What is a Cellular Automaton?
A cellular automaton is a grid of cells that evolve over time according to simple rules. Each cell looks at itself and its neighbors to determine its next state. Time flows downward, with each row showing a new generation.
How Rules Work
Each rule (0-255) defines what happens for each of the 8 possible neighborhood patterns. The binary representation of the rule number specifies the output for each pattern.
Notable Rules
Rule 110 - Proven Turing complete. Watch for 'gliders' that move across the grid.
Rule 30 - Chaotic behavior. Used by Mathematica for random numbers.
Rule 90 - Creates the Sierpinski triangle fractal pattern.
Rule 184 - Models traffic flow. Try with random initial conditions.
Boundary Conditions
- Periodic: Edges wrap around (like a cylinder)
- Fixed (dead): Cells outside are always 0
- Fixed (alive): Cells outside are always 1
- Reflective: Edges act like mirrors
Tips
- Use "single" initial condition to see the natural pattern
- Use "random" to see how rules handle noise
- Use "custom" to draw your own starting pattern
- Enable comparison mode to see two rules side-by-side