6.4 What is sonoluminescence ?
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This article is from the Acoustics FAQ, by Andrew Silverman with numerous contributions by others.
6.4 What is sonoluminescence ?
In the early 1930s Frenzel and Schultes discovered that photographic plates became "fogged" when submerged in water exposed to high frequency sound. More recent experiments have succeeded in suspending a single luminous pulsating bubble in a standing wave acoustic field, visible in an undarkened room. Generally sonoluminescence is light emission from small cavitating bubbles of air or other gas in water or other fluids, produced when the fluid is acted upon by intense high frequency sound waves. The mechanism is not completely understood, but very high pressures and temperatures are thought to be produced at the centre of the collapsing bubbles.
See "Science" 14 October 1994 page 233, "Scientific American" (International Edition) February 1995 Page 32 or "Physics Today" September 1994 Page 22, all quite readable articles.
See also the following URLs:
http://ne43.ne.uiuc.edu/ans/sonolum.html http://www.wdv.com/Sono
James Davison (TKGN58A@prodigy.com) on 28th June 1995 wrote:
[snip] .. I have been sufficiently interested to reconstruct the apparatus for producing this effect -- using a pair of piezoelectric transducers, an old oscilloscope and a signal wave generator -- materials costing only a few hundred dollars.
I am proud to say that tonight I managed to reproduce this effect -- the tiny bubble has the appearance of a tiny blue star trapped in the middle of the flask. It is distinctly visible to the unadapted eye in a dark room, and it is a very startling thing to see. [snip]
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