Built on Sand
The Science of Granular Materials
Explaining the science contained in a simple assembly of grains—the most abundant form of matter present on Earth.
Granular matter—materials composed of vast amounts of solid grains—constitutes the most abundant form of matter on Earth. Granular materials assemble in disordered configurations scientists often liken to a bag of marbles. Made of macroscopic particles rather than molecules, they defy the standard scheme of classification in terms of solid, liquid, and gas. Avalanches, for example, can be characterized as friction, geometric congestion between grains. Granular materials provide a model for various domains, including engineering, physics, and biology, shedding light on collective behavior in disordered settings in general. William Blake famously wished “To See a World in a Grain of Sand”; in this book, pioneering researchers in granular matter explain the science contained in a simple assembly of grains.
The authors begin by describing the single grain with its different origins, shapes, and sizes, then examine grains in piled or stacked form. They explain the packing fraction of granular media, a crucial issue that bears on the properties displayed in practical applications; explore small-scale deformations in piles of disordered grains, with particular attention to friction; and present theories of various modes of disorder. Along the way, they discuss such concepts as force chains, arching effects, wet grains, sticky contacts, and inertial effects. Drawing on recent numerical simulations as well as classical concepts developed in physics and mechanics, the book offers an accessible introduction to a rapidly developing field.