The Kinetic Theory of granular materials is a subject with wide ranging applications in physics, astronomy, engineering, and chemistry. The basic equation of the standard kinetic theory of molecular gases, the Boltzmann equation, can be easily extended to the particles of granular gases, such as a cloud of dust, a landslide, the grains in a silos, planetary rings, etc. In contrast to molecular particles, however, granular particles are macroscopic bodies which lose part of their kinetic energy when they collide. This gives rise to many unexpected physical properties.
