Talk:Thermodynamics/Archive 3

Archive 1

Archive 2

Archive 3

Wikipedian user boxes for those interested in thermodynamics

{{User:Sadi Carnot/Userboxes/User Thermodynamics}}

— Preceding unsigned comment added by Sadi Carnot (talk • contribs) 02:11, 28 November 2006‎ (UTC)

Thermodynamics is a Class of Theories

One source of confusion in the writing of this article was to treat thermodynamics as one theory, or -- seemingly truth. It is not true: it is science. I've learned at least a dozen different theories that can be expressed by varying the axioms or definitions. Prigogine's non-equilibrium theories number at least four.

When geologists solve geological problems, they will often divide the problem into many smaller ones, then apply one physical theory to each of these. This doesn't mix ideas. Mixing them confuses what you have when you finish.

I suggest you choose which theories to present, or sketch each and link the more important ones to separate articles. In particular, it is bad to mix classical and statistical statements in the same paragraph.

(The good news is, I've been sent a monograph by Jouguet, which I'm translating into English. Many will agree I've contributed enough here. So, it's time to break the champagne! Bye; and best of luck with this most important of articles!)

Bruce Bathurst, PhD Geologist (talk) 23:12, 29 September 2011 (UTC)

Fewer References?

It's occurred to me that the 'theories' of thermodynamics, which number as many as the varied references, may be keeping this article from a 'good' status. Every book is internally consistent with one classical thermodynamics (definitions & axioms), but they mix like apples and oranges: some define equilibrium using a characteristic function, some use homogeneity (and some wrt time, Fermi wrt the environment). In short, each reference gives a different set of opinions about what is important and what isn't.

The article might use one approach (one classical theory), which would dictate the important topics to cover, which might permit a cleaner writing style.

As an example, theories for chemists, which start with Clausius's two laws, use energy and entropy and need a quick existence theorem for temperature: the zeroth law. If one starts with fundamentals, which use thermometers, this law can be dropped.

Physicists are interested in Nernst's Theorem, and it's important in cryogenics; but no natural science but astrophysics can use it. It could be minimized. (Also it requires quantum statistical thermodynamics rather than a steam engine.)

Ironically, reducing the number of authorities might help the article. That said, I can recommend Fermi, E. 1937. Thermodynamics. NJ: Prentice-Hall; and possibly Pippard, A.B. 1957. The Elements of Classical Thermodynamics. Cambridge: University Press. Geologist (talk) 06:27, 31 October 2011 (UTC)

Structure as a branch of physics

The statement:Thermodynamics is one of the best structured branches of physics is obvious and does not need any source.--79.119.210.1 (talk) 10:14, 17 November 2011 (UTC)

It is vague and thus needs clarification and reference. What is structure (of a branch of physics)? How is it evaluated? By whom? Materialscientist (talk) 10:35, 17 November 2011 (UTC)

Without reference, it is complete and internally consistent, within the limits of its assumptions. With reference, "It is the only physical theory of universal content concerning which I am convinced that, within the framework of the applicability of its basic concepts, it will never be overthrown." A. Einstein, Autobiographical Notes in Albert Einstein: Philosopher-Scientist P. A. Schilpp (ed.), Library of Living Philosophers, vol VII, p.33, Cambridge University Press, London, 1970.

This refers to classical thermodynamics, not the explanation and extensions of it provided by statistical mechanics. PAR (talk) 16:37, 17 November 2011 (UTC)

The above statement is not obvious, and some reliable sources would say that it is not true. That Einstein thinks that classical thermodynamics will never be overthrown is not evidence about its structure. And obviousness is not a reason for a statement to go into a Wikipedia article.Chjoaygame (talk) 20:30, 17 November 2011 (UTC)

If there ever existed an equilibrium system, then one can't disprove Einstein's 'doubt': it becomes obvious. Remember, 1st law, 2d law, equilibrium are all axioms. Einstein scientifically states he doubts the theory will be overthrown (not quite the same as fail). A mathematician (and thermodynamics is a field of applied mathematics) could substitute 'A, B, C are true' for the axioms and prove the theory complete and consistent (proof by interpretation, offered by the first sentence of this paragraph). Several axiomatizations have been published. Still, I too haven't a clue what 'structure' means (in this context). Energetics? Geologist (talk) 09:10, 7 January 2012 (UTC)

Searched the article for 'structure' and found a reference by Serrin. He's an applied mathematician, so 'structure' as used by Mr or Ms ip may mean the interpretation of theory 'A, B, C' mentioned above as classical equilibrium thermodynamics. Both Bridgman and Einstein believed thermodynamics differed inexplicably from other theories in physics. Geologist (talk) 09:54, 7 January 2012 (UTC)

Structure in this case could refer to the logical structure (self-consistency etc).--79.119.218.100 (talk) 11:15, 9 January 2012 (UTC)

A question which arises next is how is the logical structure of thermodynamics compared to other branches of theoretical physics like classical mechamics and electromagnetism?--79.119.218.100 (talk) 11:34, 9 January 2012 (UTC)

I'm not a physicist. (I only quote them. :-) Neither theory takes heat into account. There may be something very appealing about heat being work degraded to a microscopic scale. One would have to ask. Geologist (talk) 00:53, 13 January 2012 (UTC)

Perhaps an article called Axiomatization of thermodynamics would be useful in this context. — Preceding unsigned comment added by 84.232.141.36 (talk) 15:44, 4 February 2012 (UTC)

Is entropy an extensive variable?

The article says “entropy in general does not fit the above definition of an extensive variable” (Section “Thermodynamic state variables”). But in the articles Entropy and Intensive and extensive properties entropy is declared as an extensive property. What is true? Greetings 2.38.190.84 (talk) 15:50, 15 December 2011 (UTC)

This is a very reasonable question.

The term of art 'entropy' was invented by Rudolf Clausius in the early days of thermodynamics. Its mathematical equivalent had been used previously by William Rankine and by Clausius. It was a variable of state of a closed thermodynamic system. Its definition has been changed over the years, because it is a difficult concept. Nowadays it is admitted by many writers (example Kondepudi 2008) that it may apply also to an open system. It was by one major classical thermodynamicist, Max Planck, early regarded as a quantity in its own right, subject to its own laws, but later Planck admitted that it had a statistical mechanical basis and could not be understood otherwise. Planck's change of mind was due to his discovery of his law of thermal radiation and to work by Ludwig Boltzmann and by Albert Einstein.

Thermodynamics is severely crippled when it cannot access the concept of entropy. Access to the concept of entropy is very safe for the study of systems, open or closed, in strict thermodynamic equilibrium. For systems not in thermodynamic equilibrium, the concept of entropy is fairly safe in the special case of local thermodynamic equilibrium. Away from local thermodynamic equilibrium the concept is unsafe. For example, a top expert on the question, Walter T. Grandy, Jr, is of the view that we do not know even how to calculate the entropy of a worm (Entropy and the Time Evolution of Macroscopic Systems (2008), Oxford University Press, Oxford UK, ISBN 978-0-19-954617-6). Classical thermodynamics has little or nothing to contribute to the definition of entropy for systems far from thermodynamic equilibrium. A probabilistic or statistical definition seems unavoidable. Grandy and Edwin Thompson Jaynes are perhaps the safest guides to trying to understand the probabilistic approach.

Some scientists do not like to feel crippled by ignorance, and have difficulty saying "I don't know", and this prejudices them, for the present problem, to postulate instead of providing reliable reason. Many writers on non-equilibrium thermodynamics thus simply postulate that an entropy function exists when they need it, and they give the impression that this is sound science. But it's often just wishful thinking, without a proper scientific basis. As part of this wishful thinking, they postulate that entropy for their non-equilibrium studies is an extensive variable.

Entropy is assuredly and safely an extensive variable for suitably defined classical thermodynamic systems in thermodynamic equilibrium.

But that does not make it extensive for far-from-equilibrium systems as wished by such wishful thinkers.

The definition of thermodynamic concepts for non-equilibrium systems must take into account that such systems can undergo major structural fluctuations, and such fluctuations will destroy the postulated basis for simple postulates of entropy for such systems. So far as I know, no one has provided a general way of calculating the entropy of practically encountered far-from-equilibrium systems, precisely for this reason. This means that in general, so far as I can find in the literature, entropy is in general not an extensive variable for far-from-equilibrium systems, although many writers wish that it were so. For a careful discussion of this question I can do no better than recommend Grandy's above-mentioned book, especially Chapter 5, headed 'The presumed extensivity of entropy'. After you have read that, perhaps further discussion might be useful.Chjoaygame (talk) 19:24, 15 December 2011 (UTC)

Many thanks for your detailed and long answer. It helped me a lot. Greetings 2.38.190.84 (talk) 19:17, 17 December 2011 (UTC)

I have been out of contact for a few days. I think that one reason why one can be confident that entropy is not extensive for systems far from thermodynamic equilibrium is that, far from thermodynamic equilibrium, the spatial arrangement of the volume elements is very important in the determination of the evolution of the process, but is entirely ignored by a simple addition of elements of entropy.Chjoaygame (talk) 22:35, 23 December 2011 (UTC)

Truly, I don't mean to be a spoiler, but isn't the above similar to arguing that skunks aren't black & white because furry mammals come in many colors?

The nice thing about positivism is that, because equilibrium fails gradually, or gracefully, we can use instruments of varying accuracy and precision to argue its existence: one need only predict certain thermodynamics quantities (within the abilities of the instruments:-) from those being measured.

The question, however, implies entropy exists; either in exact principle (realist) or fuzzy practice (positivist). So, yes, entropy is extensive if its quantity doubles when a replica of the system is added. Enjoyed Chjoayagame's 'realist' analysis, though. Geologist (talk) 08:36, 7 January 2012 (UTC)

Bias against the Existance of Equilibrium in Nature

One of the reasons, IMO, this article is flawed is its insistence that thermodynamics concludes equilibrium is only approached. (This throws unwarranted importance on theories of non-equilibrium thermodynamics.) No theory of thermodynamics I have ever seen makes any statement whether or not equilibrium is attained. (Text writers, of course, may express opinions; the article appears to misrepresent these.)

Classical thermodynamics assumed equilibrium when deriving practical relations, but the history section has 'equilibrium' Bowdlerized, making it highly flawed. Callen's statement arguing for equilibrium in nature has been used as a reference for the opposite statement. Finally, to demonstrate that natural processes are all non-equilibrium, one obscure process (hysteresis in solids--the model of non-equilibrium cycles for decades) was pulled out, seemingly from a hat. This looks like bias.

Closed systems are represented by a system and its surrounding environment, as stated in the article. Thermodynamics is used, as stated in the article, to predict the response to a perturbation.

Geologists have shown that the response keeps pace with the perturbation, such as extremely slow burial. Such a response is usually accurately predictable from the perturbation. According to Prigogine & Defay's definition of equilibrium, this is a path of equilibrium states.

Those definitions that involve time simply mean the system does not drop its Gibbs energy below a limit, an equilibrium value: a high explosive may reach this value in less than a second. In summary, equilibrium is a limiting state, but thermodynamics does not predict it is approached asymptotically. (The remark about detailed balancing and equilibrium requiring microscopic reversibility is wrong: it is the macroscopic rates of these processes that must be equal.)

Equilibrium is simply the correlation of perturbation and response, which allows prediction. Even geologists don't throw up their hands when asked to predict the perturbation from the measured response because the extents of nuclear reactions were unknown when the chemical reactions stopped. (The widely ranging compositions of univariant oxides in viscous rhyolites that equilibrated when temporarily housed in shallow magma chambers fall flawlessly along a straight line predicted by equiibrium. This serves as a test for equilibrium in nature.)

