Wikipedia:Reference desk/Archives/Science/2009 June 20

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June 20

Consistancy and Acceleration.

Apologies if this is in the wrong place. I'm still in training.

In many articles e.g. PCC streetcar, the unit of acceleration is given as mph/ps. In other articles, it's given as mphps (f'rinstance Washington Metro rolling stock).

What is meant is "miles per hour per second". So it seems to me that the correct unit would be mphps, without that extra slash(/), since that would be read as "miles per hour per per second".

Since there are over a hundred articles to be changed, it seems rather tedious to post the suggestion in each discussion page. Also, I'm not so sure that I'm correct (actually, I'm sure I am, but I have to maintain an appearance of humility), since it's possible that one use or the other is standard.

What do y'all think, should I be bold, or just let sleeping dogs lie. Bunthorne (talk) 02:30, 20 June 2009 (UTC)

Alternately, there's mph/s. Agreed that "per per second" is incorrect, so I recommend boldness (always worthwhile for obvious errors). — Lomn 02:49, 20 June 2009 (UTC)

I agree, mph/ps is wrong and mph/s is better then mphps. But where the unit occurs just once or twice in a text passage, I'd be inclined to forget abbreviating the seconds and just use "mph per second"; I think more people will easily understand that. --Anonymous, 03:21, June 20/09.

mph/ps is definitely incorrect. Fortunately, that senseless notation only exists in 3 articles. As far as what to change it to, I think mph/s is clearer than mphps, but mphps is used in twice as many articles as mph/s (14 vs. 7), so at first glance it looks like most editors prefer mphps. Red Act (talk) 03:26, 20 June 2009 (UTC)

mph/ps would be "miles per hour per picosecond". That's some serious acceleration.... --Trovatore (talk) 03:52, 20 June 2009 (UTC)

Not if the number before "mph/ps" were 0.000000000000000000000000001, for example. That might apply to the acceleration of a male smail when he sees his girlfriend in all her alluring, sultry seductiveness. -- JackofOz (talk) 07:16, 20 June 2009 (UTC)

Snails are hermaphrodites. (There's a Perry Bible Fellowship cartoon about snail sexism.) As for the units of acceleration, why not use feet per second per second? That way you don't have the confusion of two different time units in one compound unit. AlexTiefling (talk) 11:43, 20 June 2009 (UTC)

Because speeds of cars are usually measured in mph and they generally accelerate for periods on the order of a few seconds, so the odd mix of units is actually the most convenient. You can, for example, easily convert "0 to 60 in X seconds" (a common way of expressing acceleration off the line) to an average acceleration in mph/s. --Tango (talk) 16:56, 20 June 2009 (UTC)

I believe it is correct Wikipedia style to provide the customary unit (which should be mph/s in this context) followed by the appropriate metric unit in brackets (ms^-2) ? So I think you're free to go with mph/s as your customary unit - provided you also give a more "normal" unit for people who are not familiar with streetcars or who don't use "miles" as their natural unit. Think of your confusion if you were to be given the acceleration of an unladen european swallow in teaspoons per acre per square fortnight...you'd be quite justified in demanding to have the number in meters per second in brackets afterwards. SteveBaker (talk) 15:19, 21 June 2009 (UTC)

Notational point: the metric unit you speak of is not inverse square milliseconds. If you must write m/s² without using a slash, you need a space or a centered dot between the m and the s.

But is m/s² the appropriate metric unit anyway? In metric countries vehicular speeds are normally written in km/h, not m/s. This suggests that km/h per second would be more commonly used then m/s² for accelerations, but I don't know if that's true. And if this unit is commonly used, is it commonly symbolized as km/h/s (not proper SI style) or kph/s (also not proper SI style) or km/h s or km/h·s or km/s·h or what? I don't know; I haven't done enough reading of European materials where it might be used.

--Anonymous, 19:18 UTC, June 21, 2009.

Wikipedia style aside, Steve's ms^-2 is quite correct, and is the way I've always been taught to write such. You don't need the dividing dot unless there's going to be ambiguity — for example if you were also talking about milliseconds — but here it is clear that we're talking about acceleration in SI units so ms^-2 is metres per second per second. Actually with the -2 there I can't see how it could be confused anyway... nothings per milliseconds per millisecond?. --Polysylabic Pseudonym (talk) 09:02, 24 June 2009 (UTC)

I'm sorry, but you were taught wrongly. The SI allows national variations in the spelling of unit names, but the unit symbols are international and the standard is quite specific about forming them. In the edition of the standard linked in the following subsection, see page 44: "Multiplication must be indicated by a space or a half-high (centered) dot (·), since otherwise some prefixes could be misinterpreted as a unit symbol." Or if you prefer the original, see here at page 33: "Quand une unité dérivée est formée en multipliant deux ou plusieurs unités, elle est exprimée à l’aide de symboles d’unités séparés par des points à mihauteur ou par un espace." Thus ms^-2 can only mean square inverse milliseconds. --Anonymous, 22:19 UTC, June 24, 2009.

What is an SI unit?

I've split out this subthread into a separate subsection. --Anonymous, 22:12 UTC, June 22, 2009.

Yeah, I think when Steve said "metric" he meant "SI". --Tango (talk) 20:18, 21 June 2009 (UTC)

The hour is a non-SI unit, but is accepted for use with the SI and, as I said, vehicular speeds are commonly measured in km/h. --Anon, 21:59 UTC, June 21, 2009.

The SI unit for acceleration is m/s². Are you disputing that? --Tango (talk) 22:08, 21 June 2009 (UTC)

Only the first word. SI includes many units for acceleration: m/s² is one, km/s² is another, and so on. Additional units are accepted for use with the SI. --Anon, 07:52 UTC, June 22, 2009.

I've never heard of units with prefixes being called "an SI unit" they are just "the SI unit with a prefix". --Tango (talk) 14:44, 22 June 2009 (UTC)

I can't help what you've heard. The SI standard defines what units are part of the SI, and that includes the prefixed ones. (The link is to the US edition, but other editions will show the same thing.) By the way, that also includes the four prefixes in between milli- and kilo-; some people have the false idea that those are not part of SI. It is true that certain units are designated as SI base units -- the meter is the base unit of length and the second is the base unit of time -- but that's just a way of stating their definitions, and provides a convention for the construction of named derived units like newtons and watts. There is no base unit for acceleration, as it is derivable from units for length and time. --Anonymous, 22:12 UTC, June 22, 2009.

(deindent and rather late) Kilometres per second per second is rather an unusual measure, can't say I can think where it'd be used. Acceleration due to gravity, for example is in the region of 0.01km/s² or 10m/s² approximation was deliberate. --Polysylabic Pseudonym (talk) 08:56, 24 June 2009 (UTC)

Which wikiproject would best encompass an Electrical Pollution article.

Hey. I'm starting work on an electrical pollution article on my userpages. How this article doesn't already exist I don't know (Probably because of the electric companies that still try to claim that it's "false science")...

Anyways, I don't feel it's something I can do alone, and want to find some editors that know the subject a bit to help construct it with me. Which wikiproject would best cover this article? Earth Sciences? Natural Sciences? Physics? Energy? Or perhaps just the ol' Wikipedia:Editor_assistance/Requests page would be best for me. What is recommended? -- Floydian ^τ _γ 03:57, 20 June 2009 (UTC)

The content on your user-page article appears to be a less-than-accurate effort to describe Electromagnetic interference. Since we already have this article, any relevant information should be added there. "Electric pollution" is not a term in common use in radio-science or utility electric power. Wikipedia has a strong policy against coining neologisms, described here. If you feel that there are sufficient third-party reliable sources that use such terms as "electric pollution" you should find those sources. The burden lies with you, the editor, to back up such claims with reliable sources. The image you have posted, File:ElectricSineWave.jpg, does not appear to be out of the ordinary - in fact, the electric utilities document the frequency harmonics and phase/amplitude variations, and if you look closely at their technical information you will find that these variations are within the specifications they contractually agree to deliver. It is more likely that those "noise" sources, which you are viewing in the time domain, are due to load variations, not due to electromagnetic interference from cell phones or radio towers. If you don't believe me, consider looking at the frequency spectrum of electric power - there is not a lot of man-made radio activity in there, and when there is, you can clearly see it. Nimur (talk) 06:21, 20 June 2009 (UTC)

Isn't illness due to "electrical pollution" a myth? What's recommended for you is a sixth form/high school physics course......Alaphent (talk) 08:56, 20 June 2009 (UTC)

Please take your negativity and childish insults elsewhere. There are plenty of documents the back it and its effect on humans and animals up. This page lists plenty of research into it. The content on my userpage is a few days of piecing together some small things. It is far from complete and is not being placed here for peer review. I will look into the article you linked and comment later.

