ABSTRACT
The term “pattern formation” refers to processes by which positive feedbacks operating at small spatial scales give rise to self-organization at large scales that results in stationary or time-dependent spatial patterns. Numerous examples of such processes have been found and studied in various fields of science, including fluid dynamics, chemical kinetics, nonlinear optics and geophysics. Much of our understanding of pattern formation phenomena derives from controlled laboratory experiments conducted on simple model systems. Following a brief description of patterns in nature and some of their characteristic features (Section 2.1.1), we introduce two experimental model systems, the Rayleigh-Be´nard thermal convection system (Section 2.1.2) and the Belouzov-Zhabotinsky chemical reaction (2.1.3). Both systems show a variety of pattern formation phenomena and have played important roles in uncovering general mechanisms of pattern formation and dynamics.
