SPONSORS: - Exclusive Plaud Prime Day discount for Curt's viewers: use code CURT for up to 20% OFF at https://www.plaud.ai/curt - Accelerate your efficiency. Sign up for your one-dollar-per-month trial today at http://shopify.com/theories Every episode days early, ad-free, plus my essays: https://curtjaimungal.substack.com/subscribe This is a breaking podcast. We're premiering a new paradigm for quantizing 4D gravity here first, without strings. Neil Turok — inaugural Higgs Chair at Edinburgh, former director of Perimeter Institute, and 2026 Fellow of the Royal Society — believes quantum gravity may not require strings, extra dimensions, or a multiverse. The key: a 1970s theory called quadratic gravity, long abandoned over two seemingly fatal problems. Turok and Bateman argue both problems dissolve — one by reinterpreting a classical instability as ordinary gravitational expansion, the other by a subtle tweak to the Born rule that allows quantum states of negative norm without ever producing negative probabilities. One quiet assumption, Turok argues, underpins decades of string theory's necessity. Drop it, and the whole case for a multiverse unravels. Neil graciously gave me a sneak peek at his and his PhD student Sam Bateman's new research. Bleeding edge! I hope you enjoy. LINKS MENTIONED: - Neil's Papers: https://inspirehep.net/authors/985402 - Renormalization of Higher-Derivative Quantum Gravity [Paper]: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.16.953 - Quadratic Gravity: https://en.wikipedia.org/wiki/Quadratic_gravity - Asymptotic Freedom in Higher-Derivative Quantum Gravity [Paper]: https://www.sciencedirect.com/science/article/abs/pii/0370269385902485 - Ostrogradsky's Theorem: http://www.scholarpedia.org/article/Ostrogradsky's_theorem_on_Hamiltonian_instability - Krein Space: https://en.wikipedia.org/wiki/Indefinite_inner_product_space - CPT-Symmetric Universe [Paper]: https://arxiv.org/abs/1803.08928 - Pathologies of Dimension-Zero Scalar Fields [Paper]: https://arxiv.org/abs/2603.05683 - No-Ghost Theorem for Pais-Uhlenbeck Oscillator [Paper]: https://arxiv.org/abs/0706.0207 - Cancelling the Vacuum Energy [Paper]: https://arxiv.org/abs/2110.06258 - Gravitational Entropy [Paper]: https://arxiv.org/abs/2201.07279 - Neil's Lecture: https://pirsa.org/15100070 - Neil Turok on the Big Bang [TOE]: https://youtu.be/ZUp9x44N3uE - Neil Turok on Black Holes [TOE]: https://youtu.be/zNZCa1pVE20 - Carlo Rovelli [TOE]: https://youtu.be/hF4SAketEHY - Leonard Susskind [TOE]: https://youtu.be/2p_Hlm6aCok - Jacob Barandes [TOE]: https://youtu.be/wrUvtqr4wOs - Geoffrey Hinton [TOE]: https://youtu.be/b_DUft-BdIE - Harvey Friedman [TOE]: https://youtu.be/gx3uKT1qJvY - Scott Aaronson [TOE]: https://youtu.be/1ZpGCQoL2Rk - David Deutsch [TOE]: https://youtu.be/vKeWv-cdWkM - Peter Woit & Joseph Conlon [TOE]: https://youtu.be/fAaXk_WoQqQ More links at https://curtjaimungal.substack.com FOLLOW: - Spotify: https://open.spotify.com/show/4gL14b92xAErofYQA7bU4e - Substack: https://curtjaimungal.substack.com/subscribe - Twitter: https://twitter.com/TOEwithCurt - Discord Invite: https://discord.com/invite/kBcnfNVwqs - Crypto: https://nowpayments.io/donation/TOE - PayPal: https://www.paypal.com/donate?hosted_button_id=XUBHNMFXUX5S4 Guests do not pay to appear. #science