This article won't be considered a good one (well, by me at least) until the above bias is proved either non-existant or corrected. (Good luck, Mr Phelps. :-)

Geologist (talk) 20:00, 2 February 2012 (UTC)

Life is a manifestation of non-equilibrium processes. The main supply of energy that flows through living things on earth is from the massive emission of heat by the sun, a big-time non-equilibrium process.Chjoaygame (talk) 16:42, 26 February 2012 (UTC)

"No theory of thermodynamics I have ever seen makes any statement whether or not equilibrium is attained" - one of the laws of thermodynamics is the second, which is precisely concerned with the approach to equilibrium. The fact is that nothing in our world is in equilibrium, but many systems are close enough that equilibrium thermodynamics is a good approximation. Waleswatcher (talk) 19:37, 26 February 2012 (UTC)

I read once that, during the first atomic bomb test, Enrico Fermi tossed small pieces of paper straight up into the air. During the explosion, the paper moved away from the explosion. From this distance (between equilibrium states), he estimated the energy of the explosion using equilibrium thermodynamics. In any case, 'natural science' includes more than biology. Geologist (talk) 04:28, 9 March 2012 (UTC)

The Second Law states that a characteristic function will fall to a limit: for a common system, the difference in Gibbs Energy between final and initial equilibrium states is less than or equal to zero. Where here does it say equilibrium is not attained (a limit is not reached)? (If it did, would axiomatic theories have a need for a so-called 'zeroth law', which claims equilibrium is attained?) Geologist (talk) 04:28, 9 March 2012 (UTC)

Chemists us isotopes to measure the rate at which equilibrium is attained. A paper by T.S. Lee, referenced below, has a nice summary. One can even do this with a two mixtures initially at equilibrium: the crystals in one beaker have one stable isotope, those in the other have another. Mix the beakers. Sample the crystals at various times. When no isotopic difference can be measured between any two, equilibrium has been reached. (This is off the top of my head, chemists please correct me.)

This example proposes an entire crystal to be a single phase; geologists consider the rim at which growth stops to be a crystalline phase and would claim the time for equilibrium to be reached is zero, using this definition. Both definitions produce the equilibrium composition predicted by classical thermodynamics. Both claim equilibrium is attained, just at different times. Geologist (talk) 04:28, 9 March 2012 (UTC)

The 'zeroth law' is positivist: it claims equilibrium exists when no difference in predicted equilibrium qualities can be observed or measured. The definition used in this article appears to claim 'equilibrium' is a theoretical object, incorrectly predicted to not be attained by either a classical or a statistical theory; or perhaps such a statement gives 'non-equilibrium' theories an undeserved importance. Geologist (talk) 04:41, 9 March 2012 (UTC)

Metamorphic petrologists do not assume that all previous thermodynamic states, now preserved, were at equilibrium: they have their tests. T.S. Lee has these appropriate quotes: 'Needless to say, many reactions are so slow that they never come to equilibrium. An activation energy of 45 kcal. is large enough to prevent any appreciable reaction in a million years at 25 deg. C.' If one want to give it a few more million, 'As has been pointed out by many authors, there is no geological evidence that nitric acid has bee produced at moderate temperatures by the reaction of air with ocean water... .' T.S. Lee, 1959, 'Chemical Equilibrium and the Thermodynamics of Reactions', in Treatise on Analytical Chemistry, I.M. Kolthoff & P.J. Elving, eds., pt.I, v.1, p.185-317. Geologist (talk) 21:59, 12 March 2012 (UTC)

I honestly cannot figure out what you're trying to say with these comments. Do you claim that true equilibrium exists in nature? If so, that's trivial to falsify (the universe is evolving, that suffices). Are you claiming that many systems are close enough to equilibrium that they can be approximated as such? If so, we all agree with you (or at least I do). Is there some specific language in the article you find objectionable? If so, what is it? Waleswatcher (talk) 13:30, 13 March 2012 (UTC)

I claim true equilibrium exists in nature if observations or measuremets do not measurably deviate from those predicted by equilibrium thermodynamics. I claim the surface of a pond remains in equilibrium with the air just above it during a 24-hour period.

I claim thermodynamic theory makes no statement that natural states or even natural processes are equilibrium or non-equilibrium: I believe an experiment is necessary.

A careful reading of the article shows strange & awkward wording throughout to avoid claiming that equilibrium systems exist. Gibbs wrote on whether 'a process would occur spontaneously' (not about equilibrium among phases); neither Duhem, Lewis, nor Guggenheim derived 'equilibrium' relations. I claim this is not good, and ask myself why the article was so written.

I claim 'classical thermodynamics' is synonymous with 'equilibrium thermodynamics'. I claim some systems are in equilibrium, some nearly so, some far from so, from very slow to frozen (no swimming in nitric acid). I claim (as Gibbs did) that stable (water), neutral (water & ice), & unstable (water vapor nuclei) exist. I claim (with Einstein) that classical thermodynamics is the most logically deductive & accurate (predicting) thermodynamic theory. (No quantas necessary.)

I claim more systems exist in nature than the universe. I claim the article should be fixed. Geologist (talk) 00:01, 16 March 2012 (UTC)

chatty edit removed

I reverted two edits (478965001, 478965255; dated 26 Feb 2012) that were chatty editorializing, not about thermodynamics directly, but about people's responses to it and its possible significance. If that editor wants to write about such things in the Wikipedia, I suggest he work out a way of doing it other than by putting chatty comments, not supported by the cited "sources", in the present article which is about physics, not sociology.Chjoaygame (talk) 16:37, 26 February 2012 (UTC)

Waleswatcher's re-wording

Waleswatcher has apparently not read the references that supported the wording change that he re-worded and that he leaves in support of his re-wording.Chjoaygame (talk) 01:11, 14 March 2012 (UTC)

Eh, Wot? One excellent paragraph of Waleswatcher contained 'the present article takes a gradual approach to the subject, starting with a focus on cyclic processes and thermodynamic equilibrium, and then gradually beginning to further consider non-equilibrium systems'. I wish this were true. A rejection of natural, equilibrium states apparently resulted in the less happy 'chemical thermodynamics studies the role of entropy in chemical reactions'. Geologist (talk) 00:27, 16 March 2012 (UTC)

demotion of importance of concept of thermodynamic equilibrium

There has been some complaint recently that the article was underemphasizing the importance of thermodynamic equilibrium. The sentence "Thermodynamic equilibrium is one of the most important concepts for thermodynamics" was not enough to deflect this complaint. Now the new edit has deliberately demoted the importance of the concept of thermodynamic equilibrium by replacing that sentence with "Thermodynamic equilibrium is an important concept in thermodynamics."

Callen 1985 on page 26 writes: "The single all-encompassing problem of thermodynamics is the determination of the equilibrium state that eventually results after the removal of internal constraints in a closed composite system." Callen is one of the most widely cited theoreticians of thermodynamics. I think that statement of his goes too far, and is the work of a theoretician, and I am not particularly enamoured of Callen's presentation, though I recognize that it has merits. (When Callen writes "closed system", we understand that he means "isolated system".)

Most thermodynamics, theoretical as well as practical, works with at least the local thermodynamic equilibrium concept as one of its most important elements, and so I would say that the demotion was not a good move. I would like to restore the sentence "Thermodynamic equilibrium is one of the most important concepts for thermodynamics."Chjoaygame (talk) 14:58, 30 March 2012 (UTC)

The new edit downplays the fact that there are many processes of nature that progress so rapidly or irregularly that they cannot feasibly be followed by currently known thermodynamics, because they are too far from local thermodynamic equilibrium. For example, the new edit might seem to suggest that nature tends to limit her activities to those that are within the scope of a version of non-equilibrium thermodynamics based on the assumption of local thermodynamic equilibrium, which makes their study only "a little more involved but of much more practical importance".

The new edit in the introduction refers to inhomogeneity of systems, studied in engineering, before the concept of homogeneity of a system has been defined in the article. It does not make it clear at this point that there is a close relation between the concept of local thermodynamic equilibrium and the proviso required by the edit, that "the thermodynamic parameters are well defined."

The lead has already told the reader that "Thermodynamics can be applied to a wide variety of topics in science and engineering", but, in the introductory section of the article, the new edit, apparently not concerned with processes in nature, wants to further emphasize the practical importance of the engineering use of thermodynamics.Chjoaygame (talk) 00:24, 31 March 2012 (UTC)

I agree - to downplay the role of equilibrium in thermodynamics is like downplaying the role of space and time in relativity. Local thermodynamic equilibrium is simply equilibrium thermodynamics applied to a continuum of systems. It does not downplay the role of equilibrium, it emphasizes it. Other methods of dealing with non-equilibrium thermodynamics involve perturbations of the equilibrium state, again, emphasizing the importance of equilibrium. The four laws are stated for systems in equilibrium.

Yes, please restore the statement. PAR (talk) 06:42, 31 March 2012 (UTC)

Done.Chjoaygame (talk) 07:12, 31 March 2012 (UTC)

Changing the paragraph on the third law by Adwaele

The statements that at absolute zero “all processes cease” and that at absolute zero “all activity (with the exception of that caused by zero point energy) would stop” is not part of the formulation of the third law and it is incorrect. E.g. it neglects the magnificent effects of superconductivity and superfluidity which are still active at 0 K. So, I removed these remarks.

(Adwaele (talk) 21:20, 30 July 2012 (UTC))

"which are still active at 0 K." How do you know? --Damorbel (talk) 14:25, 31 July 2012 (UTC)

Reversal

I reversed Chjoaygame's latest edit because he gives no reference. Also it is completely bizarre for someone who insists that Heat is a dynamic process to define thermodynamics as only being defined in equlibrium. Chjoaygame, these are your own ideas. Please remove the contradictions you contribute such as that for heat. --Damorbel (talk) 08:23, 9 September 2012 (UTC)

Thank you Damorbel for your helpful suggestions. I have taken them aboard, and improved the wording in consequence, and supplied some references. The term thermodynamics is of historical origin, referring to heat engines. Due to that, the part-word -dynamics refers to the doing of work by the engine, which is of course a comcomitant of heat transfer through the engine, which accounts for the part-word thermo-. It is occasionally proposed in various writings that one might speak of 'thermostatics' because the classical subject admits only static or equilibrium states. This proposal does not adequately recognize the historical origin of the term thermodynamics.Chjoaygame (talk) 10:40, 9 September 2012 (UTC)

Your 'meaning of 'thermodynamics' argument just doesn't meet the situation. Sure, thermodynamics emerged from the discovery of the mechanical equivalent of heat, but a lot has happened since then. Don't you think it would be (is) absurd to invent new words everytime new features such as chemical interactions and mechanical interactions with photons involving thermal energy are discovered? No you are trying to change history, generally recognised as an academic defect.

This is why it is quite wrong to define heat as 'energy in transit', it doesn't match the experimental evidence i.e. the fact that temperature heat and thermal energy are all manifestations of particle motion. --Damorbel (talk) 12:50, 9 September 2012 (UTC)

Nuclear reactions thermodynamics

Aspects concerning how the thermodynamical concepts like entropy and free energy are applied (if they are) to nuclear reactions compared to the way these concepts are applied to chemical reactions should be inserted in the article.--79.119.220.11 (talk) 14:30, 30 April 2012 (UTC)

combined cycle power generation.

