Abstract

The second law of thermodynamics has a lot to answer for. Reichenbach claims it was responsible for the direction of time. Atkins claims that ‘the second law is one of the all-time great laws of science, for it illuminates why anything – anything from the cooling of hot matter to the formulation of a thought – happens at all’. And Hawking claims it is a tautology.

In this talk, I discuss the different concepts of time-asymmetry in thermal physics and claim that the second law has less bite than the authors above suggest. Instead of an arrow of time, it is more appropriate to say, as Uffink suggests, that the second law describes the ravages of time. Instead of considering thermodynamics to be the source of the arrow of time, I claim that statistical mechanics is the theory we should focus on. By looking at a particular framework advocated by Zwanzig, Zeh and Wallace, I discuss how the time-asymmetry in statistical mechanics arises out of the underlying time-symmetric dynamics.