Cellular Automaton

Introduction

A cellular automaton is a programm that applies a simple rule over several iterations. One might think that if the rules for a programm were simple then this would mean that its behavior must also be correspondingly simple, but this intuition is not even close to correct. Systems with simple finite rules can have complex patterns and structures.
The idea is, that complex systems for example in nature or physics are based on simple rules. Well, now we only need to find THE main rule that is behind all ;-).

Cellular Automaton b/w

This cellular automaton consists of a line of cells, each colored either black or white. At every step there is then a definite rule that determines the color of a cell from the color of the cell on the step before and its immediate left and right neighbors. The cellular automaton starts with a single black cell in the center.
The rules are defined as an 8-digit binary number, that can be converted to a decimal number. There are 256 different rules.

A particular cellular automaton can behave like this (rule 254):

But modified the rule just slightly one can immediately get a different pattern (rule 90):

Cellular automata do not only yield highly regular patterns, they can get also random patterns (rule 30):

	A particular rule can be defined by clicking on the cells to change their color. Or the rule can be directly written as a decimal number. Rule: Steps: 50 100 500 (generates PNG image)

(The idea of this cellular automaton has been taken from the book "A New Kind Of Science" by Stephen Wolfram.)