CHEMICAL CLOCKS ON THE BASIS OF ROTATING WAVES - MEASURING IRRATIONALNUMBERS FROM PERIOD RATIOS

An ink-jet printer is utilized to generate catalyst-loaded patterns su ch as circles, triangles, and squares on polysulphone membranes. These patterns define excitable domains for the Belousov-Zhabotinsky reacti on in which rotating waves can be initiated. The resulting wave propag ation is exploited for the implementation of chemical clocks with stab le period ratios. Based on this approach the irrational numbers pi, ro ot 2, and the golden mean are measured with a relative error of 0.1-0. 2%.