The proof technique for “How often do the L1 and L2 norms agree?” used as a lemma a characterization of the L1 norm of n-dimensional vectors chosen uniformly with L2 norm equal to 1. For a n-dimensional vector with unit L2 norm we can see L1 norms as small as […]

Estimated reading time: 1 minute

I have a new math chalk talk up: The Game of Infinity Questions. This is back to establishing the “reasonableness” of Kolmogorov’s Axiom of continuity (in his actual formulation of his axiomatization of probability). Remember, his argument is “it is a bit off to have strong opinions on infinite processes, […]

Estimated reading time: 1 minute

von Neumann and Morgenstern’s “Theory of Games and Economic Behavior” is the famous basis for game theory. One of the central accomplishments is the rigorous proof that comparative “preference methods” over fairly complicated “event spaces” are no more expressive than numeric (real number valued) utilities. That is: for a very […]

Estimated reading time: 28 minutes

Hollywood movies are obsessed with outrunning explosions and outrunning crashing alien spaceships. For explosions the movies give the optimal (but unusable) solution: run straight away. For crashing alien spaceships they give the same advice, but in this case it is wrong. We demonstrate the correct angle to flee. Running from […]

Estimated reading time: 8 minutes