321 | David Tong on Open Questions in Quantum Field Theory

<p>Quantum field theory is the basis for our most successful theories of fundamental physics. And yet, there are things we don't understand about it. Some of these puzzles are relatively well-known, while others are less celebrated. David Tong joins us to talk about some of the more interesting and perplexing aspects of quantum field theory. He also discusses his new project to write a series of textbooks covering (all?) important topics in theoretical physics. To date, these include <a href="http://www.damtp.cam.ac.uk/user/tong/books/classical.html" rel="noopener noreferrer" target="_blank"><em>Classical Mechanics</em></a>, <a href="http://www.damtp.cam.ac.uk/user/tong/books/quantum.html" rel="noopener noreferrer" target="_blank"><em>Quantum Mechanics</em></a>, <a href="http://www.damtp.cam.ac.uk/user/tong/books/fluids.html" rel="noopener noreferrer" target="_blank"><em>Fluid Mechanics</em></a>, and <a href="http://www.damtp.cam.ac.uk/user/tong/books/electro.html" rel="noopener noreferrer" target="_blank"><em>Electromagnetism</em></a>.</p> <p>Blog post with transcript: <a href="https://www.preposterousuniverse.com/podcast/2025/07/14/321-david-tong-on-open-questions-in-quantum-field-theory/" rel="noopener noreferrer" target="_blank">https://www.preposterousuniverse.com/podcast/2025/07/14/321-david-tong-on-open-questions-in-quantum-field-theory/</a></p> <p>S<em>upport Mindscape on </em><a href="https://www.patreon.com/seanmcarroll" rel="noopener noreferrer" target="_blank"><em>Patreon</em></a><em>.</em></p> <p>David Tong received his Ph.D. in theoretical physics from Swansea University. He is currently a professor of Theoretical Physics in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. He is a winner of the Adams Prize and a Simons Investigator. In addition to his books, he has written many <a href="https://www.damtp.cam.ac.uk/user/tong/teaching.html" rel="noopener noreferrer" target="_blank">freely-available sets of lecture notes</a> on topics in physics.</p> <ul> <li><a href="https://www.damtp.cam.ac.uk/user/tong/" rel="noopener noreferrer" target="_blank">Cambridge web page</a></li> <li><a href="https://scholar.google.com/citations?user=felFiY4AAAAJ&amp;hl=en" rel="noopener noreferrer" target="_blank">Google Scholar publications</a></li> <li><a href="https://www.amazon.com/stores/Dr-David-Tong/author/B00OH8ZMA4" rel="noopener noreferrer" target="_blank">Amazon author page</a></li> <li><a href="https://en.wikipedia.org/wiki/David_Tong_(physicist)" rel="noopener noreferrer" target="_blank">Wikipedia</a></li> <li><a href="https://www.youtube.com/watch?v=zNVQfWC_evg&amp;ab_channel=TheRoyalInstitution" rel="noopener noreferrer" target="_blank">Royal Institution lecture on quantum field theory</a></li> </ul> <p><br /></p>