Episode 92 · Quantum Biology, part 3 of 3 (finale)
The Brain and the Frontier: Posner Molecules, Microtubules, Diamond Thermometers and What Would Settle It
Day three, in a storm, with a bottle of whisky riding on the outcome. Gus teaches the three ways to estimate decoherence times (scattering, spectral density, spin relaxation) and a fourth way: test the consequence, not the coherence. Wren presents Fisher's 2015 nuclear-spin proposal, the 2018 Player and Hore critique, the 2025 PNAS lithium-isotope calcium phosphate result and a 2025 negative model. They weigh Orch-OR against Tegmark (2000), the Gran Sasso exclusion of parameter-free Diósi-Penrose collapse (Donadi et al. 2020; Derakhshani et al. 2022), Franks and Lieb on anaesthetic targets, Kerskens and López Pérez (2022) and its 2023 rebuttal, Babcock et al. (2024) superradiance, Wiest et al. (2024) epothilone B, the 2018 xenon isotope study, and Zadeh-Haghighi, Craddock, Simon and colleagues' magnesium-25 tubulin result (Science Advances 2026). Then NV-diamond thermometry (Kucsko 2013), Chrétien's 50 °C mitochondria and Baffou's heat-conduction objection, the episode 89 preprint graded, a funding list of decisive experiments, and the final ledger. Wren Halloran and Augustin "Gus" Ferreira are fictional.
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Inside this episode
- Cold open: the storm and the wager
- How decoherence times are estimated
- Why the brain is the hardest place to look
- Fisher's Posner molecules: a quantum brain built from nuclear spins
- Testing the Posner idea
- Orch-OR: consciousness, collapse and microtubules
- The critics: Tegmark, Gran Sasso and the anaesthesia question
- An isotope puzzle in anaesthesia
- New evidence, twenty twenty-two to twenty twenty-six
- Quantum sensing inside cells: diamonds as thermometers
- The mitochondria claim, placed on the ledger
- What experiments would settle things
- The final ledger and the wager
Production credits & AI disclosure
Scripts generated with Claude Opus. Synthetic narration generated with Edge TTS. Reviewed, listened to, and approved by Sankalp Thakur.