Sonoluminescence is a phenomenon where small gas bubbles in a liquid emit brief flashes of light when exposed to intense sound waves. This occurs when the sound waves create rapid pressure changes, causing the bubbles to collapse and generate extreme temperatures and pressures inside them. The light produced is extremely short-lived, lasting only a few billionths of a second. Scientists study sonoluminescence to understand the underlying physics and potential applications, such as in sonochemistry, where sound waves are used to enhance chemical reactions.