Michael Faraday has gone down in the history of science as one of the greatest experimental scientists of all time, but we cannot forget that he was one of the most important theoreticians of the 19th century, which is overshadowed by his complete absence. Mathematical knowledge of knowledge; His colleague says that mathematics is a closed book to him.
Life from 1831 to 1838 Faraday She was unusually active, and one of her main interests was understanding the nature of electricity. Between 1831 and 1833, all forms of electricity known up to that time (static, galvanic, thermoelectric…) were the same, and above all, Electricity is not a substance. Unfortunately in 1839 he fell seriously ill and was unable to work for 6 years.
In 1845, he resumed his research with one goal in mind: to determine what electrical and magnetic interactions were. He believed that they happened because lines of action filled space, like thick networks of conducting electric, magnetic, or gravitational forces. I was sure of it too Light, electricity and magnetism are related, the alleged ether did not exist and the lines of force he postulated had a real existence independent of their source; When paper is placed under a magnet with a sheet of iron, they form “lines” that run from the north pole to the south pole.
Newton got it wrong
In 1852, at the age of 60, he summarized his ideas in an essay On the physical nature of lines of force. In it, he categorically denied what most scientists of the time supported: electric charges and magnets act at a distance from each other, and nothing happens in the space between them. This view is part of what the great Newton is believed to have said, when in fact he thought the opposite, explaining in a letter to his friend Richard Bentley: “…one body can act at a distance on another. , is as ridiculous as I can think through the void No sane person can accept such a thing”.
Michael Faraday introduced the concept of a field. Photo: Istock
Faraday was unwittingly the inheritor of this completely forgotten thought from Newton, electric charge and The magnets filled the space with lines of force interacted with other charges and those arising from magnets. Faraday continued to develop his ideas, resulting in his famous essay About force protection In 1859, he analyzed the problem of interactions between two bodies. If only one were present, no attraction would appear, but the moment the other was introduced, classical theory called for the immediate appearance of a second force. He didn’t like the idea at all; It was easy for him to assume a certain ‘tension’ in space, represented by lines of force relative to matter.
A field that fills space
This is the great conceptual advance in physics introduced by Faraday: the concept Campo. Until then there was no way to explain why the apple fell from the tree or why the earth revolved around the sun. Newton had told us what gravity looked like but not how it worked: it was as if the sun exerted it. A mysterious action in the distance On planets, practically instantly. This idea was so ridiculous that very few accepted it, but the law of universal gravitation worked, so physicists put this problem in an obscure corner, and Faraday, studying electricity and magnetism, began to talk about it. camps.
We do not realize it, but the space around us is not only occupied by matter. If we could get everything from a bedroom, down to the last dust and the last molecule of air, Couldn’t tell there was anything in that room. If a pear is thrown, it will fall to the ground is conclusive evidence: there is “something” in our room that makes it fall. It doesn’t matter where we drop it: the pear will go directly to the floor from anywhere in the room; It is filled with something called gravity. It is, more precisely, a gravitational field in our bedroom. What causes it to be there? Obviously, the planet under our feet.
An empty room is not empty, rather it contains different fields. Photo: Istock
But not only that. If an electrically charged particle such as an electron is hurled in a straight line and its trajectory carefully analyzed, it can be distinguished, as was the case with the pear. “Something” changes its course, it is not attraction. If we repeat the experiment many times, we will realize that this “something” affects only electrically charged particles; Neutrals know nothing. We discover that there is another field in our room, the electromagnetic one, which only affects charged particles. where are you from A combination of different situations: electromagnetic fields produced by terrestrial magnetism, mobile phone antennas, televisions, radio stations, household wiring, kitchen appliances…
It’s not a force, it’s a field
As we have already said, Faraday revealed the existence of these fields through an experiment that all children at school did: we put pieces of iron on a piece of paper and put a magnet under it. Within seconds these are organized and form a characteristic pattern. If we remove the magnet and move the paper slightly, the strange structure disappears, that is, the magnetic field created by the magnet while it is still there. Modified space properties.
Earth creates and is surrounded by a gravitational field. Photo: Istock
In short, nothing but what we commonly call force (gravitational, electric or magnetic). Visible effect on object of space-filling field. Also important: matter has different properties (in our case we have discovered two, mass and charge) that make it sensitive to different fields; If there is none of them, for example, if its electric charge is zero, then the relevant field will not affect it, and it will be as if it did not exist. Unfortunately, we don’t know anything in this world that doesn’t have mass, so gravity is only one of the four fundamental forces of nature that affect everything in the universe.
