Talk:Temperature/Archive 6

I have undone an edit that changed "The coldest theoretical temperature is absolute zero" into "The lowest theoretical temperature is absolute zero".

At first sight the edit might seem justified, but on more consideration, it may be seen as not so.

A temperature is a numerical scale on a one-dimensional manifold of hotness versus coldness. It may be considered to extend from minus infinity to plus infinity, with the absolute zero in between.

The point here is that virtually negative temperatures are considered. They apply only to conceptually separated parts of bodies, and the parts are not themselves whole bodies in their own states of internal thermodynamic equilibrium. That why they may be regarded only as virtual temperatures. The conceptually separated parts with virtually negative temperatures are actually hotter than absolute zero, though their numerical values are lower than absolute zero.

Consequently it makes sense to say that an ideal body at absolute zero is the coldest possible even though there are conceptual parts of systems that have virtually negative temperatures that are lower than absolute zero.Chjoaygame (talk) 07:23, 29 May 2018 (UTC)

"The point here is that virtually negative temperatures are considered." That may be true in the rarified atmosphere of theoretical physics, but for us lesser mortals that live in the real world, there is no temperature lower than absolute zero.JohnthePilot (talk) 16:48, 30 May 2018 (UTC)

I changed it from 'coldest' to 'lowest' because temperature is a physical property and is a measurement. A measurement cannot be hot or cold. The definition of 'cool' according to ^[1] is 'of or at a low temperature', so coolest is 'of or at the lowest temperature'. To say 'the coolest temperature' is the same as saying 'the lowest temperature temperature'.JohnthePilot (talk) 10:12, 30 May 2018 (UTC)

Welcome to Wikipedia JohnthePilot. Thank you for your edit and your comments here on the talk page. I certainly appreciate your edit and your effort to make the language as concise as possible. In this case, the distinction between "lowest" and "coldest" is subtle, albeit very important. Chjoaygame brings up the critical point that absolute temperature (i.e. the temperature in Kelvin or Rankine) can be negative, which means that absolute zero is not actually the "lowest" temperature. There are numerical values of the temperature that are lower than absolute zero.JCMPC (talk) 16:42, 30 May 2018 (UTC)

Thanks for your comments JCMPC. Whilst this may be true in the rarified atmosphere of quantum physics, in the real world it is not possible to go below absolute zero, as to do so would break the third law of thermodynamics. Why should we discard our basic grammar for the sake of what is an extremely rare, if not impossible, event?JohnthePilot (talk) 17:43, 30 May 2018 (UTC): @JCMPC Further to my previous reply, I've just had a look at the talk page for negative temperature and there are several comments dismissing the article as rubbish. Just saying. :-) JohnthePilot (talk) 18:00, 30 May 2018 (UTC):@Chjoaygame I like the new wording and think it removes any ambiguity. Thank you.JohnthePilot (talk) 15:59, 31 May 2018 (UTC)

The new wording submitted by Chjoaygame and agreed by me has been replaced by Waleswatcher with the original disputed wording.JohnthePilot (talk) 15:26, 11 October 2018 (UTC)

I looked back at the edit history, and all I see is Chjoaygame reverting your change and putting back as "colder", which is correct. Negative temperatures are lower than zero, but also hotter. As for comments on the negative temperature wiki article, they are irrelevant. Wikipedia is based on reliable sources, not the opinions of anonymous editors. Waleswatcher (talk) 18:05, 11 October 2018 (UTC)

Chjoaygame replaced the original wording with "A body at temperature absolute zero is the coldest possible; the thermal motion of all its fundamental particles is minimum. Although classically described as motionless at the absolute zero of temperature, particles still possess a finite zero-point energy in the quantum mechanical description. Absolute zero is denoted as 0 K on the Kelvin scale," You have replaced his wording, which was acceptable to both him and me, with the original wording which is incorrect. This is where Chjoaygame made the change: https://en.wikipedia.org/w/index.php?title=Temperature&diff=843761169&oldid=843482405JohnthePilot (talk) 09:29, 12 October 2018 (UTC)

