Models of spherical supersonic bubble implosion in cavitating liquids predict that it could generate temperatures and densities sufficient to drive thermonuclear fusion1,2. Convincing evidence for fusion is yet to be shown, but the transient conditions generated by acoustic cavitation are certainly extreme3–5. There is, however, a remarkable lack of observable data on the conditions created dur...

The acoustic emission from collapsing cavitation bubbles generated using ultrasound of 20 kHz and 515 kHz frequencies in water has been measured and correlated with sonoluminescence and hydroxyl radical production to yield further information on the frequency dependence of sonochemical reactions. A reasonable correlation was found, and the results suggest differences in the predominant types of...

Sonoluminescence is explained in terms of quantum radiation by moving interfaces between media of different polarizability. It can be considered as a dynamic Casimir effect, in the sense that it is a consequence of the imbalance of the zero-point fluctuations of the electromagnetic field during the non-inertial motion of a boundary. The transition amplitude from the vacuum into a two-photon sta...