Testwiki:Featured article candidates/Equipartition theorem

The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was promoted 04:21, 5 May 2007.

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Equipartition theorem

The equipartition theorem is an important result of 19th century physics. Being one of the most general results of classical statistical mechanics, it is still used in calculating properties of physical systems, ranging from the average tumbling rate of proteins in solution to the maximum mass of a neutron star before it collapses into a black hole. The disagreements between experimental specific heats and the specific heats predicted by equipartition were the first evidence that classical physics could not be correct. Together with the ultraviolet catastrophe — likewise predicted by equipartition — these disagreements set physicists on the path to quantum mechanics and quantum field theory. The article is stable, and has benefited from a scientific peer review, a normal peer review and less formal reviews. Thank you for taking the time to consider it! :) Willow 18:39, 27 April 2007 (UTC)

• Comment Do you think you could cut down the length of the image captions; the oscillating system at "Limitations" for example has caption which is 10 lines long! It's a very technical article, which should be no barrier to FA status, but it must then provide context and explain at the very least, the meaning behind an equation. For example, it's all very interesting to derive that ${\delta }_{mn}(\frac{\partial \log \mathrm{\Sigma }}{\partial E}{)}^{-1}={\delta }_{mn}{k}_{B}T.$, but if you don't explain why you've done it, all you'll do is put casual readers straight off the article. What is this equation used for? Who first derived it? The Stellar physics section is an example of how I personally think the article should be; it's got quite a few equations in it, but it also makes bold and interesting statements about scientists can know how hot the sun is without going there; now that's interesting! Also the article doesn't link a few technical terms (hypersurface for one). I'm not going to write this article off yet; it has potential to be a challenging but very rewarding one. Laïka 19:59, 27 April 2007 (UTC)

Thank you for your comments, and especially for your faith that the article is redeemable, which I hope to justify. :)

• The caption of the normal-mode image is indeed long, but it tells a complete story. I could delete most of it and rely on the text alone to convey the ideas, but my thought was that the caption helped to distill the essential ideas.

• I agree very much that we shouldn't put our readers off, especially early in the article, which is why I relegated the derivations to near the very end. On the other hand, the readers shouldn't have to take my word for everything, which is why I start from the general formulation and take derivatives in the various Application sections. Does that seem sensible to you? Please share your suggestions on how to do a better job in maintaining the connection to the casual reader! :)

• The references in the History section do describe how the equipartition theorem was derived and by whom, right? Maybe there's a glitch somewhere in the exposition? The particular formula you cite is the theoretical definition of temperature.

• I added the hypersurface wikilink, and would be grateful for others that I should add.

Thank you again, and I would welcome your further insights or suggestions.

Willow 20:57, 27 April 2007 (UTC)

• The only other major comment I have with this article is that it uses the units Calories/(mole x kelvin). Is this a unit frequently used for calculating equipartion, or would the entirely SI joules/(mole x kelvin) be better, given that there are lots of different types of calorie? Laïka 21:14, 27 April 2007 (UTC)

The main advantage of the cal/(mol K) unit is that R is so close to an integer, 2, with the added advantage of canceling the 2 so often seen in the denominator, e.g., (3/2)R. If you think it'd be helpful, I'd be happy to convert those to SI units, though. Willow 21:23, 27 April 2007 (UTC)

• Perhaps giving the units as 6 cal/(mole·K) (25 J/(mole·K)) would be best; by the sounds of it, the calorie is the easiest unit to use in this particular field. Still, I have no further complaints about this article, so Support. Laïka 07:53, 28 April 2007 (UTC)

• Support A well written article having some great assist with the superb animations and images.Though I also feel on the similar lines of the previous comment that the equations should be tried to be given a more general readership by explaining them a bit. Also, I think that the History section should be introduced before the Formulations section. Overall the article is well referenced. DS 20:11, 27 April 2007 (UTC)

Thank you, Deepak! The placement of the History section is an ongoing source of confusion for this article's editors, some wanting it near the beginning and others near the end. For myself, I'm also wondering about leaping straight away into the Maxwell-Boltzmann probability distribution; some reviewers had wanted the quadratic derivation as a "warm-up" to the general formulation, but now it seems rather daunting to the casual reader. What are your thoughts? Willow 20:57, 27 April 2007 (UTC)

Right, offering the Maxwell-Boltzmann probability distribution and other such formulations first as a warm-up may be helpful to some readers, but I think for a casual reader, as you said, they rather look daunting and for them it would have been better to place the History section before. So, the opinion still exists divided. So as a solution to the problem, I think the present format should be kept because in other case after History section, the article would have been predominated only by large equations and even that will seem daunting to the casual reader. So let it be so. DS 07:18, 28 April 2007 (UTC)

• Support Comments. This seems as clearly-written as is possible for such a mathematical subject and has beautiful illustrations.

