTC)

Have you looked at the electric current article, particularly the section on drift speed?

List of common misconceptions is actually fairly well sourced, as articles of that class go. In cases where references are not cited, other Wikipedia articles linked in the article have the appropriate citations. If you can contribute sources where needed, please do. ~Amatulić (talk) 19:51, 10 November 2008 (UTC)

See Speed of electricity, which says that the electrons carrying current flow a t a typical rate of millimeters per second, while the impulse when current is switched on travels through copper at almost the speed of light. Electrons start entering one end of the conductor at about the same time they start flowing out the other, but the electrons are not travelling all the way through the wire that fast, because there are so many of the charge carriers present in any small section of wire. The article Drift velocity gives a mathematical explanation of the slow rate with which electrons drift through a conductor. Edison (talk) 19:55, 10 November 2008 (UTC)

Ahh, Thank you for the results, I appreciate your time looking 70.89.49.205 (talk) 20:29, 10 November 2008 (UTC)

It's not such a difficult concept. Imagine a garden hose that's been running for a while. You turn it off, wait a bit, then turn it on again. The instant you turn it on, the water starts flowing out of the other end. Even if the hose is 100' long - the water comes out almost instantly - the delay between turning the water on and getting water out of the end is probably something like the speed of sound in water. Yet the water flow itself is nothing like that fast - a few feet per second probably. It's the same deal with the electrons and the wire. The wire is already "full" of electrons - so when you push one into the wire at the battery end - there is a knock-on effect that pushes one out of the other end at about the speed of light in copper...but the individual electron meanders very slowly along the wire. I read somewhere that there was a good chance that when you put a new battery into a flashlight - there is a good chance that not one of the electrons would make it out of the battery, all the way around the circuit and back into the battery before the battery went dead. I'm not sure that's really true - but as Edison says - at a couple of millimeters per second, it's an amazingly slow process. SteveBaker (talk) 21:17, 10 November 2008 (UTC)

These explanations are still a bit misleading since they suggest that the electrical energy goes in the same direction as the charge carriers, just faster. Actually it's just as happy to go in the opposite direction. When you initially insert a battery into a circuit, it pulls charge carriers from the wire connected to one of its terminals and pushes them into the other. That leads to a cascading effect that travels around the circuit in both directions from the battery, meeting up at the far end of the circuit (the halfway point). If you're modulating the current/voltage to send a message, as with a telegraph or broadband over power lines, the signal travels from sender to receiver along both wires. (I think. There's no reason for it not to, anyway.) -- BenRG (talk) 22:55, 10 November 2008 (UTC)

A very good and profound question, regarding an issue or phenomenon that isn't covered in classical textbooks, either at high-school level or higher, introductory ones. This issue was raised during a course I gave about half a year ago, and drove changing the usual syllabus of the course. SteveBaker's explanation is a very good simplified demonstration. However, the phenomenon of electric current is far more complex. In brief, at least two phenomena are involved here. The 1st of which is the actual motion of free electrons, which is typically very small, as already mentioned before. The 2nd is a result of the appearance of a potential difference or voltage along the conducting wire, which acts as a source of disturbance. This disturbance spreads through a potential gradient in a wavelike manner, namely a pulse (physics). As all waves do, they carry energy delivered to the mettalic atoms of the conductor, thus heating it. The pulse has nothing to do with the actual free electros motion, but manifests itself as a momentary repeated change in their rate of oscillations, propagating along the conductor in approx. 70% of the speed of light. There are differences between the dynamics related to DC & AC, and other phenomena related exclusively to the latter.

To elaborate in depth on the subject, you're invited to look up at: (1) Solid State Physics, (2) Solid State Physics, by Ashcroft & Mermin, (3) Introduction to Solid State Physics, by Kittel. BentzyCo (talk) 23:15, 10 November 2008 (UTC)

Square seconds

According to the article on acceleration, SI measures it in terms of meters per square second (m/s²). What does a square second look like? --67.185.190.46 (talk) 22:31, 10 November 2008 (UTC)

It probably looks similar to what a second looks like. Mac Davis (talk) 22:46, 10 November 2008 (UTC)

Think of it in words. Velocity/speed is in meters per second - how many meters can be covered in one second's time. That is, the change in displacement/distance with respect to time. Acceleration is the change of velocity with respect to time, so it should have units of "meters per second per second." If the velocity changes by 5 m/s in one second, it's acceleration is 5 meters per second, per second. This works out to m/s² (take m/s and divide by s) --Bennybp (talk) 22:47, 10 November 2008 (UTC)

