Sonoluminescence

Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. The sonoluminescence effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of photographic developer fluid. They hoped to speed up the development process. Instead, they noticed tiny dots on the film after developing and realized that the bubbles in the fluid were emitting light with the ultrasound turned on. It was too difficult to analyze the effect in early experiments because of the complex environment of a large number of short-lived bubbles. (This experiment is also ascribed to N. Marinesco and J. J. Trillat in 1933, which also credits them with independent discovery). This phenomenon is now referred to as multi-bubble sonoluminescence (MBSL).