Langton's AntAn ant walks a grid of tiles. On a pale tile it turns right; on a dark tile it turns left; either way it flips the tile it leaves. That is the whole brain. It scribbles chaos for ten thousand steps — then, out of nowhere, locks into a repeating 104-step "highway" and drives off in a straight line forever.Chris Langton posed it in 1986. Nobody can predict the highway from the rule; it is only known to always appear because whatever mess the ant builds, its own past tiles eventually corner it into the loop — emergence you can watch happen.