Talk:Boltzmann's entropy formula

Article improvements
The article really should be called Boltzmann's equation (the common name), even though the current name is more technically accurate. Also, I'd like to include a little derivation of the equation from the assumption of additivity of entropy (for those who may think this would constitute original research, it's not - it's a standard derivation). MP (talk•contribs) 12:49, 18 May 2008 (UTC)


 * Boltzmann's equation is something different. Jheald (talk) 13:37, 18 May 2008 (UTC)

Boltzmann's Actual Definition
The statement that Boltzmann defined entropy as function of the number of microstates rather than of a probability is false. This misunderstanding is due to the fact that Boltzmann's writing was fairly difficult and few people understood it at the time. Boltzmann's original papers have never been translated from German, so most information about them is 2nd or 3rd hand from people's interpretations of them. As noted by Robert Swendsen in "Statistical mechanics of colloids and Boltzmann's definition of the entropy". American Journal of Physics -- March 2006 -- Volume 74, Issue 3: http://dx.doi.org/10.1119/1.2174962, Boltzmann interpreted the 2nd Law of Thermodynamics to mean that a system tends toward more probable macrostates. Boltzmann originally (incorrectly) identified the entropy as the probability (Wahrscheinlichkeit) of a system's macrostate. Later, in the same paper, he considers an ideal gas as a special case and calculates the logarithm of the macrostate's probability as proportional to the volume in phase space. In later papers he re-identifies the entropy as the logarithm of a macrostate's probability, but as he is usually considering the special case where all microstates are equally likely, he calculates it as proportional to the volume in phase space. Readers likely misidentified this special case as the definition of entropy since he seemed to have rarely mentioned what his definition was. Luke D (talk) 05:49, 11 May 2010 (UTC)

Rubber seems out of place
In 1934, Swiss physical chemist Werner Kuhn successfully derived a thermal equation of state for rubber molecules using Boltzmann's formula, which has since come to be known as the entropy model of rubber.

Why is this here? It seems isolated and out of place in the introductory paragraph. Is this the only time Boltzmann's formula was ever used? 89.217.15.87 (talk) 20:46, 16 March 2015 (UTC)

Confusingly expressed
''Boltzmann himself used an expression equivalent to (3) in his later work[5] and recognized it as more general than equation (1). That is, equation (1) is a corollary of equation (3)—and not vice versa. In every situation where equation (1) is valid, equation (3) is valid also—and not vice versa.''

The final sentence seems to say that (1) implies (3), which would contradict (1) being a corollary of (3). But I don't think think this is the intention. Please clarify. 89.217.3.66 (talk) 00:09, 22 March 2015 (UTC)

External links modified
Hello fellow Wikipedians,

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 * Added archive https://web.archive.org/20021219005150/http://www.chemsoc.org:80/exemplarchem/entries/pkirby/exemchem/Boltzmann/Boltzmann.html to http://www.chemsoc.org/exemplarchem/entries/pkirby/exemchem/Boltzmann/Boltzmann.html

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reasons for undo of good faith new research edit
This edit adds new material.

The new material is apparently not covered in established Wiki-reliable sources, but rather appears to be new research published only in a research journal article. As such, it is not supported by Wikipedia-defined reliable sources, and needs to be deleted.

The user who posted the new material is a one-time poster and is not a registered user, but is writing from an IP address, and so is anonymous or unidentifiable. It seems possible or likely that the user who posted the new material is, or is related to, the author of the research journal article. This would raise questions of conflict of interest and self-promotion, contrary to Wikipedia policy. Moreover, the new material would be Wikipedia-defined original research. Such is not permitted by Wikipedia policy, and should be deleted.

For these reasons, I have summarily deleted the new material.

The edit just previous to the added material was not supported by a Wikipedia-defined reliable source, and I have undone it too. The article would be improved by detailed and better reliable sourcing and by a better account of the relevant concepts.

The two undone edits were covered by rather long edit notes. Edit notes should be short. If the edit needs more cover than a short edit note, the extra cover should be provided on the talk page.Chjoaygame (talk) 09:43, 30 July 2021 (UTC)

log or ln?
I am not familiar with this topic and can't find the answer myself (I'm short on time and the first few web search results were unhelpful), does the formula use log base 10 or natural log? I would add this information like this:

... where $$k_\mathrm B $$ is the Boltzmann constant (also written as simply $$k$$) and equal to 1.380649 × 10−23 J/K, and $$\log$$ is the base-10 logarithm/natural logarithm function.

--NeatNit (talk) 17:43, 4 May 2022 (UTC)