Talk:Thermodynamic temperature/Archive 3

Temperature scale

In 1958, in a private discussion with E. A. Guggenhein I suggested that a new temperature scale be employed starting from the absolute zero, -273.16C. the suggestion was to rename this as Ln(0). or -inf. Other points on the scale would all be expressed as Ln(T). The difficulty was that all "social" scales were linear and adopting a Log scale seemed too alien. Notwithstanding the difficulties of getting used to such a scale it offered a way to state the absolute zero as -inf and to eliminate exp(-kT) from many thermodynamic functions. 72.89.83.95 (talk) 02:57, 23 July 2008 (UTC)Stanley Kravitz, Ph.D, D.I.C.

If you want to simplify expressions containing exp(-kT/E), wouldn't you want exp(T) not ln(T)? Your substitution would result in exp(-k exp(ln(T))/E). Also, you still need to exponentiate the inverse-energy factor exp(1/E) to take a meaningful exponent. Potatoswatter (talk) 04:25, 23 July 2008 (UTC)

The substitution of Ln(T) for T in equations containing exp(-KT) yields exp(-Kln(T))or simply K'T. —Preceding unsigned comment added by 72.89.83.161 (talk) 01:40, 4 August 2008 (UTC)

That's not how substitution works. If T' = ln(T) is going to be the new symbol, it needs to appear in the final expression, not the first one. Potatoswatter (talk) 10:35, 4 August 2008 (UTC)

Also exp(A*B) = exp(A)^B ≠ exp(A) * f(B) for all A and any f. That's the first thing I should've noticed! Potatoswatter (talk) 10:41, 4 August 2008 (UTC)

• Dr. Kravitz, did you mention, here on this talk page, the fact that you proposed a new temperature scale a long time ago because you were thinking this was sufficiently notable to merit inclusion in the article? Greg L (talk) 18:16, 5 September 2008 (UTC)

Greg: The common use of a Ln temp scale seems remote, but had possibilities for scientific use and for establishing Ln(0) as absolute zero. I will add it to the main page after enough discussion and suggestions. Thanks Stanley —Preceding unsigned comment added by 72.89.104.135 (talk) 22:15, 12 September 2008 (UTC)

• I see. An issue of fact (a minor one), and an observation or two: you wrote above in your 04:25, 23 July 2008 post that absolute zero is −273.16 °C. Note that a unit increment of one kelvin (or one degree celsius) is 1⁄273.16 the difference between absolute zero and the triple point of water. But note too, that the triple point of water is extremely close to +0.01 °C. That’s why the BIPM defined 0 K as being equivalent to −273.15 °C, not −273.16 °C. I would also argue that the notion that log temperature is “alien” misses the mark. I would say that few people have much facility with log math, which relegates any scale that is based on log math to only advanced purposes. I used log math myself in algorithms for compensating MOS hydrogen sensors for the effects of humidity (Patents 6,550,304 and 6,532,792); it’s a rather advanced math concept for most. And consequently, a Ln(t) scale is clearly too abstract to find any traction in day-to-day life.

  At any rate, my initial take on your specific point is that someone’s private, 50-year-old discussion with “E. A. Guggenhein” (which I take to be E. A. Guggenheim of the University of Reading) would, on its own, likely lack sufficient notability to satisfy Wikipedia’s requirements (Wikipedia:Notability). Wikipedia is supposed to communicate about how the world works; it is not generally supposed to be used as a vehicle to promote good ideas or advocate change in how it ought to work. Greg L (talk) 23:54, 25 September 2008 (UTC)

Small-text references

Headbomb. If we're gonna give the references the “small text treatment” please take the time to do as was done on Kilogram to accomplish that end: the simple citations were made references and the notes were made refnotes that are in normal-size text. Notes are meant to be truly read and Wikipedia’s small text is almost unintelligible on some browser/platform combinations. Greg L (talk) 01:32, 11 February 2010 (UTC)

Concur. Materialscientist (talk) 01:39, 11 February 2010 (UTC)

Thanks, Materialscientist.

Fair use for picture

BTW Headbomb, the entire point of Sandia's press release was about how they set a record-high temperature. This article is about thermodynamic temperature. I would feel much more comfortable if you had one of Wikipedia's better specialists on image copyright issues delete it if you want it deleted over copyright issues. Reading the copyright notes on the image makes it exceedingly clear to me that the subject is about record temperatures (as well as being about the Z-Machine) and it can be used in Wikipedia articles on either subject.

