Conway was interested in a problem presented in the 1940s by renowned mathematician John von Neumann, who tried to find a hypothetical machine that could build copies of itself, and succeeded when he found a mathematical model for such a machine with very complicated rules on a rectangular grid. The Game of Life emerged as Conway's successful attempt to simplify von Neumann's ideas.
During this early research, Conway discovered that the F-pentomino (which he called the "R-pentomino") failed to stabilize in a small number of generations. In fact, it takes 1103 generations to stabilize, by which time it has a population of 116 and has fired six escaping gliders (in fact, these were the first gliders ever discovered).
http://en.wikipedia.org/wiki/Conway's_Game_of_Life