EDIT: EMI is a cause. Electrical pollution is an effect. - Floydian ^τ _γ 09:06, 20 June 2009 (UTC)

Maaate, I fail to see where the "childish insult" in Alaphent's contribution there. As for the documents that back it up, there are documents that back anything up - and for that matter there are documents that will refute anything. Just because some "Alternative Medicine Scientists" think that it is a valid effect, it does not neccessarily mean that it is.

Anything you place on wikipedia will be criticised and reviewed, sometimes unjustifiably. Maybe it is slightly arrogant to assume that you can write an article perfectly by yourself? Perhaps consider creating the article and seeing how it goes from there? But here isn't the place for that discussion.Heinzcreamofchickensoup (talk) 09:38, 20 June 2009 (UTC)

After looking at your talk page and contributions, it seems that you have a "thing" about adding controversial unsourced "anti-establishment" information. Governments witholding information about drugs?Heinzcreamofchickensoup (talk) 09:48, 20 June 2009 (UTC)

(outdent). Wikipedia should also have articles on common conspiracy theories and junk science, as long as they are notable, so i see no problem with the concept so long as the article is balanced. There must be tonnes of credible research into this, even if it only debunks the idea. WP:SKEPTIC, WP:Pseudoscience, WP:Environment and WP:Energy all seem appropriate if the article is ever created. It is usually easiest to create the article and worry about projects after, although it is a good idea to get the projects opinions in this case, as we see even a refdesk question causes responses unpleasantly close to incivility and a determination to not answer the questionYobMod 10:52, 20 June 2009 (UTC)

Floydian, please do feel welcome to contribute to Wikipedia. To the other editors, please avoid personal attacks. That being said, a few important issues arise:

• Floydian - if your work is not to be subject to peer review, why are you asking for help? I'm a contributor to the WikiProjects you mentioned - Science, Energy, Physics, ... didn't you come here asking for input or help from these projects? You might not want to completely slough off other editors' suggestions, or they will be less inclined to help.
• Your claim that "EMI is a cause. Electrical pollution is an effect" does not seem to make sense, because EMI is an effect of electric power coupling into places it shouldn't be. It's a symptom of a broad class of phenomena. If you disagree with this concept, you should do the following:
  • Read electromagnetic interference very thoroughly
  • Read about electromagnetism in general
  • Read about electricity distribution
• The claims that your article makes, and your incorrect use of technical language (for example, emf is neither the electric field nor the magnetic field) suggests that you are new to these terms. White noise is not RF interference. Your image of clean and dirty power conveys almost no scientific information, because it is an amplitude-versus-time plot (how about showing us a power spectrum?) Do you know the difference? Do you really feel comfortable to make strong claims about an area you know so very little about?
• If you do, then perhaps you should publish your original research elsewhere, because Wikipedia is not the place to publish new ideas. You must find somebody else's published research and cite it. We will subject that research to fierce debate about whether it is reliable. Your two sources do not appear to be very reliable. Hint: any web page that starts off with an incorrect fact is likely to rank low on the subjective scale of reliability.
• If you still believe that "electric pollution" belongs somewhere in Wikipedia, by all means be bold and add it in.

I can tell you honestly that this article will be edited severely, and probably deleted, because it fails several key criteria (most importantly, the lack of reliable sources; and secondly, the coining/definition of a new term which is not in common use in scientific literature). By submitting your work to Wikipedia, it will be subject to merciless editing, including deletion. If you do not like this idea, then Wikipedia is not the place to publish your ideas. That's why we have our warning on edit-pages: If you don't want your material to be edited mercilessly or redistributed for profit by others, do not submit it. Nimur (talk) 17:11, 20 June 2009 (UTC)

Childish insult: "What's recommended for you is a sixth form/high school physics course". First of all I want to ask which scientists are correct. The ones that are hired, and payed by the companies that want to sell the stuff to come up with "conclusive" research on the topic? Or the ones that do it on their own accord? How about the university of wisconsin, which has been studying the effects of this for 25 years? What defines scientific literature in this case? Who is more credible? The electric company, or the independent not-for-profit study? I can provide well over 30 published and accepted studies that go far more in depth into this subject then a bunch of average people who just feel like slapping a conspiracy theory label on anything that is new to them. I wonder how many people told Darwin that he was a conspiracy theorist?

I am looking for advice on where to ask for help. I'm not asking for people to criticize the 3 sentences that I've written so far. I'm looking for people that actually can back up their claims that this is not real or science.

My research is not original. Everybody that has commented here has made claims without any sort of backup. I'm not sure what you are talking about with my incorrect language use because the article really isn't written and once again isn't being submitted here for review in its current state.

EMI is a cause and Electrical pollution is the effect. This is the case because EMI is a term to envelop any sort of undesired electrical signals, and electrical pollution is the effect that these signals have on our cells and our bodies. —Preceding unsigned comment added by Floydian (talk • contribs) 17:33, 20 June 2009 (UTC)

If you are not going to help me (Or those of you who aren't), then shut up and don't reply - It isn't neccessary. I did not post this to be called arrogant or anti-establishment just because I don't believe everything that I am told, especially when Pfiezer is sponsoring it. -- Floydian ^τ _γ 17:29, 20 June 2009 (UTC)

I tend to believe scientists who follow proper methodologies, irrespective of who funds them. Post your 30 sources, and I'll take a look at them, with an open mind. My professional career is built on doing lots and lots of reading (Why else would I be browsing the Science desk on a sunny Saturday morning?), so it never hurts to throw 30 more papers at me. Nimur (talk) 17:43, 20 June 2009 (UTC)

Firstly, 6 of the 8 studies posted [1] are led by "Magda Havas". I don't know who she is of course (I assume female), but it would be good to check her out for any potential conflicts of interest (although she very loosely states there are none). Secondly, the studies aren't great. The first study contains 8 non-controlled cases. The second one isn't placebo controlled, relies on participant self-reports (instead of doing any objective measurements), and the actual experiments are related to multiple sclerosis and diabetes, yet it is concluded:

"Diabetes, multiple sclerosis, ADD/ADHD, asthma chronic fatigue, and fibromyalgia are all increasing in the population and the reasons for this increase are poorly understood. Dirty electricity may be one of the contributors to these illnesses."

Although she says "may", based on some self-reports (not discussed in the paper) really it is an irrelevant conclusion (as the decrease in pirates may have caused the rise of ADHD/fibromyalgia). Also "Table 1" - which states the symptoms of radio wave sickness - lists almost every common symptom there is. Seems like a case of the barnum effect applied to a disease. Another issue I have is this quote:

"GS filters have been placed in homes, offices, and schools. People report having better sleep, more energy, and less pain. They document cognitive improvements in memory and concentration"

Now there is no reference for this, although a few lines lower it does state something vaguely similar with the ref "Havas et al., 2004". Unfortunately the reference is this:

Havas, M., Illiatovitch, M., Proctor, C. (2004). Teacher and student response to the removal of dirty electricity by the Graham/Stetzer filter at Willow Wood School in Toronto, Canada. Presented at the 3rd International Workshop on the Biological Effects of Electromagnetic Fields, 4–8 October 2004, Kos, Greece.

This is where all the claims fall down for Wikipedia standards. A presentation in Greece is not a reliable source, but I decided to read it anyway (it is on the Electrical Pollution site). From a quick glance over the results, there is no significant difference between GS filters present and absent. In some cases the GS filters caused a reported positive response, whilst in other cases there was a reported negative response. In the bottom right corner of Table 1 it summarises the overall response, and it is clearly insignificant. In all of the results, there is only one case where the GS filters produced a statistically significant improvement, and that is in "unproductive time/class (min) in grade 4 students". Unfortunately it is not stated what statistical test was used, and the sample is still pretty small (18 in GS absent group and 14 in GS present group).

I can't really be bothered to read through any more of this, I'll put my trust in Nimur's conclusions if he/she reads the studies, or I will read for my self any double blind, placebo controlled lab experiments posted in scientific journals (not case studies). --Mark PEA (talk) 19:18, 20 June 2009 (UTC)

Ok people let me put this here plain and simple. I posted this here to find editors to collaborate with. NOT to get opinions. NOT to be told that the scientific body you believe in says it doesn't exist and thus it doesn't exist. NOT to be told I have no qualifications (Because quite frankly, since you are posting to the internet under a pseudonym, qualifications are irrelevent in this discussion. As per WP:NOR, every editor's qualifications are irrelevent). I do not need to prove anything to you, as you are just as qualified as I am.

