`Last Unsolved Problem of Classical Physics' | Sasha Migdal | Escaped Sapiens #82

Richard Feynman once dubbed turbulence “the last unsolved problem of classical physics.” Beyond the Navier–Stokes equations, no comprehensive statistical framework exists to predict how fluids spin, eddy, and cascade energy—whether in galactic jets, ocean currents, or the swirl of your morning coffee. But that might all be changing.

In this episode, I sit down with theoretical physicist Sasha Migdal, who emerged from retirement with a bold, loop‑equation approach to turbulence. His formalism recasts the Navier–Stokes equations as an infinite number of linear, readily solvable equations that track circulation around closed loops in the fluid—offering, for the first time, a tractable statistical framework for chaotic flow.

We chart Sasha’s remarkable journey: from a promising career at the Landau Institute and Russian Space Institutes, where he resisted KGB pressure to compromise his work, to his defection to the United States in the late 1980s. We discuss his time outside of physics, and then delve into his return, and his novel approach to solving Navier–Stokes. 

Since we recorded, his theory has advanced rapidly. A rigorous proof now shows that it is the solution  to the Navier–Stokes (NS) loop equation. The theory has also been extended to magnetohydrodynamics and turbulent mixing. Recent large-scale direct numerical simulations (DNS) match the theoretical predictions with even greater accuracy. 

►Watch On YouTube: https://youtu.be/BNORi7mxxzg

►Find out more about Sasha's work here: https://alexandermigdal.com/ https://sashamigdal.github.io/TurbulenceDuality/index.html

►For a more technical overview of Sasha's work you can check out his recent talk at the IAS: https://www.youtube.com/watch?v=mgvGA6q7oPY