In thermodynamics, pure thermodynamics refers to the presentation of thermodynamics in its purest form.
The term is peculiar to a number of hardened thermodynamicists, in particular Gilbert Lewis and prior to him Max Planck, and to each seems to connotate a certain very specific, yet undefined meaning.
Planck uses the term several times in his 1915 Lectures on Theoretical Physics, in one point of which he states that the Ludwig Boltzmann’s probability description an ideal monatomic gas used to calculate properties of that gas allows one to reach conclusions that “lie essentially beyond those of pure thermodynamics.” [1]
Lewis used the term twice in his classic 1923 chemical thermodynamics textbook. [2] In 1930, Lewis commented famously: [3]
“Time is not one of the variables of pure thermodynamics.”
This indeed is an interesting point of view; giving way to the notion that time is something that may not exist, at least within the context of pure thermodynamics.
English theoretical physicist Alan Wilson, in the preface to his 1956 Thermodynamics and Statistical Mechanics, seems to give the indication that pure thermodynamics is what existed before the split, in the circa 1870s and the decades to follow, of thermodynamics into the versions known to the physicists (statistical mechanics) and the version known to the chemists (physical chemistry): [4]
“My own experience is that many theoretical physicists cannot follow an argument which appeals to chemists, because they are unable to distinguish between what is pure thermodynamics and what is physical chemistry.”
See also
● Classical thermodynamics
References
1. Planck, Max. (1915). Eight Lectures on Theoretical Physics (pure thermodynamics, pgs. 41, 43, 70, 103). Columbia University Press.
2. Lewis, Gilbert and Randall, Merle. (1923). Thermodynamics and the Free Energy of Chemical Substances (pure thermodynamics, pgs. 6, 384). McGraw-Hill.
3. (a) Lewis, Gilbert. (1930). “The Symmetry of Time in Physics” (abs), Science, 71: 569-76.
(b) Ben-Naim, Arieh. (2008). A Farewell to Entropy: Statistical Thermodynamics based on Information (pg. 20). World Scientific.
4. Wilson, Alan H. (1956). Thermodynamics and Statistical Mechanics (pg. ix). Cambridge University Press.
