Sonoluminescence: When bubbles glow.

In single-bubble sonoluminescence, an ultrasound-driven microbubble undergoes violent oscillations and converts part of the energy of the sound field into visible light. Since its discovery ten years ago, a consistent theory of the dynamics and stability of the bubble has been developed. The approach includes the dissociation of molecular gases inside the collapsing bubble to explain striking differences in experiments with various molecular and noble gases. A natural extension of the theory incorporates the light emission itself, identifying its mechanism as thermal bremsstrahlung from the optically thin (transparent) bubble. A direct and systematic comparison of the results of the theory with experiment shows good agreement in all characteristic features.