Strolling on the beach we notice that our feet create dry spots around them. The sand around the leopard’s feet flows while it speeds along the desert. Close to the ocean, we often notice dark striations on the sand. These phenomena are so familiar to us that we hardly ever pause to wonder their origin. The surprising fact is that we do not really understand why sand behaves the way it does. In the world of granular materials, gravity is important and temperature is not. This is stuff that we see around all around us but know very little about. For the last five years Prof. Chakraborty has been working on developing a theory of granular materials that can predict their collective behavior. The puzzling nature of granular materials is portrayed in this NSF-produced video that followed the Nature paper on shear-jamming by the Chakraborty-Behringer collaboration. Recent work has focused on constructing a statistical ensemble for granular solids, the nature of jamming in hopper flows, and the origin of rigidity in dry granular solids.
Berko Talk (Sumantra Sarkar)