Finding temporal asymmetry within the many, many worlds of Everettian quantum mechanics
摘要
Our experience of the world is temporally asymmetric: coffee spontaneously cools, glasses smash, people age and die, while the reverse processes never occur. However, our best theories of fundamental physics are temporally symmetric, making no distinction between past and future directions. This creates a puzzle: how can our asymmetric experiences emerge from a symmetric foundation? The usual solution is to posit a special initial condition for the universe. This solution, however, amounts to putting in the asymmetry by hand, and one may be left looking for a further explanation of this asymmetric boundary condition. In this paper I explore another possible solution, namely that the asymmetry of experience can be explained anthropically, via an observer selection effect. In particular, I use the formalism of decoherent histories to argue that such an explanation is available in the Everettian, or “many worlds”, interpretation of quantum mechanics. Along the way, we will discover that Everettian quantum mechanics implies the existence of many more worlds than are traditionally recognised.