Understanding the Flow of Crowds

i was interested in this pair of findings not only because i was obviously amused by the image of people just absolutely eating each other's teeth and in high speed sidewalk collisions. This is one of those ignobele subjects where, once you get beyond the mildly funny image it conjures, it actually raises quite, i think, quite deep, mysterious, fascinating questions about the emergent mathematical properties of human behavior in groups. Understanding the flow of crowds is a matter of life and death. It is a vitally important subject for all kinds of reasons.