The time in thermal time

Abstract

Preparing general relativity for quantization in the Hamiltonian approach leads to the ‘problem of time’, rendering the world fundamentally timeless. One proposed solution is the ‘thermal time hypothesis’, which defines time in terms of states representing systems in thermal equilibrium. On this view, time is supposed to emerge thermodynamically even in a fundamentally timeless context. Here, I develop the worry that the thermal time hypothesis requires dynamics—and hence time—to get off the ground, thereby running into worries of circularity.