The bidimensional motions of a heavy metal moshing

During the APS March Meeting 2013, Matthew Bierbaum with Jesse Silverberg, James P. Sethna and Itai Cohen from Cornell University, presented a curious study about the heavy metal mosh pits: studing the people during the moshing, the researchers find two types of collective motions:

mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people.

The results are published on arXiv (Collective Motion of Moshers at Heavy Metal Concerts):

Human collective behavior can vary from calm to panicked depending on social context. Using videos publicly available online, we study the highly energized collective motion of attendees at heavy metal concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered gas-like state called a mosh pit and an ordered vortex-like state called a circle pit. Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.

(via Lucia Marino)Image may be NSFW.
Clik here to view.Image may be NSFW.
Clik here to view.