Understanding the 'physics' of panic

When panic takes hold of a large crowd of people exiting a stadium or big building, the effect can be like a tsunami. In minutes, powerful crowd forces can be exerted on pressure points - enough to crumble brick walls, twist steel beams, and crush humans caught in between.

In this week's issue of Nature, Dirk Helbing and colleagues at Dresden University of Technology, Germany, present research on how crowds react in these situations. They hope to influence architectural designs that may reduce the likelihood of crowd panic.

Using computer modeling, the research team developed a "faster-is-slower effect." When panic strikes, crowds that normally exit in an orderly fashion, gain speed. As their speed increases, friction builds within the crowd and leads to inefficient outflow and more panic.

Counterintuitively, the faster the crowd tries to move, the slower it actually gets out of the building.

(c) Copyright 2000. The Christian Science Publishing Society