That's not an improvement over the current text - it's not even grammatical, and it's written quite awkwardly. Apart from the English it says pretty much exactly the same thing. So can you please explain what it is that bothers you about the text as is? Then we can work together to improve it (and it certainly can be improved). This no longer seems to be about colder versus lowest - so what is it? Thanks. Waleswatcher (talk) 13:22, 12 October 2018 (UTC)

It is about 'coldest' v 'lowest'. The original text refers to 'coldest temperature'. Temperature is a measurement and cannot be hot or cold, but only high or low. After a dispute with Chjoaygame he changed the wording to overcome the problem that absolute zero is not the theoretical lowest temperature. An object at absolute zero, however, is the coldest an object can be.JohnthePilot (talk) 14:06, 12 October 2018 (UTC)

OK - I finally understand what you are objecting to. I don't really agree that's a problem, but I'm fine with wording things in a slightly more convoluted way to avoid that issue. I made a change that does so, please let me know what you think of it. Waleswatcher (talk) 19:52, 12 October 2018 (UTC)

Thank you. I'm happy with that. This makes it consistent with the article absolute zero which "is about the minimum temperature possible", rather than the coldest temperature. We can be sloppy with English in normal use but not in a technical article.JohnthePilot (talk) 10:46, 13 October 2018 (UTC)

Footnotes

I have undone the two good-faith edits made by editor Finell.

There are several reasons for my undo. I will try to be brief. The word 'technically' gives the game away. Temperature is not technically a term defined from microscopic considerations as asserted by the undone edits. Temperature is a measure of ability to impart or receive heat, or in ordinary language and well supported by reliable physics textbook sources, of hotness versus coldness, defined for macroscopic bodies.

I sympathise with Finell that the present lead is not perfect. I guess many others think so too.

But I am not now going to try to remedy the imperfections. That may be done in due course by others. But I think editor Finell's edits were in a wrong direction; that is why I have undone them.Chjoaygame (talk) 07:01, 19 July 2018 (UTC)

I will try to do better. However, it is inappropriate for you, Chjoaygame, to revert entire edits because you disagree with part of them. That is contrary to the principle of collaborative editing that is the foundation of the Wikipedia project. Since you have access to "reliable physics textbook sources", you could help to improve the article by adding those sources.

The lede, and several sections of the article, are a mess. Insufficient sources are part of the problem. Large parts of The lede is poorly organized. A basic principle of organization is keeping likes with likes. Furthermore, paragraphs require structure; paragraph divisions should not be arbitrary.—Finell 03:22, 24 July 2018 (UTC)

Dear Editor Finell, at a rough count (I don't have the interest to make it exact), I have, over the years, contributed somewhere about perhaps three dozen reliable source references to the article.

I agree that the lead is in bad shape. It has been fiddled with by many editors. I don't intend to struggle to fix the troubles, but I can say that your new edit is in the wrong direction, for the reason that I gave before, that temperature is defined primarily as a property of a body considered macroscopically, as is evident when one reads reliable sources. Your edit gives no hint of this key fact, and seems to give nearly exclusive priority to the kinetic theory of gases, a microscopic theory. It is true that in the kinetic theory of gases, they define temperature, for their own purposes, in microscopic terms, but that is a matter for the kinetic theory of gases, not for a general article on temperature. It is in general not necessary, or even appropriate, to give specific sources in the lead because it is a summary of the rest of the content of the article, which is the place for the references to reliable sources.Chjoaygame (talk) 04:17, 25 July 2018 (UTC)

This article suggests a great need for distinction of the concept of temperature from both Macroscopic and Microscopic scales. IMO temperature is a "highly localized" phenomenon. 2600:6C48:7006:200:B056:6066:1296:EF0B (talk) 04:49, 10 December 2018 (UTC)

