155 - Tony Padilla: Mathematical Platonism, Intergalactic Doppelgängers, and Gigantic Numbers

Tony Padilla is Professor of Physics in the School of Physics & Astronomy at the University of Nottingham, where he is the Associate Director of the new Nottingham Centre of Gravity. Tony works in cosmology, quantum gravity, and related areas. He is also a host of the YouTube channel Numberphile, and the author of Fantastic Numbers and Where to Find Them: A Cosmic Quest from Zero to Infinity (Farrar, Straus, and Giroux, 2022). In this episode, Robinson and Tony discuss some of these fantastic numbers. They begin with the question of how numbers relate to physics and the world more generally before turning to Graham’s Number, Tree(3), and the question of whether or not we have doppelgängers elsewhere in the universe. Fantastic Numbers and Where to Find Them: https://a.co/d/jiLCOJe Numberphile: https://www.youtube.com/@numberphile OUTLINE 00:00 In This Episode… 00:13 Introduction 02:57 Tony’s Interest in Numbers 07:51 Are Numbers Parts of the Physical World? 20:12 Do We Have Doppelgängers Elsewhere in the Universe? 54:16 What is Graham’s Number? 01:03:22 Tree(3) 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.