Michael Freedman | A Fields Medalist Panorama | The Cartesian Cafe with Timothy Nguyen

Published 2024-07-19
Michael Freedman is a mathematician who was awarded the Fields Medal in 1986 for his solution of the 4-dimensional Poincare conjecture. Mike has also received numerous other awards for his scientific contributions including a MacArthur Fellowship and the National Medal of Science. In 1997, Mike joined Microsoft Research and in 2005 became the director of Station Q, Microsoft’s quantum computing research lab. As of 2023, Mike is a Senior Research Scientist at the Center for Mathematics and Scientific Applications at Harvard University.

#math #maths #physics #quantum #economics

Patreon (bonus materials + video chat):
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In this wide-ranging conversation, we give a panoramic view of Mike’s extensive body of work over the span of his career. It is divided into three parts: early, middle, and present day, which respectively include his work on the 4-dimensional Poincare conjecture, his transition to topological physics, and finally his recent work in applying ideas from mathematics and philosophy to social economics. Our conversation is a blend of both the nitty-gritty details and the anecdotal story-telling that can only be obtained from a living legend.

I. Introduction
00:00 : Preview
01:34 : Fields Medalist working in industry
03:24 : Academia vs industry
04:59 : Mathematics and art
06:33 : Technical overview

II. Early Mike: The Poincare Conjecture (PC)
08:14 : Introduction, statement, and history
14:30 : Three categories for PC (topological, smooth, PL)
17:09 : Smale and PC for d at least 5
17:59 : Homotopy equivalence vs homeomorphism
22:08 : Joke
23:24 : Morse flow
33:21 : Whitney Disk
41:47 : Casson handles
50:24 : Manifold factors and the Whitehead continuum
1:00:39 : Donaldson’s results in the smooth category
1:04:54 : (Not) writing up full details of the proof then and now
1:08:56 : Why Perelman succeeded

II. Mid Mike: Topological Quantum Field Theory (TQFT) and Quantum Computing (QC)
1:10:54: Introduction
1:11:42: Cliff Taubes, Raoul Bott, Ed Witten
1:12:40 : Computational complexity, Church-Turing, and Mike’s motivations
1:24:01 : Why Mike left academia, Microsoft’s offer, and Station Q
1:29:23 : Topological quantum field theory (according to Atiyah)
1:34:29 : Anyons and a theorem on Chern-Simons theories
1:38:57 : Relation to QC
1:46:08 : Universal TQFT
1:55:57 : Witten: Donalson theory cannot be a unitary TQFT
2:01:22 : Unitarity is possible in dimension 3
2:05:12 : Relations to a theory of everything?
2:07:21 : Where topological QC is now

III. Present Mike: Social Economics
2:11:08 : Introduction
2:14:02 : Lionel Penrose and voting schemes
2:21:01 : Radical markets (pun intended)
2:25:45 : Quadratic finance/funding
2:30:51 : Kant’s categorical imperative and a paper of Vitalik Buterin, Zoe Hitzig, Glen Weyl
2:36:54 : Gauge equivariance
2:38:32 : Bertrand Russell: philosophers and differential equations

IV: Outro
2:46:20 : Final thoughts on math, science, philosophy
2:51:22 : Career advice

Some Further Reading:
Mike’s Harvard lecture on PC4:    • Michael Freedman | A personal story o...  
Behrens et al. The Disc Embedding Theorem.
M. Freedman. Spinoza, Leibniz, Kant, and Weyl. arxiv:2206.14711

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www.timothynguyen.org/

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All Comments (11)
  • @MTheoOA
    Super interesting! Congratz for the Cartesian Cafe success!
  • We're about halfway through the year, but I'm fairly confident this will be the best mathematics podcast interview for 2024. Freedman's input on Perelman's proof, TQFT's relation to quantum computing, Witten lore... The quality of this content is astounding. Well done Timothy!
  • @jameson44k
    1:50 Laurent Lafforgue went to work for Huawei in 2021. Perelman was also once reported to have been working briefly at a nanotechnology company in Sweden, possibly where his sister worked at the time, but I don't know if the report was actually just speculation.
  • Incredible episode! You should get Alexander Givental or Mariusz Wodzicki both very interesting Berkeley math professors.
  • @kilogods
    Fantastic episode! Fantastic guest!
  • @knight3481
    In the usual sense of Witten TQFT, I am not sure how non-unitarity will result in from taking a diagonal SU(2) of SU(2)*SU(2) as twisted states. How to add up the twisted states /Sum_U^dagger U>1?