Death can come in half an hour.
A record number of snow-sports enthusiasts died last year in avalanches in the United States. Robinett, with the Department of Energy's Sandia National Laboratories, has a better, if unconventional, approach. Computationally, he says, finding a snow-buried skier is remarkably similar to locating the point source of a chemical or biological attack. In more complicated situations, where depth of snow burial or rocks or trees created complications, the Sandia algorithm was comparatively even faster. The group search technique, called swarming, relies upon neither a central intelligence telling the searchers what to do nor the intuition of individuals.