Sonoluminescence: nature's smallest blackbody

The transduction of sound into light through the implosion of a bubble of g as leads to a flash of light whose duration is delineated in picoseconds. C ombined measurements of spectral irradiance, Mie scattering, and flash widt h (as determined by time-correlated single-photon counting) suggest that so noluminescence from hydrogen and noble-gas bubbles is radiation from a blac kbody with temperatures ranging from 6000 K (H-2) to 20,000 K (He) and a su rface of emission whose radius ranges from 0.1 mum (He) to 0.4 mum (Xe). Th e state of matter that would admit photon-matter equilibrium under such con ditions is a mystery. (C) 2001 Optical Society of America.