When Is A Crowd Like A River?

Almost exactly two years ago today, I attended the inauguration of President Barack Obama on the National Mall in Washington, DC. I was a small person in an enormous crowd, estimated at between one and a half and two million people. It was a little scary, since crowds have been known to break into panicked stampedes, and if that had happened, escape would have been impossible.

I was thinking, again, about that day when I wrote a special article for the L'Oreal Foundation's new website Agora for Women in Science. As it turns out, the large group who gathered on the Mall that day were being protected by a special design for crowd control that works by treating the gathering of people as if they were a large river, flowing between barriers.

Read the original article here.