8 Things You Never Knew about Magnets

Published: 27th October 2009
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8 Things You Never Knew about Magnets

Magnets do far more than hold photos and notes to the fridge -they are found in a tremendous number of everyday applications including credit cards, stereos, vacuum cleaners, televisions, and telephones, just to name a few. Although we often take magnets for granted, there are a number of things about them that you may not know...

1 - Types of Magnets

There are two main types of magnets: permanent magnets and induced magnets. Permanent magnets are just as you may suspect -substances that are permanently magnetized. Induced magnets, on the other hand, are substances that are temporarily magnetized when brought near a permanent magnet. Once the permanent magnet is removed, the induced magnet loses all of its magnetic properties.

An example of an induced magnet is a safety pin that becomes magnetized when placed on or near a magnet, but has no magnetic properties when removed from the vicinity of the magnet.

2 - The Poles

The molecular theory of magnetism mandates that, when magnetized, all molecules in a magnet are aligned with their north pole facing one direction and their south pole facing the opposite direction. This theory only applies when the substance is magnetized, as any other time the poles would face random directions.

In lay terms, when the opposite poles of two different magnets are brought together, they attract. The south pole of one magnet is attracted to the north pole of the other, and vice versa. Same poles repel each other rather than attract.

3 - Making a Magnet

In most cases, magnets are made of steel or iron. However, there are special alloys of nickel, iron, cobalt, copper, and aluminum that can be made into very powerful magnets. It is possible to magnetize a piece of metal by hammering and heating it in a north to south direction, which allows the molecules to become aligned in a north-south direction. One can also magnetize an unmagnetized piece of metal by simply rubbing it with a magnet in a north to south direction or by placing it near a magnet.

4 - Demagnification

Just as you can magnetize metal, you can also demagnetize it. Simply hammering a magnet at random will causes the molecules to lose their north-south alignment and therefore lose any and all magnetic properties. Additionally, if you place a magnet into an open flame the heat will cause the molecules to face random directions, causing a loss of magnetism.

5 - Who Discovered Magnets?

It is not fully known who actually discovered magnets, but they do have a long, legendary history. One theory claims that an old shepherd named Magnes of Crete first discovered lodestone, a naturally occurring substance with magnetic properties, after it was attracted to his iron-tipped shoe. Another theory claims that Archimedes, the renowned Greek ancient scientist, discovered the magnetite magnets of Turkey centuries ago and used it to sink ships by pulling out their nails. Others claim that in 600 B.C. Thales, an ancient Greek studied the forces of attraction between magnets and amber -a hardened resin.

6 - Early Magnets

The earliest magnets were known as lodestone or magnetite. In ancient times, these stones were used to help sailors navigate the seas -as magnets always situate themselves in a north-south direction, ancient sailors made compasses with magnetic stones and bits of thread. In more primitive times, this phenomenon was referred to as a "leading stone." Other ancient people believed magnetic rocks were magical objects that could frighten away evil spirits and help heal illness and injury.

7 - How Magnets Affect the World

The discovery and use of magnets has definitely changed the world. Whether used for transportation, communication, financial, medical, or technological purposes, magnets are used in almost every sphere of life. In fact, magnetism also directly affects electricity and how we use it today. Even different therapies have been derived from the use of magnets.

8 - Magnets and the Dinosaurs

Scientists are presently studying theories suggesting dinosaurs have died out due to shifts in the earth's magnetic fields. Studying core samples from the ocean floor, rich in magnetite, scientists have found that the magnetic poles of the planet changed places, possibly causing the magnetic field to drop to zero. The effects of such a drop can result in muscle cramps and bone-calcium loss, as shown in early cosmonauts exposed to prolonged periods in space.

Magnets continue to fascinate. Though we have learned many things about magnetism and electromagnetism, we continue to study magnets to see how we can continue to fully and effectively reap their benefits.Magnets.com is a leading supplier of magnets online. From refrigerator magnets to business cards we can help you with virtual any promotional need you may have.Visit online today.

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