Bubbles that collapse = light?

[Abscissas]

Hey I heard somewhere that bubbles underwater that are collapsed by sound waves produce light, to me this in no way makes sense can anyone explain is it like swamp gas that the fabled UFOs are

 

[Jimmy]

That's known as sonoluminescence:

http://en.wikipedia.org/wiki/Sonoluminescence

 

[ZapperZ]

Also see this:



Zz.