ON RIPPLE DYNAMICS .1. MICROCOMPUTER-AIDED MEASUREMENT OF RIPPLE PROPAGATION

The effects of soluble or insoluble surface films on the propagation of capillary waves at fluid/air interfaces have been previously considered by several researchers. Their studies reveal mechanisms by which surface films affect wave propagation. Theoretical models have hitherto lacked a rigorous quantitative comparison with observation of ripples (waves in the critical transition region between capillary and gravity waves). My observations in this region establish the validity of an existing model and indicate directions for its further development. These observations were obtained with a compact and precise apparatus to elicit information from ripples, using a nondisruptive optical technique to determine ripple slope, and a Commodore 64 personal computer to sample and analyze data. The apparatus is efficient and readily duplicated.