"Sonoluminescence is the emission of light from imploding bubbles in a liquid when excited by sound"
"Sonoluminescence was first discovered in 1934 at the University of Cologne. It occurs when a sound wave of sufficient intensity induces a gaseous cavity within a liquid to collapse quickly, emitting a burst of light. The phenomenon can be observed in stable single-bubble sonoluminescence (SBSL) and multi-bubble sonoluminescence (MBSL)."
https://en.m.wikipedia.org/wiki/Sonoluminescence
"Powerful, targeted blasts of sound can create imploding bubbles in water. And if that isn't cool enough, the interior of these bubbles can reach temperatures of around 10,000 kelvins. But what is most peculiar is that light is produced.
The process is called sonoluminescence."
https://www.realclearscience.com/lists/unsolved_problems_in_physics/what_is_sonoluminescence.html
