Lex Fridman Podcast

Conversations about AI, science, technology, history, philosophy and the nature of intelligence, consciousness, love, and power.

Author: Lex Fridman

Conversations about science, technology, history, philosophy and the nature of intelligence, consciousness, love, and power. Lex is an AI researcher at MIT and beyond.
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Genres: Science, Technology

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#485 – David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy
Monday, 17 November, 2025

David Kirtley is a nuclear fusion engineer and CEO of Helion Energy, a company working on building the world's first commercial fusion power plant by 2028. Thank you for listening ❤ Check out our sponsors: https://lexfridman.com/sponsors/ep485-sc See below for timestamps, transcript, and to give feedback, submit questions, contact Lex, etc. Transcript: https://lexfridman.com/david-kirtley-transcript CONTACT LEX: Feedback - give feedback to Lex: https://lexfridman.com/survey AMA - submit questions, videos or call-in: https://lexfridman.com/ama Hiring - join our team: https://lexfridman.com/hiring Other - other ways to get in touch: https://lexfridman.com/contact EPISODE LINKS: David's X: https://x.com/dekirtley David's LinkedIn: https://bit.ly/4qX0KXp Helion: https://www.helionenergy.com/ Helion's YouTube: https://youtube.com/HelionEnergy SPONSORS: To support this podcast, check out our sponsors & get discounts: UPLIFT Desk: Standing desks and office ergonomics. Go to https://upliftdesk.com/lex Fin: AI agent for customer service. Go to https://fin.ai/lex Miro: Online collaborative whiteboard platform. Go to https://miro.com/ LMNT: Zero-sugar electrolyte drink mix. Go to https://drinkLMNT.com/lex BetterHelp: Online therapy and counseling. Go to https://betterhelp.com/lex Shopify: Sell stuff online. Go to https://shopify.com/lex OUTLINE: (00:00) - Introduction (03:00) - Sponsors, Comments, and Reflections (11:35) - Nuclear fission vs fusion (21:35) - Physics of E=mc^2 (26:50) - Is nuclear fusion safe? (32:11) - Chernobyl (38:38) - Geopolitics (40:33) - Extreme scenarios (47:28) - How nuclear fusion works (1:20:20) - Extreme temperatures (1:25:21) - Fusion control and simulation (1:37:15) - Electricity from fusion (2:11:20) - First fusion power plant in 2028 (2:18:13) - Energy needs of GPU clusters (2:28:38) - Kardashev scale (2:36:33) - Fermi Paradox PODCAST LINKS: - Podcast Website: https://lexfridman.com/podcast - Apple Podcasts: https://apple.co/2lwqZIr - Spotify: https://spoti.fi/2nEwCF8 - RSS: https://lexfridman.com/feed/podcast/ - Podcast Playlist: https://www.youtube.com/playlist?list=PLrAXtmErZgOdP_8GztsuKi9nrraNbKKp4 - Clips Channel: https://www.youtube.com/lexclips