When there is heat loss between two cyclic plants coupled in series, how is the overall efficiency of the plant affected? — Preceding unsigned comment added by 41.151.171.213 (talk) 02:09, 13 May 2012 (UTC)

This article is supposed to be for the general reader (one presumes). The article already complicates a very simple subject to the point of (IMO) near incomprehensibility. Adding Einstein's equivalence of mass & energy and the continuous fission & fusion of elements (with time) certainly mucks up the concept of (what is conserved during) a reaction. Only those applying nuclear physics would be interested in this subject. Would they really come here for information; and should one complicate the article further, just to be more inclusive? There seems no harm in referencing a classical work or two on the subject. I confess total ignorance of it, though slow fission is important in geological dating. Geologist (talk) 05:02, 24 May 2012 (UTC)

I agree with Bruce Bathurst on this point. I see no objection to a separate article on nuclear reactions viewed from a thermodynamic angle, but I agree with Bruce that this article is not a good place for that.Chjoaygame (talk) 06:43, 24 May 2012 (UTC)

Actually, it is a _grave_mistake_ to confuse thermodynamics with heat transfer or with chemical reactions solely. The basic laws of thermoynamics are of _general_ applicabilty. Energy is the ability to do work, but it is also reduced in availability by heat transfer. How much enegy is "used up" as heat in the changes of state of the system and it's sourroundings is governed by the increase of total entropy. What ammount of energy a perfect crystal has at absolute zero is established in the third law. The zeroth law is about thermal equilibrium. The laws of thermodynamics apply troughout physics, not on specific situations. Articles related to thermodynamics concepts seem to be written by people with a poor knowledge of the subject. — Preceding unsigned comment added by 186.32.17.47 (talk) 07:49, 30 October 2012 (UTC)

my physics

NEWTON SAID THAT ENERGY IS NEITHER BE CREATED NOR BE DESTROYED BUT IT CAN BE CHANGED FROM ONE STATE TO ANOTHER........

BUT WHAT I THINK IS ANY THING IN THIS WORLD IS NEITHER BE CREATED NOR BE DESTROYED BUT IT CAN BE CHANGED FROM ONE STATE TO ANOTHER........ — Preceding unsigned comment added by Viswa.sai25 (talk • contribs) 17:58, 21 October 2012 (UTC)

Thermodynamics vs. Heat Transfer

"Thermodynamics is the branch of natural science concerned with heat and its relation to other forms of energy and work" the modern concept of thermodynamics is being confused with heat transfer. Thermodynamics studies the transformation of energy into work and heat. The study of how heat is transfered is dubbed "heat transfer". I've seen a lot of _wrong_ edits on this subject on the wiki. It seems people that have never taken a course in thermodynamics are the ones writing of thermodynamics and it's laws.— Preceding unsigned comment added by 186.32.17.47 (talk) 07:10, 30 October 2012 (UTC)

Actually the first law of thermodynamics implies that _all_ of the change in the energy of the system is equal to the heat that the system releases to the sorroundings plus the work that the system exerts on the sorroundings: ΔE=Q+W. See: http://books.google.co.cr/books?id=IaLPhdMjCvEC&pg=RA1-PT54&dq=%22first+law+of+thermodynamics%22&hl=es&sa=X&ei=VMKRUP2EL5HQ8wSGuoHIAQ&ved=0CDMQ6AEwAw pp. 25-26. — Preceding unsigned comment added by 201.204.200.18 (talk) 00:38, 1 November 2012 (UTC)

Will you guys please identify yourselves? And if you cite a reference, please indentify exactly what the reference does to support your argument and, very important, how it will improve the article. Otherwise you are wasting your time and everybody else's. --Damorbel (talk) 09:39, 1 November 2012 (UTC)

I do not know what good indentifying myself does. As per sources there are plenty here and in the article on energy's talk page that I have pointed out, plus, i.e., Castellan's book on Physical Chemistry is a good source on thermodynamics, as is Smith and van Hess introductory book on thermodynamics. What I am doing is saying that these articles need the attention of a physicist spcialized in thermodynamics. I am only a chemical engineer but the wording in some parts of the thermodynamics article (specially does that do not cite sources) are plain wrong in confusing the role of thermodynamics in science and engineering with those of heat transfer. Now, if Damorbel and others prefer to keep articles that are _wrong_ in some aspects of thermodynamics then OK, so be it, I used up all the time I have to point out errors on these articles. If you wish to ignore me, fine, I'll stop "wasting my time". — Preceding unsigned comment added by 186.32.17.47 (talk) 16:32, 1 November 2012 (UTC)

Hallo 186.32.71.47 (Oh dear, have I made a mistake?) Um, you feel I "prefer to keep articles that are _wrong" do you? You are of course aware that the talk pages are here to discuss the contents of the article, not the contributors, so please stop writning about the other contributors. I invite you to check my contributions to the talk pages on matters connected to thermodynamics such as temperature before making personal remarks.

If you are a chemical engineer you should have useful knowledge to suggest improvements to the article, merely stating that you know of a good source amounts to saying nothing, there are many, many books on thermodynamics, finding references is not really a problem. However the purpose of a Wikipedia is not to be a book on thermodynamics but to give a summary guide to the most important aspects with useful links to material available on line; it is surely useless to tell the Wiki reader to get a book. Of course it might, on occasions, to indicate a book but there should be a good reason given for recommending it. Likewise, when citing a document the cited text should be indicated (or even appear) in the article, it is surely quite useless to leave the readers to work out for themselves just what point the author is making. --Damorbel (talk) 06:51, 2 November 2012 (UTC)

The link to the source is there, and there are plenty in the "energy page" talk on "wrong thermodynamics perspectives". There is also Castellan book on Physical Chemistry and Smith Van Ness introduction to thermodynamics. I have not edited the article, because I do not have the time and I _do_think_ that it requires the attention of an expert on the subject (A physicist, physical chemist or chemical physicist with a deep understanding of thermodynamics)not a mere engineer like myself. I do not know _where_ I made remarks that people would take so personal: If I offended you I am sorry: since, when commenting about aspects that are clearly wrong and require the attention of an expert, people on the wiki react with such strong emotions I will , from now on, keep from ponting out or correcting mistakes: I do not know where I made specific personal remarks against anybody.--186.32.17.47 (talk) 17:07, 2 November 2012 (UTC)

Sorry, but you do not understand why personal comments are discouraged, it is not because they may be insulting, they may not be, it is because they are irrelevant, as are generalised references to books. For example describing yourself as 'a mere engineer' is also irrelevant and thus a waste of time and space. What does offend me is contributors misusing Wiki in this way. I would be just as offended if you used these pages to say I was the most wonderful person you had ever encountered (!). --Damorbel (talk) 09:39, 3 November 2012 (UTC)

Latest revision by Chjoaygame

This revision is not coherent, so I have reversed it. The claim is that Themodynamics is empirical. Empirical means "derived from or relating to experiment and observation rather than theory". Clearly the author has no aquaintance with the laws of thermodynamics that have a sound theoretical basis, hence my reversal. --Damorbel (talk) 06:58, 8 November 2012 (UTC)

P.S. I notice that Chjoaygame did not include the word empirical in his latest revision but Chjoaygame made no discussion about his 'improvements' in these talk pages and I now invite him to do so. --Damorbel (talk) 07:12, 8 November 2012 (UTC)

Dear Damorbel, you seem to have taken upon yourself the office of policeman, prosecutor, judge and jury to dictate how I may edit in the Wikipedia. You demand that I give reasons for my edits in the talk pages. This is simply a captious demand by you, and has no proper basis. It seems obvious that you take this role as a way of responding to the fact that I accept the general consensus of Wikipedia thermodynamic editors that in physics, heat is technical concept that refers to a process not to a state, while you hold unflinchingly to your belief that heat should be treated simply as a word of the ordinary language that seems more or less to be able to be used for states as well as for processes, along with other ideas you have repeatedly expressed on this subject. If you wish to change my edits because you can improve them, that I see as your privilege. But you seem to regard it as your prerogative to simply dictate how I edit, and to undo any edit of mine that does not conform to your dictation as to how you think it should have been done.

This revision of mine was substantial only in your judgement, but looked at more objectively it was a rewording and more precise explication of what was already in the article, but not adequately explicitly.

Your stated reason for your undoing of my edit seems specious and irrational. Your stated reason is "The claim is that Themodynamics is empirical". Evidently your stated reason refers to this sentence in the article: "The macroscopic state variables of thermodynamics have been recognized in the course of empirical work in physics and chemistry." This statement in the article was not new in my edit, but had stood in the article for some long time. It is a precise statement directly based on a nearly identical statement cited in the article as from a well respected text by a respected Nobel Prize winner and a respected colleague of his. It is not my invention and is not new in this edit. The statement is not about thermodynamics in general as stated by you. It is about the finding of suitable state variables, which is stated by Prigogine and Defay, as cited, to be based on empirical work. If you had a real objection to this statement long present in the article, it would be odd that you express it only now that I repeat it unchanged. One wonders if you have really checked and considered what Prigogine and Defay have to say about this. This makes your undoing of my edit seem specious and irrational.

I regard your actions in this as simply violent and unethical.Chjoaygame (talk) 10:55, 8 November 2012 (UTC)

Chjoaygame, please explain how your revision is an improvement to the article and I will either agree or disagree. A basic objection I have to the article is that it gives no name to the kinetic energy of the particles in a thermodynamic system; without this the article has neither meaning nor value. --Damorbel (talk) 11:44, 8 November 2012 (UTC)

Dear Damorbel, you demand that I explain how my revision is an improvement to the article, with a view to your either agreeing or disagreeing. You seem to think that it would make sense that you would agree or disagree with the edit as a whole, rather than your taking the edit as a collection of items which you might consider one by one. You say that you have a "basic objection" to the article, that it gives no name to the kinetic energy of the particles in a thermodynamic system. You are trying, yet again after many previous tries, to lure me into a detailed discussion with you. I have found by bitter experience with you in the past that it is futile to try to engage in detailed discussion with you because your style is persistently irrational. That you have that "basic objection" is hardly relevant to my edit, and your demand here is just another of your attempts to hijack editorial work on the article into discussion of your "basic objection", and of other ideas of yours.

Foolishly perhaps I will try just once to help you with your present difficulties. My revision, as I indicated with my cover note, makes more explicit the fundamental logical interrelations of the constituent concepts of thermodynamics, namely, of the notions of working body of the system and of the surroundings, and the thermodynamic processes that link them. Thermodynamics mostly in the early days focused on the processes, in particular the cyclic processes. Their cyclic character ensures that they leave the working body of the system effectively intact, though the working bodies of the surroundings are supposed to change and signal the nature of the processes. An approach that is in some ways more convenient is to consider the states of thermodynamic equilibrium of the working body of the system at the times in between the times of the processes. In this approach, the states of thermodyanmic equilibrium supersede the effective intactness of the working body.

Your "basic objection" represents a fundamental misunderstanding of thermodynamics. Thermodynamics is essentially about the processes or about the thermodynamic states of the working body regarded as a macroscopic object fully specified by the state variables. It is essential here to ignore and avoid mention of "the particles in a thermodynamic system", because consideration of such particles is foreign to thermodynamics, as you may verify for yourself by checking the references or more generally reading about it. Consideration of such particles belongs to statistica mechanics. It is true that some writers of student texts think they are very clever and can teach thermodynamics and statistical mechanics at the same time, but as is apparent in your case, this tends to lead students to muddle thermodynamics and statistical mechanics in their minds. The point about thermodynamics, its peculiar and characteristic merit, is that it reveals what can be found without any consideration of the particles in the system. You are seeking to destroy the thermodynamic essence of the article in pursuing your interest in the statistical mechanical explanation of the macroscopic thermodynamics. The statistical thermodynamic explanations are not wrong and are not to be avoided in general, but they are essentially irrelevant to the basic structure of thermodynamics, and it would be a mistake to let them intrude inappropriately into an article on thermodynamics as if they were its main concern.Chjoaygame (talk) 14:04, 8 November 2012 (UTC)

Chjoaygame, Thermodynamics is about the energy in systems of particles. According to the circumstances and distribution of the energy these particles have various states giving rise to descriptors called thermodynamic states (see also Functions of state)

Now you write "It is essential here to ignore and avoid mention of "the particles in a thermodynamic system", I think you should, in the light of these references explain why you are have this view about the irelevance of systems of particles so that other authors may seek to agree with you. --Damorbel (talk) 14:56, 8 November 2012 (UTC)

Chjoaygame, you write "You are trying, yet again after many previous tries, to lure me into a detailed discussion with you." For the talk pages of a technical article do you seriously think it wrong to "have a detailed discussion"? What, please, do you think is the correct form of dicussion? After all, I would not feel comfortable having 'lured you' into the wrong sort of discussion! --Damorbel (talk) 16:59, 8 November 2012 (UTC)

edit by Maurice Carbonaro

Thank you, Maurice Carbonaro, for your thoughts on this. For the sake of civility, I am not right now undoing your edit, but I think it is retrograde step and should be undone. Contrary to your interpretation of what it attempts, the lead as it stood neither intended nor attempted to give all four laws; it intended only to summarize the main outlines. The zeroth law is a technicality and the third law is also rather esoteric. Neither of them can be readily summarized for the lead, nor do I think a summary of them is needed there. The lead is a summary of the main points of the article. I think your setting out the laws in numbered paragraphs is not going in the right direction, and is no improvement. It would perhaps be better, if you insist that the present lead needs reform, to remove the two statements that are now there than to add two more.Chjoaygame (talk) 23:21, 8 November 2012 (UTC)

The opening statement.

