Description

A soap bubble filled with helium is pierced by a .22 caliber bullet, creating a shock wave (sharply delineated in yellow). Different gasses were introduced into the bubbles in order to study the varying speed of sound through different media. The myriad refractions make the bubble resemble a living organism. The photograph required a highly complicated technique to make visible regions of varying refraction and varying density of air. Edgerton and his assistant Kim Vandiver used the schlieren interference method for this optical study. (from "Stopping TIme" (1987), p.137) (CC)