The ionized streams of gas preceding electrical discharges branch spontaeously. Now researchers have seen this splitting in the simplest possible computer simulation. Image courtesy of E. M. van Veldhuizen/Eindhoven Univ. of Tech.
Sparks branch for the same reason that coral reefs and snowflakes do, according to new computer simulations. Researchers in the Netherlands have found that even the simplest computer model of a propagating streamer--the precursor of a visible spark--predicts that the moving front spontaneously splits and forms branches. The result could help explain the electrical sprites recently observed flickering above the clouds during thunderstorms, and may lead to improved industrial techniques for chemical processing of gases and water purification.