In this episode Jonathan Oppenheim, a leading quantum information theorist at UCL, discusses the challenges of unifying quantum mechanics with gravity and explores whether spacetime is fundamentally classical. He examines quantum‑classical hybrid dynamics, path integrals, and the role of observation in collapse, offering fresh perspectives on the foundations of physics.
- 00:00 - Intro
- 01:08 - Quantum Mechanics and Classical Mechanics
- 06:05 - Quantizing Gravity
- 10:30 - How Gravity is Different
- 16:07 - Classical-Quantum Gravity
- 21:42 - Quantum Mechanics
- 25:23 - Example of Continuous Master-Equation
- 28:45 - Observation Causes a Collapse
- 35:20 - Path Integrals
- 49:34 - Intuitions
- 59:32 - Is Spacetime Classical?
- 01:03:05 - Outro / Support TOE
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RESOURCES:
- Sean Carroll on TOE: https://www.youtube.com/watch?v=9AoRxtYZrZo
- Jonathan's first appearance on TOE: https://www.youtube.com/watch?v=NKOd8imBa2s
- Jonathan's paper on hybrid classical-quantum dynamics: https://arxiv.org/pdf/2203.01332
- Jonathan's paper on a post-quantum theory of classical gravity: https://journals.aps.org/prx/pdf/10.1103/PhysRevX.13.041040
- Jonathan's website: https://www.ucl.ac.uk/oppenheim/
- List of all of Jonathan's published papers: https://arxiv.org/search/?query=Oppenheim%2C+Jonathan&searchtype=author&abstracts=show&order=-announced_date_first&size=50
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