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?