You wouldn’t think there’s much science to it: take hundreds of heavy metal fans, pack them into a live venue, put the band onstage, start the pounding lights and music and a mosh pit forms.
But little do those moshers know that they're acting like particles — and that physics professors might just be watching.
In a new study titled "Collective Motion of Moshers at Heavy Metal Concerts," researchers at the Laboratory of Atomic and Solid-State Physics and the Department of Physics at New York’s Cornell University examined online videos of mosh pits at heavy metal shows, and compared the movement of the moshers with the behaviour of particles.
“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,” wrote the researchers at the beginning of the paper. “Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.”
The researchers examined videos of both mosh pits and circle pits at the shows where, as they described it, “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.”
Using models, they transformed each human mosher into a simple soft-bodied particle that they dubbed a MASHer – Mobile Active Simulated Humanoid – then looked at how they behaved.
In the mosh pits, they found that, even though the metal fans can choose where they go, their movement did resemble that of gases. “In mosh pits, the participants (moshers) move randomly, colliding with one another in an undirected fashion,” the researchers wrote. “Qualitatively, this phenomenon resembles the kinetics of gaseous particles, even though moshers are self-propelled agents that experience dissipative collisions.”
Just like vortexes, the circle pits were more predictable, whether they were in the U.S., the U.K. or Australia, with 95 per cent of the participants moving in a counterclockwise direction and just five per cent moving clockwise. (The researchers suspect this has to do with the dominant handedness/footedness in humans.)
So why are these scientists studying the physics of mosh pits in the first place? According to the paper, the heavy metal concerts are a reliable, consistent and ethical — if exceptionally loud — way of studying human collective motion, and using physics to predict people's movements could even be used to improve human safety down the road.
“Further studies in this unique environment may enhance our understanding of collective motion in riots, protests, and panicked crowds,” says the study, “leading to new architectural safety design principles that limit the risk of injury at extreme social gatherings.”
There's no word, however, on how metal fans feel about having their mosh pit behaviour deemed "consistent with the predictions of simplified models.”