The most unexpected answer to a counting puzzleA puzzle involving colliding blocks where the number pi, vey unexpectedly, shows up.Jan 13, 2019
The unexpectedly hard windmill question (2011 IMO, Q2)Problem 2 from the 2011 IMOAug 4, 2019
Who cares about topology? (Inscribed rectangle problem)An unsolved problem, a very elegant solution to a weaker version of the problem, and a little bit on what topology is and why people care.Nov 4, 2016
Why do prime numbers make these spirals?A curious pattern in polar plots with prime numbers, together with discussion of Dirichlet's theoremOct 8, 2019
The impossible chessboard puzzleAn information puzzle with an interesting twistJul 5, 2020
Visualizing the Riemann zeta function and analytic continuationWhat is the Riemann zeta function? What is analytic continuation? This video lays out the complex analysis needed to answer these questions.Dec 9, 2016
The Brachistochrone, with Steven StrogatzA classic problem that Johann Bernoulli posed to famous mathematicians of his time, such as Newton, and how Bernoulli found an incredibly clever solution using properties of light.Apr 1, 2016
