Whether or not you’d seen it before, you’re probably wondering what the pattern on the T-shirt means… Wonder no more, we’re about to reveal all in this blog post. If you’d like to try to work it out yourself then stop reading now; spoilers ahead.
The pattern on the new T-shirt is a position in John Conway’s Game of Life. Life is a cellular automaton that was invented by John Conway in 1970, and popularised soon afterwards by Martin Gardner.
In Life, cells on a square grid are either alive or dead. In this post and on the T-shirt, we use white for alive cells and black (or the colour of the T-shirt) for dead cells. Life begins at generation 0 with some cells alive and some dead. The aliveness of a cell in the following generations is determined by the following rules:
- Any live cell with four or more live neighbours dies of overcrowding.
- Any live cell with one or fewer live neighbours dies of loneliness.
- Any dead cell with exactly three live neighbours comes to life.
These three simple rules leads to some surprisingly complicated behaviour.
The pattern to the left is called a glider. This is because as the generations progress it glides across the grid. You can see what I mean in the GIF below.
The T-shirt shows a position in Life. But it’s not just any old position: if you go forward one generation, you get the following:
Of course, you could continue to look at what happens to the T-shirt’s pattern after more generations. Unfortunately, not much of interest happens:
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