Talk:Principle of maximum work

Comments

Hi PAR, I just wanted to point out that I think you are mixing up thermodynamics and thermochemistry in Berthelot's work principle in an incorrect historical manner. See: Thermochemistry - Encyclopedia Britannica 1911, for clarification. As far as I know, Berthelot's 1875 principle had nothing to do with thermodynamics; it was a close approximation that tied together heats of reactions with chemical affinity but was later proven to be incorrect. Gibbs 1873 version was completely different, and he called it “the conditions required to find the greatest amount of mechanical work which can be obtained from a given quantity of a certain substance in a given initial state, without increasing its total volume or allowing heat to pass to or from external bodies, except such as at the close of the processes are left in their initial condition. This has been called the available energy of the body. The initial state of the body is supposed to be such that the body can be made to pass from it to states of dissipated energy by reversible processes." Talk later: --Sadi Carnot 18:21, 26 January 2007 (UTC)

Hi Sadi - I've always thought the max work priciple was something to the effect that for a reversible process, you get max work, minimum heat. Then, to be precise, I looked it up in Callen, and it is there, under that name. Thats more or less what I put in the article. Looking at the Britannica entry, it looks like Berthelot developed a principle (now considered defunct?) which he called (or was called) the maximum work principle. I hope I read that right.

Anyway, perhaps we have two different principles here, and need to edit accordingly.

(PS - I'm glad you used that Bohr picture - I can't say it was really mine, since I had read the discussion beforehand and then put in my own take on it.) PAR 23:21, 26 January 2007 (UTC)

Yes, the Bohr model image, owing to the debate, seems to be a good improvement. As to work article, they might be better as separate articles possible, i.e. principle of maximum work (thermochemistry) and principle of maximum work (thermodynamics); yet, for the moment, I’ll just put headers in to distinguish them as different. It’s hard to find information on the older principle, but we can dig around and try to build these as time goes on. Talk later: --Sadi Carnot 15:43, 28 January 2007 (UTC)

Update

So far, per the above talk, I cleaned and sorted the article a bit. It's a good start, but I'm sure it will need further work in future. As soon as I am back reading on these topics, I'll add more. --Sadi Carnot 16:13, 28 January 2007 (UTC)

We probably should cite Callen for the proof - it looks like it came directly from his book. :) — Preceding unsigned comment added by 139.102.78.19 (talk) 14:36, 22 June 2017 (UTC)