Diffusion-Limited Aggregation

One of the background animations in rotation on this site is a diffusion-limited aggregation, or DLA: sparse, dendritic frost- or coral-like branching, grown from many small scattered seed points.

DLA structures form because growth is rare and only happens at the exposed edge of existing structure — that's what makes the branches thin and reaching rather than a solid, filled-in blob. Old growth slowly erodes as new growth reaches outward, so the pattern keeps turning over instead of settling into a fixed shape.

Credits

DLA was introduced by T. A. Witten and L. M. Sander in their 1981 paper Diffusion-Limited Aggregation, a Kinetic Critical Phenomenon, and the same process describes real-world branching growths from frost crystals to mineral dendrites to some fungal and bacterial colonies.

See this effect running full-size in the effects gallery →