Reaction−Diffusion Patterns of the Chlorite−Tetrathionate System in a Conical Geometry

We experimentally study the spatiotemporal reaction−diffusion patterns exhibited by the chlorite−tetrathionate reaction in a conical piece of gel. Since the nonequilibrium states of this reaction−diffusion system depend on the thickness of the gel, one can observe simultaneously such phenomena as spatial bistability, excitability waves, and a monostable state coexisting at different height over the cone. This new geometry allows for the exploration of gel size effects on pattern selection down to smaller dimensions than in previous experiments.