Shock waves and steam heat

For more than two years debate has raged on the Internet about an ordinary-looking metal drum sitting on the concrete floor of a factory building in Rome, Georgia, 50 miles from Atlanta. Its inventor, the man about whom the Internet debate is raging, is James Griggs, an industrial heating engineer.

The invention that has brought Griggs such notoriety is a device that he began developing in 1987, that he calls the 'Hydrosonic Pump' and that many of his supporters believe is over-unity, in that it generates around 30 per cent more energy as heat than is put in as electricity.

To the skeptics, the Griggs Gadget is, at best, a case of self-delusion on a grand scale, and, at worst, a case of scientific fraud. To his supporters, the pump is the first unequivocal public demonstration of undoubted over-unity.

http://www.alternativescience.com/over-unity.htm