Puzzles
64 golden discs, three pegs, and a legend that the universe ends when it's solved
Move a stack of discs from one peg to another, one disc at a time, never placing a larger disc on top of a smaller one, using a spare peg to help. Legend has it that monks in a temple are moving 64 golden discs this way, and when they finish, the world will end. At one move per second, how long would 64 discs actually take?
Reveal the answer
About 585 billion years, far longer than the current age of the universe, since the minimum number of moves for n discs is 2^n − 1, or roughly 18.4 quintillion moves for 64 discs. The puzzle was invented in 1883 by French mathematician Édouard Lucas, who marketed it under the pseudonym 'N. Claus de Siam' and attached the temple legend as playful marketing, not genuine history.