Including the image obviously greatly enhances this article and makes Wikipedia a better product. And it is exceedingly clear from the copyright notes on the image page that Sandia doesn’t give a rip about it being used here. That it is all about “temperature” seems a no-brainer to me. Greg L (talk) 01:49, 11 February 2010 (UTC)

Incorrect. Fair use rationale may be justified for usage of Z-machine image in Z-machine article as a unique illustration of the subject. In this general article, we have to use free images only. Definitely we would make wikipedia better in a day if we added thousands of great copyrighted images from the internet, yet this is against the rules of the game. And we can't speculate on Sandia caring or not - the procedure is to ask them and obtain email confirmation. Materialscientist (talk) 01:59, 11 February 2010 (UTC)

You obviously didn’t read the link I provided. The request was made and Neal Singer, Sandia National Laboratories’ Media Relations spokesperson, provided that permission. Oh, and by they way, I also contacted Neal while writing this article to get facts about the black-body radiation emitted during the pulse; you know: Note F under the table. I do my homework. Greg L (talk) 02:04, 11 February 2010 (UTC)

Then file an OTRS ticket so people can verify this. The image is still of very little relevance to this article, especially for the lead. Headbomb {^ταλκ_{κοντριβς} – WP Physics} 02:08, 11 February 2010 (UTC)

(ec) I was just adding on that .. We have to play by the rules. Doesn't the 2005 email fit there? Have you tried to forward the correspondence to "permissions-commons AT wikimedia DOT org" and get rid of the fair use tags? Materialscientist (talk) 02:09, 11 February 2010 (UTC)

Aren't either of you guys actually reading what’s there? It wasn't me who sought the permission; it was another editor. I think you have an uphill climb if you want to make the case that the press release about the Z-machine's record-setting temperature isn't about temperature. It seems it is fair-use to me. Like I said, if you want it deleted, please, let's all stop acting like we're space-cadet experts on copyright law. Please, I would feel much more comfortable if you had one of Wikipedia's better specialists on image copyright issues delete it if you want it deleted over copyright issues. Greg L (talk) 02:12, 11 February 2010 (UTC)

The press realease may be about setting a record temperature, but this image is not. Case shut. Headbomb {^ταλκ_{κοντριβς} – WP Physics} 02:14, 11 February 2010 (UTC)

Please don't get emotional about this and please stop acting like you are an expert in these matters—you aren't. Like I wrote above, I would feel much more comfortable if you had one of Wikipedia's better specialists on image copyright issues delete it if you want it deleted over copyright issues. Greg L (talk) 02:21, 11 February 2010 (UTC)

Greg, please do not get into warring on that but instead try fixing the image status. The specialists you're asking for are sitting behind the email I mentioned above. I would not pretend I am a specialist, but it is my duty to enforce the policies. Materialscientist (talk) 02:29, 11 February 2010 (UTC)

• Very well, I'll chip in, not that I'd bill myself as a "specialist" (merely a law nut). Now, this would be perfectly acceptable under fair use if it was to illustrate our article on the Z machine, which it is; a free image is probably impossible to get. However, this is not the article on the Z machine. Nobody can say "it is impossible to get an image illustrating thermodynamic temperature", because that's ludicrous. If there is OTRS permission for this machine, all well and dandy. Greg, if the OTRS permission has not come through then, as far as the community is concerned, it's fair use or no use. Fair use doesn't apply here; get the OTRS verification and we can include it in the article. Otherwise, no use. I'd suggest you spend more time finding the email in question and lest time making personal comments about the other editors. Ironholds (talk) 02:32, 11 February 2010 (UTC)

• Thanks. Well, Brian0918 sought permission from Sandia and granted that permission. Can anyone show that Brian0918 did not receive OTRS? Or is this just assumed? Greg L (talk) 02:36, 11 February 2010 (UTC)

• With copyright being what it is, it's assumed that there is no permission until there is concrete evidence that such permission exists. I'd suggest getting Brian to tag the image with the normal "permission granted per OTRS ticket X" and we can get on with this. Ironholds (talk) 02:40, 11 February 2010 (UTC)

• I think I'd like to take the bull by the horns and get a new e-mail from Sandia explicitly stating that they have no problem with the image being used in this particular article. Getting the e-mail will be the easy part; Sandia has been exceedingly helpful to me while I was adding to this article. Please provide a link to "permission granted per OTRS ticket X". I typed “WP:OTRS” and didn’t go to something that seemed at all germane. Greg L (talk) 02:46, 11 February 2010 (UTC)

