Bp. Barber et al., SONOLUMINESCENCE, Philosophical transactions-Royal Society of London. Physical sciences and engineering, 355(1724), 1997, pp. 641-648
Pulsed light scattering off of a gas bubble trapped in a fluid by a st
rong sound field indicates that 'sonoluminescence' is accompannied by
a high Mach number implosion of the bubble's wall. Although these meas
urements support the imploding shock wave model of sonoluminescence th
ere remain many unknowns including the effects of impurities, fluid te
mperature, noble gas doping as well as the bubble size and light-emitt
ing mechanism.