Abstract
The initial growth of vapor bubbles in various liquids produced by electric sparks is described. Because of the large rate of expansion observed, an assumption is made that the heat flow across the bubble boundary can be neglected during the initial stage, i.e., the bubble makes an adiabatic expansion. On this assumption it follows that the radius of the bubble, R, is given approximately by R=Kt0.4 where t is time, and K a constant. This radius-time relation has a significant feature compared with the results obtained by both Raileigh and Plesset. Experimental results obtained by the use of a high-speed cine-micrograph are in good agreement with the theoretical prediction, although, when the gap-length of electrodes is relatively large, some corrections regarding the shape of the bubble are required.
