Warsaw Spacetime Colloquium #8 - John D. Norton (2022/02/25)
Channel: International Center for Formal Ontology
Date: 2022-03-05

Title: Eternal Inflation: When Probabilities Fail

Chair: Antonio Vassallo

Abstract: In eternally inflating cosmology, infinitely many pocket universes are seeded. Attempts to show that universes like our observable universe are probable amongst them have failed, since no unique probability measure is recoverable. This lack of definite probabilities is taken to reveal a complete predictive failure. Inductive inference over the pocket universes, it would seem, is impossible. I argue that this conclusion of impossibility mistakes the nature of the problem. It confuses the case in which no inductive inference is possible, with another in which a weaker inductive logic applies. The alternative, applicable inductive logic is determined by background conditions and is the same, non-probabilistic logic as applies to an infinite lottery. This inductive logic does not preclude all predictions, but does affirm that predictions useful to deciding for or against eternal inflation are precluded.
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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.