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David Kirtley: belief

17 Nov 2025 Lex Fridman Podcast #485 – David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy

“You want to actually take the smallest thing you can build that accomplishes the mission—and in fusion, there is a minimum size—but accomplishes the mission, and then build it quickly and build whole teams around building it quickly and incentivize folks to move quickly, iterate and learn. And the irony I think of one of the things that I’ve discovered is that by focusing on manufacturing, by focusing on low-cost, very rapid manufacturing, you actually get to do science faster.”

— David Kirtley

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Speaker
David Kirtley
Attribution
Verified speaker
Claim type
belief
Recorded
17 Nov 2025
Publisher
Lex Fridman Podcast

Transcript context

…Well, there’s a lot of really interesting business questions here, because you’re basically at the cutting edge of science, of technology, of physics, of engineering, trying to basically innovate into the future rapidly. How do you do that? Because the R&D here, the research alone, is a lot of money. So what, well, I mean, what can you say about that? Like, how to be bold and fearless in pushing this technology into the future when so much is unknown and it costs so much to just do the research? So I think about this in a couple of ways. One, the need. We look to the world and we know the world needs clean, low-cost, safe electricity. And just to meet our needs today, and not to even talk about the needs of tomorrow or the needs of AI or any of the growth that’s probably coming. Just to meet today. But fundamental to that is it has to be a product that people will buy. It has to be a generator that is making that electricity at low cost. And it’s got to be soon. So a lot of what I think about is how do we do those two things together? And a lot of that is scale, and a lot of that is thinking about… And not big scale. In fact, it’s the opposite of that. It’s small scale. It’s how do you build a product that’s mass-producible, that you can build quickly and learn quickly? And what I’ve found in my career is that they’re actually the same thing. And that the faster you can build a thing, the faster you can learn if that thing works, the faster you can now iterate on that and build the next thing. And so what I have spent my career building is teams of humans and a company that are builders, that can build high-technology things quickly. If you want to do R&D, you don’t want large-scale, multinational, complex, huge systems. You want to actually take the smallest thing you can build that accomplishes the mission—and in fusion, there is a minimum size—but accomplishes the mission, and then build it quickly and build whole teams around building it quickly and incentivize folks to move quickly, iterate and learn. And the irony I think of one of the things that I’ve discovered is that by focusing on manufacturing, by focusing on low-cost, very rapid manufacturing, you actually get to do science faster. And at the beginning of my career, I would never have guessed that. I would have thought the way to do science is to make a giant demonstration particle accelerator somewhere. Like to make a large complex science experiment is the best way to do science. And what I’ve found is actually small, iterative, just building as fast as possible gets you there faster, because you can learn, you can build, you can iterate. You can solve the problems, and then you can learn the fundamental physics, learn the scaling, learn the FRC, and the B to the 3.77 power and learn those things way sooner than if you would have just started on one mega project and then waited decades to get to the answer. There’s a profound truth in that, something about the constraints of pushing for the simple, for the low cost, for the manufacturable. That pushes everything, pushes the science, pushes the innovation. In fact, you should maybe explain that you’re, I believe, on the seventh prototype. The rate of innovation here is insane. Can you maybe speak to all the different prototypes you went through, what it took to just iterate rapidly? And maybe it would be really interesting for people, like what can you say about the teams that’s required to make that happen? Like what kind of people are required to make that happen at that fast rate? And we’re not talking about software here. We’re talking about everything, the full stack. All the way down to the physics at 100 million degrees, at speeds of 1 million miles per hour. I mean, it’s insane. Anyway, so how do you iterate the prototypes, and what kind of teams make it happen?…

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