• No, the email has to be sent to the OTRS address, where an OTRS-cleared volunteer will then read it, log it and add a tag saying "email [code number X] gives us permission to use this image". I'd suggest just getting Sandia to follow the instructions here. Ironholds (talk) 02:49, 11 February 2010 (UTC)

Greg, please don't rush, examine Wikipedia:PERMISSIONS and act accordingly. We shouldn't ask Sandia to release the image for specific article - this would be fair use which we already have. We should ask them to release the image on wikipedia (better ask several images you have in mind not to bother separately) that is under compatible share-use license. One more note - any of us saying I am specialist or not is irrelevant in this matter - we are not given privileges to assess an email evidence for permission, but people behind "permissions-commons AT wikimedia DOT org" are given such privileges. Materialscientist (talk) 02:59, 11 February 2010 (UTC)

• Materialscientist: I'm not a total green-horn on image permissions. And if you knew anything about me, I don't “rush” things and do things half-ass. I had ACPO in Australia give GNU permission for this image, which they had earlier claimed copyright privileges. But it's been a while and I totally forget what those procedures were; they may well have changed since then anyway. Thanks for the link, Ironholds. I'll do that. I'll have to see whether Sandia is willing to put the image essentially in the public domain; these extra-fancy images are often the product of outside, commercial photographers who often place limits on what their government clients may do with image. If Sandia has the latitude to place the image in the public domain, they will. Greg L (talk) 03:13, 11 February 2010 (UTC)

Latest edits

Kbrose, what expertise do you have in Thermodynamics? While expanding this article some years ago, I exchanged some sixty e-mails with Daniel C. Cole, the Ph.D. physicist who published several landmark papers (like this one) on thermodynamics and the goings-on at absolute zero. He reviewed this article a half-dozen times at my invitation as I was writing it. More to the point, I made numerous edits—per his suggestions—to explain intricate concepts in a fashion that was accessible to a general-interest readership but still maintained scientific rigor. It is difficult to make big changes to terminology and basic assertions without making something untrue because there are often obscure exceptions to the general rule.

Your latest series of edits leads me to suspect your expertise in this subject is not up to the level of Dr. Cole (inasmuch as your not having had any scientific papers published in peer-reviewed journals). Is that right? Please provide links to your papers if I am wrong on that point.

I suggest you not be so Bold out of the gate here and limit your edits to true clean up-like items at this time and discuss more about what you have in mind before embarking on more substantive changes to an article that has been quite stable—and rightly so—for years. Greg L (talk) 19:41, 23 February 2010 (UTC)

P.S. I meant helium’s “heat of fusion” in one of my edit summaries; not “heat of formation”. Greg L (talk) 20:10, 23 February 2010 (UTC)

user:Kbrose's edits here and in other articles such as specific heat capacity remind of nothing so much as the late great user:Sadi Carnot who caused much trouble before being identified as a socker in Oct. 2007. Perhaps they didn't catch all of them.

In this case kbrose is treating us to the chemical view that when crystals are melted, no chemical bonds are broken. Obviously he's not thinking about diamonds or salt crystals. Perhaps in ice or sugar crystals, he doesn't think of hydrogen bonds as chemical bonds, but most chemists do. For that matter, if metallic bonds are not chemical bonds, why discuss them in the chemical bond wiki? SBHarris 01:45, 26 February 2010 (UTC)

• I have removed the edits by Kbrose because I think they do not improve the article. Kbrose, before making such large sweeping unsupported changes to an article you should talk about them first. Especially given your previous contentious recent edits. Glider87 (talk) 03:19, 26 February 2010 (UTC)

• Thank you, gents. I see that notwithstanding my suggestion to Kbrose that he first discuss his more substantive changes here first before wading into it, he ignored the advise. I’ll try to keep more of an active eye on this article and am heartened that you two seem to be doing likewise. I’m afraid to even look at what he’s been doing to specific heat capacity I hope the community has fully reverted the damage. To Kbrose: please stop editing against consensus. Greg L (talk) 03:00, 27 February 2010 (UTC)

History

This section is good, but I can find no tie in (link) or reference to when people starting measuring temperature generally. I have a comment (from an outside source) that I was trying to verify within Wikipedia itself concerning the general temperature during one winter in a particular large area. I am not able to discover if regular people actually recorded outside temperatures on a daily basis this early (18th century).Student7 (talk) 12:00, 31 March 2010 (UTC)

