S = k ln(B(W)): Boltzmann entropy, the Second Law, and the Architecture of Hell

Tim W.E. Maudlin
New York University
New York, USA

The so-called Boltzmann entropy, in its modern formulation, is defined in terms of the volume of phase space associated with different macrostates or generic states. I will argue that the proper definition of this sort—the one that makes contact with the explanatory challenges of statistical mechanical explanation—should actually be in terms of the boundaries of those generic states rather than their volumes. This change in focus bring out the essential nature of the statistical independence assumption that underlies these explanations, and sheds light on how the direction of time comes into the explanation.