UC San Diego

This paper deals with the long-standing conflict between interpretations of thermoelectricity based on the original reversible thermodynamics of Thomson and the later irreversible thermodynamics of Onsager. It is shown that, by a slight modification of the Maxwellian relaxation treated in a previous paper [J. Goddard and K. Kamrin, “Dissipation potentials from elastic collapse,” Proc. R. Soc. A 475, 20190144 (2019)], Onsager's symmetry is simply a reflection of the underlying symmetry of equilibrium thermodynamics. It is also shown that a modern interpretation of Thomson's thermodynamics, as given recently by the present author, reveals thermoelectricity to be the analog of a fluid-mechanical transport process with the limit of thermodynamic equilibrium corresponding to the convection-dominated regime of large Péclet number.