The Future Belongs to Crowds

The future belongs to crowds.
              — Don DeLillo, Mao II

I’m spending a lot of time thinking about crowds and crowd turbulence, of late. In a presentation today, I used the the following photo from a paper on crowd turbulence as evidenced by pilgrims crossing a bridge in Saudi Arabia. The blurred areas in the time-lapse photo represent areas of the crowd where turbulence has set in.

When conditions become congested, the flow drops significantly, which can cause stop-and-go waves and a further increase of the density until critical crowd conditions are reached. Then, “crowd
turbulence” sets in, which may trigger crowd disasters.

— Source: From Crowd Dynamics to Crowd Safety (arXiv 2008)