Magnetism Short History

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Just like Beer and Pizza, magnetism has been around humanity for centuries. Before we see a bit of its history let’s understand its importance.  
How many things do you have at home that works based on magnetism? Can you think of three?

Never mind. We’ll tell you. All electronic and electric equipment has some kind of magnetic field inside it. A computer saves files on a magnetic disk called “HD” (Hard Drive). The power source of any electronic machine only works thanks to magnetic fields.  
We use magnetic fields every time we turn on a TV, a radio, a sound system, a computer, an electric blender and so on.
In a sci-fi movie from the sixties the aliens invade Earth and paralyze all the magnetic fields in the planet. This causes countless disasters because planes lose the orientation, radars don
’t work, every electric machine stops working and, of course, there is no more electricity. Indication instruments such as a compass became useless. A compass indicates always the north pole of Earth because the planet behaves like a giant magnet, where North and South poles have opposite polarity. The giant generators used in hydroelectric stations work based on magnetic fields. In a few words, the civilization as we know it, was destroyed. Exaggeration? Not so much. Remember that every time you turn on your car,  is a magnetic field that makes it possible for the engine to start. Without magnetism we wouldn’t have cars, planes, household appliances, radio, television, computers, medical machines, we wouldn’t have anything.
Another point to note: when an electric current flows trough a conductor it creates around that conductor wire) a magnetic field. This principle is present in transformers, loudspeakers, power supply sources, telephones (even cell phones), and any kind of electric device you can think of.
Do you agree that magnetism is the basis of our civilization? Just think about it. 
Lets learn a bit about magnetism history.

600 BC - Lodestone

The magnetic properties of natural ferric ferrite (Fe3O4) stones (lodestones) were described by Greek philosophers.

1175 - First Reference to a Compass

Alexander Neckem an English monk of St. Albans describes the workings of a compass.

1269 - First Detailed Description of a Compass

Petrus Peregrinus de Marincourt, a French Crusader, describes a floating compass and a compass with a pivot point.

1820 - Electromagnetism, Current

In 1820, a physicist Hans Christian Oersted learned that a current flowing through a wire would move a compass needle placed beside it. This showed that an electric current produced a magnetic field.

Andre Marie Ampere, a French mathematician who devoted himself to the study of electricity and magnetism, was the first to explain the electro-dynamic theory. He showed that two parallel wires, carrying current, attracted each other if the currents flowed in the same direction and opposed each other if the currents flowed in opposite directions.

1855 - Electromagnetic Induction

Michael Faraday (1791-1867) an Englishman, made one of the most significant discoveries in the history of electricity: Electromagnetic induction. His pioneering work dealt with how electric currents work. Many inventions would come from his experiments, but they would come fifty to one hundred years later. His brilliant mind took earlier experiments still further. If electricity could produce magnetism, why couldn't magnetism produce electricity? In 1831, Faraday found the solution. Electricity could be produced through magnetism by motion. He discovered that when a magnet was moved inside a coil of copper wire, a tiny electric current flows through the wire. These experiments, convincingly demonstrated the discovery of electromagnetic induction in the production of electric current, by a change in magnetic intensity.

1860 - DC Motor

Christian Oersted developed the discoveries of Faraday till the point of making the first DC motor.

This motor was said to be the first electric motor of commercial significance. During this period the scientists concentrated on the "motor", but meanwhile, experiments with machines producing electricity dynamically were under way.

1871 - DC Generator

Gramme introduced his motor and generator, making it possible commercial use of the generator. By 1872, Siemens and Halske of Berlin improved on Gramme's generator, by producing the drum armature. Other improvements were made, such as the slotted armature in 1880 but by 1882, Edison had completed the design of the system we still use to distribute electricity from power stations.

1917 - Cobalt Steel Magnets

K. Honda and T. Takai add cobalt to tungsten steel to increase the coercive force of permanent magnets improving industrial applications.

1919 - Commercial Steel Magnets

The first commercially available quench-hardened steel magnets were made available.

1930 - Alnico Magnets

Mishima produces the first Alnico magnet containing an alloy of iron, nickel, and aluminium. Alnico magnets are widely used in loudspeakers and headphones among many other applications, till today.

1966 - Rare-Earth Magnets

Dr. Karl J. Sternat at the U.S. Air Force Materials Laboratory at Wright-Patterson Air Force Base discovers the high-energy product (18 MGOe) of the Samarium-Cobalt (SmCo5) compound.

1972 - Advanced Rare-Earth Magnets

Dr. Karl J. Sternat and Dr. Alden Ray develop a higher energy product (30 MGOe) Samarium-Cobalt (Sm2Co17) compound.

1983 - Neodymium-Iron-Boron Magnets

General Motors, Sumitomo Special Metals and the Chinese Academy of Sciences develop a high-energy product (35 MGOe) Neodymium-Iron-Boron (Nd2Fe14B) compound.  

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