// instruments · the sandpile

the sandpile

Criticality, touchable. The plates load every cell slowly; a click places one grain; any cell past threshold sheds to its four neighbors, and the shedding chains. Bak, Tang & Wiesenfeld's sandpile, running under your cursor.

click the grid to place material. the plates load on their own — watch the blue deepen. red is a cell toppling.

events

0

last avalanche

—

largest

—

mean load

— / 4

// avalanche sizes — log-binned, log-scaled bars

1
2–3
4–7
8–15
16–31
32–63
64–127
128+

heavy-tailed, in the spirit of Gutenberg–Richter — a toy, not a fault.

seed 0 · same seed, same pile — your clicks are the only difference

// the point

your click never carries the avalanche's energy — the grid was already loaded. placements tip; the slow loading pays.

Given time, the same avalanche sizes emerge with or without your placements. The readout tags each event with its trigger; the distribution ignores the tag.

// what this is

A toy model of self-organized criticality — the sandpile of Bak, Tang & Wiesenfeld (1987), driven slowly the way Olami, Feder & Christensen's earthquake variant is (1992). Both are long-established results; this page makes them touchable, nothing more. The model shows why triggers differ from causes. It forecasts nothing; real seismicity is messier; no earthquake prediction lives here.

// kin

stress-cloud — the strain field, written up · magnets — the site's other lattice that relaxes · anxiety — slow loading, read in a person