When dealing with the article it is best to isolate (if possible) the multiple defects from each other.

The third para. has:-

The first law asserts the existence of a quantity called the internal energy of a system, which is distinguishable from the kinetic energy of bulk movement of the system and from its potential energy with respect to its surroundings.

Which is quite incorrect. It should be:

Energy can be neither created or destroyed

Plus, for clarification:-

Energy and matter are equivalent through Einstein's formula E = mc²

Further, Waleswatcher's observations on PAR's edit are quite correct; this edit should be undone, it is quite incorrect.

--Damorbel (talk) 13:06, 3 December 2012 (UTC)

PAR's recent edit

PAR edited the introduction to emphasize that the second law doesn't just have to do with entropy, but also temperature. I don't entirely agree. The second law is usually formulated in a way that does not explicitly refer to any thermodynamic quantity other than entropy. For instance, wiki's formulation is

The second law of thermodynamics states that the entropy of closed systems never decreases, because closed systems spontaneously evolve towards thermal equilibrium -- the state of maximum entropy. Equivalently, perpetual motion machines of the second kind are impossible.

While it's true all the laws of thermodynamics involve temperature indirectly, they also involve pressure, volume, chemical potential, etc. etc., I don't see why the second law should be singled out that way. Instead, I'd start that paragraph with the zeroth law to introduce temperature. Thoughts? Waleswatcher (talk) 10:30, 3 December 2012 (UTC)

response by PAR

Before you get to the second law, temperature and entropy are undefined. Prior to the laws, there are certain assumptions. For example, it is assumed that you can know when two systems are thermally connected or isolated from each other, and you know when two systems are or are not in thermal equilibrium with each other. Using the concept of equilibrium, the zeroth law then lays some groundwork for the concept of temperature, but does not define it. The first law introduces the concepts of internal energy, work and heat, but still no temperature. Work is a mechanical concept and is defined "externally" and is the only directly measurable quantity. For a simple system, its just a function of the measurable pressure and volume. The first law declares internal energy to be a state variable, and heat is defined as the energy difference between the total change in internal energy and the energy added by work. The second law then states that the heat can be expressed as the product of two new quantities: temperature and entropy ($\delta q=TdS$) and that they are state variables, unlike their product $\delta q$.

All this assumes a fixed quantity of matter in the system, another directly measurable quantity. You can go on to develop the whole train of thought assuming variable quantities of matter, which introduces the chemical potential. I'm not offering this as the absolute revealed truth of thermodynamics. Its just a step towards sorting out the logic of thermodynamics, avoiding all the circular reasoning, like introducing temperature to define thermal equilibrium and thermal connection, then using those same concepts to define the Carnot cycle, then using the Carnot cycle to define temperature, etc. PAR (talk) 16:14, 3 December 2012 (UTC)

response by Chjoaygame

In summary I will here say that I think the lead is a summary of the main points, not the place for detailed presentation of argument. I would be unhappy to see further extension of argument in the lead.

The "zeroth law" is a fancy name given in 1939 by Fowler and Guggenheim to a proposition that Maxwell stated clearly in 1871. Maxwell used the word temperature in two ways, which are now distinguished as empirical temperature and absolute thermodynamic temperature. For empirical temperature, Maxwell was happy just to say 'temperature', because the term was long established by tradition. When Maxwell meant absolute thermodynamic temperature, he said 'absolute temperature', shock, horror! Since Bryan in 1907 and Carathéodory in 1909 and Born in 1921 proposed to change the terminology, it is considered a gigantic advance of understanding that plain temperature, or empirical temperature, was re-named 'the value of the non-deformation state variable', and the word temperature was reserved for absolute temperature. It is advanced as old-fashioned circular reasoning removed by brilliantly insightful new thinking that careless confounding of empirical temperature and absolute temperature were made less likely by prohibiting the traditional usage of 'temperature' to refer to empirical temperature. If one carelessly failed to distinguish between empirical temperature and absolute temperature, one would be led into circular reasoning, not a mistake made by nineteenth century physicists, but apparently one much to be guarded against since then.

The empirical temperature as fact is built inextricably into Carathéodory's formulation, as the one extra variable, beyond those that specify directly the mechanical work processes available to the working body, necessary to fully define the thermodynamic state of a body; it is called the "non-deformation variable". This extra variable can be regarded as an empirical temparature, and is essential for the Carathéodory formulation, which however forbids the word temperature from being attached to it. This "non-deformation" variable is postulated by Carathéodory to be changeable by processes that take place through a wall said by him to be "permeable only to ″heat″", though heat as such is not admitted into his formulation. Physically, then, heat must be energy as it permeates a wall "permeable only to ″heat″", or "permeable ″only to heat″", according to Carathéodory. Physically, what kind of energy is that? It turns out to be, surprise, surprise, energy that is described by the "non-deformation variable". What is the physical meaning of this? It means that energy is transferred as heat between two bodies connected by a wall "permeable only to ″heat″" when the values of their "non-deformation" variable differ. And that silly old nineteenth century fool Maxwell thought that energy was transferred as heat when bodies that differed only in temperature were brought into diathermal connection! What fools they were in the nineteenth century! How clever we are today!Chjoaygame (talk) 00:34, 4 December 2012 (UTC)

Fowler & Guggenheim (1939/1965), apparently the inventors of the label "zeroth law", formulate the basic ideas of thermodynamics in a way, derived from Carathéodory's, that acknowledges Carathéodeory's as "most logically satisfactory [...but...] rather too abstract". Their statement (on page 60) of the second law explicitly states that the absolute temperature, T, is a function of only the empirical temperature, t. In other words, they assume the meaning of the empirical temperature, as a quantity that is represented on a scale of real numbers, as a presupposition for the second law. On examination of their text, however, one finds that their version of the zeroth law differs from the previous versions, which were not labeled as the zeroth law. Their version of the "zeroth law" offers one of the important ingredients of the notion of empirical temperature. But it is not explicit about the necessary associated context routinely expressed by those who discussed empirical temperature before them. That context, omitted by Fowler & Guggenheim, was that thermal equilibrium may be seen to be reached specifically in the interaction between two bodies with different "non-deformation" variables when they are connected by a wall "permeable only to ″heat″". Such a context is needed to get from the mere words of the "zeroth law" as Fowler & Guggenheim state it to the notion of temperature as a quantity that they assume can be represented on a scale of real numbers. Ernst Mach in the nineteenth century pointed out the ideas needed to establish temperature as a quantity represented on a scale of real numbers, but Fowler & Guggenheim do not mention these ideas in detail. Modern experts in the theory of thermodynamics, such as James Serrin, recognize the importance of Mach's discussion. Instead of referring to Mach, Fowler & Guggenheim (on page 56) define empirical temperature as Max Planck did before them, in terms of the volume of a reference body at constant pressure. Though it seems that they were the inventors of the label "zeroth law", Fowler & Guggenheim's eventual statement (on page 60) of the second law does not mention entropy, using instead the idea of free energy.Chjoaygame (talk) 06:16, 4 December 2012 (UTC)

While Waleswatcher's start to this section says that PAR edited the introduction. To be precise, he edited the lead. Reasons for keeping the lead very short are perhaps not binding on an introduction. Every Wikipedia article, I think, has a lead, but only some, perhaps the more complicated ones, have also an introduction.Chjoaygame (talk) 06:32, 4 December 2012 (UTC)

"Average" properties

The opening of the current version of the article has (1^st line): - ...defines macroscopic variables (such as temperature, internal energy, entropy, and pressure) that describe average properties of material bodies and radiation,... Some of the properties listed do not have average values, they are intensive properties i.e. they are local e.g. temperature.

I propose to remove (soon!) the word average from the above quotation. --Damorbel (talk) 07:39, 30 November 2012 (UTC)

That seems reasonable to me. Indeed I would go further and remove the words 'average properties of'. The words 'properties of' add nothing to the meaning, and indeed are pleonastic to a fault. I think "...defines macroscopic variables (such as temperature, internal energy, entropy, and pressure) that describe material bodies and radiation,...' would be better.Chjoaygame (talk) 12:10, 30 November 2012 (UTC)

Hmmmm! How is it that "The words 'properties of' add nothing"? Are temperature and pressure not properties? I agree they are not the complete properties. As for "variables", surely these are descriptors in e.g. equations - not properties as in properties of materials

There is a further problem here (line 4):-

Thermodynamics does not describe the microscopic constituents of matter, and its laws can be derived from statistical mechanics.

Agreed, thermodynamics does not describe the microscopic constituents of matter. Again, far too general. Surely it would read better as:-

Thermodynamics describes the microscopic and macrosopic properties of energy in matter, and its thermodynamic laws, which may be derived from statistical mechanics.

Surely putting a description of what Thermodynamics is not, must be seen as unnecessarily rather global! --Damorbel (talk) 12:44, 30 November 2012 (UTC)

response by Waleswatcher

Temperature is of course an average property. For instance in a gas, it is proportional to the average kinetic energy per molecule. In radiation, it is related to the average frequency of the photons. But a randomly chosen individual particle or collection of particles will not have precisely that average energy. Waleswatcher (talk) 14:10, 30 November 2012 (UTC)

How can temperature possibly be an average property? If it was why is there a need for global temperature maps when discussing climate? (See the first drawing in the 'temperature' link.)

I suggest you haven't looked at the link I gave to Intensive properties. Please comment when you have checked this link. --Damorbel (talk) 14:23, 30 November 2012 (UTC)

I'm fully aware of the meaning of "intensive", Damorbel. I'm a professional physicist and use the terms every day. Intensive quantities in thermo are precisely averages (rather than, say, totals). In the case of T, again, it's the average kinetic energy per molecule. Think for a minute - does every molecule in a container of gas have exactly the same kinetic energy at all times? Obviously not - and yet we characterize a huge collection of molecules by one number, T. Clearly, it's an average. Waleswatcher (talk)

Waleswatcher, did you look at my link? In the thermodynamics article the word average is used far too loosely. What you probably mean is equilibrium temperature, which is the temperature given by the average energy of the particles in a thermal system in equilibrium. What you should know is that a (single) temperature cannot be assigned to a system that is not in equilibrium. --Damorbel (talk) 14:49, 30 November 2012 (UTC)

Your link points to "planetary equilibrium temperature", which is not what we are discussing. We are discussing plain old temperature, which indeed is strictly only defined for equilibrium ("planetary equilibrium temperature" is an example of how one might try to define it away from equilibrium). In any case, since you say "the temperature given by the average energy of the particles", it seems you now agree that temperature is in fact an average? Waleswatcher (talk) 17:26, 30 November 2012 (UTC)

Indeed "planetary equilibrium temperature" is not immediately relevant, that is something for advanced students.

But you seem not to be fully aware of the meaning of "intensive quantities"? Or the meaning of temperature. A temperature can only be defined for a system in equilibrium, a system not in equilibrium has two or more temperatures, the requirement for a single temperature being that the particle energy has a Maxwell Boltzmann distribution

Of course, as I remarked before, the temperature of a thermodynamic system is independent of the size of the system; rather intuitive don't you think? This drives one to the logical conclusion that the smallest system that can have a temperature is a system comprising only one particle!

