John Bohn

Balls of clay may stick to each other when they collide. This is because the original energy they had before the collision gets so mixed up in heating the clay that the balls have none left to separate. Molecules, particularly small ones, don't generally act this way, since there are not many places for the energy to disappear into.

It is widely known that mixtures of Bose-Einstein condensates (BEC's) can "phase separate" under circumstances where the mutual repulsion of the two BEC's overcomes their self-repulsion. Typically, one BEC goes to one side of the enclosure, and the other goes to the other side. Now, along with Chris Ticknor and Eddy Timmermans, Ryan Wilson has expanded this notion to include dipolar BEC's that possess a roton instability.