Michel Jullian wrote:
----- Original Message ----- From: "Stephen A. Lawrence"
<[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Tuesday, January
23, 2007 5:06 AM Subject: Re: [Vo]: Energy *Violations* using
*standard* physics
...
Good, then you do acknowledge there is *real work* being done
while two magnetic dipole moments rotate toward alignment.
Absolutely! The "magnetic fields do no work" mantra fails. It is
false.
Forgive me for jumping into the discussion without having followed it
all. "Magnetic fields do no work" wouldn't make sense anyway. Work is
done by forces. It's the _force on a moving charge due to the
magnetic field_ qv × B which does no work (I don't suppose you
dispute that?), not the magnetic field per se.
Yes, of course. The way I've generally seen it stated, though
(particularly during arguments) is "Magnetic fields do no work", even
though that's imprecise. And then, of course, people take that
imprecise statement which actually was talking about the Lorentz force
law for moving charges, and they try to apply it to "prove" that
permanent magnets acting on each other must "do no work".
And no doubt some number of amateurs in this area are confused about
what causes the field of a permanent magnet, just as I was before
someone on Vortex pointed out to me that it primarily results from spin
dipoles.
...
Another option is perhaps there's a decrease in electron
velocity. The electron must always be in motion, correct?
Therefore, there's always room for the electron to slow down.
I don't think so. The linear motion of the electron is not at
issue; its dipole, which is providing the energy here, is due
entirely to its "spin".
Well not quite entirely, the current loop consisting in the orbiting
motion has got to contribute _some_ magnetic dipole moment to the
atom, however small this effect may be compared to that of the
rotating motion.
Yes, that's true.
I don't know what the story is with orbital dipole moments -- orbital
behavior is also quantized, so it's not clear that an "orbiting"
electron can "slow down" any more than its "spin rate" can decrease.
OTOH the energy in the field of an orbital dipole was presumably
"invested" when the compound was formed and is retrieved when the
compound breaks up, unlike the spin dipole, which seems to be truly
permanent.
Michel
