Complex Flows, Simple Rules

Seeing bare tree branches silhouetted against a sunset sky is one of the best things about winter. Bereft of leaves, the trees reveal their intricate skeletons--almost fractal, reminiscent of neurons, or the network of blood vessels that perfuse the body. These complex patterns of growth and branching are produced by an invisible algorithm--less a blueprint than a computer program--encoded in the tree's DNA, optimized over millions of years of evolution. Taking data on sunlight, airflow, and pro...