Friday, May 27, 2016

Party on Wayne; Party on Garth

In my continual pursuit to understand the physical world, some recent reading in the prestigious Physical Review Letters journal, I encountered this article: “Collective Motion of Mashers at Heavy Metal Concerts.”

To quote an excerpt:

Human collective behaviors vary considerably with social context. For example, lane formation in pedestrian traffic, jamming during escape panic, and Mexican waves at sporting events are emergent phenomena that have been observed in specific social settings.

Here, we study large crowds (102 − 105 attendees) of people under the extreme conditions typically found at heavy metal concerts. Often resulting in injuries, the collective mood is influenced by the combination of loud, fast music (130 dB, 350 beats per minute), synchronized with bright, flashing lights, and frequent intoxication. This variety and magnitude of stimuli are atypical of more moderate settings, and contribute to the collective behaviors studied here.

Videos filmed by attendees at heavy metal concerts highlight a collective phenomenon consisting of 101 −102 participants commonly referred to as a mosh pit. In mosh pits, the participants (moshers) move randomly, colliding with one another in an undirected fashion. Qualitatively, this phenomenon resembles the kinetics of gaseous particles, even though moshers are self-propelled agents that experience dissipative collisions. To explore this analogy quantitatively, we obtained video footage, corrected for perspective distortions as well as camera instability, and used PIV analysis to measure the two-dimensional (2D) velocity field on an interpolated grid.

The results of the study shows the motion of the moshers duplicates quite closely the behavior of molecules in a gas. These gaseous phenomenon have been carefully studied from a perspective of thermal behavior (the effects of “temperature”) and advanced mathematics such as Maxwell-Boltzmann statistics. This is thermodynamics models at their loudest.

Ask not what Heavy Metal has done for you (or to you). Ask what you have done for Heavy Metal.

And there you have the shortest article I have ever written. Especially if you realize the majority of the text is a quote from another publication. People just don’t realize that I’m terse and laconic. Nor do they realize that physics is all around us … even at a rock concert.

For those so inclined, here's the original article: