Magnetism
Magnets have fascinated me since I was a child, and I expect many of us can say the same thing. I, however cannot tell you much more than you probably already know about the common magnet. They are fun to play with and I have a few around my place. You know of their north and south poles and how they react to each other.
Magnetism goes along hand in hand with electromagnetic. I will get into that a bit in the next topic page on Electricity. In the subject of electromagnetism I have been, pretty well dipped, having a background in electrical, and electronics.
Historically there were magnetic Lodestones. This makes the magnet real. Also, with what we know today... magnetism is an important part of our Universe, as well as for technology. For the theory of electromagnetism; in 1831, Faraday's experiment of Inducing Current into a wire loop with some of it coiled, by only moving a magnet close to it__ pretty well started it all off. From there, it was also found that by moving a wire loop through a stationary magnetic field, also induces current into the loop. Thus, we now have electro-magnetism.
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...Site updating 06-05-2011...
If we use iron filings and sprinkle them around a single bar magnet; they form a pattern of lines. These lines converge at one end of the bar, and spread out as they circle about the bar, and then converge on the other end. If the bar magnet is suspended, the lines will spread out as three dimensional, from end to end. If the magnet is enclosed in a vacuum chamber, eliminating any influence from air, the lines are basically still the same. The iron filings form into lines because they gain magnetism, and when side by side running sort of parallel, their like charges repel to separate them into lines. The same effect is very noticeable when a person or animal's body has an electro-static charge; their hair will spread out away from their body trying to get as far away from any like charged hair next to itself. Running a comb through your hair on a dry low humidity day gives a little of this effect, when your hair won't lay down.
What we can surmise, from the iron filings externally around and about the magnet, is that this external area or region has some phenomena existing, that is not a hard chunk of the metal bar magnet. We can imagine that some invisible rays are being continually radiated; charging the space surrounding the magnet possibly... Or, instead, by doing some more recent musing about this situation... what if we first think about the inner Space within the atoms of the bar magnet. If this space is filled with invisible, idle, almost mass-less particles, as quarks or photons... do you suppose they would have some attributes that are associated with the magnetism of the magnet? Could they be aligning themselves in some magnetic specific motions, and or directions for example? And, since there are no walls on the Space of the atom... this Space of the inner atoms is probably touching the intermediate Space in and about the outside of the magnet. Would it seem reasonable for these external idle intermediate idle particles to also be set into some same attributes like inside the magnet atoms? This would mean that there would be no radiated beams, rays, or particle radiation required. It would be idle particles in close proximity to each other interacting internally and externally. This has similarities like a sponge; holding a lot of water, but if we put it in a bucket of water... it would seem reasonable the water in the sponge, and in the bucket would interface with each other, and the temperatures would even out without any physical radiation.
Now that I have set up this train of thought... lets go for two bar magnets in a vacuum... suspended in fixed positions, with 'unlike' ends a short distance apart. Again with the iron filings. This time they do similar to the single bar magnet but longer lines, and the region between the two interfacing ends, has iron filings aligning in semi-parallel lines between these two unlike ends. We all know that unlike magnet ends come together. I need also to point out that there are a lot of iron filing lines out and about, and they converge towards the head ends of the magnets, and come closer together as they converge into the ends of the magnets; but, there may be a thinning out of these lines, like blank regions very near the ends. This is due to these regions being the stronger areas of magnetism; which would seem like there should be many lines... But, it is like having a lot of people trying to push a dozen elephants side by side down a narrow alley; they will not fit! There is a high density of forces, but the iron filings repel each other side by side, and will not fit close together near the ends. The lines emanating from the two unlike ends in close proximity, go from one magnet to the other. If the two magnets are allowed to come together they become as one longer magnet. If you put your hand between them... you can feel the pressure squeezing your hand. It is obvious that there is pressure involved, and the directions of its motion. Without knowing exactly how the magnetic force actions work... we cannot say for sure what is happening, but I can definitely state: there is pressure involved.
If we reverse one magnet 180 degrees, we have 'like' ends facing each other a short distance apart. Again we know what they are trying to do... repel each other. Repelling is pushing, or exerting pressure resistance against any motion trying to shove both magnets together. Both magnets have lines of iron filings surrounding them as before, but the lines of like polarity on the near ends, are trying to bend away from each other. We know that like magnetic polarities push away from each other, but exactly how; is not known, but again there is pressure, and it is measurable.
