Philosophy of Physics Graduate Lunch Seminar

Abstract: Standard presentations of the first law of thermodynamics take the work-heat decomposition as a primitive. They do not derive from the microscopic particle dynamics what makes a process work-only. This talk provides a microscopic realization of this split using the Hamiltonian mechanics of the constituent particles. I treat the confined phase space as a fiber bundle over a manifold of macroscopic controls. First, using local spatial trivializations, I induce an Ehresmann connection, where work and heat appear naturally as the horizontal and vertical components of the internal energy differential. Then, through microcanonical averaging, I integrate out the microscopic degrees of freedom, obtain gauge-invariant macroscopic thermodynamic forms, and recover Jauch’s conservation law directly.

_{Philosophy of Physics Graduate Lunch Seminar Convenors: Paolo Faglia, Gregor Gajic and Rachel Pedersen}