Overlapping Temperature

This article seems to me to include too much material about the general aspects of temperature, which should be incorporated into that article. This article should focus on the scale of temperature and stress its prominence among all kinds of scales due to its independence from working material.--Netheril96 (talk) 08:43, 5 October 2010 (UTC)

About the derivation of thermodynamical scale

First of all, I think it should be renamed as "definition" instead of "derivation" since it is a concept rather than a theorem. Second, this section should be raised to the beginning of the page because it is the origin; how do we discuss thermodynamical temperature without first knowing what it is exactly? At last, there is a mistake here. The article prior to my revision states that

"Because q_C andq_H correspond to heat transfer at the temperatures T_C and T_H, respectively, the ratioq_C/q_H should be a function f of these temperatures:

${\frac {q_{C}}{q_{H}}}=f(T_{H},T_{C})\qquad (2).$"

This does not make sense. The efficiency does depend on the temperatures of the reservoirs, but how could you conclude so easily that it is the function of only temperatures?--Netheril96 (talk) 09:20, 5 October 2010 (UTC)

Other heat sources on Earth?

Solar influx isn't the only heat source. There's radioactive decay and perhaps also gravitational compression. It would certainly be useful to mention these and their magnitudes, if only to note that they are much smaller. LADave (talk) 17:13, 18 August 2011 (UTC)

Name

Would it be appropriate to introduce this article as: Thermodynamic Temperature or Absolute Temperature? The first two lines seem to suggest these terms are interchangeable - in a rather long-winded way. --Moemin05 (talk) 14:01, 14 November 2011 (UTC)

File:Sun at 304 Angstroms.jpg Nominated for speedy Deletion

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Nonsense from 14/10/2010

--Netheril96 (talk) made this | edit removing the text:- "Since an efficiency greater than 100% violates the first law of thermodynamics, this requires that zero must be the minimum possible temperature. This has an intuitive interpretation: temperature is the motion of particles, so no system can, on average, have less motion than the minimum permitted by quantum physics."

Which makes a nonsense of the article. The same (or similar) text has not been removed in the article on temperature which, appart from being weird, puts the question - why two articles on temperature? Isn't it about time to combine them? --Damorbel (talk) 14:07, 16 July 2012 (UTC)

It's hard for me to see how you can "make a nonsense of the article" by leaving something out, even if that thing were accurate and useful. You can make it incomplete, but not nonsense; if what is left was correct before, it's still correct.

However, the removed claim is not correct, and therefore was correctly removed (though there is something correct to say along those lines, if better contextualized, and a better choice might have been to provide that context). See our fairly decent article on negative temperature for details. --Trovatore (talk) 17:15, 16 July 2012 (UTC)

The article on negative temperature explains "negative temperature is a strictly quantum phenomenon." There are other 'strange' effects that occur quantum defned systems. If you have studied semiconductor physics you may have come across the Krönig-Penney model for electrons moving in a periodic field, this reports electrons with a negative mass. Simmilarly Esaki diodes, entirely passive devices, exhibit negative resistance.

There are a large number of electron devices that work in this way. But the concept of 'negative energy' indicated by temperatures below 0K is a non starter, it puts you firmly back into the field of perpetual motion. Think about it, removing energy and the temperature rises! The perfect free energy machine! (Could be dangerous, there might be no way of stopping it!) --Damorbel (talk) 18:16, 16 July 2012 (UTC)

This is a quantum-mechanical universe, so strictly a quantum phenomenon includes everything (well, everything physical, anyway). Negative temperature does not mean negative energy (negative-temperature systems are hotter than positive-temperature ones), so you seem to be objecting to something that's not part of the concept. Similarly for the perpetual-motion part.

When you remove energy from a negative-temperature system, the temperature does not rise, it drops. The peculiarity of negative-temperature systems is that removing energy increases the entropy, not the temperature. --12.202.168.34 (talk) 18:40, 16 July 2012 (UTC)

1/ 12.202.168.34 Please identify yourself. 2/ "Negative temperature does not mean negative energy" in the article that is what it says. If you disagree, please explain. 3/ You are making up arguments as you go along, you have no support for what you write, e.g. "The peculiarity of negative-temperature systems is that removing energy increases the entropy, not the temperature. " But entropy is S = Q/T - so if T is negative S is going to be negative also which means the state of disorder is negative which is meaningless (order can only be between 0 (total chaos) and 1 (perfect order). --Damorbel (talk) 20:35, 16 July 2012 (UTC)

Sorry, wasn't logged in. If the article claims that negative temperature means negative energy, please point out where it says that, so it can be corrected.

