Sands, Powders, and Grains: An Introduction to the Physics of Granular Materials

The physics of granular materials comes from an illustrious lineage. It includes names like Coulomb during the reignofLouis XVI, Faraday and Reynolds in the nineteenthcentury, andBagnold,aremarkableEnglishmanwhobecameenthralled by the sands ofthe desert, perhaps even more so than T. E. Lawrence, to the point that he resolved to understand its laws. Inspiteofsuchgreatpioneersandtheirvaliantefforts, themechanicsofpowders remains largely a mystery. Even seemingly trivial questions lack clear answers. Whatistheweightdistributionofapileofsanddumpedonthefloorofanapartment under constmction? Does it depend on the way it was dumped? No one really knows. Suchquestionshappento bequiteimportantinavaIietyoftechnicalfields. They have applications to situations ranging from agricultural facilities storing corn in silos to the spaceexplorationofSaturn'srings-this "fascinatingmerry-go-round ofrocks," to quote Guyon and Ie Troadec. I have just mentioned two contemporary authors. They recently wrote a book entitled Le sac de billes (The bag ofmarbles), published in 1994 by Odile Jacob. It is a fascinating introduction to these problems, as well to somewhat unusual objects like porous materials. Yet, there is a need for a more advanced textbook for the benefit ofour science students. For the last few years, Jacques Duran has taught acourse in granularmaterials aimed at undergraduates in their senior year.