Hottest Star in a Jar

Sonoluminescence is the light emitted from tiny bubbles of gas in a liquid, which collapse rapidly under the influence of sound waves. Under laboratory conditions, stable bubbles can be sustained which rapidly pulsate, emitting light with each contraction. Scientists are still debating exactly which physical processes cause this phenomenon, nicknamed the ‘star in a jar’, but estimates of the temperature inside the collapsing bubbles range from 10,000 C to over 1 million C. In October 2001 scientists reported that the collapse of cavitation bubbles, caused by the snapping shut of the claws of shrimp, also produces the same phenomenon - the first of its kind witnessed in the animal kingdom, and nicknamed 'shrimpoluminescence'.