What does a second look like while we're at it? Acceleration is the rate of change of speed - its units are "meters per second, per second" (ie if you are accelerating at 2 ms^-2, your speed will have increased by 4 ms^-1 after 2 seconds), and (ms^-1)^-1 becomes ms^-2. (ec: wow, beaten to the punch - twice.) 81.102.34.92 (talk) 22:50, 10 November 2008 (UTC)

If units are used to describe physical quantities, the "derived unit" of ms^-2 describes how distance and time might be related in this situation. Mac Davis (talk) 23:03, 10 November 2008 (UTC)

Seconds squared by itself is a meaningless unit. However, meters PER second squared is acceleration. One cannot arbitrarily pull part of the unit out of the definition and make it meaningful. For example, let's say your name was John Joseph Smith, and I were to ask "what does ephsmi mean?" That's essentially what the OP's question does to the units; though I admit that it looks like seconds squared is an "operative" part of the unit, it's REALLY just a mathematical convenience. The real physical quantity is (meters PER second) PER second which is mathematically identical to meters PER second squared. --Jayron32.talk.contribs 23:48, 10 November 2008 (UTC)

I chalk it up to either my own personal density or my poor education that I only figured out as an adult that all it means is that for each second the thing is falling, it adds X meters per second to its velocity. --Sean/76.182.94.172 (talk) 00:00, 11 November 2008 (UTC)

Occasionally (rarely) it is pronounced "Meters per second per second", if that helps you at all. APL (talk) 01:38, 11 November 2008 (UTC)

The significance of the exponent is that it implies the distance travelled has a linear relationship with the square of the elapsed time. The fact that the units are in the form distance/time^2 is not a coincidence; it means that the two quantities are related. --Bowlhover (talk) 02:57, 11 November 2008 (UTC)

It's really only a notational convenience. We square (and cube and more) all sorts of peculiar units. The 'volt' and the 'watt' (for example) both have seconds-cubed in their expansions - the units of 'permittivity' have seconds to the fourth power. If your rate of acceleration is changing - you might have seconds-cubed - if the rate at which your rate of acceleration is also changing you have seconds-to-the-fourth power. It's just notation. SteveBaker (talk) 03:12, 11 November 2008 (UTC)

Calling the unit "metres per square second" raises the question: what on earth is a "square second"? It sounds very strange!

In my experience with the terminology, I have never before heard it called that. "Metres per second squared" is usual IME, and (as noted above) that is simply an abbreviated way of saying "metres per second per second". CBHA (talk) 06:59, 11 November 2008 (UTC)

Yeah - I've never heard "meters per square second" either. I suppose that when some people are talking about units of (for example) density, we could talk about kg.m^-3 as "kilograms per cubic meter" rather than "kilograms per meter cubed" - but scientists don't often do that unless they are talking casually to laymen - and they certainly only do it that way when it makes physical sense (which it doesn't with 'squared seconds'). But we need this kind of nomenclature. Saying "meters per second per second" is easier for the layman to understand than "meters per second squared", but when we get into some units, that convention quickly becomes unwieldy. An "ohm" for example would be a "meter meter kilogram per second per second per second per ampere per ampere" - or a "farad" would be an "ampere ampere second second second second per meter per meter per kilogram"! You simply have to use the mathematical convention of calling an object that's multiplied by itself a "square" and an object that's multiplied by itself three times a "cube". We do that just to make the words easier to understand. It doesn't have a physical meaning - but this is math - so it doesn't have to have physical meaning. It all relates back to Dimensional analysis - in which the units can be treated like variables in an equation and can be multiplied and divided - cancelled out or raised to some power as needed. SteveBaker (talk) 13:55, 11 November 2008 (UTC)

Nuclear reactor efficiency numbers

I'm looking for some numbers on nuclear power plant efficiency and I'm having a hard time getting them. Any help? I'd like to compare them to solar, wind, coal, and oil. Mac Davis (talk) 22:45, 10 November 2008 (UTC)

Can you define more precisely what you want? There are different ways to look at it. Fuel is not totally depleted, heat is not totally converted to electricity, capacity is not fully utilized, etc. Dragons flight (talk) 22:59, 10 November 2008 (UTC)

Heat not totally converted to electricity. What is the word for this? Thanks. Mac Davis (talk) 23:04, 10 November 2008 (UTC)

Thermodynamic efficiency, I guess, but I don't see how you can meaningfully compare different types of power plant this way. The important differences are in things like the construction cost, the cost and availability of the fuel, the environmental impact, and the risk of serious accidents, not the amount of waste heat they produce (unless it's enough to be a pollutant, I guess). All else being equal a power plant that produces less waste heat is better, but all else is rarely equal. -- BenRG (talk) 23:27, 10 November 2008 (UTC)

