Magnetism

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= = = = = Make Your Own Compass = =Sources=

=**// Natural Magnets // **= Magnetism is the force where objects are attracted or repelled to one another. The term, "Magnetism," comes from a region in Asia minor called Magnesia. In Magnesia, Lodestone, a naturally magnetic iron ore, was once found. That is why some scientists still call natural magnets, "Lodestones," today. A magnet has a north pole, and a south pole; one on each side. When you have two magnets, the opposite poles attract, and the same poles repel. If you line up the magnets so that the north pole on one of the magnets faces the south pole on the other, the magnets will attract. However, if you line the magnets up so that both north poles or both south poles are facing each other, the magnets will repel. You may think that if you break a magnet in half, one half will have the north pole, and the other half will have the south pole. This is, however, not the case. If you break a magnet in half, each half will become a smaller magnet and contain its own north and south pole instantly. Both new smaller magnets will have half the magnetic power of the original magnet. If you break a magnet into five parts, you will have five small magnets and each one will have one fifth the magnetic power of the original magnet. = = =// How Do Magnets Help You? // = = = Magnets help you with a lot of every day things that you don't even think about. If you didn't have magnetism, you could kiss your phone good bye, and you wouldn't even have an i-pod or a laptop to use in the meantime. No more microwave popcorn or movies on T.V. Headphones, stereo speakers, computer speakers, telephone receivers, phone ringers, microwaves, doorbells, refrigerator magnets, the seal around your refrigerator door, batteries, TV's, computers, dishwashers, and even showers are only a fraction of the everyday things in our lives that need magnetism to function properly. If we didn't have magnetism, our lives would be a lot different. We wouldn't be able to shower, or cook food in a microwave. We wouldn't even know when someone is at the door. No more ordering pizza because we wouldn't have phones. We would have to do all of our dishes by hand, and we wouldn't be able to store food because we wouldn't have refrigerators. So if you didn't think magnetism is a big deal, think again!

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=// How A Compass Works // =  A magnetic compass consists of an extremely light weight magnet balanced on a nearly frictionless pivot point, and you can think of the earth as having a "giant bar magnet" skewered through it from the earth's north pole to the earth's south pole (as shown below). This "giant bar magnet" is the earth's magnetic field, or declination. The earth's north pole holds the giant bar magnet's south pole, and the earth's south pole holds the giant bar magnet's north pole. Remember that opposite poles always attract, causing the north pole point of the magnetic needle in the compass to always point toward the south pole of the giant bar magnet. The south pole of the "giant bar magnet" is at the north pole of the earth. Therefore, the needle is always pointing toward the earth's north pole, so when you look at a compass, the needle always points north. There is not actually a "giant bar magnet" in the earth. It's really just a magnetic field, and a "giant bar magnet" is just an easy way to explain it. The needle in the compass must be very light weight, and the pivot point has to be nearly frictionless because otherwise, there is not enough strength in the earth's magnetic field to rotate the needle. No one is exactly sure what causes there to be a magnetic field in the middle of the earth yet.