The American Society of Mechanical Engineers (ASME) publishes the following Standard on Temperature:

ASME PTC 19.3 - Temperature Measurement — Preceding unsigned comment added by Angellguzman1981 (talk • contribs) 14:01, 25 July 2018 (UTC)

• Please provide hyperlink. No slam on ME's, but I expect some Physical Society to define Temperature. Am waiting for a proper reference. 2600:6C48:7006:200:B056:6066:1296:EF0B (talk) 04:53, 10 December 2018 (UTC)

I object to the image of what appears to be some sort of colorized image in the main article regarding (perceived) Global temperature to the actual physical measurement and definition of Temperature. The image is very much politically charged. I insist that this main article, including the headline image, be modified to define and describe temperature based on internationally accepted physical definitions of temperature. There is not a single reference provided to the first paragraph to define temperature or substantiate it. --2600:6C48:7006:200:B056:6066:1296:EF0B (talk) 05:55, 10 December 2018 (UTC)

Politically charged to show the temperature as warmer near the equator than the poles? The temperature of the air is probably the most common use of temperature people come across Define temperature in precise physical terms in the first sentence? That would certainly be one long sentence and would make the article unapproachable! The answer is no, I see nothing in what you said that would contribute to improving the article. Dmcq (talk) 11:04, 5 February 2019 (UTC)

It's not apropriate for physical temperature. As it's an average, it loses the properties of the physical temperature. It's no longer an intensive value and if you insist to consider it a temperature, you can quickly make a perpetuum mobile, as heat could flow from a 'colder' system to a 'warmer' one. The average temperature is not a state function of the system and has little to do with the thermodynamic temperature (except that it was derived from it by some sort of a numerology). That picture is highly misleading and has no place here except if used as propaganda. — Preceding unsigned comment added by 79.119.22.212 (talk) 08:18, 12 April 2019 (UTC)

I have undone some edits.

The SI unit, the kelvin is written without the ° symbol. It is a mistake to write it with the ° symbol.

In physics, the word heat is defined strictly as referring just to transfer between two systems, not as a property of one simple system, such as temperature. Therefore, in physics, it is a mistake to say that temperature expresses heat. Before 1907 or so, it was more or less acceptable to speak of heat in reference to just one system, but thereafter it has been considered unacceptable.Chjoaygame (talk) 15:20, 5 May 2019 (UTC)

This entire section is incorrect in very significant ways, does not agree with the parent article, and is unsourced. It asserts that temperature cannot "really" be negative (less than 0 K), which is simply false. Unless there are good arguments to the contrary, I intend to delete it and replace it with something much shorter (and correct). Waleswatcher (talk) 15:31, 13 May 2019 (UTC)

It is good to see you here again, Editor Waleswatcher. It is wise to distinguish laws of physics from convenient approximations to them. For many purposes, it is very useful to use approximations, for example, non-equilibrium approximations to entropy and temperature. If such approximations were, instead, strictly and rigorously valid, we would perhaps have many important problems solved. It is possible to use the word 'entropy' ambivalently, to refer (a) to non-equilibrium and unsymmetrical statistical mechanical assumptions and definitions, and (b) for the macroscopic thermodynamic quantity entropy, which expresses the full symmetry of thermodynamic equilibrium. Negative temperatures occur only in situations where there are transients or where there are macroscopic flows; they cannot occur with thermodynamic equilibrium. Then, use of the word 'temperature' is handy, but approximate. I think it better for Wikipedia readers that these facts not be hidden for the sake of making it seem that thermodynamics is currently more omniscient it really is. Instead of promoting approximations beyond their proper scope, it would be better if you were to use your deep and extensive knowledge to provide the reliable sources that you find missing from the present section. The parent article is not a reliable source as defined by Wikipedia.Chjoaygame (talk) 23:22, 13 May 2019 (UTC)