That is not the correct definition of entropy, and I am not making any of this up. Please take a look at Thermal Physics by Kittel and Kroemer — it's a nice, small book, not too heavy-going, that you should be able to find in any academic library, and a fundamental reference for anyone who wants to contribute on thermo. --Trovatore (talk) 21:00, 16 July 2012 (UTC)

Sorry (too!). I was looking at an old version {01:04, 11 February 2010}([[1]]) where it has under "Derivations of thermodynamic temperature" and that efficiency becomes greater than 100% for T_C<0. Currently under Definition of thermodynamic temperature it has "and that efficiency becomes greater than 100% for T_C." The '<0' has been removed. As described this is not a statistical quirk that occurs when the slope of the entropy changes sign due to quantum effects.

I have a copy of Kittler & Kroemer and on matters of temperature I find it too unreliable. The explanation of thermodynamic temperatures on p449 is just too inadequate and 'negative temperature' (p461) has a temperature with an infinity(ies) clearly derived from division by zero; I need to look at it more closely. --Damorbel (talk) 21:03, 17 July 2012 (UTC)

Getting infinity by dividing by zero makes perfect sense in context. See real projective line for the mathematical treatment. --Trovatore (talk) 06:04, 18 July 2012 (UTC)

"dividing by zero makes perfect sense in context". I'm rapidly losing interest in contributions like this. Just how is it 'in context'? Do pay attetion to the matter in hand which is the article stating "efficiency becomes greater than 100% for T_C."

Division by zero is a perfectly respectable matter but there is no single approach to it, one approach establishes the Sin(x)/x function; that is the problem with Kittel & Kroemer, they start from what seems to me to be an arbitrary system of binary states, perhaps it really should be zero point energy. --Damorbel (talk) 09:19, 18 July 2012 (UTC)

Oh, well that particular "matter at hand" should probably just be deleted. If you meant deleting the "<0" part made nonsense of the sentence, of course you're right about that; the whole sentence should either have been deleted or better explained, but certainly not a piece of it left. If that's all you were saying, of course I agree; sorry if I misinterpreted.

The binary states (I assume you're talking about the system of magnetic spins, in an external magnetic field?) is just an example; K&K's theoretical framework includes that example along with more classical ones (like ideal gases) in a seamless tapestry. --Trovatore (talk) 23:26, 18 July 2012 (UTC)

Magnetic field? How is a magnetic field relevant? (It is, but not here!) "a seamless tapestry"? Um. Oh yes, I see a tapestry! These are minor matters. The article is quite inadequate for helping the wiki reader. Even this section, Definition of thermodynamic temperature is the 5th section, why put it half way through, way below Practical realization? Even so, as a definition it opens "Strictly speaking, the temperature of a system is well-defined only if its particles (atoms, molecules, electrons, photons) are at equilibrium," It has nothing to do with "Strictly speaking"; if the system is 'out of equilibrium' a temperature cannot be defined for it, that is the basis of thermodynamics and statistical mechanics. --Damorbel (talk) 06:17, 19 July 2012 (UTC)

The origin of heat energy on Earth?

What does a section entitled The origin of heat energy on Earth have to do with an article enttled Thermodynamic temperature? Thermodynamic temperature is the absolute temperature scale, a scientific tool, not a astrophysical observation. Deletion? --Damorbel (talk) 13:39, 19 July 2012 (UTC)

Mega-footnote three

It seems that mega-footnote three adds very little to (and is redundant with) the ZPE article. -- 66.103.112.85 (talk) 00:09, 15 August 2012 (UTC)

kinetics is over-emphasized; statistical mechanics is shorted

This article as it stands is almost entirely from the kinetic viewpoint. In my opinion that's a problem. From a statistical-mechanics point of view, temperature has little to do with kinetics per se; it's about the relationship between energy and entropy, and there are systems (such as spin systems in a magnetic field) where the energy involved is not kinetic energy at all.

The stat-mech concept of temperature is present, but it's really buried; it's way down at the end of section 4, and it is not indicated as a definition of temperature. (Yes, the section itself is called "Definition of thermodynamic temperature", but on my screen the heading does not even make it onto the same page as the definition.)

I'm not really comfortable making fundamental edits to this article, but I think someone who is should correct the balance. --Trovatore (talk) 04:53, 5 January 2013 (UTC)