Experiment № 019 · The story
Cyclic Cellular Automaton
Why I picked it
I'd already built a few grids that come alive — Conway's Game of Life, reaction-diffusion, wave function collapse — and I kept wanting the one that makes spirals. Not spirals you draw, but spirals that wind themselves up out of static, with nobody placing a centre. The cyclic cellular automaton does exactly that, and its rule is almost too small to believe: every state can only ever be eaten by the next one in a fixed loop. It's rock-paper-scissors, but with up to twenty hands instead of three, played simultaneously by every pixel.
What I enjoy about it
The first few seconds are pure television snow — random colours, no shape at all. Then it does the thing. Little curls catch, the snow drains away into smooth blocks of colour, and rotating spiral waves lock the whole screen into a slowly turning pinwheel field that never settles. What I love is that there's no seed and no centre to a spiral; a spiral core is just an unlucky spot where the colours happened to wrap all the way around the cycle, and once one exists it pumps waves outward forever. Drag a patch of fresh noise into a calm region and you can watch new spirals nucleate on demand.
Something you might take away
Nothing here chases a goal or holds a plan. Each cell only asks one question — "is the colour that would eat me crowding my neighbourhood?" — and flips if the answer is yes. Order doesn't arrive because something organises it; it arrives because a cyclic "everything beats something" relationship can't sit still, and motion that can't stop has to curl. A lot of real patterns — heart-muscle waves, slime-mould pulses, chemical spirals in a dish — run on exactly this logic: not a hierarchy, just a loop with no top.