Jonathan Oppenheim: Why Gravity Might Not Be Quantum After All

Jonathan Oppenheim (UCL) challenges quantum gravity orthodoxy, arguing spacetime remains 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 TOESPONSORS:- I personally subscribe to The Economist. SUMMER SALE to Aug 17, 2026: 50% off the annual subscription! No other podcast has this! https://economist.com/TOE- Indeed: Get your jobs more visibility – https://indeed.com/theories ($75 credit to book your job visibility)- HelloFresh: FREE breakfast for life – https://www.HelloFresh.com/freetheoriesofeverythingRESOURCES:- 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- Patreon: https://patreon.com/curtjaimungal (early access to ad-free audio episodes!)- Listen on Spotify: https://open.spotify.com/show/4gL14b92xAErofYQA7bU4e- Become a YouTube Member Here: https://www.youtube.com/channel/UCdWIQh9DGG6uhJk8eyIFl1w/join- Join TOEmail at https://www.curtjaimungal.org- Crypto: https://nowpayments.io/donation/TOE- PayPal: https://tinyurl.com/paypalTOE- TOE Merch: https://tinyurl.com/TOEmerch- Instagram: https://www.instagram.com/theoriesofeverythingpod- TikTok: https://www.tiktok.com/@theoriesofeverything_- Twitter: https://twitter.com/TOEwithCurt- Discord Invite: https://discord.com/invite/kBcnfNVwqs- iTunes: https://podcasts.apple.com/ca/podcast/better-left-unsaid-with-curt-jaimungal/id1521758802- Pandora: https://pdora.co/33b9lfP- Subreddit r/TheoriesOfEverything: https://reddit.com/r/theoriesofeverything Theories of Everything with Curt Jaimungal features long-form, technically detailed interviews with leading researchers in physics, mathematics, consciousness, and philosophy, exploring topics at the level of active research. For academics, graduate students, and anyone seeking depth beyond popular science. FOLLOW: Substack | Spotify | YouTube | Twitter Learn more about your ad choices. Visit megaphone.fm/adchoices