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John Baez's user avatar
John Baez's user avatar
John Baez
  • Member for 14 years, 8 months
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I'm a mathematical physicist. I have a lot of expository material on math and physics on my website, and you can follow me on Twitter. I used to work on n-categories and fundamental physics, but now I'm thinking about network theory and environmental problems.

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94
Quasicrystals and the Riemann Hypothesis
Jun 13, 2013
83
Which finite abelian groups aren't homotopy groups of spheres?
Nov 26, 2020
63
Bourbaki's definition of the number 1
Apr 14, 2020
57
Is Lebesgue's "universal covering" problem still open?
Dec 6, 2013
55
Do unit quaternions at vertices of a regular 4-simplex, one being 1, generate a free group?
May 1, 2015
48
How many ways can you inscribe five 24-cells in a 600-cell, hitting all its vertices?
Dec 14, 2017
46
Why do Bernoulli numbers arise everywhere?
Apr 11, 2011
41
What are the main structure theorems on finitely generated commutative monoids?
May 19, 2013
40
Why is conformal invariance only possible for massless theories?
May 18, 2017
38
How many morphisms from 1 to 1+1 can there be?
Apr 19, 2019
Top network posts
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27
Sequence with convergent subnets but no convergent subsequences
19
Why is nitrogen (with 7 protons and 7 neutrons) so much more abundant than any other odd-odd isotope?
14
Implementing Category Theory in General Relativity
14
When is the ring homomorphism $\mathbb{Z} \to R$ an epimorphism?
11
Who predicted the existence of the muon neutrino?