The Time in Thermal Time

Eugene Chua – University of California, San Diego

Tuesday, October 4, 2022
1:00pm–3:00pm (East Coast time)

[Registration Form] (Abstract and Video Below)

• The Foundations of Physics @Harvard series is co-sponsored by the Department of Philosophy
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Video (YouTube), Draft Paper (PDF)


Open Discussion and Q&A


Attempts to quantize gravity in the Hamiltonian approach lead to the ‘problem of time’; the resultant formalism is often said to be ‘frozen’, non-dynamical, and fundamentally timeless. To resolve this problem, Connes & Rovelli (1994) suggest the adoption of a ‘thermal time hypothesis’: on one interpretation of this hypothesis, the flow of time emerges thermodynamically from a fundamentally timeless ontology. While statistical states are typically defined to be in equilibrium with respect to some background time, the proposal is that we instead define time in terms of these statistical states: statistical states define a time according to which they are in equilibrium. To avoid circularity, we better have a good conceptual grasp on notions such as ‘equilibrium’ and ‘statistical state’ which are independent of time. However, I argue that these concepts either implicitly presuppose some notion of time, or cannot be applied justifiably yet to a fundamentally timeless context.