Crystal Growth — DLA

Diffusion-limited aggregation: fractal crystals emerge from random walks
Particles diffuse randomly until
they touch the growing aggregate.

Color = deposition order (rainbow)

Fractal dimension d_f ≈ 1.71
(2D DLA, Meakin 1983)

0 particles deposited

Same physics governs:
• snowflake arms
• lightning channels
• electrodeposition
• mineral dendrites