Galton BoardDrop a bead onto a triangle of pegs. At each peg it goes left or right on a coin flip, then piles up in a bin at the bottom. One bead is pure chance — but thousands of them always stack into the same bell curve.Francis Galton built this in 1874 to show his skeptical friends the “normal law of error.” Each bin count is n coin flips (a binomial), and the Central Limit Theorem says many small independent nudges always add up to a Gaussian.