Wednesday 19 June 2013

Collective Motion, Heavy Metal, and exercises for the interested reader

In this video, Professor Moriarty summarises a paper in Physical Review Letters, entitled  "Collective Motion of Moshers at Heavy Metal Concerts". I suggest watching to the end.

The paper in short form: - and more from the researchers:

Abstract: 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 gaslike state called a mosh pit and an ordered vortexlike 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.

Those of you who can enjoy the mathematics may also enjoy the source code for the simulations, available at github and linked to in the short form article, and anybody can play with the simulation, here.

On reading the reasearchers' summary and looking at the short form paper, I'm not yet convinced that this research really predicts or explains anything, but I'd like to know if it could.

In my view, moshing is a kind of social dance. Obviously you could throw yourself around to heavy metal music all alone, but the true experience, I would have thought, is the one where you get to bounce off other people in the presence of a band.

I have a lot of questions about lots of social dance phenomena that might be answered by research of this kind. People argue about them endlessly, with no conclusions, and that makes me think they must be simpler than they appear to be.

For example:

How simple can a simulation of a (social, progressive, partner) dance be and generate a plausible simulation of a dance floor? How about an orderly line of dance in a specific direction? What variations can you introduce and still have it work? What variations can you introduce and have it fall apart?
I say that lighting - or rather, its effect on the ability of dancers to accurately estimate the distance and velocity of other dancers - matters. Can we support or falsify that with evidence?
I also say that layout matters. Hard or soft edges to the dancefloor matter. Irregular corners matter. A dancefloor that is too big in relation to certain characteristics of the dancers, will always be disorderly. Can we model, support, or falsify any of this?

I say that flocking behaviour matters a lot: and that, if everyone does it just enough, you still get order, but if some people do it not at all, others have to do it more to create order. I say that this interacts with the size of the floor compared to the number of dancers. Can that be shown?

What rules or conditions do you actually need, and what rules are unnecessary? That seems to me like it should be an answerable question.

It would also be very straightforward to Dance Your PhD afterwards.

Friday 7 June 2013

Dancing tango in Taksim Square, Turkey

Just a really quick one: Demare in Gezi Park, Taksim Square. Posted yesterday on Youtube.

They seem to have turned out a decent number of dancers. Go, Turks! Let's get it some views. Were you there?