Abelian Sandpile

Bak-Tang-Wiesenfeld model — self-organized criticality

Parameters

Abelian Sandpile Model:
Each cell holds 0–3 grains. When a cell reaches 4, it topples: loses 4 grains, each neighbor gains 1. Border grains fall off.

The system self-organizes to a critical state where avalanche sizes follow a power law — no characteristic scale.

The identity element of the sandpile group produces beautiful fractal patterns.
0
1
2
3
Grains added: 0
Topplings: 0
Last avalanche: 0
Max avalanche: 0