A thin liquid crystal film on a surface of photoactive dye turns into a wonderland of exotic moving patterns if just illuminated by a simple lamp. Spirals move and oscillate across the surface in the form of advancing wavefronts, encountering and annihilating each other. This represents an especially attractive model system for studying dynamic non-equilibrium patterns, also found in biological, chem ical, and physical systems ranging from organization of slime mold cells, to crystal growth from nuclei with screw dislocations.
