General relativity from first principles – Adam Brown
Jul 10, 2026 · 1:38:25
Adam Brown, lead of Blueshift at Google DeepMind, explains general relativity from two clues: the finite speed of light and the equivalence principle—inertial and gravitational mass equal to one part in 10^15. Einstein inferred gravity as an inertial force: free-falling objects follow straight lines in curved spacetime. Brown describes black holes: the event horizon at 2GM/c^2 where escape is impossible, gravitational time dilation slowing clocks near the horizon by sqrt(1-2GM/rc^2), and extracting 100% of rest energy. He recounts the 1919 eclipse confirming light bends twice Newton's prediction, LIGO's detections, and the Event Horizon Telescope. Finally, he considers AI could rediscover such theories by exploring consistency, and might become superhuman explainers.
