Thermodynamics and history of physics

A venerable narrative says that teleology died during the Scientific Revolution. McDonough (2020) recently objected that the principle of least action (PLA) shows teleology surviving into Enlightenment physics. Both narratives get the story wrong. The PLA’s history shows that what really happened is much more interesting. When a metaphysical principle became specifiable as a precise physical principle using increasingly sophisticated mathematics, it faced mathematical challenges to its viability, a new norm constraining metaphysics emerges and, far from surviving, teleology in physics is put to rest by novel means.

Taking the formal analogies between black holes and classical thermodynamics seriously seems to first require that classical thermodynamics applies in relativistic regimes. Yet, by scrutinizing how classical temperature is extended into special relativity, I argue that it falls apart. I examine four consilient procedures for establishing classical temperature: the Carnot process, the thermometer, kinetic theory, and black-body radiation. I show how their relativistic counterparts demonstrate no such consilience in defining relativistic temperature. As such, classical temperature doesn’t appear to survive a relativistic extension. I suggest two interpretations for this situation: eliminativism akin to simultaneity, or pluralism akin to rotation.

Two conceptions of thermodynamics are distinguished. On one, thermodynamics is a resource theory, a theory about how agents with specified means of manipulating a physical system can exploit its physical properties to achieve specified ends, such as obtaining useful work. On the other, thermodynamics has been severed from its roots in technological considerations, and is a theory of the macroscopic bulk properties of matter. I argue that the envisaged severance has not and cannot be wholly achieved, and that recognizing this sheds light on the philosophical conundrums associated with thermodynamics, in particular its relation to statistical mechanics.

Thermodynamics is an unusual theory. Prominent figures, including J.C. Maxwell and E.T. Jaynes, have suggested that thermodynamics is anthropocentric. Additionally, fruitful contemporary approaches to quantum thermodynamics label thermodynamics a ‘subjective theory’. Here, we evaluate some of the strongest arguments for anthropocentrism based on the heat/work distinction, the second law, and the nature of entropy. We show that these arguments do not commit us to an anthropocentric view but instead point towards a resource-relative understanding of thermodynamics which can be shorn of the ‘subjective gloss’.