The Tower of Hanoi
Disks can be moved one at a time from one peg to another as long
as a disk is never placed on top of a smaller disk.
According to an ancient myth, there is a tower in Hanoi where monks
are transferring 64 gold disks from one peg to another. Every move
takes 1 second. The world will end when they finish the puzzle.
How long after the monks started will the world end?