Patterns in the sand
(Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080,China)
AbstractThe formation of patterns and its underlining mechanism in granular systems are discussed from a physicist's point of view. These findings may help us understand the patterns formed in other more complex non-equilibrium systems. It is found that the randomization and dissipation properties of non-equilibrium systems are the underlining mechanisms for pattern formation. The symmetry of the system and the ratio of the weight factors of the above two mechanisms determine the pattern shapes. A final and key factor for pattern formation is the 2nd law of maximization of the entropy, which determines if a system is organized orderly or disorderly. Examples in granular systems are given to illustrate the above view points.
Keywordsgranular matter, pattern formation, complex system ......