J.J. Thomson and Duhem’s Lagrangian Approaches to Thermodynamics†
AbstractIn the last decades of the nineteenth century, different attitudes towards mechanics led to two main theoretical approaches to thermodynamics: an abstract and phenomenological approach, and a very different approach in terms of microscopic models. In reality some intermediate solutions were also put forward. Helmholtz and Planck relied on a mere complementarity between mechanical and thermal variables in the expressions of state functions, and Oettingen explored the possibility of a more demanding symmetry between mechanical and thermal capacities. Planck refused microscopic interpretations of heat, whereas Helmholtz made also recourse to a Lagrangian approach involving fast hidden motions. J.J. Thomson incorporated the two mechanical attitudes in his theoretical framework, and put forward a very general theory for physical and chemical processes. He made use of two sets of Lagrangian coordinates that corresponded to two components of kinetic energy: alongside macroscopic energy, there was a microscopic energy, which was associated with the absolute temperature. Duhem put forward a bold design of unification between physics and chemistry, which was based on the two principles of thermodynamics. From the mathematical point of view, his thermodynamics or energetics consisted of a Lagrangian generalization of mechanics that could potentially describe every kind of irreversible process, explosive chemical reactions included. View Full-Text
Share & Cite This Article
Bordoni, S. J.J. Thomson and Duhem’s Lagrangian Approaches to Thermodynamics. Entropy 2014, 16, 5876-5890.
Bordoni S. J.J. Thomson and Duhem’s Lagrangian Approaches to Thermodynamics. Entropy. 2014; 16(11):5876-5890.Chicago/Turabian Style
Bordoni, Stefano. 2014. "J.J. Thomson and Duhem’s Lagrangian Approaches to Thermodynamics." Entropy 16, no. 11: 5876-5890.