The meaning of the Maxwell Boltzmann distribution (an important thermodynamic concept) is statistical of course; (possibly from statistical mechanics - do you think?) In a Maxwell Boltzmann distribution the particles have an equal probability of accessing the system states. --Damorbel (talk) 19:58, 30 November 2012 (UTC)

response by Chjoaygame

There are various viewpoints about temperature. One view, from statistical thermodynamics, is put by Balescu, R. (1975), Equilibrium and Nonequilibrium Statistical Mechanics, Wiley–Interscience, New York, ISBN 0-471-04600-0, on page 43. He writes: "... we cannot define the temperature as an average of a microscopic function taken with an arbitrary distribution function [as implied by Eq. (2.2.4)]: It rather appears as a parameter characterizing the particular distribution function describing the system in thermal equilibrium. He adds in a footnote that the statement of temperature as an average kinetic energy for an ideal gas is correct, but that it is not a definition. Another source might be Chapman, S. Cowling, T.G. (1939/1970), The Mathematical Theory of Non-Uniform Gases. An Account of the Kinetic Theory of Viscosity, Thermal Conduction and Diffusion in Gases, Cambridge University Press, Cambridge UK. They give several discussions of the difference in formal status between the thermodynamic and the kinetic theory of gases definitions of temperature, and proceed to examine how far they give coincident physical results. For the case of mixtures of rare gases, they say on page 8 of the third edition that "The kinetic theory is able to give a fairly satisfactory affirmative answer to this question (4.3), to this extent justifying its procedure as regards temperature definition." They then discuss how this may relate to temperatures for processes involving materials other than gases.

Dear Damorbel, by the way, you write above "... the Maxwell Boltzmann distribution (an important thermodynamic concept)..." This is not in accord with the views of some sources on thermodynamics who take a viewpoint different from the pedagogical strategy, for example, of Kittel & Kroemer and of Reif. The viewpoint of Adkins, C.J. (191968/1983), Equilibrium Thermodynamics, Cambridge University Press, Cambridge UK, ISBN 0-521-25445-0, may be summarized by the following from page 2 of the third edition: "The laws of thermodynamics enable us to interrelate the macroscopic quantities without making any microscopic assumptions at all. The great generality of thermodynamics is a direct consequence of this."Chjoaygame (talk) 03:12, 1 December 2012 (UTC)

     response by Damorbel

Chjoaygame, I have looked at your ref. "Another source might be Chapman, S. Cowling," and I find what they say on p36 ff. under definitions and theorems section 2.4.1 - Temperature. In this section you will find what I am arguing is the theoretical basis for the concept of temperature. At the bottom of p37 last paragraph, it has:-

The kinetic theory definition of temperature, being applicable whether or not the gas is in a uniform or steady state, is more general than that of thermodynamics and statistical mechanics, where only equilibrium states ... etc., etc.

Now this is your ref. and I recommend its definition of temperature to you (to get a proper idea you will need to read the complete section). With such a definition I suggest the article may be considerably improved. --Damorbel (talk) 12:57, 1 December 2012 (UTC)

You will also be pleased that the (upper) section (2.4) of your ref. provides a definition of Heat that also will improve the Heat article. On p36, section 2.4, it has :-

Heat - The amount of translatory kinetic energy possessed by the molecules in the element r,dr at time t ... etc., etc. --Damorbel (talk) 13:19, 1 December 2012 (UTC)

Chjoaygame, your ref. is also very good on the conservation of energy and momentum, the basis of the thermodynamic laws. Care to comment? --Damorbel (talk) 14:00, 1 December 2012 (UTC)

• I don't have that reference, but unfortunately neither heat nor temperature can be defined generally in terms of kinetic energy, because that's not the case for all systems. Thermal and statistical physics is much more powerful and general than that. For instance there are well-studied systems in which the temperature is negative. Still, in most familiar cases the "temperature is average kinetic/vibrational/rotational energy per molecule" is true, and can and should be used as an example in these articles. Waleswatcher (talk) 13:47, 1 December 2012 (UTC)

Chjoaygame's ref. can be seen here:- http://www.amazon.com/Mathematical-Theory-Non-uniform-Gases-Conduction/dp/052140844X/ref=sr_1_1?s=books&ie=UTF8&qid=1354362881&sr=1-1&keywords=The+Mathematical+Theory+of+Non-Uniform+Gases.+An+Account+of+the+Kinetic+Theory+of+Viscosity%2C#reader_052140844X --Damorbel (talk) 14:00, 1 December 2012 (UTC)

Chjoaygame' you write above:-

"... the Maxwell Boltzmann distribution (an important thermodynamic concept)..." This is not in accord with the views of some sources"

If you read chapter 3 in your Chapman ref. (THE EQUATIONS OF MAXWELL AND BOLTZMANN) you will find an extensive explanation of just why the Maxwell-Boltzmann distribution is fundamental to thermodynamics and why it must be recognised as such. --Damorbel (talk) 14:27, 1 December 2012 (UTC)

• Waleswatcher is right, Damorbel, when he refutes your comment and writes as above: "...neither heat nor temperature can be defined generally in terms of kinetic energy, because that's not the case for all systems ..." As you may see, the kinetic theory of gases definition of temperature is specific for that theory, which is about gases, while, as I have noted several times, though it seems to have escaped your eagle eye, the kinetic theory of gases has not much to say about liquids or solids. The greater generality claimed by Chapman & Cowling is that they refer to a gas not in equilibrium, but their definition does not extend to non-gaseous materials. As I recall, you are habitually very keen to insist that temperature belongs only to an equilibrium state. It is inconsistent of you now to crow about a definition of temperature that claims to be for a non-equilibrium state.

Dear Damorbel, you are lost, not aware of which article you are writing in. You are trying to put the kinetic theory of gases definition into the article on thermodynamics. The thermodynamic definition is primary in an article on thermodynamics; the Chapman & Cowling book on the kinetic theory of gases carefully notes that thermodynamics does not rely on the kinetic theory of gases definition of temperature. Your enthusiasm here shines a light on how you persistently fail to look at context, and so your thoughts are muddled. And you want to drag us into your muddle with you. You endlessly and petulantly demand that we attend to your comments, but, sad to say, they are mostly merely repetitive, and you endlessly fail to hoist in the responses we offer you.Chjoaygame (talk) 14:52, 1 December 2012 (UTC)

Chjoaygame, you write above:-

the Chapman & Cowling book on the kinetic theory of gases carefully notes that thermodynamics does not rely on the kinetic theory of gases definition of temperature

Oh really? Just where is this noted?

So when I see in your ref. Chapman & Cowling on page 37 section 2.4.1 "The temperature T of a gas in a uniform steady state at rest or in uniform translation is defined directly in terms of the peculiar speeds of the molecules, by the relation $\displaystyle {\frac {1}{2}}mv_{rms}^{2}={\frac {3}{2}}kT.$

where k is a constant, the same for all gases, whose value will be assigned later; it is called the Boltzmann constant."

For you, that this is the kinetic definition of temperature is merely an illusion peculiar to me? --Damorbel (talk) 17:45, 1 December 2012 (UTC)

It seems you feel entitled to demand of us that we spoon feed you every word of the way. You have skimmed C & C with your usual selective blindness, passing over the parts that don't suit your fancy. You seem unable to read and pick up related context for yourself, apparently because of your burning and fixed need to see the kinetic theory of gases as the only theory that can define temperature, ignoring its very restricted scope. You seem to feel entitled to demand of us that we spend unlimited time of ours feeding you the information left out by your lack of skilful reading. Should I apologise in advance that the spoon I feed you with is not a silver one?

For obvious copyright reasons, I cannot here quote in full every word that is needed to satisfy your feeling of entitlement. If you want to find out the full meaning of the material in the book you will need to get the contexts by actually reading and thinking about it for yourself.

You have already quoted in italics above the following sentence: "The kinetic-theory definition of temperature ... is more general than that of thermodynamics and statistical mechanics ..." This is making it clear, at least to someone who is not purblinded by a fixed idea to the contrary, that the kinetic-theory definition is not the thermodynamic definition; they are distinct, and C & C are saying that there is an onus of proof for someone who wants to make them equal to one another. Your failure to read context is exemplified by your misleading quote above, "The temperature T of a gas in a uniform ...", from which you left out the important preparatory context "... in theoretical work they use the absolute temperature of thermodynamics. In the kinetic theory, on the other hand, ..." which makes it clear that the kinetic-theory and the thermodynamic definitions of temperature are distinct.

As Waleswatcher has patiently and kindly noted for you above, the kinetic-theory idea of heat is not adequate for materials not covered by the kinetic theory of gases, and is therefore not adequate as a general definition of heat.

I have to ask myself, 'is Damorbel just playing with me, to see how much of my time he can lure me into wasting?' I now feel entitled to say that you have exhausted my patience.Chjoaygame (talk) 19:32, 1 December 2012 (UTC)

Chjoaygame, your argument making a distinction between kinetic theory for gases, and heat energy in liquids and solids, fails because the energy contained in freely coliding gas molecules (particles) is exactly equal to that in the various degrees of freedom in molecules subject to intermolecular forces such as solids, liquids, crystals, vibrating gas molecules such as CO2 and H2O etc. All particles in an equilibrium system, molecules in gases, liquids and solids, electrons confined in a conduction band (but not quantum confined electrons in an atom), have equal amounts of thermal energy, explained by a theorem called the equipartition theorem.

Your ref. book is useful on equipartition, try p.80 section 4.3, or the index. The equipartition theorem is an important theorem in understanding particle thermal physics. Failure to take this theorem into account is making a complete mess of the thermodynamics article , the heat article and the temperature article. --Damorbel (talk) 21:35, 1 December 2012 (UTC)

PS You may not be aware of it but the concept of the equipartition theorem is the same as the fundamental postulate in statistical mechanics, I suspect a distinction created by academics seeking to expand their field of research!--Damorbel (talk) 09:21, 2 December 2012 (UTC)

     response by Waleswatcher

The true definition of temperature is T=dE/dS. But since both E and S (contrary to PAR) are defined by averages and/or expectation values, T is an average quantity too. Regarding language - "constituents" or "particles"? The former is more accurate and general, but the latter may be better as it is more familiar and clear. Waleswatcher (talk) 04:00, 1 December 2012 (UTC)

Waleswatcher, you write:

The true definition of temperature is T=dE/dS.

I would very much like an explanation of this, what do you have? --Damorbel (talk) 15:29, 5 December 2012 (UTC)

Balescu, as quoted just above, is not alone in the view that in statistical mechanics, the temperature is a parameter of a distribution. Fowler, R., Guggenheim, E.A. (1939, reprinted 1965), Statistical Thermodynamics. A version of Statistical Mechanics for Students of Physics and Chemistry, Cambridge University Press, Cambridge UK, on page 38 write [their italics]: "Thus θ is a parameter helping to define the state of our assembly which must have the same value for all sets of systems in the assembly." The same view is proposed by Tolman, R.C. (1938), The Principles of Statistical Mechanics, Oxford University Press, London, who writes on page 563: "...the parameter θ characterizes only the particular kind of ensembles, with canonical distribution, which we use to represent systems in thermodynamic equilibrium." The kinetic theory of gases, which explicitly defines its own version of temperature as an average kinetic energy, and as distinct from thermodynamic temperature, is closely related to statistical mechanics, but applies mainly to gases, without much consideration of liquids or solids.Chjoaygame (talk) 05:03, 1 December 2012 (UTC)

As is often the case, Chjoaygame, I can't tell what the point of your comment is. I disagree with nothing in your last comment, and nothing in your last comment disagrees with anything I wrote here. Waleswatcher (talk) 09:50, 1 December 2012 (UTC)

Proposal to community topic-ban User:Damorbel

After his latest efforts at Talk:Boltzmann constant I've made a proposal at WT:PHYSICS that User:Damorbel be community topic-banned from further editing articles and talk pages related to thermodynamics.

