The 'Game of Life'

In 1970 when computers looked like huge switch cabinets and a mouse was solely a small grey rodent yet, Conway was brooding over a tricky problem: he tried to simulate life processes with the simplest possible rules. The hard part was to find a rule set with a balanced ratio of 'birth', 'survival' and 'death'. The game was meant to be played on a flat field with a grid pattern and was intended to simulate the change of a 'population' over a number of time steps.

1) Every living cell with less than 2 living neighbours dies (underpopulation)

2) Every living cell with more than 3 living neighbours dies (overpopulation)

3) Every living cell with 2 or 3 living neighbours stays alive

4) Every dead cell with exactly 3 living neighbours comes alive

In each generation, these rules are applied to every cell, resulting in the population to change accordingly. Therefore the field's occupancy depends solely on the previous generation's occupancy.

These rules form the basis for a very complex and seemingly chaotic behaviour: structures may completely disappear, stabilise, grow chaotically, repeat over a period, influence other structures, generate new objects or even 'move' across the field (example: the glider).

In the early days Life was played using pen and paper or with counters on a grid pattern board, e.g. a Go board works very well. The lucky ones with access to one of the few computers around could of course program these and save a lot of pains. Back then computing time was very expensive yet so Life was widely considered 'a fun way to waste CPU cycles'. With the coming of private computers, Life gained a lot of interest from the late 70's on and brought forth a lot of modified versions. Many users let their computers run overnight in order not to let the precious computing time lapse away.

With fast modern computers Life gained an undreamed-of popularity from the 90s onwards for now the largest and most complex structures could be computed. There are numerous software versions for different operating systems, some of which can be played online without installation (see links).