Chjoaygame, what you write is false, but this is not the place to debate physics. The current section is almost entirely unsourced and therefore cannot remain as is. Waleswatcher (talk) 00:48, 16 May 2019 (UTC)

Hello, this is N9le. This is addressed to CLCStudent. I am new here and apologize if I’ve done anything wrong. The problem I have regarding your actions is that without my edits, the wrong formulas in the article are referred to (this is an indisputable fact). I think that reversing the edits is deconstructive; you’ve put in extra work to return the article to an incorrect state. Please let me know how I can edit things better in the future, and/or if my currently expressed view has flaws. In order to improve Wikipedia, I suggest you spend less time picking on changes that are correct, and more on those that are incorrect or ambiguous. If nobody makes these minor edits then there will forever be minor mistakes.

The changes in question are gone now, and we are back to the confusing state of the article where we are directed to the wrong formulas. I cannot seem to follow how the article is better off like this. N9le (talk) 05:09, 8 July 2019 (UTC)

It seems to me that the foregoing comment by N9le is right, and I have restored the undone valid corrections.Chjoaygame (talk) 19:35, 8 July 2019 (UTC)

Editor Sensify has made some edits that call for some talk.

The following isn’t true if celsius vs fahrenheit:

“There are various temperature scales that nearly or approximately agree with one another, but differ slightly because of the various characteristics of particular thermometric substances.” Tedtoal (talk) 18:50, 24 November 2019 (UTC)

Thank you. I have tried to fix that.Chjoaygame (talk) 10:28, 25 November 2019 (UTC)

I have undone this edit. I suppose it was in good faith.

Not every physics text uses the term 'hotness', but some very respectable and reliable ones do; see the citations in the article. The term 'hotness' is more abstract than the more specific term 'temperature'. 'Hotness' is useful for discussion of general ideas about temperature. For example, it facilitates theoretical comparison of different kinds of temperature. A particular example is saying that two temperatures, on different scales, refer to the same hotness.Chjoaygame (talk) 04:42, 29 December 2019 (UTC)

This edit has undone this fresh edit.

The edit cover note of the undo reads "rv to better version. Indefinite article is inappropriate ("a temperature"), there is only one property called temperature, misc.". Such a cover note is inadequate. More is involved than an indefinite article. The "better version" is not an accurate summary of the article, such as is proper. The article is clear that there are two kinds of temperature.

More than such a cover note is due for such an undo. A post on this talk page is due.Chjoaygame (talk) 00:18, 26 January 2020 (UTC)

Judging by the lead paragraph alone, the original (and current) one is better. BernardoSulzbach (talk) 00:47, 28 January 2020 (UTC)

There are two distinct conceptions of temperature: that through the kinetic theory for microscopic particles, as in statistical mechanics; and that through the macroscopic theory of transfer of energy as heat, as in thermodynamics, in the original definition by Kelvin. The term 'thermal energy' is apt for the kinetic theory conception. The kinetic theory conception does not admit negative absolute temperatures, but the thermodynamic conception admits them for special kinds of non-equilibrium systems.

The term 'hotness', as defined in some (perhaps arcane) physics texts, is useful to give definite physical meaning to such sentences as 'Heat transfer from a hotter to a diathermally connected colder body is spontaneous'. In physics, hotness is a body's ability to impart energy as heat to another body that is colder.^{[1][2][3][4][5]}Chjoaygame (talk) 06:12, 2 February 2020 (UTC)

References

I have undone this edit for the following reasons.

The undone edit was apparently in good faith. It reflects views that might be suitable for a dictionary of ordinary language, but are not suitable for this Wikipedia article on physics.

The undone edit offers a lead definition of temperature that reflects thinking that is apparent in ordinary language, taken from an admirable dictionary of ordinary language, as distinct from being a summary of the article as based in reliable sources on physics, and not informed by the principles of physics.

