We explain what magnetism is and what is the history of this phenomenon. In addition, its relationship with electricity and its applications.

Magnetism acts through attractive or repulsive forces.

What is magnetism?

When we talk about magnetism ormagnetic energy, we refer to one of the two components of electromagnetic radiation (together with electricity) that manifests itself through forces attraction or repulsion between certain types of materials and a magnetic energy field (magnetic field).

While all substances are affected by magnetism, not all do it in the same way. Some materials, such as certainmetals ferromagnetic (especially iron, nickel, cobalt and its alloys) are particularly prone to it and therefore may constitute magnets. Some of them can be of natural origin and others of artificial origin, for example, as a consequence of the action of electricity on certain materials (electromagnets).

Most magnets are magnetic dipoles: they have a positive pole and a negative pole. Each of these poles exerts a force on other magnets, or ferromagnetic metals that are in their area of ​​action, according to a law that states that similar poles repel, while opposites attract.

These dipoles can occur on a macroscopic scale (for example, in the planet Earth there is a North pole and a South pole, each exerting a magnetic influence that allows the operation of the compasses) or microscopic (for example, in the orientation of certain molecules organic due toelectric charge his atoms). And these forces of magnetism play an important role among the elemental forces of nature.

Thus, there are diamagnetic (weakly magnetic), paramagnetic (moderately magnetic) or ferromagnetic (highly magnetic) materials.

History of magnetism

The understanding of magnetism gave way to the invention of compasses.

The human being has known magnetism since early times. Its effects were described in Greek antiquity by Thales of Miletus (625-545 BC) and other similar philosophers, who noted that certain stones from the town of Magnesia of the Meander (Asia minor) attracted iron. That's where the name comes frommagnetism.

Somehow the human being managed to understand terrestrial magnetism from an early age, using it in the manufacture of compasses towards the twelfth century, before the emergence as such of the Sciences who would then devote themselves to the study of this phenomenon.

The first properly formal treatise on magnetism was written in the 13th century by the Frenchman Peter Peregrinus de Maricourt, a prelude to those of future scientific studies by William Gilbert and especially Hans Christian Orsted, who discovered that magnetism was not limited only to magnets. , but had a close link with the electric current.

This opened the door for André-Marie Ampère, Carl Friedrich Gauss, Michael Faraday and others inaugurated the field of electromagnetism, and then James Clerk Maxwell determined it through his famous set of equations.

Electricity and magnetism

Magnetism and electric current are closely linked and together they make up electromagnetism, one of the elemental forces of theuniverse. The manipulation of magnetic fields, for example, through the acceleration of magnets, it can generate a usable electrical current, as in fact occurs in some types of generators.

And at the same time, by circulating an electric current through certain types of metals, they can be turned into electromagnets and made to attract certain metals or ferromagnetic materials.

This relationship is based on the atomic nature of materials, in which electrons (-) from the farthest orbit of the nucleus of the atom (+) can be torn off or transferred from one molecule to another, thus generating an electric flow (current) and polarizing the whole, that is, tilting the electric charge to one side ( negative pole) and leaving another with less charge (positive pole).

Magnetism Applications

Magnetism is used in medicine to do MRIs.

Magnetism has been employed by the humanity for a long time. The invention of the compass and its use to orient oneself (marking the fixed direction of the North of the planet) dates back hundreds of years and was key in the development of navigation and in the exploration of the world.

On the other hand, large magnets are used in the industry of electricity generation, in medicine (for example, magnetic resonance examinations), in engineering (the development of motors, the conduction and storage of electric charges, etc.) and, above all, in the electronics.

The computing, for example, depends to a great extent on the use of magnetism for the recording of information, combining it with electric current and knowledge of semiconductors.

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