<- All entriesEntry 003 21 SEPT 2026 note
Sandpiles and thresholds Reading notes on self-organised criticality, and why the abelian sandpile is a useful mental model rather than a claim about brains.
#criticality #reading
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·##··#···#··# #+++++··## #++# ##··++++++# ## ## #··##· The abelian sandpile is almost embarrassingly simple: add grains to a grid, and any cell holding four or more topples, passing one grain to each neighbour. Run it long enough and avalanches of every size appear, with no parameter tuned to make that happen.
The image at the top of this entry is a real sandpile, computed when this page was built: twelve thousand grains dropped on the centre cell and allowed to settle.
Why it is interesting here It is a clean example of a system that sits near a boundary on its own. Whether anything similar is useful for computation in artificial networks is the open question. The sandpile itself offers no answer, only a picture to think with.
A lens, not a law.