Mathematical Impressions: Spontaneous Stratification

Isn't it fascinating that this has been on front page most of the day, and it has but one comment? I suppose I'll fill this echo chamber.

This sort of work is absolutely fascinating to me. Emergent behavior like this can be so varied and complex, and getting any handle on it at all is often impossible. The fact that mathematics is starting to approach such problems, and may one day discover a great edifice of knowledge that explains what happens when a few simple rules interact—why, I would love to see the day. Recall that programming, too, often involves putting together just a few small pieces in an intricate arrangement, which causes beautiful behaviors to take place. Imagine understanding that phenomenon on a deep level!

That was very interesting! thank you for posting that. i've forwarded your link to a scientist i know who works on sedimentation in riverbeds who'll find it a very nice reference. (e.g. 'angle of repose' is a surprisingly complicated concept)

Looks like the sorting occurs in the cup, not in the receiving container. It shows the red particles suddenly stacking up on the slope from the bottom, which means only red particles were coming out of the cup at that instant.

Very cool. I wonder if this mechanism for stratification is the one responsible for the strata commonly seen in rock, or if there are more important mechanisms. (seasonal variation?)

Looks like something that could be modeled with some cellular automata rule.