Drop grains of sand onto a grid. When a cell reaches 4, it topples — one grain to each neighbor. The pile self-organizes. Fractal patterns emerge from the simplest possible rule.
Mode
Grid size
201
Total grains
50,000
Color palette
Speed
3
Grains placed: 0
Topplings: 0
Max height: 0
Per Bak, 1996: "Self-organized criticality is the only known general mechanism to generate complexity." Sandpiles, earthquakes, neural cascades, financial crashes — perhaps all the same mathematics.