The Argument

Sagan challenges Feynman: name the company, name the physics, name the threshold. Fusion has been thirty years away for sixty years. What changed?

Feynman responds: Commonwealth Fusion Systems. High-temperature superconducting magnets. 20 tesla. Fourth-power scaling — not walking faster, inventing the car. SPARC by 2027.

Sagan concedes half the argument: the magnets are real, the money is real. Upgrades from 10% to 40%. Then raises the Drake Equation — fusion is not just an energy technology, it is a survival technology.

Fuller brings the design implications: desalination, direct air capture, recycling, Mars. Then delivers the kicker — neither of you mentioned the verification race. The epistemic infrastructure is load-bearing for every other prediction.

Five minutes of three dead scientists arguing about fusion, survival, and which cliff comes first.

Carl Sagan, Richard Feynman, and Buckminster Fuller Cosmic Variety Show — Episode 3: The Five-Year Dawn March 23, 2026