John Donoghue: We Have Already Quantized Gravity (And It Works)

Theories of Everything with Curt Jaimungal

Curt Jaimungal

Physics, Philosophy, Society & Culture, Science

4.6 • 606 Ratings

🗓️ 11 March 2026

⏱️ 69 minutes

🔗️ Recording | iTunes | RSS

🧾️ Download transcript

Summary

Professor John Donoghue explains why quantum physics and gravity actually work perfectly together. He tackles quadratic gravity, effective field theory, and random dynamics, arguing that grand unification and naturalness aren't required for a theory of everything. I personally subscribe to The Economist. TOE listeners get 35% off the annual subscription. No other podcast has this! https://economist.com/TOE SUPPORT: - Support me on Substack: https://curtjaimungal.substack.com/subscribe - Support me on Crypto: https://commerce.coinbase.com/checkout/de803625-87d3-4300-ab6d-85d4258834a9 - Support me on PayPal: https://www.paypal.com/donate?hosted_button_id=XUBHNMFXUX5S4 JOIN MY SUBSTACK (Personal Writings): https://curtjaimungal.substack.com LISTEN ON SPOTIFY: https://open.spotify.com/show/4gL14b92xAErofYQA7bU4e TIMESTAMPS: - 00:00:00 - Limits of Quantum Mechanics - 00:06:35 - Effective Field Theory - 00:12:24 - Gravity: Geometry or Force? - 00:18:46 - QFT and Gravity Tension - 00:24:59 - Quadratic Gravity Theory - 00:34:16 - Dueling Arrows of Causality - 00:41:57 - Random Dynamics and Anti-Unification - 00:48:13 - The Naturalness Problem - 00:53:40 - Questioning Hidden Assumptions LINKS MENTIONED: - John's lectures: https://www.youtube.com/@johndonoghue469/featured - John's papers: https://arxiv.org/a/donoghue_j_1.html - The Renormalization Group and Critical Phenomena [Paper]: https://www.nobelprize.org/uploads/2018/06/wilson-lecture-2.pdf - Anthropic Considerations in Multiple-Domain Theories [Paper]: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.80.1822 - Old "Ghost" Theory of Quantum Gravity Makes a Comeback [Article]: https://www.quantamagazine.org/old-ghost-theory-of-quantum-gravity-makes-a-comeback-20251117/ - Unitarity, Stability and Loops of Unstable Ghosts [Paper]: https://arxiv.org/pdf/1908.02416 - An Effective Field Theory of Gravity for Extended Objects [Paper]: https://arxiv.org/abs/hep-th/0409156 - Not Quite a Black Hole [Paper]: https://arxiv.org/pdf/1612.04889 - On Quadratic Gravity [Paper]: https://arxiv.org/pdf/2112.01974 - Quadratic Gravity [Paper]: https://arxiv.org/pdf/1804.09944 - Renormalization of Higher Derivative Quantum Gravity [Paper]: http://www.weylmann.com/stelle.pdf - Quantum Theory in a Nutshell [Book]: https://www.amazon.com/Quantum-Field-Theory-Nutshell-nutshell/dp/0691140340 - Field Theory: A Modern Primer [Book]: https://www.amazon.com/Field-Theory-Modern-Frontiers-Physics/dp/0201546116 - Origin of Symmetries [Book]: https://amzn.to/4qxnLzj - String Theory Iceberg [TOE]: https://youtu.be/X4PdPnQuwjY - Neil Turok [TOE]: https://youtu.be/zNZCa1pVE20 - Avshalom Elitzur [TOE]: https://youtu.be/pWRAaimQT1E - Sir Roger Penrose [TOE]: https://youtu.be/iO03t21xhdk - Ted Jacobson [TOE]: https://youtu.be/3mhctWlXyV8 - Leonard Susskind [TOE]: https://youtu.be/2p_Hlm6aCok - Jonathan Oppenheim [TOE]: https://youtu.be/NKOd8imBa2s - Peter Woit [TOE]: https://youtu.be/TTSeqsCgxj8 - Joseph Conlon & Peter Woit [TOE]: https://youtu.be/fAaXk_WoQqQ - Michael Levin [TOE]: https://youtu.be/c8iFtaltX-s 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. Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

Transcript

Click on a timestamp to play from that location

0:00.0	I remember the doubt before launching this podcast. What if no one listens? What if I'm wasting my time?
0:06.2	If you've ever felt that way about starting a business, Shopify is the partner that turns uncertainty into momentum.
0:12.9	They power millions of businesses and 10% of all U.S. e-commerce from all birds to gym sharks to brands just getting started.
0:20.7	No straggler left behind.
0:22.7	Shopify's AI tool writes your product descriptions for you.
0:26.4	It enhances your photography.
0:28.0	It builds you a stunning store from hundreds of templates.
0:31.6	Forget about the dormative haze of bouncing between separate platforms.
0:36.1	Shopify puts inventory payments and analytics under one roof
0:40.3	with the propriety of a true commerce expert.
0:43.9	Their award-winning 24-7 support means you're never alone.
0:48.6	And that iconic purple shop pay button,
0:51.3	it's the backbone of their checkout,
0:53.3	the best converting on the planet, turning
0:55.8	abandoned carts into actual sales. It's time to turn those what-ifs into with Shopify today.
1:04.5	Sign up for your $1 per month trial at Shopify.com slash tow. That's Shopify.com slash T-O-E.
1:14.9	I think the popular phrasing is totally wrong. Quantum physics and gravity go perfectly well,
1:21.7	as well as any other theory we know about. One of the biases of the field is that things unify. And we don't really have any
1:29.1	evidence for that. I'm actually a champion of a crazier theory. You've heard it before.
1:35.9	Quantum theory and general relativity are fundamentally incompatible. But is that actually true?
1:42.0	Or is it something we just say so often we start to believe it?
1:45.2	Professor John Donahue thinks this entire framing is misleading.
	...

Please login to see the full transcript.

Previous episode | Next episode

Disclaimer: The podcast and artwork embedded on this page are from Curt Jaimungal, and are the property of its owner and not affiliated with or endorsed by Tapesearch.

Generated transcripts are the property of Curt Jaimungal and are distributed freely under the Fair Use doctrine. Transcripts generated by Tapesearch are not guaranteed to be accurate.