Secondly, there is not one all-powerful all-knowing scientific body that declares things as fact or fiction. You do not have this power either. Thirdly, the GS filters are something I believe to be BS, and I myself will not introduce that to this article. Fourth, why is a presentation in Greece any less reliable than a presentation in America? You do not know the size or importance of this meeting, and your claim is unfounded. Fifth, lets see proof pointing the other way if you feel so strongly that it doesn't exist. Sixth, objective reports of "I feel sick" are just as valid as having some machine spit out a number that says "This means she is feeling sick". Seventh, 100 years of western medicine doesn't automatically invalidate several millenia of alternative and natural medicine. Eighth, is scientific research done by a company that sells the product it is "researching" proper methodology? By that standard, I should ingest half the pills I see on TV because I have one of the symptoms they list. Almost anything can be made to appear true. I feel myself that research done into a subject matter by a company that makes profit off that subject matter is not as valid as a third party's independent look.

Here are plenty of articles. They are hosted by electrical pollution.org (Which by the way, please back up your claim that this site is not reliable. The publisher is a big part of the studies conducted by the university of WI in Madison.), and each in themselves also reference countless published and reliable articles. I have not read through all of these yet, and only have them selected thus far as potential sources for information. First off, here is the requested power spectrums, published by Dr Martin Graham, Professor Emeritus at University of California in Berkeley. I admit I am not qualified and cannot read them. I'm an editor here though, not a scientist.

• NFAM research article
• Karl Maret (Md, M.Eng) report
• Canadian Human Rights Commision, Margaret E. Sears (PhD, M.Eng)
• Shocking News, a regular newsletter by Dr. Donald Hillman, Professor Emeritus, Department of Animal Science, Michigan State University
• David Stetzer and Magda Havas, World Health Organization workshop on electrical hypersensitivity
• Case study of three minnesota schools with the filters, using dummy filters for control group
• California EMF program final report on effects of EM Fields (Chapter 21 in particular)
• International Association of Firefighters (IAFF) votes to dtudy health effects of cell towers on fire station
• Association for Comprehensive Neurotherapy, report on global problem
• This study is 12 years old and may be slightly outdated

Granted, this is not 30. But again, I do not need to prove myself at this point. The article is not being submitted for review, I am looking for editors that want to collaborate with me and not against me. -- Floydian ^τ _γ 20:12, 20 June 2009 (UTC)

I would be happy to look at a draft. But you would do well to edit the existing articles or section which cover the topic. Right now it seems to be covered in Electromagnetic radiation and health#Health effects of electric power transmission. Additionally, cell phones, radio and television, and wireless broadband could be examined.They are covered in Mobile phone radiation and health Also leakage from microwave ovens, and occupational exposure to radar. There is Wireless electronic devices and health. There is some duplication. There have been many books and journal article published over the last 30 years or so dealing with the question of whether electromagnetic radiation from power lines (and more recently, from cell phones) causes cancer or problems with the immune system. The null hypothesis has seldom been rejected (of no effect). But a principle of "prudent avoidance" has led many to get rid of the electric blanket, and to avoid sleeping in the bedroom with only a brick wall between it ant the distribution line going overhead down the alley. It should be covered in an article, and I expect it is, somewhere. Early studies(Wertheimer and Leeper, 1979) just coded for the presence of power lines without measurements, and noted cancer cases. Later studies did measurements. Lifetime dosimetry of power line EMF exposure is difficult. Incidence of cancer among power company employees tended toward the null hypothesis. See Google book search at [2] for 215 books citing Wertheimer. Some are sensational crap, others are reliable sources. If "the power companies were covering it up" there would not be so many studies looking carefully at the effects. Edison (talk) 20:16, 20 June 2009 (UTC)

There are lots of studies, but many of them contradict the studies published by the power companies. The power companies almost always conclude "there is no such thing", while other studies almost always conclude that there is some sort of effect happening here, but that its not fully understood. -- Floydian ^τ _γ 20:21, 20 June 2009 (UTC)

You are wrong about the studies finding no measurable effect being published by the power companies. Read the articles/sections cited in my post above. Edison (talk) 20:27, 20 June 2009 (UTC)

I never stated that only the power companies publish these studies, I only stated that studies published by the power company (almost) always claim there is no measurable effect, or no noticeable effect on human health. If I am wrong, please link studies and not wikipedia articles for me to decipher and find sources in. My burden of proof doesn't lie on the reference desk, so can we please stop discussing whether or not my article is relevent? I am removing the link to my article in my userpages. It is irrelevent to what I am asking, and it seems that everybody is judging it no matter how many times I state that it is not in any way, shape, or form completed in any sense. It will be at least a C class article before I go ahead and publish it on the encyclopedia. At that point, everyone is free to make whatever comments they wish. -- Floydian ^τ _γ 20:40, 20 June 2009 (UTC)

Fourth, why is a presentation in Greece any less reliable than a presentation in America? You do not know the size or importance of this meeting, and your claim is unfounded.

Firstly, I thought it was quite clear from my sentence that I meant that any presentation is not a reliable source, whether it be in Greece, the USA or on Mars. Wikipedia requires evidence published in a scientific journal, because if not the presentations I've done at University could be cited and I could quack on about anything. Secondly, my claim is not unfounded. The "paper" that was discussed at the presentation was [3], and I discussed (not really 'claimed') its lack of significant results earlier.

Fifth, lets see proof pointing the other way if you feel so strongly that it doesn't exist

The burden of proof is not on me to disprove it. You prove to me that Russel's teapot doesn't exist, along with the Flying Spaghetti Monster.

Sixth, objective reports of "I feel sick" are just as valid as having some machine spit out a number that says "This means she is feeling sick"

No they are not. See: demand characteristics

Eighth, is scientific research done by a company that sells the product it is "researching" proper methodology? By that standard, I should ingest half the pills I see on TV because I have one of the symptoms they list

How would I know without looking at the studies? I have very little knowledge of electricity and "electrical pollution". What I do know is that when someone claims something to exist, they must provide solid evidence of its existence (as mentioned earlier re: burden of proof).--Mark PEA (talk) 11:39, 21 June 2009 (UTC)

Okay, I'm done. I can't take any more. I reviewed as much as I can, and I'm just ... well, did you even read the sources you provided? Three out of three reviewers strongly do not believe that EMF is a universal carcinogen. Half of your papers were self-published. Three apparently centered around an eight-person conference in Kazakhstan, a nation which (according to the conference brief you provided) conducts no research in this area. Nimur (talk) 00:05, 21 June 2009 (UTC)

Also, as I mentioned on your talk page, it is very ironic that you are critiquing "the scientific establishment" at large for conflict of interest, while citing reports that are little more than an advertisement for a bogus commercial "filter thingie". I believe that is the technically correct term for ... whatever this is. Nimur (talk) 00:36, 21 June 2009 (UTC)

The Wikipedia articles I found and cited above, in turn cite reliable sources. It is not reasonable for you to demand that I list the references here because it would be too much trouble for you to read the relevant articles and see what references are cited. Please provide a link to your draft article if you would like commentary and advice. One somewhat dated (from 1973) book I really liked was Power over people[4]," which criticized the EMF that utilities exposed people to, and encouraged ways of minimizing the effects. Edison (talk) 03:29, 21 June 2009 (UTC)

To answer Floydians question(!!!), possibly many projects, from Environment and Ecology to Industry and Electricity, not to mention various other projects this topic would fall under (I've seen four or five projects on a talk page many times), that is to say, so many you will probably just have to pick a couple you feel best, stick their banner on the talk page and invite them to come edit. Try to pick the ones that will gladly read it and wish to edit it, (I would go to Wikipedia talk:WikiProject Environment to ask, "Why is there not (or) which project is, the WikiProject for pollution" and ask more questions from there.) Everything you post on Wikipedia of a scientific or historical nature will be judged by the standard "Is that what they say on the Discovery channel?" (and it's true so don't give me a hard time for saying it) You may be everything from misled and idiotic, to unlearned and unable to speak English (I have heard these things many times but what you have here is certainly mild compared to the process at WP:AFD (deletions) where they won't even insult you, rather, just two or three people will say "don't beleive in it" and delete the whole thing forever, ignoring any arguements and feeling much worse than having some university students telling you to go back to school). There are strong arguements to say that human effects on global warming are about as strong as spitting in the ocean, but, you try to publish that or ask questions about it on Wikipedia you are a) saying the world is flat and b) claiming the holocaust didn't occur. Even articles about quite sensible scientific topics are easily deleted if, for instance, most of the work has been done by one person and he/she is not Albert Eintstein. For scientific theories you can have two things 1) previously published in a major English language/European scientific journal or 2) covered in high-ranking tabloids in a major English language speaking/European country. After that you have a) topics covered in websites that look or sound important (this will not count if the website covers only one topic so, on its own, electricalpollution.org will not withstand a deletion review here) and b) you have the Wikipedia Lottery that even though people ask to delete the topic, nobody wants to because amusing, interesting, signifigant or some other reason (and Electrical pollution will probably get a year or two on that last ticket unless it is truly absurd). I hope this is a helpful preparation for creating articles on more obscure scientific projects. If you can't read what I said, (I wonder sometimes) he said, "They will be more skeptical when they delete it and wont even suggest going back to school, try asking WikiProject Environment." ~ R.T.G 12:49, 21 June 2009 (UTC)

THANK YOU!!! You just did what about half a dozen people were incapable of doing. You answered the question that I actually asked! Thank you very much.

