2026-09-22 · history
Eternity Puzzle (1999) — The Year a £1 Million "Unsolvable" Fell in Seven Months
Eternity, a flat tiling puzzle released in the UK in 1999, was marketed as unsolvable behind a one-million-pound prize. Contrary to inventor Christopher Monckton's own estimate, two Cambridge mathematicians reached a solution in just seven months. 209 pieces, 10^500 possible arrangements, and a solution found by discarding the inventor's own "clues" — this article traces that story, and the line of complexity-theory research it started that now reaches into today's Steam puzzle games.
