I've always liked John Conway's Game of Life, a classic math experiment that demonstrates that a
simple system can give rise to surprisingly complex results.
The rules are simple: on a square grid
like a big chessboard, each square can hold either a living 'cell', or
nothing. A giant metronome ticks, and at each tick, every cell with
exactly two or
three living cells among its eight neighboring squares will survive; an
empty square with exactly three living neighbors will spawn a new cell,
other living cells will die. The babies grow up fast, and at the next
tick it all happens again.
The results vary wildly depending on the
One pattern of five cells glides across the grid, wriggling like a
tadpole; another expands into an oscillating flower; another spawns a
roiling storm of chaos.
Implementing this "cellular automaton"
as a web applet is nothing new.
There are probably thousands, if not millions, of implementations. But
I recently saw a very
clever one by Patrick Mineault. Instead of churning through the
whole grid of cells in a big slow ActionScript loop, he hands off the
problem of counting up neighbors to an image convolution filter. That
lets the Flash player - maybe even the graphics hardware - do the work,
instead of ActionScript.
That's so clever I just had to try it
out for myself. Patrick's version has some nice bells and whistles, but mine is just the basic Game: