Crowd as a Fluid: The Physics of a Crush ⚡ экспресс
In a dense crowd, people interact not only psychologically but also physically: pushes and pressure (contact forces) dictate movement, much like stress transfers between particles in a granular material. Classic models that treated pedestrians as independent particles are giving way to new ones that account for these forces. This review analyzes existing approaches and emphasizes the need for experiments and fresh models to accurately predict dangerous situations in dense gatherings.
In tight spaces, a crowd behaves like water in a pipe: the more people, the higher the pressure. At the same time, entropy — a measure of chaos — increases, and a single push triggers a compression wave that, like gravitational waves, travels instantly through the crowd, knocking people off their feet. Previously, crowd movement was modeled as an ideal gas, ignoring physical contact. Now scientists account for compressive forces: at a density of more than 6 people per square meter, the lungs can't expand, and a person suffocates while standing upright. Such analysis helps architects design safer spaces. Surprisingly, a silent crowd is often more dangerous than a screaming one — silence hinders awareness of the threat until it's too late.
🎯 The highest recorded density is 9 people per square meter: the chest is compressed so much that breathing is impossible.
🎬 Asimov's psychohistory in real time.