The offered definition reads "Temperature is a physical property that expresses the degree or intensity of heat in a substance or matter.^[1]". This definition more or less accords with the ordinary language idea of heat but contradicts the definition of heat used in physics, particularly in thermodynamics. The discrepancy between the offered definition and the present definition is enough to undo the proposed version.

The rest of the undone edit is a rearrangement of the present content of the article and is not in contention for the present purpose, though it has flaws.Chjoaygame (talk) 02:09, 1 March 2020 (UTC)

The new edit here has an edit cover note

"Adding less circular definition".

It is regrettable that such an edit is felt to be called for. The current lead of the article has conceptual flaws that create such feeling. Part of the problem is that there are at least two fundamentally different concepts of temperature, those of thermodynamics and of statistical mechanics, along with a largely empirical concept, and for some the concept of negative absolute temperature. These distinctions are not apparent in the present lead of the article. Further comment along these lines is at Talk:Temperature#a post on this talk page is due above.Chjoaygame (talk) 08:17, 5 March 2020 (UTC)

This edit rewrites the section on thermodynamic temperature.

The now replaced version was not perfect, nor is the rewrite. There is a major conceptual error in the rewrite that was present also in the now replaced version.

The thermodynamic temperature is defined in thermodynamic terms. That distinguishes it from the kinetic theory temperature, which is defined in terms of kinetic theory. Thermodynamics is about macroscopic physics, and knows nothing of atoms, photons, molecules, nor other elementary particles. Kinetic theory rests entirely on knowledge of elementary particles. Thermodynamics concerns macroscopic cardinal energy functions, such as internal energy and enthalpy, that conjoin energies that are distinct in kinetic theory, namely kinetic energies (belonging to a single body, and called thermal energy in kinetic theory) of independently moving elementary particles, and interaction energies of mutually bound elementary particles. Thermodynamics does not make the latter distinction, and does not admit a 'thermal energy' as a state variable of a single body; rather, its cardinal energy functions measure total energy without that distinction. Kinetic theory in most cases has little handle on the interaction energies that it conceptually distinguishes from its kinetic energies of independently moving elementary particles, its so-called 'thermal energies'.

The absolute zero of thermodynamic temperature is not to be defined in terms of kinetic energies of elementary particles, so-called 'thermal energies'. Thermodynamic temperature is defined by a ratio of quantities of heat transferred, and its zero is characterised by an ideal state of a hypothetical body from which heat transfer is always zero, and to which heat transfer is non-zero from every actual body brought into thermal connection with it. The third law indicates that no actual body can be in the ideal absolute zero state, though actual bodies can be brought arbitrarily close to it. In the ideal limiting state of the hypothetical body at zero temperature, the specific heat is also zero, according to the third law.Chjoaygame (talk) 12:13, 17 March 2020 (UTC)

I have undone a sequence of edits that ended with this one.

The citation that the edit added was neither reliable nor contributory.

The wikilinks to the Heat and the Cold articles were not helpful.Chjoaygame (talk) 16:15, 3 February 2021 (UTC)

I agree with this. The reference was wp:CIRCULAR, and we don't do that here. - DVdm (talk) 19:15, 3 February 2021 (UTC)

I have undone a sequence of edits ending in [this one].

The edits were apparently made up off the top of his head as the editor went along. A main mistake is failure to observe that ${\displaystyle {\frac {\partial U}{\partial S}}}$ has the dimensions of a ratio of extensive variables.

It may be observed that there is some track record here.Chjoaygame (talk) 07:48, 26 March 2021 (UTC)

It most certainly was not "made up off the top of my head". I was establishing that temperature is a relation between the temperature scale base and the temperature of the object in question. Thus, for the Celsius and Fahrenheit scales, it's a variable which consists of the ratio of two intensive variables, whereas for the Kelvin scale, since the base of the Kelvin scale is an absolute, temperature is an absolute... you'd be surprised by how many people don't make this simple connection... despite the section just above where I edited stating so in more obfuscated terms... perhaps you missed that.

