The Primer Fields - Breakthrough in our understanding of magnetism

[TinselKoala]

@crazy.... the conventional wisdom says it's not possible. And if you think about what "field lines" are and what they represent it makes sense that it would not be possible. Field lines are closed loops, this fact is contained in Maxwell's equations as Gauss's Law: Div B = 0. Divergence of B is zero, meaning that all field lines are closed loops or extend to infinity,  and magnetic monopoles can't exist.

This is a descriptive kind of law, though; I don't think monopoles are forbidden, exactly, and lots of people are looking for them. I think that the conditions that might produce them are way out of the reach of the amateur scientist, though, and will require huge energies and "big science" kind of equipment.

The magnetic field around a straight, current carrying wire is a good example of how field lines behave. In a PM, the moving charges are unpaired electrons in the material, with aligned spins. If you think of a simplistic electron "orbiting" a nucleus in a circular orbit, there's your single loop of wire carrying a current, and the field will loop around the orbit of the electron in continuous loops just like the circles of field around a wire, and all these add together to give the bulk magnet its big field. So you can think of a bar magnet as kind of a self-powered solenoidal coil, with field lines to match.

Of course this isn't as exciting as the Davis model.... but as I said before, you can just take an ordinary compass and probe around the Earth, or a bar magnet, and see that his representation isn't a reflection of what really happens. The "dip" of the Earth's field is into and out of the  poles, and is almost zero (horizontal, no dip) around the equator, in contrast to the Davis sketches above.

[Liberty]

@crazy.... the conventional wisdom says it's not possible. And if you think about what "field lines" are and what they represent it makes sense that it would not be possible. Field lines are closed loops, this fact is contained in Maxwell's equations as Gauss's Law: Div B = 0. Divergence of B is zero, meaning that all field lines are closed loops or extend to infinity,  and magnetic monopoles can't exist.

This is a descriptive kind of law, though; I don't think monopoles are forbidden, exactly, and lots of people are looking for them. I think that the conditions that might produce them are way out of the reach of the amateur scientist, though, and will require huge energies and "big science" kind of equipment.

The magnetic field around a straight, current carrying wire is a good example of how field lines behave. In a PM, the moving charges are unpaired electrons in the material, with aligned spins. If you think of a simplistic electron "orbiting" a nucleus in a circular orbit, there's your single loop of wire carrying a current, and the field will loop around the orbit of the electron in continuous loops just like the circles of field around a wire, and all these add together to give the bulk magnet its big field. So you can think of a bar magnet as kind of a self-powered solenoidal coil, with field lines to match.

Of course this isn't as exciting as the Davis model.... but as I said before, you can just take an ordinary compass and probe around the Earth, or a bar magnet, and see that his representation isn't a reflection of what really happens. The "dip" of the Earth's field is into and out of the  poles, and is almost zero (horizontal, no dip) around the equator, in contrast to the Davis sketches above.

"So you can think of a bar magnet as kind of a self-powered solenoidal coil, with field lines to match."

What is your explanation of why the bar magnet is "self-powered"?  What causes it to not deplete?

[TechStuf]

Independent verification of the Davis model by Howard Johnson.

[soda]

Any one have any luck finding these patents? It'd be great to understand how the bowl field emitters are magnetized.

[crazycut06]

"So you can think of a bar magnet as kind of a self-powered solenoidal coil, with field lines to match."

What is your explanation of why the bar magnet is "self-powered"?  What causes it to not deplete?

Hi Liberty,
I think TK was trying to imply that when a soleniod coil is powered, it is like a bar magnet that produces its north and south poles.


@Tinselkoala,
Thanks for some info. Im not like you guys Guru's of science