I don't know where in my 2 year absence wikipedia became such a disinclusionist community. Just because every scientist doesn't agree, or hasn't yet, doesn't mean a subject is not notable or that discussion on it can't persist. So many here just right away jump to researching away articles... Kinda defeats the purpose of calling wikipedia the "compendium of human knowledge". Should be changed to the "compendium of important human's knowledge".

And as I haven't released the article, the burden of proof does not lie on me yet. Further to that, I have produced several reports. No matter how much you contest them or their reliability, nobody has provided anything that proves that electricity and electromagnetic fields produces no effect on the environment. -- Floydian ^τ _γ 18:01, 21 June 2009 (UTC)

I beg to differ. RTG's answers are almost always wrong - check back through his history here on the science ref desk. What you really mean is that RTG told you what you wanted to hear...which may make you happy - but won't do you much good. The very first answer to your question was correct - what you are writing is either already covered by Electrical interference - or it isn't a referenceable topic for an article - which will indeed result in it being deleted. Wikipedia has grown up - we have standards - we are actively excluding junk. SteveBaker (talk) 21:59, 21 June 2009 (UTC)

And nobody has provided anything that proves that the Flying Spaghetti Monster, Russel's teapot, the Invisible Pink Unicorn, Steve Baker's Pink Aardvarks and an infinite number of other ideas don't exist, whilst others have produced reports on their existence (hence me mentioning them). That doesn't mean they are suddenly scientific truths. --Mark PEA (talk) 21:21, 21 June 2009 (UTC)

In fact, there is a type of human "allergy" to electrical emissions. It's called electrosensitivity. ~AH1^(TCU) 00:58, 22 June 2009 (UTC)

Getting cancer and our destiny

I apologize beforehand if I am posting this in the wrong section...

I took a workshop a few weeks ago and the teacher mentioned that we choose our own destiny and people that get cancer choose to get it. Even though I don't agree with the second part, I am interested in an explanation to why some people believe this. I know this is not a place for discussion, but can someone please point me to where I can find more information about this? I am having a hard time finding it on my own.

Thanks for your time —Preceding unsigned comment added by 76.166.207.196 (talk) 05:45, 20 June 2009 (UTC)

You are basically asking, "Why does somebody choose to believe patent nonsense?" Some people are just stupid. I wish I had a nicer or more pleasant answer, but it's true. Explaining things scientifically, in simple terms, with factual evidence, building from simple ideas to complex consequences, is not enough to convince some people. These people are just stupid. Nimur (talk) 06:27, 20 June 2009 (UTC)

Yes, Nimur, I think you are largely correct... but those who choose to smoke cigarettes, let's just say, are choosing to increase their risk of a number of cancers unnecessarily. But otherwise, it sounds like the teacher may have been pretty ignorant on the subject of cancer. – ClockworkSoul 06:31, 20 June 2009 (UTC)

Sorry, I may have been a bit harsh. To remedy my harsh language, let me provide some helpful references. Many of our cancer articles have entire sections or at least some content related to misconceptions - I found a lot by searching for this combination. These articles may also point to off-site links, such as Popular Myths about the Causes of Cancer and Myths about HPV. You might find cognitive dissonance and ignorance useful articles. Although not about cancer, we have HIV and AIDS misconceptions; this may illuminate some persistent misunderstandings about health and diseases in general. Nimur (talk) 06:37, 20 June 2009 (UTC)

I believe there may have been a little bit of a misunderstanding about what I meant in my original question. I should have been a bit more clear, sorry for the confusion. When I mentioned people choosing their own destiny and choosing to get cancer, I meant choosing to get cancer in an indirect way, not in a direct way. I am sure no one really "chooses" to get cancer or really wants to get cancer unless they are crazy. I'm kind of having a hard time explaining what I am trying to say. The teacher did not really explain it, he just mentioned it. This was not a topic of the class, it is 2 courses from now, but I wanted to look into it beforehand.

I appreciate the links, I read all that stuff in school, I used to want to become a pharmacist so I have taken several biology courses, so I know all about all that stuff. When the workshop instructor mentioned destiny and cancer I disagreed, but I am very open to other people's opinions so I wanted to look into it. —Preceding unsigned comment added by 76.166.207.196 (talk) 08:49, 20 June 2009 (UTC)

The placebo effect is a real and measurable effect that depends on belief. I can think of no scientific reason that a "negative placebo effect" couldn't cause illness in people based on their beliefs. Psychological states have been shown to effect the immune system (eg. clinical depression), so why can't believing you will get ill do the same? Resisting pseudo-scientific nonsense (of which there is a lot!) does not mean we should ignore real possibilities.

That said, i expect the teacher will actually talk about subconcious changes in life-style that pre-dispose people to certain illnesses, rather than direct psychosomatic effects. YobMod 10:47, 20 June 2009 (UTC)

Your question is pretty meaningless without context (is it a science setting, social, philosophical, religious?) and your offhand response I read all that stuff in school kind of implies that you are not really listening to any kind of answer you get at the science desk. But to have a try at it, possibly the point being made was that everyone arrives at the point they are at in their life due to the decisions they have made on the way. In that respect your decisions are responsible for the situation you are now in whether or not you could foresee, or intended them. But that is little more than a truism and has no scientific value since it is completely devoid of predictive power or falsifiability. SpinningSpark 11:09, 20 June 2009 (UTC)

Re: YobMod's comment about the "negative placebo effect": Here is the article: Nocebo effect. --NorwegianBlue ^talk 13:50, 20 June 2009 (UTC)

Wow, that's a facinating read - many thanks for the link. We have articles on everything!YobMod 14:06, 20 June 2009 (UTC)

The teacher may have been referring to the concept of karma or spiritism, which are not scientific and so don't belong in this section!--TammyMoet (talk) 15:59, 20 June 2009 (UTC)

I saw a bumper sticker that said "Sorry, my karma ran over your dogma." Edison (talk) 03:34, 21 June 2009 (UTC)

The teacher most certainly was talking about the relationship between behavior and cancer. Lung cancer, for example, has a VERY strong positive correlation with smoking; the incidents of lung cancer are very low in people without exposure to cigarette smoke, or in some cases with other environmental concerns, like asbestos exposure. Yes, there are anecdotal accounts of people getting lung cancer for no reason, but these are not statistically significant; at the actuarial level (i.e. when looking at millions of cases) there is an extremely strong correlation between lung cancer and enviornmental factors, especially smoking. Likewise, there are some correlations between colon cancer and diet; though less strongly so. Our articles on lung cancer provide the evidence and are quite well referenced to reliable sources. Thus, you have a case where the #1 cancerous cause in men, and the #2 cancerous cause of death in women, has a 90% correlation with a chosen behavior (smoking), then the teacher's comment, while certainly glib, is not entirely inaccurate. --Jayron32.talk.contribs 22:24, 25 June 2009 (UTC)

mecca

Does the city of mecca really lies on the Golden mean point of Earth??? They claim that the ratio of the distance from the North Pole to mecca and from mecca to South Pole is exactly equal to the Golden Mean Ratio which is supposed to be a standard ratio followed by the Supreme Being in the design of the entire universe. —Preceding unsigned comment added by 121.246.174.130 (talk) 13:38, 20 June 2009 (UTC)

I'm confused - wouldn't every place at that latitude have the same ratio of distances to the poles? For it to be a point, doesn't the longitude have to be defined too?YobMod 14:08, 20 June 2009 (UTC)

Yes, it would be everything on a line of latitude. Let's see, though -- Mecca is at 21°25' N, so it's 68°35' to the North Pole and 111°25' to the South Pole. The Golden ratio is ~1.618. Mecca's latitude ratio, South to North, is 1.624. Close, but not quite. Of course, the ratio of North to South is way off, about .616. So no, this is not true. — Lomn 14:13, 20 June 2009 (UTC)

