> >> a violation of energy conservation? No. Electric > >> potential energy is decreasing somewhere, > >> I'll let you find where :) ... > ...We want > to know, lol! :-)
Oops I have found in the meantime that my initial explanation was wrong, so it's just as well I kept it to myself ;-) Electric potential energy has nothing to do with the matter as I realized (my apologies for the misleading hint). Still it seemed obvious to me that _some_ potential energy had to be decreasing, since it takes work to bring the dipoles back to their non-aligned initial state. Same reasoning as in the non-rotating case where magnets are just attracted to each other, similar to a mass falling off a table as previously mentioned by Stephen. This led me to Googling "magnetic potential energy", and bingo, there is such a thing, and it decreases all right when magnetic dipoles align! You'll find a good explanation at the url below, for the case where one small dipole swivels inside another, larger one (see their drawing for the geometry). In this simple case no linear motion is involved, just the rotation to alignment we are concerned with, very much like a compass needle aligns with the Earth's magnetic field without being pulled as a whole one way or another. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magpot.html : "A magnetic dipole moment in a magnetic field will possess potential energy which depends upon its orientation with respect to the magnetic field. Since magnetic sources are inherently dipole sources which can be visualized as a current loop with current I and area A, the energy is usually expressed in terms of the magnetic dipole moment: U = -µ . B where µ=IA The energy is expressed as a scalar product, and implies that the energy is lowest when the magnetic moment is aligned with the magnetic field..." Therefore if the small magnet swivels without friction it should oscillate like a pendulum around the aligned position, with energy being similarly transferred back and forth between potential energy (max at max disalignment) and kinetic energy plus field energy (max at alignment). Variation of the latter can probably be neglected in the small magnet vs big magnet case, just like one neglects the complete system's gravitational field energy variation when deriving the pendulum's motion in the Earth's gravitational field. Energy conserved in standard physics, unsurprisingly. Michel ----- Original Message ----- From: "Paul" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, January 24, 2007 6:22 PM Subject: Re: [Vo]: Energy *Violations* using *standard* physics > Michel Jullian wrote: > > ----- Original Message ----- > > From: "Paul" <[EMAIL PROTECTED]> > > To: <[email protected]> > > Sent: Wednesday, January 24, 2007 3:46 PM > > Subject: Re: [Vo]: Energy *Violations* using > *standard* physics > > > > > >> Michel Jullian wrote: > >>> Indeed both kinetic and magnetic field energies > are > >> increasing in the process. Is this > >> a violation of energy conservation? No. Electric > >> potential energy is decreasing somewhere, > >> I'll let you find where :) > >>> Michel > >> > >> The old "I know, but I don't want to tell you" > trick? > >> :) > > > > Not at all, I will give the answer eventually, say > on Sunday if nobody finds it before, > which I doubt very much. The fun is in the searching, > I have given away far too much > already :) > > > > Your variations don't change the issue BTW, so > let's stick to your original experiment. > > > > Michel > > > Michel, > > Why don't you tell us now. It's probably some effect > we're not aware of or know very > little about. If it is such an effect then I'll plug > it in my latest simulation program > and see what happens. > > I'm no QM expert, which is why I asked dozen+ QM > physicists, but do you know something > they're not aware of? Why wait for Sunday? We want > to know, lol! :-) > > > Regards, > Paul Lowrance > > > > ____________________________________________________________________________________ > Do you Yahoo!? > Everyone is raving about the all-new Yahoo! Mail beta. > http://new.mail.yahoo.com >
