We explain what magnetic energy is, its history, advantages, disadvantages and more characteristics. Also, how it works and examples.
What is magnetic energy?
Magnetism is a phenomenon associated with electromagnetic force one of the elemental forces of the universe. It affects all existing materials to a greater or lesser extent, but its effects can be seen mainly in certain metals, such as nickel, iron, cobalt and their different alloys (known as magnets).
This force manifests itself in the form of magnetic fields capable of generating attraction or repulsion between interacting elements, depending on their magnetic polarities: like poles repel, opposite poles attract.
Magnetic energy can be understood as the ability of the magnetic force to do mechanical work but we also refer to it when we talk about the energy that is stored in a conductive element or a magnetic field. This energy is capable of radiating through space, even in the absence of a physical medium, through what is known as electromagnetic radiation.
Magnetic fields are formed by magnetic radiation. Visible light, for example, is made up of electromagnetic fields and occupies only a strip of the electromagnetic spectrum. Depending on the properties of the waves that make up this spectrum, there will be visible light, ultraviolet radiation or infrared radiation, for example.
Magnetism, furthermore, is a phenomenon with countless applications used by humanity contemporary, especially in its borders with electricity, as in the case of motors, superconductors, alternators, etc.
See also: Electromagnetism
History of magnetic energy
magnetic energy It was discovered by humans in ancient times. It is said that magnetic phenomena were first observed in Ancient Greece, in the city of Magnesia on the Meander, where the mineral magnetite was particularly abundant. That's precisely where its name comes from.
The first student of magnetism was the Greek philosopher Thales of Miletus (625-545 BC). However, in Ancient China it was also studied in parallel, as evidenced by a mention of it in the Devil's Valley Master's Book from the 4th century BC. c.
Magnetism was widely studied in subsequent centuries, both by alchemists, naturalists and religious people, as well as by explorers and philosophers, and especially after the invention of the compass in the 13th century. Besides, The Earth's magnetic field was discovered in Greenland in 1551.
However, only in the 19th century were the foundations of magnetism scientifically revealed, thanks to advances in physics, chemistry and electricity. Hans Christian Orsted, André-Marie Ampère, Carl Friedrich Gauss, Michael Faraday and especially James Clerk Maxwell, with his famous equations, played an indispensable role in this.
How does magnetic energy work?
magnetism occurs due to the movement of electrical charges in objects that interact: if the charges present in two objects (for example two current wires) move in the same direction, the objects experience an attractive force; but if they move in opposite directions, this force is repulsive.
Around moving charges there will always be a magnetic field, generated precisely by the movement of said charges. If other moving charges approach that magnetic field, they will interact with it. It is essential that charges are in motion for magnetic fields, forces or energy to exist. Charges at rest (still) do not produce magnetic fields or magnetic phenomena. Magnets have their own magnetic field due to the particular movement and orientation of electrons within atoms.
magnetic energy can be produced by electromagnets which consist of a coiled electrical wire that covers a magnetic material, such as iron. It can also be produced by magnetizing susceptible materials, whether temporary (those in which the magnetic field is external and, therefore, weakens and disappears) or permanent.
Characteristics of magnetic energy
Magnetic energy has a variable intensity depending on the materials that produce it or the intensity of the electric current that generates it. Due to the direction of electron movement, magnetic materials always have two poles: positive and negative. This is known as a magnetic dipole.
Although everything that exists is susceptible to a certain degree of magnetic response (the so-called magnetic susceptibility), depending on its degree of susceptibility we can talk about:
- Ferromagnetic materials. They are strongly magnetic.
- Diamagnetic materials. They are weakly magnetic.
- Non-magnetic materials. They have negligible magnetic properties.
Advantages of magnetic energy
Magnetic energy in the contemporary world is extremely advantageous since its storage and production have very important applications for human life, for example, in transportation, medicine or the electricity generation industry.
Many magnetic materials They help make our lives easier from the magnets we stick on the refrigerator, to the magnetic materials inside our computers and the alternator of our cars, through transformers and a whole series of electricity modulators, which use magnets to manage it.
On the other hand, experiences with this type of energy and applications to modern initiatives are becoming more promising every day. could bring us closer to clean energy sources in the near future.
Disadvantages of magnetic energy
The weak side of using magnetism lies in the fact that naturally magnetic materials lack the necessary magnetic field strength such as to mobilize massive objects or to transmit their energy indefinitely to other systems. Therefore, the usual thing when using magnetism is the use of the electromagnet, which requires a constant input of electrical energy.
Examples of magnetic energy
Some examples of magnetic energy:
- The compass. Its metal needle aligns with the Earth's magnetic field to constantly point north.
- Electrical transformers. They are huge cylindrical boxes that are usually found on electricity poles and that operate internally through the force of several magnets, to modulate the flow of electric current and make it consumable in our homes.
- Magnetic tomographs. They are medical devices used to send and receive electromagnetic waves through the body, which allow us to get an idea of how things are inside us without having to operate.
- maglev trains. They are in operation in many first world countries, and are able to stay in the air due to the repulsive thrust of electromagnets at their base.
- The northern lights. Although indirectly, they are evidence of the power of the Earth's magnetic field, capable of repelling the solar wind (particles of solar plasma ejected into space). The lights that can be seen in the areas near the poles are these particles when they are brushing the atmosphere and traveling in the direction of the magnetic field without penetrating towards the planet.
Continue with: Physical phenomena
References
- “Magnetism” on Wikipedia.
- “What is magnetic force?” at Khan Academy.
- “Magnetic Energy” in Universe Today.
- “Magnetism (physics)” in The Encyclopaedia Britannica.
