I appreciate this view from above. It is like a shock-wave. It is made of individual people but the shock-front looks circular: the fact that people are facing forward most doesn’t count. I wonder how close crowds come to doing this, but just stop short. Can we measure the tipping point? This is the sort of thing that AI is good at.
I do not like big crowds. Football fans who individually may be nice people give up their identities to be an atom in a crowd, and attack people on the other side because they are the other side and nothing more. This shows my unreasoning fear has some sort of mathematics behind it, and I am wiser for the seeing.
