Is it still possible to make a case for string theory? And should we treat the multiverse as a serious idea and explore it mathematically? Here to discuss these fundamental questions with me today is the one and only Brian Greene. Brian Greene, of course, needs no introduction. He is an American theoretical physicist and mathematician. He’s a professor at Columbia University and the director of Columbia’s Center for Theoretical Physics.  Greene has gained a lot of popularity through his books that bring complex physical issues closer to general audiences: The Elegant Universe (1999), Icarus at the Edge of Time (2008), The Fabric of the Cosmos (2004), and The Hidden Reality (2011), a book he promoted in the TV show The Big Bang Theory!  In this episode, Brian and I discuss the experimental relevance of string theory, the multiverse hypothesis, the likelihood of alien life, and much more.  Tune in! Key Takeaways:  Intro (00:00) What’s the experimental minimum? (01:05) String theory’s experimental relevance (08:35) An alternative path to Einstein’s equations (20:17) Are we neglecting some ideas? (25:35) Calabi-Yau manifolds in string theory (34:26) Lorentz invariance and signals that are faster than the speed of light (40:13) The multiverse and its implications for science (57:47) Inflation doesn’t resolve all questions (1:02:18) The role of a scientist as an educator (1:15:04) UFO sightings and the likelihood of alien life (1:27:45) Outro (1:38:26) — Additional resources:  📢 Ownership of your health starts with AG1. Try AG1 and get a FREE 1-year supply of Vitamin D3K2 and 5 FREE AG1 Travel Packs with your first purchase 👉 https://drinkag1.com/impossible 👨‍💻 Check out AppSumo's Black Friday offers: http://appsumo.8odi.net/BRIAN ➡️ Check out Brian Greene:  📚 The Hidden Reality by Brian Greene: https://a.co/d/3LUjEA2  💻 Website: https://www.briangreene.org/  ✖️ Twitter: https://twitter.com/bgreene  ➡️ Follow me on your fav platforms: ✖️ Twitter: https://twitter.com/DrBrianKeating  🔔 YouTube: https://www.youtube.com/DrBrianKeating?sub_confirmation=1  📝 Join my mailing list: https://briankeating.com/mailing_list  ✍️ Check out my blog: https://briankeating.com/blog.php  🎙️ Follow my podcast: https://briankeating.com/podcast  — Into the Impossible with Brian Keating is a podcast dedicated to all those who want to explore the universe within and beyond the known. Make sure to follow so you never miss an episode! Learn more about your ad choices. Visit megaphone.fm/adchoices