Our timesymmetric lifestyle Speaker(s): Marina Cortes
Abstract:
Fundamental physics traditionally views the dynamical laws governing the world as time reversal invariant. The evident arrow of time of nature is then held to be an accident, emerging as we coarse grain and originating in the improbable choice of initial conditions. The main pillar which supports this timesymmetric lifestyle is the fluctuationdissipation theorem, which connects purely timesymmetric microscopic equations to the emergence of a macroscopic arrow of thermodynamics. I will describe arguments from statistical physics claiming that existing proofs of this theorem are faulty and do not demonstrate the emergence of an arrow from timesymmetric laws. I will argue that, as a result of this assumption of time symmetry, we cosmologists stand to pay an unreasonable price concerning what we’re expected to explain. I argue for instead to turn this picture around and propose a fundamental theory of cosmology and quantum gravity which is fundamentally time asymmetric and based on timeirreversible laws. I will describe a new class of models of quantum spacetime, energetic causal sets, in which spacetime itself, as well as aspects of quantum theory, emerge under natural conditions. The framework is based on arXiv:1307.6167 and subsequent papers in collaboration with Lee Smolin. Date: 14/05/2019  11:00 am
Series: Cosmology & Gravitation
