The Story of Loop Quantum Gravity From the Big Bounce to Black Holes

The Story of Loop Quantum Gravity From the Big Bounce to Black Holes

What happens at the centre black holes? What happened before the big bang? A quantum theory of gravity is needed to answer these questions . Many of the leading scientists who developed Loop Quantum Gravity, one of the most promising attempts, tell the story of how it was developed in this film. We also go on to explore how the theory may be tested via observations of black holes or probing the very early universe. We interview Carlo Rovelli, Lee Smolin, Abhay Ashtekar, Sir Roger Penrose, Aurélien Barrau and Francesca Vidotto. The film tackle some of the biggest questions of existence. Since we filmed this last year Francesca Vidotto has been appointed professor at the University of Western Ontario!. Congratulations Francesca. A timeline of the subjects is below: 00:00 Intro 00:58 Scientists introduce themselves 3:07 First steps , early attempts at quantum gravity 7:05 What is a gauge theory ? 8:10 Ashtekar’s rewrites relativity 11:00 Lee, Carlo and Abhay on each other. 12:40 Lee and Ted solve the quantum gravity equation 13:22 Getting rid of the Lattice. 14:30 Lee and Ted are stuck 15:34 Carlo solves the problems 18:27 Why Loop Quantum Gravity is not about loops 19:45 It’s been done before 21:17 Roger Penrose spin networks 25:30 How Abhay came to work for Roger 26:50 The entropy of black holes 30:33 Loop theorists on string theory 34:25 Loop Quantum Gravity and dynamics 35:53 The big bang 36:56 Martin Bojowald resolves the singularity ]37:30 The big bounce 37:45 Improved big bounce model 38:39 Signatures of the big bounce in the sky 42:50 Hawking Hartle No boundary proposal from LQC? 43:53 No singularities can form in the early universe 44:14 Predicting the duration of inflation 45:05 Effects from the universe before the bounce 45:27 Has the universe always existed? 47:10 Penrose Hawking singularity theorem 48:03 BGV theorem 48:49 Wall theorem 49:20 Why was the big bang such low entropy? 50:40 Erebons 52:02 Gravitational entropy 53:40 Are contracting universes unstable and so what if they are? 54:58 Fine tuning and the multiverse 57:05 Is inflation fine tuned , LQC versus GR 57:55 Lorentz invariance? 1:01:20 Where do the new spacetime atoms come from? 1:01:50 Black holes in Loop Quantum Gravity 1:03:01 Bouncing black holes 1:05:10 Testing bouncing black holes with fast radio bursts and other methods 1:10:22 Going through the bounce 1:11:37 What comes next? 1:13:14 What’s it like to gamble your career on a bold new idea?