For what it's worth, we can work out what the latitude of the Golden ratio circle would be -- it's 90-(180/(1+φ)), which is 21°15' S if you want your north-to-south ratio equal to φ. — Lomn 14:15, 20 June 2009 (UTC)

The Chicxulub crater seems to get rather closer though, do you think God is trying to tell us something? SpinningSpark 14:55, 20 June 2009 (UTC)

It might be pointed out that it doesn't matter much if you divide the larger part by the smaller and compare it to φ = 1.618... or divide the smaller part by the larger and compare it to 1/φ = 0.618... Sure, the former is the one that gets the Greek letter, but it's really no more special than its inverse. So saying that 0.616 is "way off" is a little much—it's slightly below 0.618, for the very same reasons that its inverse is slightly above 1.618. (I don't doubt you know this, but the OP might not.) —JAO • T • C 16:01, 20 June 2009 (UTC)

Of course, given enough constants, reference points, units of measure, etc. some sort of cosmological significance can be found for thousands of locations in the world. And if God/Allah was trying to send a message by the location of Islam's holiest city, I don't think it would have really cost Him much more effort to be a bit more precise. 64.252.193.6 (talk) 19:34, 20 June 2009 (UTC)

Maybe he was precise - how much have the tectonic plates shifted since Mecca started being an important place in Islam and in what direction? (I'm clutching at straws here, admittedly, but if you are going to rule it out on grounds of precision it is a question you need to answer (I'd rule it out on grounds of "What would be the point?", personally!).) --Tango (talk) 19:50, 20 June 2009 (UTC)

With respect to the african plate (which is taken as nearly stationary), the arabian plate is moving at about 20 mm/yr to the north, so since the time of Ibrahim (or Abraham) when according to Islamic tradition Mecca was founded around 2000 BC, that's about 80 m north, so not very far. Mikenorton (talk) 20:13, 20 June 2009 (UTC)

I'd prefer it relative to the North Pole. You also need to account for the North Pole moving due to axial shift/precession/whatever. --Tango (talk) 20:18, 20 June 2009 (UTC)

Why has no one mentioned Ley lines in this post yet, are all the fringe theory nutters on holiday today? SpinningSpark 21:16, 20 June 2009 (UTC)

Several independent points, not intended to argue to any conclusion:

• It's not just the whole line of 21°15'N, or more accurately 21°14'46"N, that meets the criteria; it would be equally notable if the two distances were in the reverse ratio, so the whole line of 21°14'46"S qualifies as well.
• The city of Mecca is not a point, so it's not accurate to say that the whole city is "at" 21°25'N. But the city's not so large that it extends to touch the line of 21°14'46"N latitude. Looking at Google Maps satellite imagery, that line of latitude misses the built-up area by about 10 km.
• Because the Earth is not a sphere, there are two different ways to measure latitude. Geographers use geodetic latitude, based on the direction of the local vertical at a place. But it would be equally valid, if less convenient, to use geocentric latitude, based on the direction to the center of the Earth, which gives slightly lower values. According to Latitude#Comparison of selected types, the difference at the latitude of Mecca is about 8 minutes, which means that 21°15'N geocentric latitude just about skims the south edge of the city's built-up area -- I'd need to do a more accurate conversion to be sure whether it hits it or not.

--Anonymous, 23:59 UTC, June 20/09.

"It's not just the whole line of 21°15'N, or more accurately 21°14'46"N, that meets the criteria; it would be equally notable if the two distances were in the reverse ratio, so the whole line of 21°14'46"S qualifies as well." -- Hey, isn't that the latitude of Rio de Janeiro? 76.21.37.87 (talk) 05:43, 21 June 2009 (UTC)

No. Algebraist 20:09, 21 June 2009 (UTC)

Right, it's 22 deg. 54 min. S, or about 100 miles south of the 21°14'46"S line. I stand corrected.

76.21.37.87 (talk) 00:08, 23 June 2009 (UTC)

niper-2009

i got 2824 rank in niperjee 2009 n i hav sc reservation n female .......will i get a seat in niper institutions? —Preceding unsigned comment added by 117.195.181.1 (talk) 15:32, 20 June 2009 (UTC)

Googling niperjee only results in 26 matches...if you could be more specific it may helpHeinzcreamofchickensoup (talk) 16:15, 20 June 2009 (UTC)

It seems to be a reference to this. --Tango (talk) 16:48, 20 June 2009 (UTC)

We have an article on National Institute of Pharmaceutical Education & Research (NIPER), and presumably this question is referring to the NIPER Joint Entrance Examination test. You should contact individual schools with regards to their admissions standards, I don't think Wikipedia keeps rigorous statistics on admissions requirements in any of our school or university articles. You should be sure to use proper spelling and grammar when contacting these schools, as informal web-speak is generally not well regarded in the context of university admissions. Nimur (talk) 17:34, 20 June 2009 (UTC)

Sigfigs

As part of a chemistry assignment, I have to do the arithmetic problem 8.937–8.930 to the correct number of significant figures. The obvious answer would be 0.007, which, since leading zeros are not counted as significant, would have only 1 significant digit. Preserving the answer with 4 sigfigs such as both 8.937 and 8.930 have would yield the answer 0.007000, which seems ridiculous. Which one is it, and why? 64.252.193.6 (talk) 17:11, 20 June 2009 (UTC)

Addition and subtraction do not preserve the number of significant digits. They only preserve the accuracy of the result. This can increase or decrease the number of significant digits from the input (for example, consider the exact addition of 3 + 8 = 11. The inputs had 1 digit each, and the output is an exact answer with two significant digits). For more subtleties of the rules regarding significant figures, check the article. Your correct answer is 0.007, with only one significant digit. Nimur (talk) 17:30, 20 June 2009 (UTC)

Significant figures are a pretty useless way of expressing precision (because of problems like this) and are virtually never used at a higher level. For that reason, the "right answer" is simply whatever is on your teacher's answer sheet. --Tango (talk) 17:46, 20 June 2009 (UTC)

Keeping aware of sigfigs is quite important to avoid expressing a result with too many digits. They are always used at "higher levels" by anyone hoping to publish a result without being laughed at by editorial reviewers at a journal. Edison (talk) 20:04, 20 June 2009 (UTC)

No, they aren't used. The actual precision is stated. For example, you may see a value quoted as "4.586(34)" (the number is brackets indicates the precision) or as "1.65 +/- 0.023", or sometimes other notations. You virtually never see a number written with the precision given simply by the number of significant figures. --Tango (talk) 20:26, 20 June 2009 (UTC)

Additional question: for the problem (5.1 + 6.3) * 0.245 (just an example), do you give the answer to 2 sigfigs as in 5.1 and 6.3, or do the addition first, change the equation to 11.4 * 0.245, and give the answer to 3 sigfigs? 64.252.193.6 (talk) 21:47, 20 June 2009 (UTC)

I'd work it out using "interval arithmetic". You interpret 5.1 as 5.1 +/- 0.05, etc. and then work out what the smallest answer you can get is and what the largest is. In this case, that's easy - the smallest is by using the smallest value for each term, so you have (5.05+6.25)*0.2445=2.76285, and the largest is similar: (5.15+6.35)*0.2455=2.82325. You can then say the answer is 2.79305 +/- 0.0302. If you really want it just in terms of significant figures then you find the most figures you can do without giving false precision. In this case, that would be 2 sig figs, or 2.8, since that means 2.8 +/- 0.05, so the smallest possible value is 2.75, smaller than the real smallest value, and the largest is 2.85, larger than the real largest, so we're not stating any false precision. If we added another significant figure we would be narrowing the range too much and it would be false (you can work out the numbers for yourself!). --Tango (talk) 22:29, 20 June 2009 (UTC)

Tango's "interval arithmetic" assumes that the figures in the example problem are quantised approximations. But if that is not stated then it is reasonable to take them at face value. The answer is 2.793. Exactly. Cuddlyable3 (talk) 23:31, 20 June 2009 (UTC)

If we are talking about sigfigs and rounding then obviously we are in the context of uncertain data. --Tango (talk) 23:58, 20 June 2009 (UTC)

Not true that is is un-used past school. I often weigh small amounts to 0.000001 g precision, but i ony report the result down to 3 s.f. as that precision is not needed. Sigfigs usually do not mean the one has uncertain data, just that further precision is useless. This is probably why you do not find them often in other fields - it is often possible in chemistry to measure variables far more precisely than we ever need to: this is not uncertain data. It would be difficult to find any Organic Chemistry Professor that ever reported errors in simple measurments or even had the possibility to calculate them (they would need a full time postdoc position just to continuously calibrate and validate machines), so sig figs are the best one can hope for. Physics is not the only science around! :-)YobMod 12:57, 21 June 2009 (UTC)

