"Lightning Forks Illuminated," by Philip Ball. Nature Science Update, 10 April 2002.
The apparent similarities in branching in systems as diverse as blood vessels,diverging streams, and lightning forks has captivated many imaginations. NowDutch researchers have given a mathematical explanation for these similarities.Their study shows how lightning forking arises out of a condition calledLaplacian instability, which was already known to be behind many other kinds ofbranching behavior.
--- Rafe Jones