posted on Feb, 4 2012 @ 03:46 PM
It's a very tiny bubble lasting small fraction of second, high temps. Not much anomalous energy it seems, still obeys conservation of energy.
Cavitation is brought about by incredibly low pressure in water, probably close to vacuum pressure, this causes a bubble made entirely of water vapor.
Boat propellers could generate this but must be avoided by design as it erodes even metal propellers!!