The views of those who've interacted with him on this talk page would be useful, since he appears to have edited here extensively as well. Jheald (talk) 21:45, 8 December 2012 (UTC)

Thermodynamics of small systems

How about including a section with this title? Thermodynamics only applies in the limit of number of constituents goes to infinity (the thermodynamic limit). As systems get small, the laws of classical thermodynamics break down and other equations have to be used instead. Quantities that are constant in classic thermodynamics become stochastic variables (right?). I think that a section discussing this would help make the transition between the behavior of single molecules and that of macroscopic systems clearer (I would certainly appreciate it).

For references, Hill's classic "Thermodynamics of small systems" is almost impossible to obtain. I have found an open access article by John Rowlinson, whose authority cannot be doubted, however it is not as focussed as I'd like. I also found a nice little open access article in PNAS on the thermodynamics of single protein molecules. We need some better candidates, IMHO. Surely there must be a recent review?

What do you think of this idea? AlanParkerFrance (talk) 10:58, 6 January 2013 (UTC)

For my part I suggest it may be difficult to define what a small thermodynmic system is. Thermodynamics is the physics of particles and their interactions, the relevant physical interactions are independent of the systen size. Obviously as the sample size decreases the variation in the measurements such as e.g. pressure must deviate increasingly from the mean. For pressure this variation shows up as random accoustic noise. --Damorbel (talk) 12:04, 6 January 2013 (UTC)

branch of physics

Here editor 86.158.238.108 has changed the overarching subject named from natural science to physics. I am indifferent about this, but I note that some would say that thermodynamics is also a branch of chemistry and some might say that it is also a branch of engineering. The link to natural science was there for that reason. I have no intention of trying to change the overarching subject named. I don't know if anyone else cares about it.Chjoaygame (talk) 01:07, 6 November 2013 (UTC)

I have reverted that change. You are right. --Bduke (Discussion) 02:16, 6 November 2013 (UTC)

surroundings and environment

There is a new edit by Editor Zedshort that changes the word 'surroundings' to the word 'environment', with links to an article Environment (systems). That article is more like a dictionary entry than an encyclopaedia article. The sole reference in that article is to Richard Dawkins, not a book about thermodynamics.

The cited references in the present article on thermodynamics are Guggenheim and Kondepudi. On page 9, Guggenheim writes "... the rest of the universe (its surroundings)" twice. On page 4, Kondepudi writes "... dividing the world into a 'system' and its 'exterior'". Looking a little further, I find Bailyn on page 20 writing of a "uniform environment". I find Adkins on page 4 writing that "Everything outside the system is called the surroundings". I find Callen on page 15 writing of the "“walls” that separate it [the system] from its surroundings." Planck on page 114 writes of "such changes in the surrounding medium". On page 108, Pippard writes "If the system is open to the surroundings ...". On page 127 Partington writes: "All things outside the system are spoken of as external bodies. ... so that no heat or work can be exchanged with the surroundings." Kirkwood & Oppenheim on page 1 write "The surroundings are the rest of the physical world. ... An isolated system has no interactions with the surroundings." On page 6, the translator of Münster writes "A system is called closed when it can exchange energy with its surroundings but cannot exchange matter ..."Chjoaygame (talk) 22:24, 12 January 2014 (UTC)

article structure comment in Introduction

The end of the Introduction section has the following statement

"The present article takes a gradual approach to the subject, starting with a focus on cyclic processes and thermodynamic equilibrium, and then gradually beginning to further consider non-equilibrium systems."

Is it right to describe an Encyclopedia article as if it is a textbook chapter? J mareeswaran (talk) 13:17, 22 August 2014 (UTC)

Thermodynamics is a large subject. The purpose of the sentence is to alert the reader to the logical structure of the article. It starts with a particularly simple case and then moves to the more general.Chjoaygame (talk) 04:53, 24 August 2014 (UTC)

undid good faith edit; reason

I removed the new image of a steam engine. The image is colourful, juicy, and interesting. It might well relieve the rather dry nature of thermodynamics. But I think not suitable for where it was posted.

The reason is that the image is very much a moving picture. Classical thermodynamics, the main topic of the article, is essentially about states of thermodynamic equilibrium, in which the kind of movement in the image has ceased. The moving image would give the reader a false sense of direction. Classical thermodynamics is used in the consideration of such movement, but only as an idealized limiting case. It is misleading to present an idealized limiting case as if it were typical.Chjoaygame (talk) 05:33, 12 April 2015 (UTC)

promotion

To judge from their edit summaries, it seems that editor HenryGroupman's destructive edits here and here were revenge for the removal here and here of some promotional material that he posted here and here. Editor HenryGroupman's contribution record shows those as his only activities, and I infer that he is a single-purpose promotional user with a conflict of interest that makes those activities inappropriate. If so, we are looking at a conduct problem as distinct from a content problem. I would ask editor HenryGroupman to desist from such activities, so as to avoid further process over conduct, in an administrative forum. Right now I am not undoing the vengeful destructive edits, because to do so might not be helpful.Chjoaygame (talk) 20:46, 22 July 2015 (UTC)

request for clarification

Editor Isambard Kingdom has here and here restored his requests for clarification at particular points of the section headed Introduction. It is good to see his quick vigilance. Since he is deprecating my positive attempt at clarification, I have undone it.

It would help if he would give some guidance as to how he finds unclarity at those particular points. I accept that the sentences to which he refers are summary, but I think more detail about their meaning is to had by reading further in the article, and that more detail at points he has indicated would be deteriorative. It seems to me hardly reasonable to expect complete clarity of a subtle subject to be evident in every isolated sentence. Would he kindly give some indication of what kind of further clarity he is requesting?Chjoaygame (talk) 14:34, 13 August 2015 (UTC)

There's no need to remove the statement on energy that you previously contributed. I just think more needs to be done. My putting some of these "clarification" notes in is simply an attempt to motivate additional input by editors. In my opinion, this article could benefit from some discussion of specific examples that illuminate the very general discussion and history that the article already contains. I also note that parts of the article sometimes have lots of citations for very specific points, but then other parts of the article could benefit from citations, say, specific parts of introductory textbooks (the online Feynman lectures, perhaps, but others as well). Isambard Kingdom (talk) 15:23, 13 August 2015 (UTC)

There are requests for clarification, here, here, and here.

I have here above requested specific reasons for the flags, and have been answered here above, by Editor Isambard Kingdom's statement that I read as meaning that the flags are to indicate general dissatisfaction with the text, not by indications of specific reasons. I think general dissatisfaction with the text is always reasonable, and is adequately flagged in this case by this tag at the head of the article.

I regard these requests as seeking more detail than is appropriate for the places where they they were posted. Such detail would distract from the line of thought of the text. My preferred remedy is to trim or delete the sentences that carry the flags, as opposed to adding the apparently requested detail that I would regard as distracting.Chjoaygame (talk) 04:05, 19 August 2015 (UTC)

undid good faith edit; why

I undid this good faith edit. It stated the principle of conservation of energy. There is a Wikipedia article devoted to that topic, which is not the same as the first law of thermodynamics, which is briefly summarized in the present article. It is true that some textbooks conflate the two, but the best sources distinguish them, and the Wikipedia articles follow those sources.Chjoaygame (talk) 07:54, 14 September 2015 (UTC)

is 'conserved' not explicit enough?

I am responding to a notice about good faith edit undos needing talk page comment. I have undone this one. I think the edit put in too much of a good thing.Chjoaygame (talk) 07:28, 22 September 2015 (UTC)

several edits

I am responding to three successive edits by one editor, Editor Josophie, starting with this one. I am responding here because there is a notice recommending talk-page response.

The edits are good faith edits, apparently intended to generally improve readability. As I read them, they do not purport to change the substance of their subject matter. As it appears to me, they are not based on their editor's new collection or surveying of reliable sources. Their editor has been active in making such edits in a range of articles. Their editor very recently made other edits to this page, upon which I commented just above, under the heading is 'conserved' not explicit enough? My comment did not receive a reply.

The first of the present edits is covered by this edit summary:

revised definition of thermodynamics — prior one was too complicated

The prior wording was

Thermodynamics is a branch of physics concerned with heat and temperature and their relation to energy and work. It defines macroscopic variables, such as internal energy, entropy, and pressure, that partly describe a body of matter or radiation.

The edit changed that to

Thermodynamics is a branch of physics that deals with the laws governing the energy and work of a system, which may be described as the exchange of heat energy to and from other forms of energy within a system. More specifically, it defines macroscopic variables, such as internal energy, entropy, and pressure, that partly describe a body of matter or radiation.

I think the edit summary was misleading. I think the edit was deteriorative.

I think that will be enough comment from me for now.Chjoaygame (talk) 03:22, 26 September 2015 (UTC)Chjoaygame (talk) 05:08, 27 September 2015 (UTC)

The new version is unsatisfactory in that it waffles with talk of "the exchange of heat energy to and from other forms of energy within a system." "Heat energy" verges on 'thermal energy', which is not a properly defined term in physics. The words also may too easily be read as implying that heat is a form of energy that is available for transfer. The new wording, contrary to the claim of its edit summary, is more complicated than what it replaces, with no added meaning.Chjoaygame (talk) 20:50, 28 September 2015 (UTC)

faulty good faith edit to the first sentence of the lead

I wish to avoid editorial conflict, so I am going first to the talk page. Editor Spinrade has made a good faith edit here, with the edit summary "Tighten up definition of thermodynamics". The newly offered first sentence of the lead is

Thermodynamics is a branch of physics that deals with the relationship between heat and mechanical, electrical, or chemical work.

This overwrites the former first sentence of the lead that read

Thermodynamics is a branch of physics concerned with heat and temperature and their relation to energy and work.

I think this edit should be undone. First, it omits mention of temperature, which is highlit by Guggenheim's first chapter's first sentence "The most important conception in thermodynamics is temperature". Second, it lists "chemical work". Sad to say, there is no such thing as 'chemical work'. There is what is often enough called electrochemical work, but that is work that is work because it is primarily electrical, and secondarily has the qualification -chemical because the electrical factors are driven by chemical processes, which are always irreversible, contrary to a prime feature of work as it is often conceived. The definition of work requires that it be defined by forces outside the system. The chemical change is inside the system. Chemical changes are indicated by chemical potential and by mole number, which are often called "generalized work variables" because of how they appear in equations, but this does not justify a proposed notion of 'chemical work' as a kind of work proper. Work is a very fundamental notion in thermodynamics and it would be meddlesome and harmful to try to make out that 'chemical work' is a sound notion. Thirdly, newly offered list is incomplete because it lacks the generality of the former term Work (thermodynamics). This formerly included term includes magnetic and gravitational work, and perhaps others, which are omitted, without good reason, from the new list. Fourthly, the edit also omits mention of energy, an important general notion for thermodynamics.

Thinking about this, I think the above reasons are sound, and I will therefore shortly undo the edit without waiting for debate.Chjoaygame (talk) 11:22, 26 November 2015 (UTC)

I agree with your reasoning to revert to the original Lede definition J mareeswaran (talk) 12:34, 26 November 2015 (UTC)

promotion

The edits, for example this one, by Editor K Sikdar, were in effect commercial promotion for an institution. Moreover, they were not improvements.Chjoaygame (talk) 13:29, 16 March 2016 (UTC)

3RR

Editor K Sikdar has made 4 reverts of the same material in the same article within 6 hours. He seems new to Wikipedia editing.Chjoaygame (talk) 22:31, 16 March 2016 (UTC)

Yes, look at his/her edit history. It happens. Thankfully this is not vandalism. Isambard Kingdom (talk) 22:35, 16 March 2016 (UTC)

The 3RR is not only against vandalism. It is also against good-faith edits that cross the line. I am right now not seeking to enforce it, because the editor is new. But it should be noted.Chjoaygame (talk) 22:59, 16 March 2016 (UTC)

Not a promotion

The source is a video lecture by a government organisation in India. — Preceding unsigned comment added by K Sikdar (talk • contribs) 13:32, 16 March 2016 (UTC)

Perhaps not. But a government organization is not in general a reliable source. Either way, the new words seem better to you, but not to other editors. I for one find them lacking in specific information such as is needed for that place in the lead.Chjoaygame (talk) 21:10, 16 March 2016 (UTC)

Of course, lots of good scientists work for governments. IIT are Indian Government technical universities, I believe. Before dismissing the editor's efforts, lets encourage him/her to supply reliable and checkable sources for the suggested changes. Thanks. Isambard Kingdom (talk) 22:23, 16 March 2016 (UTC)

The main issue is whether the edit is an improvement. The sourcing is less critical.