• Are refs with partial page numbers correct? Such as the first citations in ref 15 and 16.

I haven't been able to get hard copies of those references, so I don't know what their final page numbers are. :(

link p330 indicates some were on a single page

1286 1906 ANNALEN DER PHYSIK 22 (1): 99-106 Wigand A Temperature speed of specific heat solid elements link

• Need ref for The average temperature of a star can be estimated from the equipartition theorem. maybe repeat the citation from the review in the paragraph above?

OK, although I should check that first!

• Lacks summary style, you need to add links in each sub-section to other relevant articles.

You mean like Template:Tl links?

Exactly.

• "Graham's law of effusion, which is used in purifying radioactive isotopes of uranium." I thought they used centrifuges? :)

That's the new way (I think); effusion was the old way. Another fine Scotch scientist, Dr. Graham, by the by. ;) Thanks for your bon courage, Willow 22:53, 27 April 2007 (UTC)

Yes, but however solid, a theory doesn't hold much gas. You might want to say "which is applied in purifying isotopes of uranium."

Check! I'm on it, boss. ;) Willow 23:02, 27 April 2007 (UTC)

TimVickers 22:42, 27 April 2007 (UTC)

Thanks, Tim! The article's much better for your attention to details. Good luck with the big E; you're much braver than me, but I'll help where I can... Willow 23:05, 30 April 2007 (UTC)

• Oppose, too soon after the 1 − 2 + 3 − 4 + · · · fiasco. I question the need to promote more esoteric maths pages at this time. —freak(talk) 12:41, Apr. 28, 2007 (UTC)

I think that is the weird reason to oppose. DS 13:58, 28 April 2007 (UTC)

Opposition to an article must be actionable; is there anything that could be done to this article to improve it? Laïka 14:23, 28 April 2007 (UTC)

The Wikipedia:Featured article criteria are not dependent on subject. This objection is not actionable. TimVickers 14:26, 28 April 2007 (UTC)

When I expressed my concerns regarding the numerological parlour tricks of 15 April, I was flatly advised that the fault was my own for neglecting to voice my opposition for said article at the time of its nomination. I am trying desperately to avoid making that same mistake twice. —freak(talk) 17:46, Apr. 28, 2007 (UTC)

Hi Freakofnurture. When commenting on a FAC, you are expected to assess if the article meets the Wikipedia:Featured article criteria. If you have any questions about how this review process works, or find these criteria unclear, just drop me a note on my talk page. TimVickers 18:34, 28 April 2007 (UTC)

Hello yourself. This is not a personal matter — I've never heard of you either, actually (and no, I don't forsee dropping any notes on your talk page) — nor am I concerned with the criteria to which you refer. I merely feel that topic would be an ill-advised featured-article selection at this time (or in the near future), for the simple reason I've outlined above. If my opinion ultimately counts for nothing (and frankly I suspect it will), then so be it, but you are in no position to decide that. —freak(talk) 19:34, Apr. 28, 2007 (UTC)

Perhaps your objection would be taken more seriously if you could explain in more detail what the problem is. So far it looks just like you don't like two science/mathematics-related articles appearing on the front page within a month or so of each other. If this is your reason, probably people whose tastes differ from yours can't really see a problem. --C S (Talk) 07:33, 30 April 2007 (UTC)

Just because an article reaches featured status, it does not necessarily mean it will be featured on the Main Page. CloudNine 19:47, 28 April 2007 (UTC)

If you oppose the article appearing on the main page then think the page you want is WP:TFA/R, assuming this article is ever nominated there. As Tim said, this page is for assessing articles against a set of criteria, not to decide if the article will appear on the main page. Cheers, darkliight^[πalk] 23:44, 28 April 2007 (UTC)