The summation of the actions of the magnets, is that, mutually the magnets act for or against each other's regions surrounding each. The the magnets hold each other together as one when unlike ends come together, but there is a lot of pseudo 'action at a distance' seeming to happen externally without the magnets touching physically. It is not a function of air since we made a vacuum to experiment within. Since all bodies of matter are 99.999... % Space it would appear, to me at least, there is some "goings on" in this inner atom Space arena... I see no reason why inner, intermediate, and outer Space wouldn't all interact with each other. We talk about fields, charges, and etc.. but seem to ignore that Space is all pervasive. There is no good logic to think that Space surrounding a physical body, is not intimately in contact with the Space within the atoms of the same body. It is like matter is super-imposed upon Space, and goes along with at least some actions of Space, or Space conditions.
Herein this above update I have related some things that are at this point pure fantasy... But, there is nothing wrong with fantasy if related as such. And, these items I have written, were thoughts triggered from looking at some photos in a physics book I recently was looking through again... So I put them here for me to wonder about, and possibly you. It seems a reasonable possibility from the iron filings... the phenomena of magnetism is involved with the space surrounding it and any space within itself. But, yes it is true, I really do not know what gives magnets their motivation.
I would like to mention that these two bar magnets are common matter, and as well as their having properties of magnetism, they have measurable mass, and will offer pressure resistance, and their magnetic strength as well as inertial strength can be measured with pressure sensing devices. Exactly how the magnetic force actions work, is still a mystery, as with gravitation. I say again, no matter how magnets work, there is physical pressure action being exerted; when magnets accelerate together or accelerate apart. As far as I can tell... you cannot have actions of magnetism without physical pressure brought to bear.
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We use the principle of the electro-magnet in things like solenoid valves and audio sound speakers. When a solenoid valve is energized there is a coil of wire that makes a magnetic field that draws a metal core up into the coil actuating the valve. Solenoid valves are use by millions, in industry. In our lives you will find them inside clothes washing machines, and refrigerator drinking water systems, for example. This same type of action happens in an audio loudspeaker. A varying current, alternating at an audio frequency, of electricity is passed through a coil that moves the plunger which also has attached a circular movable diaphragm. This diaphragm pulsates the air to give us sound waves. In reverse, a diaphragm spoken into, is hooked to a magnet that can move back and forth through a coil of wire, and will induce audio varying current in the wire. This last sentence describes early types of microphones. (There are also other types of microphones.) However, just about all speakers still use the principle stated. This means speakers in your radios, televisions, hearing aids, stereos, music amplifiers, computers, phones, headsets, and movie sound speakers would almost disappear if you took away electromagnetism. Give a thought to what life for us, without speakers, would be like!
Most all credit cards with the strip on the back are magnetic. Now, many motels and hotels use magnetic swipe cards for door keys. Company and governments use swipe ID cards for authorized entry clearance identification. Now we have magnetic Passport swipe cards.
Lastly here I need to mention that motors and generators have what is called a stator. These stators are the stationary electromagnetic windings inside, and sometimes actually physical permanent magnets mounted to the motor housings. Think about how many electric motors we have, and use. Most every vehicle has an electric starter motor. We gave up the hand crank cars quite awhile ago. Tape decks & cassette drives, and CD & DVD drives, without motors would be a problem. Drills, lathes, routers, rotary saws, conveyor belts, blowers, appliances, compressors, elevators, are just a few items using mostly electric motors... and just imagine how many more are out there. They require magnetism to run!
And, permanent magnets are for holding cupboard doors closed. Magnets are used to actuate switches. There are plastic/magnetized flexible signs and cards that can be put on vehicle doors, or refrigerator doors. There is an abundance of toys that use magnets.
If magnetism was taken away from us... it would be a disaster! At least for modern mankind.
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Page Relevant Quotes
""The idea that bodies of matter can "attract" one another is, according to Einstein, an allusion that has grown out of erroneous mechanical concepts of nature. ...Today scientists no longer say a magnet "attracts" a piece of iron by some kind of mysterious but instantaneous action-at-a-distance. They say rather that the magnet creates a certain physical condition in the space around it, which they term a magnetic field; and that this magnetic field then acts upon the iron and makes it behave in a certain predictable fashion."" The Universe and Dr. Einstein, by Lincoln Barnett