Re: [math-fun] Packing problem

So the difference between the two cases (bubble of light particles starting at bottom, bubble of heavy particles starting at top) is differing flow of the injected gas around the two populations.

This is purely geometrical. A spherical obstruction or a wedge will have relatively low drag, and usually mostly laminar flow, but a *concave* wall (droplet is poor word choice in my opinion, and misleading) can be expected to cause a node in the streamline pattern, which then causes scattering. This mechanism has nothing to do with mass difference. Possibly rough reconnection behind a droplet explains why some of the particles get bounced out and stranded alone (how sad). --Brad