The University of Chicago Granular Physics Group

dense flows	avalanches	convection	force chains	surface waves	inelastic gasses	sound

"Who could ever calculate the path of a molecule? How
do we know that the creations of worlds are not
determined by falling grains of sand?"

- Victor Hugo, Les Miserables

Welcome to the Granular Physics Group at the University of Chicago. Here you can find information about research on a class of materials that sometimes behave like solids, sometimes like liquids, sometimes like dense gases, and often like all of these at once. These granular materials are large assemblages of individual solids ("grains") and include such familiar items as coffee beans or grounds, gravel, powders, pharmaceutical pills, fertilizer, grain, seeds, ....., or sand. They are materials that are all around us and which are of tremendous importance for many industrial processes. Yet even though granular materials appear simple, they display an astounding range of complex behavior that has largely been unexplored.

• granular jets: pictures and high-speed movies, including fast x-ray movies
• size separation in granular materials: a new twist to the Brazil Nut Effect.