In the wake of Black Friday's shopping frenzy, several media outlets have reported on shoppers being trampled during the rush for bargains. While this problem rears its head every year, physicists have been researching this area for years. And they have some suggestions for preventing crowd disasters.
To model crowd interactions, physicists often turn to computer simulations of particles. In particular, researchers pored over video evidence of a stampede during a crowded religious pilgrimage that killed over 300 people several years ago. Their research culminated in a highly-cited paper that motivated several changes to the pilgrimage, making it much safer the next year.