I was thinking economically, a major factor would be how much of the produced heat could be turned into electricity. Might the about the same 30%-50% for all of them? Mac Davis (talk) 00:15, 11 November 2008 (UTC)

It's probably not a big factor economically. Think about it—if the cost of a unit of heat is really different between technologies, then one could be far less efficient and be still be really profitable. What you want from an economic point of view is cost per kWh and things like that. --98.217.8.46 (talk) 01:09, 11 November 2008 (UTC)

I would imagine it would convert heat to electricity identically to coal - the turbine arrangement ought to be pretty similar. Maybe the operating steam temperatures are different - but I kinda doubt it matters. But I'd echo what others have said - the problems with nuclear are not to do with generating the heat...you've got heat to spare...so efficiency isn't really the issue. It's all about cost-of-ownership, safety and waste disposal. But coal also generates low level radioactive waste - and it's worst waste product (the CO2) is still untrappable. The worst that a nuclear plant has ever done (Chernobyl) when criminally badly operated - with all of it's safety gear disabled - didn't really cause any more problems than coal plants do when they are operating ordinarily. SteveBaker (talk) 03:03, 11 November 2008 (UTC)

SteveBaker, very well said. Mac Davis (talk) 22:53, 11 November 2008 (UTC)

I suspect the 100,000+ permanently displaced people would consider the Chernobyl event rather different than what "coal plants do when they are operating ordinarily". Dragons flight (talk) 04:56, 11 November 2008 (UTC)

Um, well, Chernobyl did make a huge area of land uninhabitable and dispersed pretty radioactive materials over a large area. I would consider that qualitatively different than the sorts of ills caused by coal. But it's not really the point, and using Chernobyl to discount all nuclear technology is extremely short-sighted, I am sure we would agree... --98.217.8.46 (talk) 03:13, 11 November 2008 (UTC)

Have you ever flown over Wyoming or Kentuky? Coal mining has rendered huge areas effectively uninhabitable also, and the health effects in these areas (mostly black lung disease but also mining disasters) are much worse overall than those from Chernobyl. Nuclear has a dramatically lower overall impact that coal, even when you count in the criminal negligence of the designers and operators of the Chernobyl plant. -Arch dude (talk) 15:22, 11 November 2008 (UTC)

As SteveBaker said, if the steam turbine technology is comparable between nuclear and coal plants then it can be ignored if all you're doing is comparing those two technologies. What matters for the comparison is the differences between the heat sources, including the plant designs and whether one heat source has a much different cost than the other. If you're trying to get a single efficiency number then you'll have to define what you mean by efficiency. Nuclear fuels can produce more fuel from what is otherwise waste, and can generate electricity without a steam cycle. One can also generate heat with uranium by exploding it, or by stacking it a mile high on geothermal piping. -- SEWilco (talk) 04:06, 11 November 2008 (UTC)

(unindent) A sea level rise of just 20cm could create 740,000 homeless people in Nigeria alone. If you buy into the theory that the unprecedented force of hurricanes in the USA over the past few years is related to global warming - then if even ONE of them was caused by CO2 from coal-fired power stations - then Chernobyl is like a damp squib. Most major hurricanes cause 1000+ deaths (many have caused over 8,000) - Chernobyl caused only 47 immediate deaths (although the increased cancer risk will ultimately have shortened the lives of thousands more). If they hit a major city - hurricanes can easily temporarily displace a million people (Chernobyl displaced only 300,000). Well over 300,000 did not return to New Orleans after Katerina which certainly trumps Chernobyl's 100,000 'permanently displaced' people. The Chernobyl disaster has actually benefitted local wildlife - there are species of wild donkey previously thought to be extinct that are now florishing in the depopulated area. Now think about Polar bears...(no, the cute baby ones...yeah - that's it!). SteveBaker (talk) 15:29, 11 November 2008 (UTC)

geting back to the original question, "Power plants employing saturated or only weakly superheated steam have a thermodynamic efficiency of 35% or less. Such power plants include nuclear power " from the google summary of http://www.freepatentsonline.com/3992884.html although i can't find it on the site now, and "35% to 45%" from http://wiki.answers.com/Q/What_is_the_thermal_efficiency_of_the_nuclear_process_for_generating_electricity_and_how_does_it_matter&src=ansTT. seems in the right ballpark, offhand. Gzuckier (talk) 20:04, 11 November 2008 (UTC)