121 - Julian Barbour: Thermodynamics, Boltzmann Brains, and a New Theory of Time

Julian Barbour is a physicist working in the foundations of physics and quantum gravity, with a special interest in time and the history of science. In this episode, Julian and Robinson discuss thermodynamics and the arrows of time, including a new theory of time developed by Julian and his collaborators, which is laid out in his book, The Janus Point: A New Theory of Time. If you’re interested in the foundations of physics—which you absolutely should be—then please check out the John Bell Institute (Julian is an Honorary Fellow at the JBI), which is devoted to providing a home for research and education in this important area. At this early stage any donations are immensely helpful. Julian’s Website: http://platonia.com/index.html The Janus Point: https://a.co/d/4NVOGqq A History of Thermodynamics: http://platonia.com/A_History_of_Thermodynamics.pdf Quantum without Quantum:  https://arxiv.org/abs/2305.13335 The John Bell Institute: https://www.johnbellinstitute.org OUTLINE 00:00 In This Episode… 00:56 Introduction 04:42 Julian’s Interest in Time 07:27 Time’s Arrows 23:34 The Problem of Time-Reversal Symmetry 25:54 A Potted Overview of Entropy and Thermodynamics 38:21 Entropy and Time’s Arrow 52:32 The Janus Point and a New Theory of Time 01:07:00 Intuition and The Janus Point 01:21:21 Entropy and Entaxy 01:26:00 Cosmic Inflation and Its Problems 01:44:05 Quantum Mechanics without the Wave Function Robinson’s Website: http://robinsonerhardt.com Robinson Erhardt researches symbolic logic and the foundations of mathematics at Stanford University. Join him in conversations with philosophers, scientists, weightlifters, artists, and everyone in-between.