3D Galton Board: Binomial Converging to Normal

This is the classic physical embodiment of the Central Limit Theorem, rendered in 3D. Balls drop one at a time onto a triangular lattice of pegs; at each row a ball independently bounces left or right with a chosen probability, and where it lands at the bottom depends on the sum of all those bounces. Unlike directly averaging random samples, this builds a bell curve from an accumulation of many independent binary decisions — watch the growing bin bars trace out a binomial distribution that looks increasingly normal as the number of peg rows increases.