You might report your final results to 3sf, but I would hope you either keep the full precision while doing the calculations or keep track of the precision properly. If you don't, you run a very high risk of getting the wrong answers. --Tango (talk) 15:35, 21 June 2009 (UTC)

I keep them, but never use them. Percentage yields are always reported to the nearest percent - so 3 sf is already far more precise than needed when weighing products for example. Keeping track of errors is nice in theory, but practically not possible - i wouldn't even know how to estimate systematic errors produced by the balance, and would not have time to do so even if i could, and any error study would be unpublishable as non-novel. This is the case for a large portion of scientific endevour.YobMod 08:51, 22 June 2009 (UTC)

Sigfigs are a somewhat useful rule of thumb - but they shouldn't be regarded with the same religious furvor that they are taught in most schools. Keeping careful track of error limits is a much better way to manage error tracking. After all - what's so special about base 10? If you're working in base 2, what do you do about preserving significant digits? (You CERTAINLY arrive at a different answer that way!) Very often, the concept of sigfigs goes horribly wrong because of the order of operations - you can get a different "significance" in your answer if you calculate AxB+AxC than if you do Ax(B+C). So the whole concept is very approximate - and should be treated accordingly. Of course if you have to get through a high school exam - do what the teacher says - get your passing grade - and THEN treat this technique with the lack of respect it deserves! SteveBaker (talk) 15:09, 21 June 2009 (UTC)

The error I was referring to above is the obvious one of measuring diameter as 75 millimeters, multiplying it by pi and reporting the circumference as 235.619 mm. That would get a manuscript sent back by return mail, and should get points taken of in a lab or exam. It is a sort of error that became very common among high school and college students in intro science courses after calculators became common, which was rare when all used slide rules (good to about 3 digits). Edison (talk) 18:09, 21 June 2009 (UTC)

Sure, but it's not that you need to quote to an appropriate number of sigfigs, it's that you need to quote to an appropriate precision. If the diameter was measured accurate to the nearest millimetre at 75mm then you would quote the circumference as 235.6(16), or something (in some contexts you may specify a few more decimal places, but I see little point). That is significantly more useful than quoting "240mm (2sf)", which is what you would do if you followed the standard rules taught in schools. --Tango (talk) 20:15, 21 June 2009 (UTC)

That's a really good example - let's do it the proper way - preserving the information we actually have: If you know the diameter is 75mm (plus or minus 1mm) then the circumpherence is 235.619 plus or minus 3.14159 mm). To put it another way, if the diameter is between 74mm and 76mm then we know that the answer lies between 232.4778mm and 238.7610mm. The sigfigs approach says that the answer is 240mm plus or minus 5mm...which is far from the mark! It's unnecessarily increased the error bar at the top end by 2.3 millimeters - implying that the answer could be as large as 245mm (which is in fact impossible) - and at the bottom end, it's saying that the smallest the answer could be is 235mm - when in truth, it could be 2.5mm less than that: 232.5mm! That's very, VERY wrong - completely unscientific - mathematically untenable! By using the sigfigs approach we've widened the error range from it's true value at one end and limited the possible error at the bottom end.

But it's worse than that - we arbitarily decide to round to the nearest DECIMAL digit! Why decimal? Because it's kinda convenient when we're working in base 10...because humans have 10 fingers! That's not good math nor good science. Mathematical statements should be independent of the number base you choose. If we did the math in binary notation and used the "sigfigs" approach, we'd say that the diameter is 1001011mm (rounded to the nearest millimeter). The circumpherence comes out of your pocket calculator as 11101011.100111101mm - which we'd have to round to 7 binary digits: 11101100mm...which in decimal is 236mm. 240mm is 11110000mm in binary. So by choosing to impose these supposedly universal rules - but in a different number base - we get a different answer! If you do the math in hexadecimal (base 16) you get an even more vague answer! This is ridiculous! Science and math shouldn't depend on how many fingers you have! Why is base-10 sigfigs treated as "The Right Way"?

The true and only valid reason to teach this approach is to use as a rough rule-of-thumb to prevent people stating ridiculous amounts of precision - but by codifying these ridiculously complex (and wrong!) rules - you are misleading people into believing that its "The Right Way" to do science...which is far from the truth.

SteveBaker (talk) 21:35, 21 June 2009 (UTC)

Side Note: The Drake Equation is uncertain by as much as 20 orders of magnitude! (hence SETI is little more than pseudoscience and hope). ~~ Ropata (talk) 04:33, 25 June 2009 (UTC)

How big a population is needed to sustain the current technological society?

If the world's population is too small, a lot of the technologies that we have would be infeasible due to a lack of economy of scale. For example, if the world's population were a mere million, it would be too small to support a space exploration program. There are many other examples I can think of. Has anyone come up with a (well-reasoned) estimate of how big a population is needed to sustain the current state of technology? --173.49.12.233 (talk) 18:41, 20 June 2009 (UTC)

I think it is going to depend on the details. For example, if the population shrank due to wiping out everyone living in sub-Saharan Africa that might well improve the state of technology in the developed world due to the reallocation of resources currently going on humanitarian aid to that region. Another key detail is how spread out the remaining population is. If there are a million people left spread out all over the world, chances are good that they will be unable to remain very technological at all due to an inability to sustain reliable electricity production (a diesel generator per family would work at first, but you would struggle to produce and distribute the diesel). A million people all in one city wouldn't have any problem there at all. --Tango (talk) 19:47, 20 June 2009 (UTC)

Why could a population of a million not support a space exploration program? If they were all the "right" kind of people, like Wikipedia users say, and had access to present-day industrial plants, libraries and an abundance of the resources that 6 billion people consume today they could achieve anything they wanted. Look at it this way: You are the latest of a long line of ancestors none of whom failed to develop, thrive and explore whatever the current population was. Apropos electricity, the Internet could be run on hand generators. Cuddlyable3 (talk) 23:23, 20 June 2009 (UTC)

The cost per person would probably be too high if the only return was scientific development. --Tango (talk) 23:57, 20 June 2009 (UTC)

A keyword here is "specialist" --- one would not be able to have specialist doctors for all sorts of "advanced" diseases, for example, if population was too small. Similar for space engineers, etc (and even carpenters and similar if population becomes very small) Jørgen (talk) 00:45, 21 June 2009 (UTC)

I've searched around the articles on wikipedia concerning societies, civilizations and trying to find models for these. These aren't the fields best covered on Wikipedia, as is understandable giving the intricate models required by even simple questions on the subject. This has already been explained to some extent: Given different factors (population spread or centered), the answer will vary. Until exact numbers are provided, the solution is not... quantifiable, and a mathematical model would be abhorring. For instance, a population requires a constant source of food. Too small a population, and any dent in the agricultural production can have severe consequences. If there is any step back in technology, so to speak, each service's output (agriculture, industry, medicine and so forth) will diminish by a certain bit, and the society can support itself less, possibly spiralling downwards. This is of some importance since you ask "current technological society", which suggests there is a benchmark already to which we can hold all offices and organizations.

One could also add that some industries that exist today rely on multi-million markets (units or buyers) for them to be able to progress financially and thus lend their money to research. The answer to your question, for now, will be that no such thing exists, although I am afraid of answering so absolutely. 90.149.144.31 (talk) 11:10, 21 June 2009 (UTC)

It's a tough question - certainly it took the combined skills of at least a million people to get a man on the moon. Between skills in electronics, software, propellants, engines, aerodynamics, biology, machining, space-suit design, parachute technology, helicopter piloting...you name it! So I think a million people would make that difficult - but perhaps not impossible. Certainly it could be done as a multi-generational thing. We would have to be very careful to preserve knowledge from one generation to the next because it's perfectly possible for one entire generation to have not one single expert in some obscure field like (say) quantum chromodynamics - but you'd want to be sure that such a thing would not be forgotten forever. Education would be very important - and ensuring that we did not have too many people crowding into one area of study to the extreme neglect of another would be tough. But consider it like this...if we imagine that Wikipedia represented the whole of human knowledge (at least in scope, although obviously not in depth) - then with 2.8 million pages and 1 million people - each person would only have to be a 'deep expert' in the subject areas of roughly three articles to have all of human knowledge fully represented. But an awful lot of those 2.8 million pages are things like rock bands, TV shows, movies, descriptions of cities, biographies characters in "The Simpsons"...things that humanity doesn't need to have live, human experts on. We could have a dozen "history of music" people and another dozen "history of TV shows" people who would be able to keep the necessary information "alive" and be available for consultation as needed - so we could still afford to have 1000 mathematicians, 1000 biologists, etc. My guess is that if we considered the topics that are more than mere listings of information (things like math, chemistry, etc) - then we might have less than a million articles that "matter". So one person could be the world expert on (say) Aardvarks - another on Boyles gas laws, another on Xeno's paradox...those are awfully narrow areas of study. So I think the knowledge and skills we need could be retained by a million people. The difficulty with a space mission is that you might need (say) 1000 software engineers to write the software. There might (just) be a thousand software engineers in the world - but could we spare them all on getting a man to mars? I don't think so.

