While reading the link provided by Entropic, I've stumbled at the mention of the so-called MEG-device of Tom Bearden. I normally regard all the guys in the "free-energy aka snake-oil" business as terminal clinical charlatans, but this time I read through the alledged confirming evidence report [url]
jnaudin.free.fr/html/megv2.htm
[/url] and something smelled different to me. While theoretically the particular MEG seemed to me rather improbable to work, something similar could; and here's why -
Consider a permanent magnet whose field is short-circuited by an external ferromagnetic core connecting its poles, magnet being put into a gap in the circled core. The magnetic flux in that core contains energy proportional to the flux magnitude squared and to the length of the said core, assuming crossection constant. Now if we use a core twice as long, there must be twice as much energy in that core, since the very same flux is supplied by the magnet. Permeability figures of good modern transformers' cores are too high to lose too much of the flux, so doubling the length hardly introduces any loss of the flux. Consider also that, putting the magnet into the gap in the core requires negative work and produces mechanical energy, since the magnet is pulled into the gap and held there and not pushed away as we put it there. The question is - whence the extra field energy in the longer core comes from????!
I must admit, I'm at a total impasse here. Someone, please, falsify my deduction!
