Langton's Ant

Langton's ant travels around in a grid of black or white squares. If she exits a square, its colour inverts. If she enters a black square, she turns right, and if she enters a white square, she turns left.

If she starts out moving right on a blank grid, for example, here is how things go:

Start the ant running by clicking on the Run button. You can also stop it, step through it, or reset it. At the beginning or after a Reset, you can add or take away nodes by clicking on them.

The evident long-term behaviour is remarkable, and unexplained.