Uses Of Magnets
The Many Uses Of Magnets
When you look into the uses of magnets in the average household, a few examples are quite obvious. We usually don't have to look much beyond the refrigerator and all the things that are attached to it, to appreciate how helpful magnets can be. The uses of magnets go far beyond sticking things to the refrigerator door however. If we didn't have magnets, or magnetic materials, our life, including life in our own homes, would be vastly different than it is today.
Magnesia - The Greeks and Chinese are generally given credit for discovering magnets, although it could just as easily been some other culture, but as is often the case, the Greeks had a word for it. One source of magnetic materials in ancient Greece was a district named Magnesia, hence the name magnet.
It's fair to ask what a magnet is, but the answer to why a magnet behaves as it does is not really answerable. Magnetism is like electricity. There are phenomena of physics, in fact one will create the other, as anyone studying electromagnetism is fully aware of. Yet why either exists is a question that can't be answered. A dog is a dog and a magnet is a magnet.
Stud Finders - A magnet is a material which will align itself to the direction of a magnetic field, just as the needle of a compass aligns itself the earth's magnetic field, or any magnetic field it happens to come into contact with. A stud finder is a compass of sorts. Normally if kept in isolation it would have a tendency to point to the north. A steel nail in the wall however influences the direction of the earth's magnetic field. Not much, but just enough to cause the stud-finder to point to the nail when in close proximity. A battery-powered stud finder works in a similar manner but creates its own magnetic field, which the nail interrupts, and is thereby located.
Electromagnets - So far we've mentioned three uses of magnets: refrigerator magnets, compasses, and stud finders. How about electromagnets? Wrap some wire around a piece of iron, hook up the wire to an alternating current, and one creates a magnetic field which can be very powerful. This is an electromagnet, and can it be made powerful enough to pick up an automobile in a junkyard, move it to another location, and when the electricity is turned off, drop it there.
Magnetic fields cause certain metals to move, the automobile being moved by electromagnetism being a case in point. That's how a solenoid works. If you have a bar of metal, and subject it to a sudden magnetic field, it will move, closing a relay, locking or unlocking a door, or closing the circuit which allows your car starter to operate.
Things That Would No Longer Work - Without magnets, your TV wouldn't work, your computer would be next to useless since you couldn't store any information at all, and while your radio might work, you probably wouldn't hear much, since radio transmitters require magnets to operate. Even if the radio worked, the speaker wouldn't. Neither would headphones. Both depend upon magnets. You'd have to lock your refrigerator door shut the same way one used to lock the door of an icebox in the old days, as there would be no magnets to hold the door firmly shut. Credit cards wouldn't work, which might be a blessing, though a clerk could probably type in the number, unless the number was being entered into a computer, which wouldn't work if there were no magnets.
The Maglev Train - One of the more spectacular uses of magnets is in the field of transportation. Here magnets, electromagnets to be specific, power maglev trains, maglev standing for magnetic levitation. Magnets have been constructed which are powerful enough to hold, or levitate, a train above its track. The distance the train is held above the track is very small, just enough to eliminate much of the friction. At the same time, electromagnetism propels the train forward, at up to several hundred miles per hour. We even need magnets to allow the engines in our diesel trains to run. Without magnets, we'd be back to steam engines, something many train enthusiasts would probably welcome.