∂U/∂t = Du∇²U − UV² + F(1−U) · ∂V/∂t = Dv∇²V + UV² − (F+k)V — activator-inhibitor reaction-diffusion producing stable spots, stripes and mazes. Click or drag to seed.
Alan Turing's 1952 morphogenesis model: two diffusing chemicals — a fast-diffusing inhibitor (U) and a slower autocatalytic activator (V) — self-organise into stable spatial patterns from a uniform starting state. Small changes to F and k move between spots, stripes, mazes and coral-like growth.