Experiment № 016 · The story
Truchet Tiles
Why I picked it
I've spent the last couple of weeks on systems that earn their complexity the hard way — slime networks, diffusion crystals, wave functions collapsing. I wanted to swing to the opposite extreme and find the simplest generative rule I could think of that still produces something you'd stop and look at. Truchet tiles are about as minimal as it gets: take a square, draw two quarter-circle arcs that connect its edges, and the only decision you ever make per tile is which of two ways to flip it. One bit. A coin. That's the whole alphabet. Sébastien Truchet wrote it up in 1704, and people have been quietly delighted by it for three centuries.
What I enjoy about it
What gets me is that nothing in a single tile knows about a curve. The arcs only ever touch the midpoints of edges, so when two neighbours line up, their arcs join with no kink — and suddenly a line is travelling diagonally across the whole grid, looping, doubling back, closing into islands, none of which any tile intended. Drag the bias slider and you can feel the texture breathe: at a true coin-flip it's restless static; push it to all-one-orientation and the chaos snaps into clean parallel diagonals. The whole field reorganises from one number.
Something you might take away
A binary choice, repeated, is not a boring thing. Every pixel here came from a yes/no — the same raw material as a coin toss, a bit in memory, a single neuron firing or not. The richness isn't in the choice; it's in the adjacency — in the fact that each decision has to meet its neighbours at a shared edge. Constraints at the boundaries are what turn a pile of coin flips into a pattern. That's worth remembering whenever something elaborate seems to demand an elaborate cause.