Sandpiles & Avalanches

Self-organised criticality

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A square with 4 or more grains topples, giving one to each neighbour.
• The final pile doesn’t depend on the order of topplings (Abelian property).
• Avalanche sizes follow a power law: self-organised criticality.

Steps

1. Grains on a grid
2. One topple
3. A pile from one spot
4. Does order matter?
5. Avalanche sizes
6. Self-organised criticality
7. A one-dimensional pile