Philosophy of Physics Seminar (Thursday - Week 6, HT19)

Philosophy of Physics

In this talk I consider how to reduce the second law of thermodynamics. I first discuss what I mean by ‘reduction’, and emphasis how functionalism can be helpful in securing reductions. Then I articulate the second law, and discuss what the ramifications of Maxwell’s demon are for the status of the second law. Should we take Maxwell’s means-relative approach? I argue no: the second law is not a relic of our inability to manipulate individual molecules in the manner of the nimble-fingered demon. When articulating the second law, I take care to distinguish it from the minus first law (Brown and Uffink 2001); the latter concerns the spontaneous approach to equilibrium whereas the former concerns the thermodynamic entropy change between equilibrium states, especially in quasi-static processes. Distinguishing these laws alters the reductive project (Luczak 2018): locating what Callender (1999) calls the Holy Grail – a non-decreasing statistical mechanical quantity to call entropy – is neither necessary nor sufficient. Instead, we must find a quantity that plays the right role, viz. to be constant in adiabatic quasi-static processes and increasing in non-quasi-static processes, and I argue that the Gibbs entropy plays this role.

There will be a dinner following the seminar (this week at Carluccio's), open to all (at your own expense). Please email by Wednesday morning before the seminar if you would like to attend.

Philosophy of Physics Seminar Convenors for HT19: James Read and Simon Saunders