But (since this evidently relates to the earlier sustainability question), I think 1 million people is too few. 10 million or perhaps even 100 million would be a more realistic target. With that number of people, I think humanity could have a few dozen MAJOR projects being worked on in each generation and still have enough people to produce food, repair machinery, etc.

Space missions might become a thing of the past - or they might be considered important enough to be the main work of an entire generation - or something that we'd be happy to take the "long view" of and stretch over 10 generations. Certainly the work of mankind would have to be a more 'focussed' affair - there would be little scope for petty bickering about what would be the work of this generation.

But with no more worries over food shortages, energy shortages - with everyone being able to live on large estates with comfortable lives - with everyone having the responsibility to be THE one singular world expert on something that matters to them - I'd hope that the world would become a more peaceful, relaxed place than it is now. Fighting wars would become exceedingly difficult with so few people spread out so widely! There could probably only be a few thousand soldiers in the world - dropping a nuke on a "major city" might kill a few dozen people. That could be serious in terms of loss of expertise in some key areas - but nothing like the scale of horror such a thing would mean today.

SteveBaker (talk) 14:59, 21 June 2009 (UTC)

If you only have one expert on each area you could keep current knowledge alive, but it would be difficult to develop new knowledge. A lot of academia is focused around collaboration. Without anyone the exchange ideas with, new work would dramatically slow down (by more than just what you would expect from fewer people working on it). I would expect people to live close together, rather than all spread out. You can live a much more comfortable lifestyle that way, so a well placed nuke could wipe out a sizeable portion of the world's population. --Tango (talk) 15:32, 21 June 2009 (UTC)

I think I've mentioned before, but there is a very very bad historical precedent for these sorts of societies, where individuals exist solely because they are "needed." What happens when you have un-needed individuals? Do you euthanize? Even the most effectively planned society will experience environmental and situational changes that will skew the instantaneous need for certain professions and certain individuals. Pol Pot claimed he only needed about one million Khmers for his ideal society; and everyone else was ... well, no loss. All for the benefit of the Planned Society where everyone had a proscribed job and glorious equality among the classes! The idea of having to breed exactly the correct number of individuals, and then forcing them into a particular career path, seems to be a major step backwards in human society. It's important to keep in mind that in our society, even the most unproductive individuals, who are of no "use" to some particular agenda, still have a right to exist. Nimur (talk) 23:36, 21 June 2009 (UTC)

Heating canned goods directly

I seem to remember reading or hearing many years ago that it was a very bad idea to heat canned food directly over a heating element in the can (say a low flame on the range top). Now, mind you, I am not talking about an unopened can! The pressure danger there is or should be evident to most people. Is this true? If so, why? The only thing I can think of is leaching of the metal but most modern store bought cans are made from steel (not mercury or lead etc.)--141.155.143.180 (talk) 19:47, 20 June 2009 (UTC)

Someone asked this question on Yahoo. Hopefully someone here can corroborate the answers. Sifaka ^talk 19:56, 20 June 2009 (UTC)

Someone at Yahoo answers correctly pointed out that it is cooked in the can during the canning process. How would stove-heating be worse, unless it got hotter than at the cannery? Edison (talk) 20:02, 20 June 2009 (UTC)

Assuming the paper label will not be catching fire, then there is the question of any lead in the solder sealing the can, or any chemicals in the coating inside the can which could leach into the food. Many years ago, I recall a vending machine which had cans of chilé and soup kept hot inside and dispensed hot when purchased. Such long-term heating would probably be worse than brief heating on the stove. If steel, the cans are likely coated with tin inside. I have seen some which appeared to be coated with zinc inside, from the mottled appearance. Edison (talk) 20:00, 20 June 2009 (UTC)

Thanks for the answers. I think I'll refrain but I was curious.--141.155.143.180 (talk) 20:35, 20 June 2009 (UTC)

In addition to the can interacting with its contents, the bottom lid is crimped to the side walls. The bottom lid is designed to disburse impact stresses and resist heat expansion of the content at temps. around boiling. It is not designed to deal with the heat expansion caused by direct exposure to temperatures above 1000°F. It is likely to warp, which is in turn likely to put strain on the crimping and the seam on the side of the can. Material failure can be instantaneous and is unlikely to be pretty (launched lunch). The fact that the can not being the right size for your heating element the uneven heat absorption will damage the heating element of your range will probably be the least of your worries. 68.208.122.33 (talk) 21:21, 20 June 2009 (UTC)

This article cites reports that when taken together could imply that the food in 0.5% of tested cans (that's a LOT of cans) contained enough tin to cause nausea, vomiting, and diarrhoea. Heating of acidic food like fruits and vegetables may exacerbate this. Cuddlyable3 (talk) 23:07, 20 June 2009 (UTC)

I do not see how a can of food, with some liquid content, could be heated anywhere near 1000 F on a stove burner. In fact, it is possible to boil water in a paper bag over open flame (Ref: Michael Faraday, Mr. Wizard). The content keeps the container cool. The can should not get much above 212F/100C. Edison (talk) 03:39, 21 June 2009 (UTC)

Agreed. Also about the canning process being far more harsh than any reasonable re-heating method. It seems some canned food may contain tin, but cooking food in the can should do nothing to increase this level significantly. And cans can easily maintain their shape in a camp-fire. Cooking canned beans on the camp-fire is done all the time, and i have never seen any ill effects.YobMod 12:48, 21 June 2009 (UTC)

A can is made of thinner material than a pot. This accentuates any of the contemplated problems above. I doubt there is any problem involved in placing an opened can (of food) inside a pot of water and then heating the water, resulting in the contents of the can becoming heated. Something like a trivet could even be placed beneath the can to further separate it from the source of heat. Bus stop (talk) 13:55, 21 June 2009 (UTC)

But there is no need. A can can easily withstand the direct heat of a typical camp fire. Don't belive me? try it, the same as 1000s of people do every day. Repeated experimental observations surely count for something - any experienced camper should have seen this done, even if they prefer to carry around pots and pans. Camprecipes says it works for any canned food that just needs heating.YobMod 14:26, 21 June 2009 (UTC)

(un-indent)There may not be much of a need. But it is probably best to utilize low heat. And it is probably best to try to endeavor to apply heat in a way that doesn't concentrate it on one spot on the can. Any possible failure in the materials or construction of the can is likely to be exacerbated by both high heat and very unevenly applied heat. Bus stop (talk) 14:40, 21 June 2009 (UTC)

My guess would be that the canning company would use a label saying not to heat in can so that someone does not try heating up an unopened can and sue the company. 65.121.141.34 (talk) 14:26, 22 June 2009 (UTC)

Aren't some cans plastic lined -- to battle the metallic taste caused by direct contact of metal and acidic foods? --70.167.58.6 (talk) 14:38, 22 June 2009 (UTC)

"Homeopathic"?