I then went on to establish that temperature can also be described as the ratio of two extensive variables (making temperature an intensive property because the mass or volume of each extensive variable cancel), such as internal energy and entropy.

In short, I was attempting to make the article more amenable to neophytes... it's sad that a neophyte such as yourself has admin privileges to revert these beneficial edits.71.135.39.16 (talk) 23:34, 26 March 2021 (UTC)

I have undone this edit for the following reasons.

The edit was posted by an IP, without a username to make it easy to chat. The poster is apparently unfamiliar with Wikipedia editing.

A post in an article must be supported completely by Wikipedia-defined reliable sources; the edit cited no source.

A post in an article must not be constituted by a synthesis of sourced ideas, nor of original research; the edit seemed to violate those rules.

The edit was also of inappropriate form, chatting about several topics, not formed as part of a summary of the body of the article as is required in the lead.

The IP user may well have useful contributions to make, but they must be made properly in accord with Wikipedia editing rules. If the IP user intends to try again, it would be pleasant for other editors if he gave himself an anonymity-preserving username. It is safe and easy to do so; best to think up your anonymity-preserving user name before starting the registration procedure. For successful contribution, the user needs to familiarise himself with Wikipedia policies and rules. If he wants to go that way, I wish him well.Chjoaygame (talk) 03:57, 14 August 2021 (UTC)

I have undone this edit.

The edit cover note proposed "A few words where abstract noun phrase was needed instead of adjectives.".

Temperature is an attribute of a body; so are hot and cold. No reason to use a substantive noun phrase.Chjoaygame (talk) 02:38, 11 October 2021 (UTC)

This section is very confusing, redundant, and probably erroneous...

All physically reasonable temperature scales are related by affine relations of the form T' = a T + T0. I believe the article should only mention the Fahrenheit and Celsius "relative scales" (i.e. defining a 1° difference) and the Kelvin scale (absolute zero at 0, same 1° difference than Celsius). The reader should understand that °C or °F are 2 definitions of ° difference, with their respective offsets, and that K is like °C up to an offset. Olivier Peltre (talk) 09:17, 28 August 2022 (UTC)

Hi @Olivier Peltre:. Thank you for your concern. Yes, the article is overloaded with part repetition, and even confusing, and could do with improvements. If you find things in it that are "probably erroneous", please identify them, settle whether they are actually or just probably erroneous, and get them corrected, all by use of reliable sources. Quite likely there are erroneous things in the article. Much in Wikipedia is erroneous.

Perhaps all "physically reasonable" temperature scales would be of the form ${\displaystyle T^{\prime }=aT+T_{0}}$; indeed, I suppose that all physically reasonable absolute temperature scales are so. But by that criterion, there are notable temperature scales that are "physically unreasonable". In particular, there is no general way of relating empirical temperature scales precisely affinely to the absolute scales. Material thermometric properties are often nearly but rarely precisely so. Much practical thermometry is empirical.

There are many notable temperature scales beyond the SI, Kelvin, Celsius, and Fahrenheit.Chjoaygame (talk) 15:36, 28 August 2022 (UTC)

There are a few references to manifolds in this article, i.e. "Hotness may be represented abstractly as a one-dimensional manifold." In this context, it seems like this introduces unnecessary jargon, and is less precise: there are only two one-dimensional manifolds, the circle and the real line, and hotness is represented abstractly as the real line, not the circle.

Before making this change, I want to check in with people that I'm not missing some historical reason to use the term manifold here--my background is in math, not physics. ProboscideaRubber15 (talk) 00:09, 13 February 2022 (UTC)

Hi @ProboscideaRubber15:. The literature contains discussions of temperature in terms of a hotness manifold. I haven't thought much about this, but I guess that so-called 'negative temperatures' can be seen as residing in the circle.Chjoaygame (talk) 15:57, 28 August 2022 (UTC)

How is the real line a two-dimensional manifold? 81.225.32.185 (talk) 22:10, 15 September 2023 (UTC)