Total sand: 0
Topplings: 0
Mode: identity
About: The abelian sandpile model (Bak-Tang-Wiesenfeld 1987) places sand grains on a grid; when a cell reaches 4 grains it topples, distributing one grain to each neighbor. The set of stable configurations forms an abelian group under addition-then-stabilization. The identity element of this group has a striking fractal structure with self-similar triangular patterns — a remarkable emergence of order from simple local rules. The identity is computed by adding a maximal stable config to itself and stabilizing.