In 600 BC the history of magnetism began but people were only beginning to understand it in the 20^th century. Then they were able to use their knowledge about magnetism to develop technologies based on it. Magnetism was first observed by the Chinese in the 4^th century BC. They discovered that lodestone attracts iron and wrote research papers on the matter. Lodestone consists of iron oxide which is a chemical compound of iron and oxygen. It attracts other pieces of the same material and iron. In Europe the Greeks were said to be the first to discover the lodestone’s abilities.

In the 16^th century William Gilbert, an Englishman, was the first to investigate the phenomenon of magnetism. He also discovered that the earth itself is a weak magnet. Carl Friedrich Gauss investigated Gilbert’s discovery after his death. In the 18^th century Frenchman Charles Coulomb established the inverse square law of force. The law states that the attractive force of two magnets is proportional to the product of their individual fields and inversely proportional to the distance between them. Hans Christian Oersted discovered a few years later the link between magnetism and electricity.

In the 19^th century the theoretical foundation of the physics of electromagnetism was built. The theoretical foundation states that electricity and magnetism are two aspects of the same fundamental force field. In the early 20^th century the Curies, which were husband and wife, and Pierre Weiss examined the effect of temperature on magnetic materials. They observed that magnetism suddenly disappears in materials like iron above a certain temperature. They explained this by using the theory that magnetism is based on an internal molecular field which is proportional to the average magnetization spontaneously aligning the electronic micro magnets in magnetic matter.

Today’s understanding of magnetism is based on the theories of the two German scientists Ernest Ising and Werner Heisenberg. Their theory is called quantum electrodynamics which is about the motion and interactions of electrons in the atom. Heisenberg was also one of the founders of the modern quantum mechanics. All these scientists gave the world the opportunity to fully understand and use magnetism.

Magnetism is used in many different objects. People are mostly not aware of the use of magnetism in their everyday life. It is surprising how many objects use magnetism and how these objects have changed the people’s life in the past.

Most of the people know that a compass uses the magnetic north pole to determine one’s current position. Compasses were used over hundreds of years and are still used today. When getting lost in the woods with no landmarks to orientate on a compass can be used to find the way out of the woods. Most of the explorers and adventurers use a compass to make sure they do not get lost. Of course in today’s life there are signs everywhere which lead the way to all kinds of places. But when staying in an area which not much people live in a compass can be very useful.

Another use of magnetism can be seen in tapes and discs. Video tapes, audio tapes, DVDs, CDs and other things all work because of magnetism. So one could say that without the discovery of magnetism people would not be able to listen to their favorite music or watch their favorite movie on disc or tape. Many people are not aware that these objects use magnetism to work and do not really care about this fact either. The only thing that matters to them is that the objects work the way they are supposed to.

Magnetism is also used in electric motors and generators. It also has another use in transportation: the maglev or magnetic levitation transport. It is mostly used in trains. Maglev uses electromagnetic force to guide vehicles, like trains. Many big cities already have a transportation system like that.

The use of magnetism in medicine is in MRI machines. MRI stands for magnetic resonance imaging. It is used to spot problems in patient’s organs without invasive surgery. All in all one can say that magnetism is used in many different ways in today’s society and without the discovery of magnetism life would not be the same.