Bursting of Air Bubbles at the Surface of Sea Water

Abstract

IN recent communications, Woodcock et al. ¹ and Knelman et al. ² have described experiments in which they have studied the fragments produced by the bursting of bubbles at an air–water interface. Both groups of workers have obtained high-speed photographs of the later stages of bubble bursting which show a small jet of water being projected vertically into the air and breaking up to form a few drops. The main differences between the results of the two sets of experiments lie in the fact that whereas Knelman et al. used bubbles of a few millimetres diameter, Woodcock et al. used much smaller ones (0.2–0.02 cm. diameter) which produced much finer jets and correspondingly smaller drops. But, besides the drops produced by the jet, Knelman et al. also found some much smaller droplets which, they suggested, may have been produced by break-up of the bubble film. The American workers³ report that the formation of such a group of smaller droplets was not associated with the bursting of their very small bubbles and suggest that this second mechanism occurs only in larger bubbles. It may be, of course, that the droplets produced by the disruption of very thin films are too small to be detected by normal methods, particularly as they will evaporate very quickly.