Sorry, F of N, but I don't know the 1 − 2 + 3 − 4 + · · · fiasco. I can assure you, though, that this article is about physics, not math. The math here is straightforward multidimensional calculus — ok, maybe that's an oxymoron ;) — and uncontroversial, nothing as arbitrary as summing divergent series. If it's any comfort, this article seems unlikely to ever reach the Main Page, when there are so many great articles on more interesting topics. Besides, the balloon-animal rights activists would hound me relentlessly if it did. ;) Willow 10:01, 29 April 2007 (UTC)

• Support A well-written article. I too had a concern about the rather detailed image caption, but then realised it would hard to explain elsewhere. However, I'm not sure about the Sun image. It's cyan background is a little off-putting (a purely stylistic issue of course!), and I'm not sure how relevant the diagram itself is. CloudNine 14:43, 28 April 2007 (UTC)

I've taken the liberty of replacing this figure with a version with a white background. TimVickers 14:52, 28 April 2007 (UTC)

Thanks, Tim! :) Willow 09:38, 29 April 2007 (UTC)

• Comment. I believe the "thermal motion" image looks too much like a set of points in 3D space representing a dog walking on its hind legs while quickly plucking the hairs from a teddy bear. Is this actionable? Thanks, $⟨Outriggr⟩$ (aha!) 03:14, 29 April 2007 (UTC)

You must have either had a very unhappy childhood or great drugs as an adolescent. It is obviously a weasel riding a broomstick. TimVickers 03:23, 29 April 2007 (UTC)

Actually, all four. –Outriggr § 03:48, 29 April 2007 (UTC)

My daughter got a balloon animal that looked like it. I put it out of it's misery. -Ravedave 03:57, 29 April 2007 (UTC)

I hope that $⟨Outriggr⟩$ isn't the "mean Outriggr"; I liked the nice one! ;) This is fun, like looking at the clouds — I totally see them! :) Now I'm going to get some long colored balloons and try to recreate Dave's poor creature... ;) $⟨Willow⟩$_mwahaha... 09:35, 29 April 2007 (UTC)

After days of rapt contemplation, I've received the insight that Figure 1 is actually a picture of three mice riding uphill on a friendly catepillar. Happy May Day, everyone! :) Willow 15:39, 1 May 2007 (UTC)

• Layman's Support. I'm in agreement with DS, the history section should go at the beginning. Casual readers (assuming some reach this article :) might see the formulas and move on to elsewhere. I believe the intro should have when the theory was proposed (as it gives context re:Einstein & relativity) and also probably mention Waterson as well. I love the sedimentation example, it's an excellent way to draw readers in. Perhaps that should be a DYK. Should there be one more step in the Ideal gas law derivation, converting it to the more familiar PV = nRT? I did a copy edit pass on the whole article, here's my diff feel free to revert any of it. Another great Willow article. -Ravedave 03:57, 29 April 2007 (UTC)

Thanks, Dave! I'll work on the History section; I definitely see how launching right into the math could be off-putting. I'm glad that you love the sedimentation example; I was grinning from ear to ear as I wrote about the "infinitely tall bottle of beer". The friendly message from darkliight on my talk page inspired me. :) Willow 09:24, 29 April 2007 (UTC)

• Support as a well written article that seems to meet all of the criteria, with two small issues to be fixed.
  • please fix the citation needed in the History section.
  • References 14, 22 are missing the date of publication - Peripitus (Talk) 12:10, 3 May 2007 (UTC)

Thank you very much, Peripitus, especially for your sharp eyes in detecting those two glitches. I've fixed the references and added the needed citation. Sweet thanks from Up Over for the support from Down Under, Willow 18:09, 3 May 2007 (UTC)

• Comment. Please fix WP:MSH in Derivations — don't repeat words in sub-sections. Can you put Further reading in alphabetical order by last name? And, there's a newfound requirment; you're never supposed to specify px size on thumb image — you need to take those out so that user preferences take precedent (that's somehwere in WP:MOS and was the subject of a bid deal on WP:AN). I wish I had time to read it ! SandyGeorgia (Talk) 03:01, 4 May 2007 (UTC)

  I've fixed the section headings and Further reading - thanks for pointing this out! I'm sorry to hear thumbs caused a big deal at WP:AN, but this is only a recommendation, not a requirement in WP:MOS#Images. Anyway, none of the images in the article are thumbnails: the thumb tag is simply used to scale down some large images with captions to recommended sizes for articles, per Wikipedia:Picture_tutorial. However, I've been through the article replacing thumb by frame for those images which have not been scaled. Geometry guy 13:23, 4 May 2007 (UTC)

The above discussion is preserved as an archive. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.