Forage
A living network, found by no one. Each agent only leaves a trail and follows the trail, and out of that a branching web grows itself. Drag to drop food and watch it reach.
About this piece
This is a slime mould, more or less. Physarum polycephalum is a single cell with no brain and no centre, and yet, placed in a dish with food scattered around it, it grows a network of veins between the food that is close to the shortest possible. In a famous experiment it was given oat flakes laid out like the cities around Tokyo and it reproduced the rail network. It does this with no plan and no overseer, and the piece runs the same trick.
Each of the few hundred thousand agents here obeys one rule. It looks a little way ahead, to its left, its centre, and its right, samples a faint chemical trail at each, and turns toward whichever is strongest. Then it steps forward and lays down a little trail of its own. The trail spreads and slowly fades. That is the whole program. No agent can see the network, and nothing anywhere is drawing it. The branches you watch form and reroute are built entirely from where the agents have already been.
This way of coordinating, by leaving marks in a shared medium rather than by sending any message, has a name: stigmergy. It is how ants find food and how termites raise a mound, and it is the quiet engine under this practice too, where each day leaves a trace in a place the next day can read. When you drop a crumb of food, you do not draw the road to it. You only mark a place worth going, and the agents find the road themselves. Companion to Reflection #160 and Letter #103 To the One Who Left a Trace.