In the spirit of AGF, I'm going to put this under "Science". I started to feel the symptoms of a cold coming on while visiting my family and my step-mum offered me a treatment that was apparently popular in the US (where she lives). It was some kind of spray that you apply to the back of your throat containing zinc and said on the packaging that is was "homeopathic". My understanding of homeopathy is that the remedies contain (prior to dilution, anyway) organic substances understood to be the cause of the malady. That suggests that this zinc thing wasn't actually homeopathic. In discussion with her, we came to the conclusion that the term in used in the US for any complementary medicine. Firstly, is this true? Secondly, does anyone know what this zinc treatment was and whether there is any evidence to support the claims? --Tango (talk) 20:09, 20 June 2009 (UTC)

A few comments for Tango. It is true that some people who don't understand what homeopathy really is may sometimes use the term to mean alt med, but that's an obvious misuse. Homeopathy is just one of many forms of alternative medicine, IOW untested, unproven, or disproven methods. (That doesn't mean they can't ever be proven to be effective, but it's increasingly rare for that to happen.) Homeopathic "remedies" are based on the use of substances which in their undiluted form would cause the same "symptoms" as a disease, which is not the same as using what would actually "cause" the malady. That means that extremely many substances can be used as the starting base for many preparations to treat ONE malady. This is based on the pseudo-doctrine of signatures. It sounds symmetrical and appealing, but it's nonsense in the real world when the rubber meets the road. Homeopathic remedies can be made from organic and inorganic substances, and even from things so exotic as moonrays and starlight. This is simply an expression of the fact that to be able to believe in homeopathy, one has to have some form of fundamental defect in logic, but that only applies if one really understands how it really "works". Otherwise such belief is just based on ignorance and what "sounds" appealing and superficially logical. As one guy put it: "Homeopathy is bullshit. Only very, very diluted. It's completely safe to drink." - Peter Dorn. Also: "Homeopathy is God's way of thinning the flock". - dpr; and "Homeopathy, where a little of nothing is better than something at all." - Jeanne E Hand-Boniakowski, R.N.[5] It's all an interesting subject. -- Brangifer (talk) 02:38, 23 June 2009 (UTC)

The Mayo Clinic says of zinc cold remedies that they "probably don't work", and WebMD says studies are "inconclusive". Still, if you take enough of it, there's some chance you'll develop some kind of super-power, and will fight crime as Rust Resistant Man. 87.115.17.119 (talk) 20:18, 20 June 2009 (UTC)

The article Zinc gluconate cites reports about cold treatments containing zinc and mentions a warning on 16 June 2009 from the FDA about nasal products from Zicam. The Zicam article cites a NY Times report on the same date that the manufacturer has withdrawn Zicam from the US market. It was (or is) marketed as a homeopathic remedy with some additional ingredients. Please see the articles concerned. Wikipedia can only cite reliable sources and will offer no medical advice. Of course you know that but it had to be said. Be cautious and get well soon. Cuddlyable3 (talk) 22:52, 20 June 2009 (UTC)

Thanks for the kind words, but the cold never really materialised (which isn't uncommon for me - I must have a good immune system). I think some of the symptoms were actually caused by dehydration, which I worked out a little latter and treated homeopathicly by drinking lots of plain water! (I would have switched to rehydration salts if necessary, so you don't need to warn me about the perils of rehydrating with only water!) --Tango (talk) 01:20, 21 June 2009 (UTC)

Oh - my - God - Tango. Don't you know that that "plain water" contains the succussive remnants of every other homeopathic remedy ever applied? And they've been getting ever stronger with dilution. This can be simply proved by the fact that water flows to the ocean, which is succussed by gravity waves, so you've clearly crossed the 200C barrier. You're invulnerable to all common ailments now. If there are any actual zinc molecules in the preparation you're spraying in the area of your lungs, you may have a small case of metal fume fever, but I'd recommend you counter that with a dilute application of chromium or vanadium. Remember to use fewer than zero atoms to get the maximum effect though. ;) Franamax (talk) 23:28, 21 June 2009 (UTC)

Homeopathic can mean more than the diluted bit but I have a hard time finding any justification for labeling the zinc treatment as being homeopathic. I agree in this case it seems to be just be a synonym for "alternative medicine" in general. --98.217.14.211 (talk) 01:34, 21 June 2009 (UTC)

"we came to the conclusion that the term in used in the US for any complementary medicine. Firstly, is this true?" No, not as far as I know. It sounds like the term is being misused. I'm surprised that the packaging said this. Perhaps this is just marketing-speak? 'Alternative medicine' is the term we generally use in the US (I live in Chicagoland). A Quest For Knowledge (talk) 02:01, 21 June 2009 (UTC) TC)

Homeopathy does not refer to "alternative medicine" in general but instead has a more precise meaning. An extremely accessible explanation of the origins of homeopathy and the scientific consensus regarding homeopathy is presented here by James Randi. The term is however abused to refer to any complementary/alternative medicine. Whatever you do, do not use a zinc-based "cold remedy" without reading the recent FDA warning regarding Zicam. --71.58.103.112 (talk) 09:42, 21 June 2009 (UTC)

Be careful with that stuff. The FDA recently issued a warning that Zicam may destroy your sense of smell. Guettarda (talk) 14:05, 21 June 2009 (UTC)

Yes. To be clear, according to the FDA, the manufacturers of Zicam have on record complaints from several hundred people who discovered the hard way that Zicam can PERMENANTLY destroy your sense of smell. And since almost all of what most people imagine to be their sense of taste is actually their sense of smell - you can pretty much write off ever enjoying food again - all of the subtle flavors reduce to salty/sweet/sour/bitter/savory. I don't understand how Zicam can be classified as "homeopathic" and still have enough active ingredient to cause this - it seems to me that they must have been abusing the "loophole" that allows homeopathic drugs to get onto the market without adequate testing. The only reason that loophole exists in the first place is because true homeopathic "drugs" are nothing more than water...they are a horrible scam - but they shouldn't be dangerous. If they actually have measurable amounts of (for example) Zinc in them then they aren't homeopathic and they should be undergoing a full swath of clinical trials, etc, etc. If the law allows measurable amounts of active ingredients in homeopathic medicines then they become more than just a scam - you should read that word on the label and mentally translate it to "Completely untested - use at your own risk!" SteveBaker (talk) 14:29, 21 June 2009 (UTC)

I should clarify - I turned down the offered treatment. I know better than to trust anything with the work "homeopathic" on it, regardless of whether it is correctly used or not! This particular treatment was apparently intended to be sprayed on the back of the throat, rather than the nose, which should prevent it destroying your sense of smell. It also would seem to prevent it working if the claimed mechanism regarding mucus membranes in the nose (as described in the pages linked to above) is correct. --Tango (talk) 15:20, 21 June 2009 (UTC)

Mucous membranes. Mucus is a noun, mucous is an adjective. By the way you made the same mistake on phosphorus/phosphorous a few threads back (at least I think it was you). --Trovatore (talk) 22:24, 21 June 2009 (UTC)

I don't remember talking about phosphorus or phosphorous recently, but my spelling has never been ideal. I am far too reliant on spell checkers, so that kind of mistake is quite common for me! I will try and remember the distinction in future, thanks! --Tango (talk) 00:07, 22 June 2009 (UTC)

In US drug regulations "homeopathic" is a specific class of treatments based on homeopathic principles and accepted into the Homeopathic Pharmacopoeia. Inclusion generally requires that the remedy closely follows some traditional alternative medical practice with a long history of use. While they are regulated for safety, and for the kinds of claims they can make, most homeopathic "medicines" are not reviewed for their effectiveness. They are allowed to be sold alongside over-the-counter medications, which can often be confusing. Dragons flight (talk) 22:14, 21 June 2009 (UTC)

• Above, "SteveBaker" said, "Zicam can PERMENANTLY destroy your sense of smell". <-- How did you reach this conclusion? "If they actually have measurable amounts of (for example) Zinc in them then they aren't homeopathic" <-- Is this part of the FDA's regulatory position? "Completely untested" <-- Strange, but the Wikipedia article Zicam cites at least one clinical study that tested the zinc nasal gel and the sales figures suggest that millions of people have used these products. --JWSchmidt (talk) 02:36, 22 June 2009 (UTC)

Well, me not being SB and all, but: "permanently destroy" may come from the same sources the NY Times used when they quoted the FDA director of compliance saying "This disabling loss..may be..permanent..." - would that do? [6] And of course, anyone actually reading the Zicam article can easily ascertain which compounds are claimed to be homeopathic, none of them are zinc, that's just a metal you likely shouldn't be spraying into your respiratory system. And I'd be interested in the peer-review and full text of the clinical study to which you refer (is it one which found damage to health, or the metastudy which suggested that further study is required to verify primary efficacy and doesn't mention side-effects in its abstract?[7]). Oh, and millions of people have used crack cocaine, crystal meth, alcohol, tobacco, asbestos and benzene too, what was your point there? Franamax (talk) 04:00, 22 June 2009 (UTC)

The Wikipedia anosmia article makes it clear that anosmia can be permanent. Infections such as the common cold can cause anosmia, so people who do not use Zicam get anosmia. Who do they sue? Where does the FDA say that Zicam causes anosmia? This is the published study I noticed in the reference list at Zicam. It is certainly wrong to suggest that when you see the word "homeopathy" on a package it means "completely untested". Franamax, I don't know what your point is in mentioning crack cocaine, crystal meth, alcohol, tobacco, asbestos and benzene. Part of the testing of drugs comes after they are introduced into the market and used by large numbers of people. Should we count the number of conventional drugs that have been withdrawn by the FDA only after they were given to millions of people? --JWSchmidt (talk) 14:30, 22 June 2009 (UTC)