Abelian Sandpile
Self-organized criticality — click to drop grains
Controls
Grid size:
80
Drop rate:
1
grain/frame
Drop location:
Center
Random
Click only
Run / Pause
Step
Clear
Identity
Grains: 0
Topplings: 0
Avalanche: 0
0
1
2
3
When a cell reaches 4 grains it topples — distributing one grain to each neighbor. The pattern is fractal and abelian (order-independent). Self-organized criticality → power-law avalanche sizes.