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Lex Fridman 17 Nov 2025 30 here now

David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy | Lex Fridman Podcast #485

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.
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Outstanding interview and amazing clarification of the multiple ways we are approaching fusion power as we move to full scale application.
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I retired from Helion Energy in 2021. I spent 35 years working as a technician on FRC machines. About half of that at the University of Washington. 2 of Helion’s founders came from the UW. I would like to give a shout out to some of the pioneers of FRC research. These are some of the scientists I worked with over the years. Alan Hoffman. John Slough. Richard Milroy. Ed Crawford. George Vlases. Bob Brooks. Adam Pietrzyk. The other 2 founders George Votroubek and Chris Pihl. It was a privilege to work alongside these men. I’m glad I retired when I did. They were going from R&D to manufacturing. I’m a R&D guy.
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The fact that Helion is choosing speed of production over absolute precision is what will make them the leader in the field. The biggest hurdle of the years ahead is not how much is changing but how fast it’s changing. We need solutions delivered at the same pace.
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Great episode. I’d just like to clarify that the historical photo showing water cannons, fire, and smoke around the 24-minute mark actually depicts the Cosmo Oil refinery fire in Ichihara, Chiba Prefecture, Japan - not the Fukushima Daiichi Nuclear Power Plant. The earthquake caused the supports of a spherical LPG tank to collapse, rupturing pipes and releasing gas that ignited. The blaze spread to nearby tanks, triggering multiple explosions and a massive fire that burned out of control for ten days. Unfortunately, this image is often misused by anti-nuclear activists to evoke fear and sow doubt about a safe, clean, and reliable energy source.
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David makes me feel like I'm a PhD graduate in Nuclear Physics. So articulate and great communicator. Thanks Lex, as always skilfully holding space for your guests to unleash their world.
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Lex once upon a time you had an amazing, non partisan podcast, where you would challenge and explore people’s ideas.
Let go of all the sociopaths and narcissists who have attached themselves to you for their own benefit. This includes many of your favourite people..
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I'm currently in 9th grade, and discovered a video featuring Helion while in Science class on YouTube. XD Ever since that, I've been really intrigued and interested in nuclear fusion and fission. My dad listens to your podcasts, and I just happened to overhear him playing this, which is why I am now here, listening to this podcast. I usually don't listen to podcasts, but this has piqued my interest. Thank you, Lex. : >
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Lex is so good at nailing the right questions that his Guest apreciates and smiles !
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Such an interesting episode! The idea of harnessing star energy for future electricity is mind-blowing. The graphics made everything so easy to understand & genuinely fun to watch. Another great show
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It took me 3 days of commuting to enjoy this entire interview and I'm sad that it's over. I hope that his company and his people achieve a reset of expectations for mankind and our potential future.
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Absolutely OUTSTANDING. Dr. Kirtley is obviously an amazing person. I've been following Helion since about 2018 and when I understood that they were trying to induce electric fields for transmission rather than steam I was like Eureka! Super exciting. I hope it works.
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Helion’s FRC approach is probably the most innovative and effective approach to containing plasma & ultimately creation and distribution of abundance susceptible energy. David is an awesome leader…
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It's crazy this guy looks exactly like Dr.Octopus and he works with nuclear energy.
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Please make these technical podcasts more often, not all the time because it would be really heavy to listen to but i love these once in a while.
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@mousepaddd From YouTube ↗ 21 Nov 2025 55
Editor has been doing a heavy work with those visuals. Good work.
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Yaaaay! A conversation between two intelligent people who don't say "like" every fourth word, who don't say the same thing 3 times in a row and who don't talk over each other. Then there's the fascinating subject matter. And the graphics are cool but non-essential, so I can listen like and old-school radio broadcast. Nice work all round.
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It's mind-blowing that I can watch such valuable interviews for free
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@anluifb From YouTube ↗ 21 Nov 2025 407
I'm a physics professor. I was so bored at the start and by the end I wanted to leave academia to go work at Helion. This guy's enthusiasm is contagious.
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More of these more technical interviews please. I’m not a phd. I’m a regular guy. But I can handle this. Keep it coming.
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@lexfridman From YouTube ↗ 21 Nov 2025 109
Thank you for listening ❤ Check out our sponsors: lexfridman.com/sponsors/ep485-sa
See below for timestamps, transcript, and to give feedback, submit questions, contact Lex, etc.
0:00 - Introduction
3:14 - Nuclear fission vs fusion
13:14 - Physics of E=mc^2
18:28 - Is nuclear fusion safe?
23:50 - Chernobyl
30:17 - Geopolitics
32:12 - Extreme scenarios
39:07 - How nuclear fusion works
1:11:59 - Extreme temperatures
1:17:00 - Fusion control and simulation
1:28:54 - Electricity from fusion
2:02:59 - First fusion power plant in 2028
2:09:52 - Energy needs of GPU clusters
2:20:16 - Kardashev scale
2:28:12 - Fermi Paradox

Transcript:
lexfridman.com/david-kirtley-transcript

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EPISODE LINKS:
David's X: x.com/dekirtley
David's LinkedIn: bit.ly/4qX0KXp
Helion: www.helionenergy.com/
Helion's YouTube: youtube.com/HelionEnergy

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