We explain what magnetism is and what the history of this phenomenon is. Also, its relationship with electricity and its applications.
What is magnetism?
When we talk about magnetism or magnetic energy, we refer to one of the two components of electromagnetic radiation (along with electricity) which manifests itself through forces of attraction or repulsion between certain types of materials and a magnetic energy field (magnetic field).
Yes ok all substances are affected by magnetism Not everyone does it the same way. Some materials, such as certain ferromagnetic metals (especially iron, nickel, cobalt and their alloys) are particularly prone to this and can therefore constitute magnets. Some of them may 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 found in their area of action, according to a law that establishes that similar poles repel each other, while opposite poles attract.
These dipoles can occur on a macroscopic scale (for example, on planet Earth there is a North pole and a South pole, each exerting a magnetic influence that allows the operation of compasses) or microscopic (for example, in the orientation of certain organic molecules due to the electrical charge of their atoms). And these forces of magnetism play an important role among the elemental forces of nature.
Thus, there are diamagnetic (weakly magnetic), paramagnetic (medium magnetic) or ferromagnetic (highly magnetic) materials.
History of magnetism
Human beings have known magnetism since early times. Its effects were described in ancient Greek times by Thales of Miletus (625-545 BC) and other similar philosophers, who noticed that certain stones from the city of Magnesia on the Meander (Asia Minor) attracted iron. That's where the name comes from magnetism.
Somehow the human being managed to understand terrestrial magnetism early on, using it in the manufacture of compasses around the 12th century before the emergence as such of the sciences that would later 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 (1600) and especially Hans Christian Orsted (1820), who discovered that magnetism was not limited only to magnets, but had a close link with electric current.
This opened the door for André-Marie Ampère, Carl Friedrich Gauss, Michael Faraday and others to inaugurate the field of electromagnetism, and then James Clerk Maxwell to determine 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 the universe. The manipulation of magnetic fields, for example, through the acceleration of magnets, can generate a usable electric current, as is indeed the case in some types of generators.
And at the same time, by circulating an electric current through certain types of metals, they can be converted into electromagnets and made to attract certain metals or ferromagnetic materials.
This relationship is based on the atomic nature of materials, in which the electrons (-) from the orbit furthest from the nucleus of the atom (+) can be removed or transferred from one molecule to another, thus generating an electrical flow (current). ) and polarizing the set, that is, tilting the electric charge to one side (negative pole) and leaving the other with less charge (positive pole).
Applications of magnetism
Magnetism has been used by humanity for a long time. The invention of the compass and its use for orientation (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 exploring the world.
On the other hand, large magnets are used in the electricity generation industry in medicine (for example, magnetic resonance examinations), in engineering (the development of motors, the conduction and storage of electrical charges, etc.) and, above all, in electronics.
Computing, for example, depends largely on the use of magnetism to record information, combining it with electric current and knowledge of semiconductors.
