Lee Smolin is a founding and senior faculty member at the Perimeter Institute for Theoretical Physics. He is best known for contributions to quantum gravity as a co-inventor of loop quantum gravity and deformed special relativity. Beyond his work in other areas of physics, Lee has written a number of best-selling books, the most recent of which is Einstein’s Unfinished Revolution: The Search for What Lies Beyond the Quantum (Penguin, 2019). In this episode, Robinson and Lee discuss one of the main tenets that has characterized his work over the past decades: Realism. They first talk about realism in quantum mechanics before moving on to Lee’s version of radical presentism, in which only what is occurring in the immediate present can be said to exist, before finishing the main body of their conversation with mathematics and its relation to both physics and cosmology. The episode ends with brief digressions on biology and living with Parkinson’s disease. Lee is also an Honorary Fellow of the John Bell Institute for the Foundations of Physics. If you’re interested in the foundations of physics—which you absolutely should be—then please check out the JBI, which is devoted to providing a home for research and education in this important area. Any donations are immensely helpful at this early stage in the institute’s life.Einstein’s Unfinished Revolution: https://a.co/d/7GHcebpThe Singular Universe and the Unreality of Time: https://a.co/d/hZqLT59Lee’s Website: https://leesmolin.comThe John Bell Institute: https://www.johnbellinstitute.org/homeRobinson’s Website: http://robinsonerhardt.comRobinson 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.