Sheep are rarely dangerous to skiers, but otherwise they have a lot in common with avalanches. That’s what physicists say after mathematically modeling the ungulates’ behavior (and staying well out of their path).
Francesco Ginelli, who researches complex systems at the University of Aberdeen in Scotland, had already studied flocks of birds and schools of fish. But he was curious to learn what was different about the movement of sheep or other grazers. Animals like these have a simple goa