What is string theory, really? Why does it need extra dimensions? Neil deGrasse Tyson and comedian Chuck Nice welcome theoretical physicist and mathematician Lara Anderson to guide us through string theory, higher dimensions, and finding a unifying theory of everything. Could it be the long-sought bridge between quantum mechanics and Einstein’s theory of gravity? We explore the problem between relativity and quantum physics, and why things break down when combined. Could strings be the key to unifying these two frameworks? How do strings explain particles? And if they’re so small we can’t detect them, how can we confirm the theory? Have we reached a fundamental particle yet? Lara walks us through the geometry of hidden additional dimensions and how to get around untestable theories. Learn about the math behind string theory and the vision Chuck had about the dimensionality of the universe. Can you have two time dimensions? Or a compactified time dimension? Discover how there are an infinite number of quantum theories for not our universe and what it means to consider a spherical cow. Can string theory produce the particle physics we see? We tackle string theory skepticism, the “string landscape,” and the unexpected discoveries made along the way, like the holographic principle to dualities that link seemingly unrelated theories. What does it mean when two different geometries produce the same physics? And is string theory actually connected to the physics we observe? Can AI help us navigate the math? Plus, we discuss the topology of knots and why you can tie a knot in four dimensions. Could string theory be the gateway to new physics? Thanks to our Patrons Rachel Burns, GTH, Ali Al-Mubarak, Tinashe Munyaradzi Majada Duma, Lester Hairston, Shelbi Frowein, Daryl Sheppard, Carlos Fernandez, Bryan Skelton, SHONE JOE, Beverly Jo, Dr. Rob Bryan, Mark Swehla Jr, Jake, Jake, Parvaneh Alavi, Caleb Rohrer, Cryosminitar, Joe Oggier, A Tedla, Chris Crisco, Olga, Colby Hyde, Trevor Morrison, Elizabeth P, Adam Haynes, ice age, craig henry, McKenna Lineback, Emily Martinez, Laura V Pagliaro, Tactalpotato750, Raymond Hal Bonnin II, Vladlen Kogan, Matthias Sabourin, Allan Watson, Jimmy Rose, Joe DiRosa, Cal Mathison, Lex Hayes, Quince Poston, Kathleen OBrien, Ryan Enright, Mahi, and Thomas S. for supporting us this week. Timestamps: 00:00 - Introduction: Lara Anderson 03:14 - What is String Theory? 6:50 - Can We Keep Getting Smaller? 11:01 - Extra Dimensions Necessary 17:00 - Can You Test String Theory? 23:50 - The String Landscape 27:53 - Quantum Phenomenology 29:40 - Discovering the Holographic Principle 34:00 - Knots in Four Dimensions 41:16 - Using AI for String Theory 42:57 - Can String Theory Bring New Physics? 46:17 - Less Supersymmetry & Celebrating Symmetry 54:38 - Mirror Symmetry & Calabia Manifolds 1:00:10 - A Cosmic Perspective Check out our second channel, @StarTalkPlus Get the NEW StarTalk book, 'To Infinity and Beyond: A Journey of Cosmic Discovery' on Amazon: https://amzn.to/3PL0NFn Support us on Patreon: https://www.patreon.com/startalkradio FOLLOW or SUBSCRIBE to StarTalk: Twitter: http://twitter.com/startalkradio Facebook: https://www.facebook.com/StarTalk Instagram: https://www.instagram.com/startalk About StarTalk: Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up! #StarTalk #NeildeGrasseTyson