Magnet is not something about what a man could claim he invented it. Magnets were there since the beginning of this universe in different forms. Earth in one sense is a giant magnet having two poles, north and south. Lodestone is one kind of naturally occurring magnet which was first discovered by ancient Greeks according to some historic references.
The word magnet comes from ancient Greece which meant “stone from magnesia”. Magnesia was a part of ancient Greece where lodestones (loadstones) were found. The earliest use of magnet was as a compass for navigation. Today, magnets are widely used and are important part of most appliances.
Magnets play major role in modern life today. Their importance can never be denied. Almost every major revolutionary invention uses some sort of magnet or interact with magnetism. From mobile phones to speakers, fans to computers, satellites to vehicles all take advantage of magnetic power and brings comfort and luxury in human life. If we start listing works performed by magnets and devices and appliances which use magnets, the list will go endless.
There are different kinds of magnets used for different purposes molded into different shapes and sizes. Permanent magnets are those which have atoms aligned and produce their own magnetic fields. Electromagnets produce magnetic field when electricity flows through a substance capable of conducting electric current. Manufacturing permanent magnets is not a complex task. Even a piece of iron can be magnetized by simply rubbing it with a permanent magnet.
Magnets have different applications. Permanent magnets in combination with electromagnets are used in motors and generators. Debit, credit and ATM cards have magnetic strips on them which help to encode information to let people connect to the banks where their money is kept. Cassettes, floppies, hard disk drives, speakers, microphones, CRT displays, electric guitars and compasses are famous devices which rely on magnetic power. In medical field, MRI (magnetic resonance imaging) is used to identify problems in patients’ organs from outside of body. Maglev or magnetic levitation transport uses electromagnet to propel vehicle above the tracks at maximum possible speed. Cranes in junkyards use strong electromagnets to lift heavy metal objects including vehicles and other depreciated machines.
These days, internet especially YouTube is flooded with so many ‘zero point energy’ and ‘free energy magnetic generators’ videos and related information. These magnetic generators basically follow the principles of perpetual motion which according to current physical laws, is not possible within non-isolated systems. So, their working is questioned by many. Many inventors claim that they have devised techniques by which magnetic energy can be tapped and it can be harnessed to generate useful energy especially electricity without putting anything obvious into the system. This obviously violates the law of conservation of energy. But it is explained by them that magnets actually draw energy from surrounding and resulting perpetual motion produced by these does not violate any laws of physics. If such systems are possible, their explanation can be found only in quantum physics. Many conspiracy theorists believe that oil companies and ruling bodies are forcefully suppressing such technologies because these will change the coarse of future and these companies will literally go out of business.
Magnets on one hand are extremely beneficial but on the other hand are also damaging. Magnets have the ability to wipe the data from hard disk drives, cassette tapes, floppy disks and other magnetic storage media. Magnets can distort temporarily or permanently CRT screens. So, magnets should be kept away from television and computer monitors. Neodymium which is a rear earth magnet is flammable and can caught fire while drilling or grinding. So, extra measures should be taken to deal with it. Pacemakers and some electronic gadgets can be sensitive to magnetic fields. Though static magnetic field has almost no effect on human body still small magnets must be kept away from the reach of small children as they can swallow it.