The new edit reads:

Thermodynamics is a fundamental subject that describes the basic laws governing the occurrence of physical processes associated with transfer of energy or transformation of energy and also establishes the relationship between different physical properties which are affected by these processes.

In my view, this is vague and over-inclusive, to the point where it is not an improvement. There are many laws that govern physical processes. Thermodynamics describes only a few of them. The new edit fails to make this clear, and is in that way likely to mislead. The edit doesn't specifically indicate the nature of thermodynamics, and is therefore an unsuitable leading sentence. New sourcing, if offered, would not fix those flaws, considering the already supplied sourcing in the article. It would mislead the new editor to give him the impression that sourcing is a significant factor here. The main factor is improvement.Chjoaygame (talk) 22:52, 16 March 2016 (UTC)

Thank you. Useful. Isambard Kingdom (talk) 22:56, 16 March 2016 (UTC)

I also felt that "thermodynamics is a fundamental subject" is unnecessarily vague and unsatisfactory compared to the original "thermodynamics is a branch of physics".--Srleffler (talk) 01:17, 17 March 2016 (UTC)

copy-and-paste from my talk page

Ok, so you guys are the wiki mafia I guess. Do whatever you like (including just deleting info). I am a mechanical engineer and I thought I knew better about thermodynamics but you are the experts in everything after all!!! — Preceding unsigned comment added by K Sikdar (talk • contribs) 02:59, 17 March 2016 (UTC)

No comment.Chjoaygame (talk) 03:24, 17 March 2016 (UTC)

Oh by the way, could you tell me what was wrong about the edit? Should it not be there just because you guys don't think so? — Preceding unsigned comment added by K Sikdar (talk • contribs) 03:06, 17 March 2016 (UTC)

These were on my talk page.Chjoaygame (talk) 03:17, 17 March 2016 (UTC)

I will reply here and not on my talk page, since this is a matter of general concern.

The question for editing purposes is not whether your edit was wrong, but whether it was an improvement. I have above tried to say why your edit was not an improvement.Chjoaygame (talk) 03:17, 17 March 2016 (UTC)

undid good-faith IP edit

I undid this good-faith IP edit.

The edit posted a reference, that I have read, about the notion of a macroscopic system in quantum theory. This is far from helpful at this point in the article. It would distract and confuse the reader. The thermodynamic notion of macroscopic system is defined without thought of quantum theory. The reference is focused on quantum theory.Chjoaygame (talk) 22:45, 17 March 2016 (UTC)

undoing a good-faith edit; why

Editor K Sikdar is new. He has put his citation in his edit summary. The citation should go in the text so that a reader can check it. The citation should give the page location in the source. It is best to give especially reliable and established sources in a topic such as the present one, for which the potential sources are legion. Engineering texts are reliable within their scope, but the present topic is not in the same scope as engineering.

As for the content of his edit. The part of the article where he placed his edit is structured as an ultra-brief summary, not an expression in detail. The edit inserts inappropriate detail.

It is far from evident that the "Kelvin-Planck" statements are to be preferred, even if it were granted that such detail were appropriate at that point in the presentation in the article.

The edit is not wrong, but doesn't fit where it is placed, and consequently does not improve the article.

For these reasons I am about to undo the edit.Chjoaygame (talk) 20:57, 18 March 2016 (UTC)

Here follows in blue font a cut-and-paste from my talk page:

If you think that the Kelvin-Planck and Clausius statements haven't been put in the right place, then kindly put them in the right place but don't just delete them. I am quite sure that Kelvin-Planck and clausius statements are very important and need to be in the article. With all due respect, what Kelvin, Planck and Clausius have said about the second law is definitely more important than your opinion about whether their statements should be included or not. With that in mind, I am undoing your edit and placing the statements again. If you disagree about the position on the page where the statements should be placed, then kindly put them under the proper heading instead of potraying that your opinion is more important than what Kelvin, Planck and Clausius have to say about the second law of thermodynamics. — Preceding unsigned comment added by K Sikdar (talk • contribs) 05:16, 19 March 2016 (UTC)

The above in blue font is a cut-and-paste from my talk page.Chjoaygame (talk) 07:44, 19 March 2016 (UTC)

My response: The place for these details is in the article on the second law of thermodynamics. I think they are already there.Chjoaygame (talk) 07:47, 19 March 2016 (UTC)

Further cut-and-paste from my talk page:

Your second reasoning about the "second law o thermodynamics" makes complete sense. Thank you. Your previous reasoning was nonsensical. — Preceding unsigned comment added by K Sikdar (talk • contribs) 10:04, 19 March 2016 (UTC)

End of cut-and-paste from my talk page.Chjoaygame (talk) 10:28, 19 March 2016 (UTC)

Revert to old version

I think in many ways the older versions are superior to the current article - for instance https://en.wikipedia.org/w/index.php?title=Thermodynamics&oldid=417201632 . It's more concise, and I think the language is much clearer in most places (however it may be missing some important elements that were added later). I'm considering reverting to that old version (or a similar one) and then adding back anything that seems notable enough, but I'm asking for comments here first since it would be a major change. Waleswatcher (talk) 15:28, 26 May 2016 (UTC)

Best to wait a few days because it takes a few days to read the present version. (Thirteen screens to six for the old.) Maybe put a notice in the physics project as well? This is the main article of a branch of physics. YohanN7 (talk) 09:26, 27 May 2016 (UTC)

No comments against, so I'm going ahead with the revert. Waleswatcher (talk) 14:17, 1 June 2016 (UTC)

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Reductionism

As far as I know, there is no known mathematically rigorous reduction of thermodynamics to mechanics! David edwards (talk) 15:34, 3 March 2018 (UTC)David Edwards

It's okay but i never knew that there is any law called zeroth law. — Preceding unsigned comment added by Tomisin davey (talk • contribs) 12:27, 12 December 2018 (UTC)

wording of the lead

I have changed the wording of the first two sentences of the lead, working from the edit https://en.wikipedia.org/w/index.php?title=Thermodynamics&diff=prev&oldid=889166040.

I think the edit was very good. It brought attention to the basis of thermodynamics in the behaviour of matter, which was regrettably absent from the previous versions. It also gave an opportunity to emphasize that thermodynamics is mostly concerned with macroscopic bodies of matter, as distinct from idealized systems of point masses, and from quantum systems, which demand different forms of description.

I have changed the wording, mainly because the edit was, I think, unduly emphatic in writing "in all of its states". Thermodynamics may speculatively wish to deal with all states of matter, but at present it is far from doing so. Entropy is one of the key concepts of thermodynamics. In most of the literature, entropy is strictly defined only for states of thermodynamic equilibrium. Much literature considers also physical processes involving matter that is so close to thermodynamic equilibrium that the approximation of local thermodynamic equilibrium holds nearly enough. Such consideration does not, however, escape the basic restriction to the concept of thermodynamic equilibrium, however much one would like to do so. But states further from thermodynamic equilibrium are hardly within the scope of thermodynamics as it is known today, and it is mere wishful thinking to believe otherwise. True, a concept of "second entropy" has been proposed for systems not in thermodynamic equilibrium, but there is little or nothing known of how to measure it. Consequently, the concept is more in the realm of speculative research than in the scope of extensive reliable sources.

One is not altogether happy to say that temperature has "effects" on the states of matter. It would be happier to say that temperature is evident in the states of matter.

If the editor of edit https://en.wikipedia.org/w/index.php?title=Thermodynamics&diff=prev&oldid=889166040 intends to keep editing, it will be more comfortable for other editors that he or she do so with a Wikipedia user name, than with a mere IP address. It may be felt advisable to choose a user name that does not advertise the personal identity of the user; then I think it is quite secure and safe to set up a Wikipedia user name.Chjoaygame (talk) 23:56, 23 March 2019 (UTC)

I was the one who made the first edit. My apologies if the wording wasn't the best. I simply wanted to note that thermodynamics wasn't just about studying the named quantities, but also about how they can explain the properties of matter. Your consideration is much appreciated. =) --186.185.182.16 (talk) 01:04, 24 March 2019 (UTC)

Yours was a great edit.Chjoaygame (talk) 02:49, 24 March 2019 (UTC)

disorder → dispersal

In this edit have changed the words "state of disorder" to 'degree of dispersal of energy'.

The reason is that, though the word 'order' has, over years, often been used in that way, it is now rather outdated, because it does not cover the situation as well as does the word 'dispersal', which is to be preferred. So far as I know, one of the earliest authoritative and reliable sources to use the term 'dispersal' was Edward Armand Guggenheim in 1949, see Guggenheim, E.A. (1949), Statistical basis of thermodynamics, Research: A Journal of Science and its Applications, 2, pp. 450–454, Butterworths, London. Another, more recent, reliable source, criticizing the term 'order', is Grandy, Walter T., Jr. (2008). Entropy and the Time Evolution of Macroscopic Systems. Oxford University Press. p. 21, chapter 3. ISBN 978-0-19-954617-6.{{cite book}}: CS1 maint: multiple names: authors list (link) Further information on this topic is in the Wikipedia article Entropy (energy dispersal), though that article seems unaware of the priority and authority of Guggenheim, or of the criticism by Grandy.Chjoaygame (talk) 01:54, 30 March 2019 (UTC)

Perhaps it's not a big deal, but...

I feel that the red link at the end of the lead description ruins it. Given how long it's been there, should there at least be an article on "axiomatic thermodynamics" so the link becomes blue? I would remove the link as long as the article has yet to be created, but I want to ask here first just in case. --186.82.84.206 (talk) 14:09, 18 September 2019 (UTC)

sounds fair, I'm fine with it if you remove the link. MaxwellMolecule (talk) 16:43, 18 September 2019 (UTC)

I agree.Chjoaygame (talk) 22:10, 20 September 2019 (UTC)

Alright, I have removed it. --186.82.84.206 (talk) 04:56, 22 September 2019 (UTC)

Explaining latest edit

I already provided an explanation to my edit in the history, but I'll record it here with a little more detail: While it's true that many concepts of thermodynamics have been historically developed when studying chemical systems, the phenomenology at its core (thermal energy) is still physical. The user who argues that thermodynamics is "both a branch of physics and chemistry" on the basis that chemistry "also contributed to thermodynamics" is missing an important remark on how, during the start, things weren't rigidly separate in science. Physics also contributed to many branches of mathematics (i.e. calculus and complex analysis), as those mathematical concepts were developed for a more advanced understanding on classical mechanics. Biology contributed to organic chemistry (in fact, organic chemistry itself was born in biology), and physics itself led to the development of quantum chemistry. Yet, calculus and complex analysis remain branches of mathematics, while organic and quantum chemistries remains branches of chemistry. The same thing goes with thermodynamics. Doubtlessly, many of its concepts and practices have been seminal to chemistry, and some of them were even conceived while dtudying chemical systems (such as the chemical potential), but since many of those physico-chemical concepts are only tailored for physical chemistry, they're of little use for the other fields of science that apply thermodynamics, be it physics or any other. Furthermore, nearly all official definitions of thermodynamics have consistently defined it as a branch of physics; the only deviations are those that merely define it as "the science of heat". Lastly, chemistry already has chemical thermodynamics and thermochemistry for chemical applications of thermodynamics, and however many thermodynamic concepts a chemistry student may need to learn can be found in them already.

