What is time? Isaac Newton described it as absolute, but Einstein proved that time is relative, and, shockingly, that time and space are intricately interwoven. Now recent work in string theory and quantum gravity suggests that space and time may not be fundamental. If this is true, what new picture of reality will emerge? This program is part of the Big Ideas Series, made possible with support from the John Templeton Foundation. Subscribe to our YouTube Channel for all the latest from WSF. Visit our Website: http://www.worldsciencefestival.com/ Like us on Facebook: https://www.facebook.com/worldsciencefestival Follow us on twitter: https://twitter.com/WorldSciFest Original Program Date: May 31, 2015 Host: Jim Holt PARTICIPANTS: David Z. Albert, Vijay Balasubramanian, Carlo Rovelli, Lee Smolin Jim Holt's introduction 00:00 Participant Introductions 02:34 What intellectual changes happened between Newton and Einstein? 04:22 How does simultaneity break down in special relativity? 09:55 Lee's 5 things to know about Special Relativity. 14:50 Does knowing what time is have any practical purpose. 19:28 Why didn't Einstein have the last word on time? 24:15 What is loop quantum theory? 29:46 Albert has different theories that isn't loop theory or string theory. 35:30 VJ metaphor about Love to explain time. 40:49 Lee and Carlo disagree over the reality of time. 42:16 Is time fundamental, and space is emergent? 51:55 Are doing we science or metaphysics? 01:01:45 David disagrees with Lee's viewpoint on time. 01:03:03 VJ and Carlo answers if this is metaphysics or physics. 01:06:23 Carlo's studies with black holes. 01:14:42