Stephen A. Lawrence wrote: [snip] > > They attract until they are perfectly aligned NS NS. > > When they're aligned > > N > | > | > | > | > S > N > | > | > | > | > S > > they can flip (rotate) so that they're aligned > > NS > || > || > || > || > SN
Sure if you ***add*** energy Stephen. That takes energy. I have written far too many simulations to know. I have seen physical grids of permanent magnets on swivels and you are completely wrong on this. Magnet dipole moments prefer NS....NS. At curie point the magnetic dipoles moments are in chaos, mostly pointing in random directions. As the material cools down they begin to align in NS....NS to form a complete closed magnetic loop such as four domain wall. It is well known that the net magnetic field in such domains is intense with or without any applied magnetic field. At curie temperature the net magnetic field is considerably lower (higher magnetic entropy), which is why the material heats up when an applied magnetic field is added, hence MCE (Magnetocaloric Effect). BTW, your drawings of dipoles are way out of proportion. You are drawing cigarettes. An electron is not in the shape of a cigarette, lol. There is more magnetic attraction from max alignment --> NS....NS as compared to half alignment --> NS . . . . SN You first need to understand the field is twice the magnetic density in front as compared to sides of magnetic dipole moment. > NS > || > || > || > || > SN > > and, in fact, if you jiggled them a little and then let them have > their way, that's exactly what they'd tend to do. No chance Stephen. It simply doesn't happen in real life or in simulations. Please study the javascript code at --> http://www.netdenizen.com/emagnet/offaxis/iloopcalculator.htm Plug that equation in a simulation program and let her rip. You'll see it's in total agreement with real physical experiments. > It's a lower > energy configuration than the end-to-end configuration, which is most > apparent when you model them as magnetic monopoles stuck to the ends > of rods. > > In any case, if they're aligned NSNS they'll attract, and if they're > side by side aligned N/S S/N they'll attract, also The difference being one has higher magnetic entropy. This is really not a difficult problem and should not require computer simulation. Just think a little deeper enough. :-) > , and in both cases > the torque will be zero because the torque is proportional to the > mis-alignment of the dipole vector and the field vector. And, of > course, the field vector points straight out the end (parallel to the > dipole), but for positions "next to" the magnet it points opposite to > the direction of the dipole. > > > > >, and in that case the fields cancel as they > > approach. > > > > That's not true. When aligned they are NS NS. That > > is full magnetic alignment and they > > do *not* cancel. The net field increases. > > It increases versus a single magnet, that's true. But compared with > two distant magnets? I'm not so sure; we need to ask: No, the net magnetic field increases from two nearby fully aligned magnets as compared to if they were far apart. > Does the field increase or decrease as they're drawn apart along a > line? More of the fields overlap as they approach each other in fully alignment. > [ snip ] > > > Two aligned electromagnets do not repel. They > > *attract*. > > Arrgh. We're both right. If they're end-to-end they attract when > they're aligned. If they're side by side they attract when they're > misaligned. Correct, but what you seem to miss is the front magnetic density is twice as compared to the sides, which is why the PM's have less entropy in full alignment as compared to half alignment. > > That's backwards. :) As they attract and move closer > > there's back EMF, which consumes > > energy from the battery. > > Yes, no matter the alignment, we "pay" for the work done as they pull > themselves together, by pumping in electrical energy. Yes, but again that is not the point. We are trying to figure out where the energy comes from such a gain in both kinetic and magnetic energy. When you pull the magnets apart you are adding energy, but to what? This is still a mystery, one day to be solved when humanity learns exactly what sustains the electrons existence. Who know, may the energy comes from God. :-) Regards, Paul Lowrance ____________________________________________________________________________________ Any questions? Get answers on any topic at www.Answers.yahoo.com. Try it now.
