Magnetism - Explanation and definition of magnetism

What is magnetism

Magnetism is defined as the physical phenomenon whereby some materials has the ability to attract or repel other materials, based on the origin of the motion of charged particles magnetism is part of the electromagnetic force, that is one of the fundamental forces of nature.

Many of us have experienced with magnetism using magnets, a magnet is a material that has a high magnetic ability to attract ferromagnetic materials such as iron, steel, nickel... as well as to repel or attract other magnets, the origin of such attraction or repulsion forces liesin the distribution at atomic level of the electrons that form the magnet.

As described in the definition of magnetism their physical origin lies in the existence of the motion of charged particles, so the electrons are considered as small magnets due they are charged particles which move or orbit around the atomic nucleus and rotating around its own axis of symmetry (spin). All these movements of electrons create small magnetic forces that are responsible for the ability of a magnetic material.

In fact all materials are magnetic what happens is that there are materials that have an uneven distribution of electronscancelling the different magnetic forces that originate, on the other hand there are materials that have a large number of electrons distributed in the same direction so that different magnetic forces generatedare added creating a magnetic effect on a macroscopic scale.

On the other hand when we circulate a flow of electrons through an electrical cable, we apply an electric current, we get magnetism due to the movement of these electrons through the cable, so that electricity and magnetism are closely linked being considered both as a single physical phenomenon known as electromagnetism which along with gravity, weak and strong nuclear compose the 4 fundamental forces of nature.

This close relationship between electricity and magnetism makes that any magnetic field have an associated electric field and vice versa, knowledge of these phenomena have led to the development of electric generators by rotating magnets around a coil and the development of the electric motor which by application of electric current nearby a magnet produces a mechanical movement which can be exploited to move for example the wheels of a motorcycle.

Discovery and history of magnetism

The phenomenon of magnetism was known to ancient civilizations such as the Phoenicians, Egyptians and Persians among others, but it was the Greek philosopher Thales to be the first written testimony about this strange phenomenon by stating that the magnetite had souls to be able to attract iron particles.

But it was not until 1600 when the doctor and researcher William Gilbert published his famous book "De Magnete" where all his research on the phenomenon of magnetism was collected. William Gilbert was the first to identify our planet Earth as a giant magnet whose poles are close to the geographic poles explaining the orientation of the compass pointing north, on the other hand described the phenomena of magnetization on other materials as well as the influence of temperature on the magnetic capabilities.

Later in 1820 the physical and chemical Danish Han Christian Oersted demonstrated the relationship between electricity and magnetism when to place a compass magnet near a wire through which flowed a certain electric current observed as the needle of the compass moved and placed perpendicular to wire, Oersted was the first scientist to coin the word electromagnetism.

The great experimenter physicist and scientific Michael Faraday deepened about the experiments of Oersted discovered electromagnetic induction through which developed the first electric motor of history.

In 1865 the mathematician and physicist James Clark Maxwell developed the mathematical equations describing all phenomena discovered and previously described by Faraday and Oersted, thanks to the Maxwell equations the electromagnetic theory revolutionized physics at that time due to relate mathematically magnetism and electricity under one theory and to predict the existence of electromagnetic waves which were discovered by the physicist Heinrich Hertz in 1888 being the basis for development of the world of telecommunications such as radio, television or telephone.

Applications of magnetism

As previously stated magnetism is part of one of the fundamental forces of nature, without it there would be no life and universe as we know it. The core of our planet generates a protective magnetic field that surrounds us from north to south protecting us from dangerous cosmic radiation that come from all over the universe.

The compass was one of the first instruments in which a magnetized needle pointing to magnetic north land, helping sailors and travelers to explore new territories and roads.

Thanks to the discoveries of Faraday and knowledge about the electromagnetic phenomenon we have developed generators that produce the electricity needed to power all the electronic devices we use daily, on the other hand we have developed electric motors used in a wide range of devices such as fans, breast pumps, appliances, elevators, motorcycles, etc...

Maglev trains, mass spectrometers, digital storage systems such as hard disk files, MRIs, metal detectors, speakers, microphones, materials classifiers and even particle accelerators like the LHC base their operation on the phenomenon of magnetism.

Now that you know what is magnetism, did you know that in the universe exist magnetars ?, these highly compressed neutron stars have the strongest magnetic fields around the world, without a doubt the strongest magnets around the cosmos.

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