Excitation Waves in Planar, Inhomogeneously Illuminated Systems

Spencer Kirn


This purpose of this project was to build a system and begin to examine the propagation of excitation waves traveling through an inhomogeneous, light-sensitive Belousov-Zhabotinsky (BZ) system. Theoretical work by Schebesch and Engle produced a prediction of how the wave will be affected by a checkerboard inhomogeneity. We used a checkerboard transparency to create an inhomogeneous illumination pattern below the BZ system. The wave reacts to the light and travels at different speeds depending on the light intensity, the brighter the light the slower the wave propagates. A camera is used to track the wave as it propagates. The wave front is analyzed to create time-space plots as it travels through the BZ system. Codes were written for collecting an analyzing data, including: a program to take and save images of the wave propagating, a program to eliminate the background in every image, and a program to create time-space plots of the wave.