Special Issue: Disordered Solids

Millions of years separated the formation of the first sedimentary rocks on our Earth from the emergence of the central nervous system. Some aspects of these very disparate systems have recently yielded to the language and methods of physics: The porous structure of sedimentary rocks can be modeled as a fractal, and neural networks, which provide models for understanding some simple aspects of the nervous system, may be regarded as dynamical systems. By collecting in a special issue of PHYSICS TODAY articles on sedimentary rocks and neural systems, which traditionally have been regarded as too complex for physicists, with ones on topics such as random magnets and disordered electronic systems, we hope to show that a common thread runs through these diverse subjects. That thread is the physics of disorder.