Tim Roughgarden, mathematician at Institute for Advanced Study and head of research at a16z Crypto, on quantum computing, blockchain as a laboratory for social science, and AI transforming mathematics right now the way it transformed coding six months ago. 1:35 — The story from Turing to 2026 3:43 — Quantum was "25 years away" for 25 years, then something changed 4:25 — Q-Day prediction + Shor's algorithm + how to spot a quantum agenda 6:37 — Positive quantum applications + we're not doomed on cryptography 9:16 — Post-quantum migration is a coordination problem 12:22 — Blockchain as a laboratory for social science 15:50 — The sociology big bang analogy 17:37 — Computation is a law of nature 19:56 — AI is transforming mathematics right now 25:54 — Start with what you want to build @Tim_Roughgarden