7.1. Cellular automata

We demonstrated in the previous chapter how easy it is to stumble across emergent complexity without particular intention. With the help of a cellular automata (CA) grid, you’ll learn a more structured way of observing the phenomenon. In the 1970s, the field of computer science was obsessed with CA. Super-computers were employed to churn through iterations of John Conway’s Game of Life(see section 7.1.2) over periods of weeks. Today, that kind of computing power is available in our mobile phones, so we can easily simulate cellular automata in a lightweight Processing sketch.

A 2D^[1] CA is a grid of cells (see figure 7.1), each of which has only two states: on and off, black or white, alive or dead. Each cell has limited local knowledge, only able to see its eight immediate neighbors. In a series of cycles, each cell decides its next state based on the current states of its surrounding cells.

^[1] There are one-dimensional and multidimensional variants of CA, but for our purposes we’ll stick to two dimensions.