From: utzoo!henry
Newsgroups: net.physics
Title: Re: perpetual motion puzzle? 
Article-I.D.: utzoo.2720
Posted: Wed Dec 29 18:22:41 1982
Received: Wed Dec 29 18:22:41 1982

I've never seen one of the beasts, so I can't say for sure, but I do know
one way of building "perpetual motion" machines.  It is possible to get
*small* amounts of energy literally "out of the air" by picking up and
rectifying the 60-Hz signal from nearby power wiring.  This signal is
omnipresent in industrial civilization (well, it's 50 Hz some places...).
You can't get much power, but it can be enough to keep a low-friction
device going.  What bothers me is that the description of the "perpetual
top" implies a fairly small base, and it's hard to get practical amounts
of power from the power-wiring radiation without a sizeable antenna.

						Henry Spencer
						U of Toronto