[cmehdy]

Two things that would deserve clarification (although outside of the scope of the research here) are:

(1) When is it time to leave? At what threshold? Is it around an arm's length of free space between people?

And (2) Where to go? Straight line towards an exit? Perpendicular to the crowd? Exactly against the flow? Along the flow but towards edges? Probably depends on a lot of parameters..

[wongarsu]

A naive application of fluid dynamics would suggest that the answer to 2 is to go perpendicular to the flow until you reach a wall, then go against the flow towards an exit.

In the middle of a crowd/fluid your motion is determined by the humans/molecules around you. The closer you get to a wall, the fewer particles have an influence on you. Just make sure it's not a wall people are moving towards.

Not sure if anyone has studied how well this holds up to humans. Human crowds have very fluid-like behavior, but of course they don't behave perfectly like a liquid in a pipe

[alwa]

Is there anything to the notion that you might prefer to be batted around in the “soft body” portion of the dense-crowd “fluid” rather than pinned between several tons of soft bodies in motion and a hard limit? You seem rather more crushable than an individual molecule might be…

(edit: “crowd crush safety expert” Paul Wertheimer, who came to some notoriety through studying mosh pits from within them, apparently suggests—at least in situations where the crowd is moving toward a clear focal point—you’re right: he recommends the edges

https://www.cnn.com/2021/11/13/us/how-to-stay-safe-at-concer...

That said I note that the authors of TFA draw a distinction between dense-crowd situations undergoing unidirectional flow and the steady, confined dense crowd whose behavior they describe.)

[xeonmc]

> Human crowds have very fluid-like behavior, but of course they don't behave perfectly like a liquid in a pipe

Hypothetically, how would the dynamic change if it were a crowd of cats instead?

[thfuran]

Non-cat fluids don't usually spontaneously draw knives and start cutting themselves apart.

[vxxzy]

I don’t recall where, but for some reason I remember learning that if people start to bump into you too many times, that’s a warning shot to get out. It was something like “bumps per second”.