If something is possible, has the universe tried it? Are all physical possibilities inevitable? Neil deGrasse Tyson sits down with theoretical astrophysicist Janna Levin to launch “In Theory,” a new StarTalk series celebrating the weird, wacky theories of the universe and the theorists who chase them. Out on YouTube October 29, 2026! What if nature has already tried every experiment the laws of physics allow? We explore whether every solar system combination has been attempted, if our big bang is the only big bang, and if there are multiple universes, do they collide and overlap? We discuss why theorists sometimes wait centuries for vindication and whether the laws of physics were just a roll of the dice. Are we pre-Copernican for the universe? We discuss we’re not even made of the stuff that makes up most of the cosmos, and Neil and Janna imagine what dark matter beings would make of us. How long would it take dark matter scientists to notice the matter universe? Next, theories nobody saw coming: surprise particles, Schwarzschild’s black hole solution from the front lines, Einstein’s doubts, dark matter & energy, Newton, Eddington’s eclipse, and the planet Vulcan. Is the universe actually knowable? They ask whether relativity must nest inside a quantum theory of gravity and whether the universe is only describable statistically. Finally, wormholes, negative energy, conjectures like chronology protection, cosmic origami, and what to do when a theory’s predictions can’t be found in the universe. Plus, what does it mean to make a prediction that can’t be found in the universe? Timestamps: 00:00 - Introduction: In Theory… with Janna Levin 02:58 - Is the Universe Trying Every Experiment? 05:18 - The Multiverse Deposing Us from the Center 09:50 - Dark Matter Scientists Studying Us 11:40 - The Stuff That No One Saw Coming 13:35 - The Black Hole Solution 16:53 - Everything is Conceivable 18:05 - Einstein’s Contradictions 19:14 - Is the Universe Knowable? 25:55 - The New Frontier 30:05 - Wormholes & Conjectures 33:28 - In Theory Topics 37:43 - Are There Things We Can’t Discover? 39:00 - Closing Thanks to our Patrons Elamar, Natalia Nelicheva, Kyron Laskosky, Stanley Tai, Jan, Chris Tringali, Nikki Tea, Jay Kapadia, Sean Moran, SnakeSurfer, Roddie, Sam Sillmon, Graham West, Ben Fisk, ChexVC, aitor clemente ramos, Max Forkel, George Fox, and HKRDiary for supporting us this week. Get the NEW StarTalk book, 'Lost in Space: 5,000 Facts for Navigating the Universe' on Amazon: Order Take Me to Your Leader here 👇 Check out our second channel, @StarTalkPlus Support us on Patreon: FOLLOW or SUBSCRIBE to StarTalk: Twitter: Facebook: Instagram: 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! © 2026 Curved Light Productions. All rights reserved. STARTALK is a registered U.S. trademark of Curved Light Productions. Curved Light Productions also maintains rights in the A/legs design logo, STARTALK, STARTALK+, STARTALK PLUS in the U.S. and various countries throughout the world, and these and all other associated logos, marks, and trade dress are the property of Curved Light Productions. This video, including all audio, video, graphics, and accompanying materials, is the exclusive property of Curved Light Productions. No part of this video may be reproduced, distributed, publicly performed, transmitted, or used to create derivative works, in whole or in part, in any medium now known or hereafter devised, without the prior express written permission of Curved Light Productions. Unauthorized use, including reuploading, re-editing, or incorporation into third-party content, is a violation of United States and international copyright law and will be enforced. For licensing and permissions inquiries: licensing@ #StarTalk #NeildeGrasseTyson