Four simple rules, and entire computers emerge with no players at all
Conway's Game of Life plays out on an infinite grid where each cell is alive or dead, and every generation is decided by simple rules based on how many living neighbours each cell has. No player ever makes a move after the first generation, yet complex, self-sustaining patterns emerge on their own. What's the simplest possible pattern that never stops moving across the board?
Reveal the answer
The 'glider,' a five-cell pattern, translates itself diagonally across the grid every four generations, forever, the simplest of the 'spaceships.' Life turned out to be Turing complete: patterns exist that simulate entire computers within the game itself. Devised by mathematician John Horton Conway and popularized in Martin Gardner's 'Mathematical Games' column, Scientific American, October 1970.