Posted: Sun Feb 10, 2008 12:44 am Post subject: Reply with quote
mgmirkin wrote:
Time for some arm chair rambling from me then? Wink
I think it probably does boil down to an electrical phenomenon, at the atomic level. Granted, the charge carriers are "relatively" bound. IE, the electrons are more or less bound to their atoms. Though, in metals, the electrons are somewhat free to move about...
Doesn't current theory somewhat say that it's the collective motion of these charge carriers that qualify as the atomic or sub-atomic "electron currents" (around the nucleus or in circuits around several nuclei {?}) that sustain the magnetic field?
IE, in a magnet, perhaps the electrons end up in some kind of a lockstep with other electrons in the overall material, thus creating something like a molecular current.
One assumes the protons are relatively "bound" to the nucleus, thus don't move as much as the electrons, so the electrons are probably the prime movers and shakers in the dance. {?}
So, I'm thinking that in non-magnetic substances, the electrons are in relatively random motion about their nuclei, so no overall "current" exists. Rather they're in something more like a state of excited random motion.
Whereas, in magnets, they've somehow (externally applied magnetic field and/or electric current) been forced into lockstep, where they all move in much the same path around their respective nuclei, or in some shared path around various nuclei?
Electric current is ostensibly the bulk flow of like charge in the same direction. So, if you've got all the electrons doing the same dance, in the same direction(s) at the same time, perhaps that qualifies as the driving "current" to set up the magnetic field?
It's late, and I'm either being really smart, or really dumb (it's always a cr@pshoot late at night; sublime or ridiculous?). Maybe I'll let someone else decide that.
Cheers,
~Michael Gmirkin
Some random thoughts, not necessarily following the same sequence as yours above (I'm too lazy at the moment to separately quote individual paragraphs):
1)
Wikipedia <cough><cough> - Magnet wrote:
Magnetization
Main article: Magnetization
Magnetic poles
Although for many purposes it is convenient to think of a magnet as having distinct north and south magnetic poles, the concept of poles should not be taken too literally: it is merely a way of referring to the two different ends of a magnet. The magnet itself may be homogeneous; there are not distinct "north" or "south" particles on opposing sides, and no Magnetic monopole has yet been observed. If a bar magnet is broken in half, in an attempt to separate the north and south poles, the result will be two bar magnets, each of which has both a north and south pole.
At best, the idea of north and south poles is a sometimes-useful simplified model for understanding a magnet's behavior. This is called the "Gilbert Model" of a magnetic dipole.[1] However, this model does not always give correct results. A much better model is the "Ampère Model", where all magnetization is due to macroscopic "bound currents", also called "Ampèrearian currents". For example, for a uniformly magnetized bar magnet in the shape of a cylinder, the net effect of the atomic currents is to make the magnet behave as if there is a sheet of current flowing around the cylinder, with local flow direction normal to the cylinder axis. A right-hand rule due to Ampère tells us how the currents flow, for a given magnetic moment. Align the thumb of your right hand along the magnetic moment, and with that hand grasp the cylinder. Your fingers will then point along the direction of current flow.
Pole naming conventions
The north pole of the magnet is the pole which (when the magnet is freely suspended) points towards the magnetic north pole (in northern Canada). Since opposite poles (north and south) attract while like poles (north and north, or south and south) repel, the Earth's present geographic north is thus actually its magnetic south. Confounding the situation further, the Earth's magnetic field occasionally reverses itself.
In order to avoid this confusion, the terms positive and negative poles are sometimes used instead of north and south, respectively.
As a practical matter, in order to tell which pole of a magnet is north and which is south, it is not necessary to use the earth's magnetic field at all. For example, one calibration method would be to compare it to an electromagnet, the poles of which can be identified via the right-hand rule.
http://en.wikipedia.org/wiki/Magnets
Sounds like geographic north (i.e. magnetic south) as referenced above and true magnetic north represents the dual N/S at each pole seen as illustrated in the topology graphic of the N/S duality on pg 1 of this thread.
2.
PowerLabs Plasma Globes Page wrote:
When current flows, people have described electrons moving in one direction and positive ions moving the other way. This in fact occurs in certain circuits, which rely on the electrochemical transfer of atoms of an electrode through an electrolyte material. This process occurs in batteries. This does not occur in IGDTs (Inert Gas Discharge Tubes) or typical semiconductor circuits. While the electrons do in fact move from atom to atom, the atoms themselves pretty much remain where they are. Light is emitted when an atom loses an electron, thereby changing to a lower energy level. This happens to the atoms in the slurry of gas millions and millions of times per second as the electrons make their way along the plasma trail. This means they are constantly changing their state of charge relative to their neighbors and they'll just bounce around willy-nilly all over the place. As a result, the positive ions do not remain positive ions for long. Even if they did and even though it is true that positive ions would be slightly attracted to a negatively charged electrode at one end, they really don't move much because the physical forces of pressure continuously act to keep the gas evenly distributed throughout the tube. Some people call the places left behind when an electron leaves an atomic orbit a hole oddly enough, which technically makes the atom a positive ion. It is said that the holes move one way while electrons move the opposite way. Holes are not actually things or particles as electrons are so even though both statements made about what is moving is technically true, I prefer to say the electrons are moving rather than the absence of them or the nothingness. In either case, the atoms themselves pretty much stay put. Proof of this is simple to observe. Just look at the light emitted in a normal florescent tube. Pretty evenly distributed isn’t it?
http://www.powerlabs.org/plasmaglobes.h ... %20Details:
Sounds related to the idea I have about the relationship of void to substance.
So maybe substance (protons, ions) more or less sits there and vibrates/oscillates to beat the band while electrons "drift," leaving "holes" (cavities, voids) which can also be considered to flow in the opposite direction from the electron drift. While energy is transmitted instantaneously through the media of all this relatively stationary vibratory field(s). And through transduction it (the energy) is transformed into all the manifold wonders for which we have sensory receptors and beyond.
3) How commercial grade permanent magnets are produced is interesting. Sintering. Pressure and temperature. I've forgotten most of what I've studied in the past and probably should revisit it. I recall at the time thinking, "wow, the 'entrainment' conditions for making these things sound pretty catastrophic" Wink
4) Plastic permanent magnets are being produced now, I think. Again, I've forgotten all I've read about it 3 or 4 years ago. Not sure what that has to do with anything. Just one of those random thoughts.
I had other stuff but I've forgotten now what it was. This stuff can be mentally stupifying! Shocked Time to sit back and let it ferment a little.