thousands of simple agents share one chemical field — highways emerge with no planner.
try paint two blobs of food → watch a highway form between them → switch to wall and cut it — the network reroutes.
Philosophy — infrastructure without planners. Physarum polycephalum is a single cell, sometimes metres across, with no brain and no centre. It still solves mazes, and when researchers laid oat flakes out in the pattern of Tokyo’s suburbs, it rebuilt the rail network overnight — comparably efficient, no engineer involved (Tero et al., Science 2010). The trick is stigmergy: the agents never speak to each other. They write to the world — a chemical trail — and read what the world says back. The network is not in any agent; it lives in the field between them. That’s also how termite mounds, footpaths, markets, and Wikipedia work. When you paint food here, notice what you’re doing: you can’t command a single agent, you can only change the landscape’s incentives — and the network reorganises itself around your change. Governance by landscape, not by decree.
Technique — two layers, four verbs. This is Jeff Jones’s 2010 model: agents and a trail field, coupled. Each tick every agent does four things — sense (three sniffs: ahead, ahead-left, ahead-right), turn toward the strongest, move, deposit. Then the field does two: diffuse (a 3×3 blur) and decay. Diffusion is what turns yesterday’s paths into today’s gradients — it widens a sharp trail into a slope other agents can feel from a distance. Decay is forgetting, and it’s load-bearing: without it the field saturates and no path is better than any other. All the pattern regimes live in ratios — sensor angle against turn angle sets the vocabulary of curves an agent can draw; sensor distance sets the scale of the mesh; decay sets its patience. Food is a cell that re-deposits every tick, a permanent rumour. Walls read as dead air to the sensors, so agents steer off them before they ever touch.
Aesthetics — the palette is an argument. Nothing here glows. The glow is a claim we make by mapping trail density through a colour ramp — exposure decides what counts as visible at all, and the ramp decides what the thing is. Bioluminescent says deep-sea organism; ember says slow fire; ink says a cartographer drew this — the same network, presented as evidence rather than creature. Isaac King’s dot sim, which started this whole set, takes the ink position: black marks on paper, no trails, no drama, and it’s mesmerising anyway because the motion carries everything. Flip between ink and bioluminescent here and watch your own read of the system change — same rules, same field, different ontology.