Two last things before I conclude the post:

• • That X field is defined as a branch of Y doesn't mean that the other major scientific fields cannot or should not learn from X; therefore, there's no need to say that X is also a branch of Z. That's not how science works, as there is no need or urge to claim an "ownership" for a specific branch. At its core, thermodynamics is a branch of physics in the sense it studies physical interactions between thermal energy and matter (dilation, thermal equilibrium, phase change, efficiency and cycles, heat transfer, etc.). But it CAN be applied to other fields of science, hence black hole thermodynamics, biological thermodynamics, the aforementioned chemical thermodynamics, etc.
  • Wikipedia went through this conundrum before, actually. It's been a very long time ago, but it happened. The worst thing we could do right now is to have these "It's mine!" / "No! It's mine!" kinds of posts yet again.

Thanks in advance for your understanding. --2601:701:300:3D10:BDCE:3FD:5F98:5586 (talk) 13:59, 29 January 2020 (UTC)

Good to see you state your case on this talk page. Fair enough.Chjoaygame (talk) 15:08, 29 January 2020 (UTC)

Short description

I added a short description to this page as part of a run through all the remaining level-3 vital articles that still lacked them. Per WP:SHORTDESC, the target maximum length is 40 characters and the goal is to help users understand what this page is about when they're making searches, not to comprehensively define the topic (for instance, at pages like History of music we just use Aspect of history). The Wikidata description for this page was branch of physics concerned with heat, work, temperature, and thermal or internal energy (88 characters), which I shortened to branch of physics concerned with heat and temperature (closer to the target at 53 characters), going off of the lead sentence, which begins Thermodynamics is a branch of physics that deals with heat and temperature. Chjoaygame reverted and went to the description Branch of physics concerned with heat, work, temperature, and energy (68 characters).

I'm not a thermodynamics expert, but the lead also seems to indicate that mentioning work/energy isn't strictly necessary, and if we can keep the short description within the 40 character guideline or closer to it, we ought to. So I'd like to hear from everyone here: how necessary is mentioning work/energy to the essence of the topic, and is there any other way to communicate the essence in as short/simple a way as possible? {{u|Sdkb}} ^talk 05:19, 22 June 2020 (UTC)

Here's a suggestion: "Branch of physics describing transformations of energy". Probably not the greatest alternative, but it's factually accurate and comes in at 54 characters. MaxwellMolecule (talk) 05:31, 22 June 2020 (UTC)

Good suggestion, but thermodynamics is essentially based on the distinction between heat and work, not energy in general. I think the short wording "Physics of …" is practically synonymous with "branch of physics concerned with …", and gives more space for useful accuracy.Chjoaygame (talk) 05:41, 22 June 2020 (UTC)

I mean, it is true that heat and work (including chemical work) are the main processes of energy transformation in macroscopic systems. So I think thermodynamics does give a fairly general coverage of energy in macroscopic systems. On the other hand, there are important concepts my suggestion leaves out (besides the heat vs work distinction), such as the requirement that systems be in equilibrium. So thermodynamics can really only describe energy transformations in terms of a comparison of initial and final equilibrium states, which leaves out the vast topic of energy transformations out of equilibrium. [edit: the "macroscopic" qualifier is another important concept missing in my suggestion.]

But anyway, there is some subjectivity in constructing a general definition, and of course for the purposes of Wikipedia we'd better go with 2-3 reliable sources rather than our opinions. So I won't push more any more debate.

For reference, here is a definition from "Statistical Physics of Particles" by Mehran Kardar:

"Thermodynamics is a phenomenological description of properties of macroscopic systems in thermal equilibrium"

(a bit more than 40 characters, unfortunately) MaxwellMolecule (talk) 21:30, 22 June 2020 (UTC)

The problem with that definition is that not all of thermodynamics studies systems that are in thermal equilibrium. Non-equilibrium thermodynamics studies systems that aren't. --2601:701:300:3D10:1555:2987:E27D:A0C0 (talk) 02:44, 24 June 2020 (UTC)

That's the problem with definitions in general: they are partly subjective. The notion of "nonequilibrium thermodynamics" is still a subject of debate. The "thermo-" prefix refers to the concept of temperature and by extension other state variables. But there is still debate over the extent to which nonequilibrium systems can be described by such variables, and if so, whether it makes sense to still talk about "temperature-like" and "pressure-like" quantities. For some nonequilibrium systems, it is known for a fact that state variables and an equation of state do not exist. MaxwellMolecule (talk) 20:23, 24 June 2020 (UTC)

May I preface my comment by saying that, as a general rule, I think that etymology is no more than partly a guide. But I think that the 'thermo-' of 'thermodynamics' refers to heat, and its '-dynamics' refers to work.

And I agree with MaxwellMolecule on 'non-equilibrium thermodynamics'. Central to thermodynamics is entropy. It is rigorously defined only for states of thermodynamic equilibrium.Chjoaygame (talk) 23:10, 24 June 2020 (UTC)

Reasons for undo

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

Editor WMSwiki made the edits that I undid. Evidently he is unfamiliar with Wikipedia editing. His edits did not comply with Wikipedia editing policies. Wikipedia editors do not promote their own work. Articles published in journals are in general (with exceptions) not admitted as reliable sources for Wikipedia. Such an article as that of Editor WMSwiki would need to be quoted from a citation of it by a reliable third party textbook.Chjoaygame (talk) 03:09, 3 February 2021 (UTC)

reasons for undo of good faith edit

I have undone this edit. My reason is that Carathéodory's formulation is not the one covered by the article to which the undone link leads.

The undone link was a promotion of an article that has its own merits, but is not covered in the present article on thermodynamics. The lead summarises the present article. It is not a place to advertise other Wikipedia articles.Chjoaygame (talk) 16:50, 16 April 2021 (UTC)

reasons for undo of good faith edit

I undid this good faith edit for the following reasons.

Thermodynamic work occurs by the mechanisms by which the system, consequent upon a suitable thermodynamic operation, such as change of wall permeability, can spontaneously do work on its surroundings. Friction internal to the system is then not transfer of energy. When the surroundings do work on the system, there is always, according to the second law of thermodynamics, friction within or on the surface of the system. This entails transfer of some energy to the system that is seen by the surroundings as work done on the system, but by the system as heat transferred to it; accordingly it is not counted as thermodynamic work. Accordingly, work measured as done by the system on the surroundings can have a negative sign, depending on the precise mechanisms of energy transfer.Chjoaygame (talk) 08:03, 24 June 2021 (UTC)

reasons for undo of good faith edit

I have undone this edit.

My reason is that the edit was advocacy of a special research topic.

To give the flavour of why the word 'advocacy' fits, here is a quote from the abstract in the linked item:

When thermodynamics is understood as the science (or art) of constructing effective models of natural phenomena by choosing a minimal level of description capable of capturing the essential features of the physical reality of interest, the scientific community has identified a set of general rules that the model must incorporate if it aspires to be consistent with the body of known experimental evidence. Some of these rules are believed to be so general that we think of them as laws of Nature, such as the great conservation principles, whose ‘greatness’ derives from their generality, as masterfully explained by Feynman in one of his legendary lectures.

The linked article is advocacy of advanced special research.

The term 'non-equilibrium thermodynamics' is used in various ways. Sometimes it refers to processes that are near enough to equilibrium to make entropy nearly enough defined. For truly far-from-equilibrium states, entropy in the classical sense is undefined. The linked research article advocates the blurring of this distinction. A different point of view, advocated by another researcher, is that for substantial departure from thermodynamic equilibrium, the classical entropy is to be replaced by a two-time entropy function (or even by a several-times entropy function), that gives information about rates of reaction, such as is not given by the classical entropy, which is timeless. This is advanced research, beyond the topic of the present Wikipedia article.Chjoaygame (talk) 20:15, 27 October 2021 (UTC)

reasons for undo

I have undone a sequence of edits that ended here.

My reason is that the edits are based on research reported in journals, not on reliable and established textbooks. Wikipedia is not a news reporter. It is an encyclopaedia of established principles and facts.

The edits that I removed verge on propaganda or promotion of a viewpoint. Thermodynamics is an established body of principle and fact. Chjoaygame (talk) 08:41, 3 December 2021 (UTC)

Dear Chjoaygame:

1. Peer-reviewed journal articles are legitimate sources.
2. While Thermodynamics is an old and established field, there is tremendous current research that uses and extends the field. A major limitation to this page is that it does not give any flavor to the modern usage of thermodynamics, critical to so many other important modern endeavors. A reader of this page can come away with the idea that it is no longer an active subject, and that it was completed in the 19th century, which is not true.

While the recent additions are not perfect, they are in line with the spirit of Wikipedia in crowd-sourcing information on a topic. Please restore the edits and work to improve them to be suitable for the page. You could even mark some of the sections as needing additional work. Thank you Jeffreyjgray (talk) 03:11, 20 December 2021 (UTC)

Thank you for your careful thoughts. I am sorry that what I have to say on this is hardly what you would like me to say.

May I summarise my thinking? The phrase 'modern thermodynamics' often refers to an approximation in which bodies with sufficiently slow internal macroscopic flows are treated by relying on local thermodynamic equilibrium. In this case, time rate of local entropy production is considered. When the system is in a steady state of slow internal macroscopic flow, this makes some sense. When the internal macroscopic flows are unsteady, the general 'geography' of the system is changing; it is no easy matter to define the entropy change due to changing 'geography'. The actual contribution of thermodynamics to the solution of such problems is practically nil. The phrase 'modern thermodynamics' might also be regarded as indicating true and fundamental advances into non-equilibrium thermodynamics, in which local thermodynamic equilibrium does not prevail, so that true non-equilibrium generalisations of entropy have to be defined, and seem reasonable provided the departure from local thermodynamic equilibrium is small enough. So far as I know, there is little or nothing known about how to actually measure the functions that are so defined. It is mostly abstract theory.

I still think that the edits that I undid are more in the realm of journalism than of encyclopaedic material. Wikipedia generally does prefer established texts. Most peer reviewed journal articles are unreliable, sad to say. Crowd-sourcing of thermodynamics would be chaotic, to describe it charitably! I think the article should aim to help the reader know the truly reliable concepts of thermodynamics. That is a noble undertaking.Chjoaygame (talk) 11:02, 20 December 2021 (UTC)

Chjoaygame, I agree with your removal of the section but not with the reasons you give. Science articles here cover material well beyond that which ends up in textbooks. Peer-reviewed journal articles in the sciences are not equivalent to journalism and are accepted as sources, with limitations, on Wikipedia. The distinction we do make is between primary and secondary sources. An individual researcher's or group's work is a primary source. Even though peer-reviewed and published in a reputable journal, they may be wrong or their work not yet accepted. Secondary sources, such as review papers, are preferred in most cases. We have an essay at Wikipedia:Identifying reliable sources (science) which explains this. See the definitions here. StarryGrandma (talk) 21:47, 20 December 2021 (UTC)

StarryGrandma, you put the situation well. Thank you.Chjoaygame (talk) 18:45, 21 December 2021 (UTC)

Explaining latest two edits

I want to post here that I reverted a small series of edits by an user who changed the sign convention on the First Law section, on the basis that many articles on thermodynamics use the minus sign convention, switching only to the plus one for srticles on thermochemistry and associated topics. Changing the sign in this article shouldn't be done unilaterally, since the wiki needs to keep consistency on the sign that is being chosen, and only this article was having the minus sign switched to plus. --206.62.162.123 (talk) 00:16, 18 January 2022 (UTC)

Explain the factors affecting the thermodynamic stability with example?

Please publish answer. 117.233.90.234 (talk) 13:13, 26 April 2022 (UTC)