Langton's ant is now the star of a
computer program used to show the difference between understanding a complete
theory of the
Universe and totally understanding its
consequences.
The ant wanders around on an
infinite square grid of
black and
white squares. When the ant walks onto a white square, it changes
colour from white to black and the ant turns
right and if it walks onto a black square the square changes to white and the ant turns left.
The ant first moves around the grid in very simple
steps, making
simple and
symmetrical patterns. This happens for the first hundred or so moves.
After that, the movements of the ant appear to be
chaos. Of course, it's still following the same rules as before, it just doesn't look so
structured.
Finally, order emerges. The ant begins to build a
highway. It goes through a
series of 104 steps then after which it has moved out two squares
diagonally and the shapes and colours along the edges are the same. The ant repeats this
behaviour for ever.
It seems that the ant follows this
pattern whatever
configuration of black and white squares is used at the start. The ant shows that simple rules can have complex
consequences.