Warsaw Spacetime Colloquium #1 - Carlo Rovelli (2020/10/02)
Channel: International Center for Formal Ontology
Date: 08/10/2020

Title: Why can we decide what we shall do tomorrow, but we cannot decide what we did yesterday? Time reversibility and the physics of an agent

Chair: Antonio Vassallo

Abstract: Much of the confusion in the philosophy of spacetime stems from the failure to recognize that 'space' and 'time' (and a fortiori 'spacetime') are layered concepts used to denote a variety of different notions.  I disentangle the different uses of these words, and discuss what we understand about the different layers in contemporary physics.  In the second part of the talk I discuss in particular the arrow of time: the reason why the past is fixed and the future open. I show that we remember the past (not the future) and we can affect the future (not the past) because of the entropy gradient.  Hence the fact that the past is fixed and the future is open is a macroscopic, statistical, phenomenon.
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The Colloquium's goal is to provide a window into the state-of-the-art in the foundations of spacetime physics. It brings together top-level philosophers and physicists willing to share their current research with an international audience. The Colloquium is organized by the Philosophy of Physics Group at the International Center for Formal Ontology, Faculty of Administration and Social Sciences, Warsaw University of Technology.