How do magnets work? We more or less know how a computer works, what a black hole is, and we can even master the ritual of filing a tax return, but… how does a magnet work? If we are given a magnet and look for pieces of metal that respond to it, we can lose ourselves for long minutes. If you give two instead of one, minutes become hours. They fascinate us, in part, because they continue to appear to us almost magically, even when we more or less understand how they work.. We know that a magnet always has a north pole and a south pole, and even if it is broken into pieces, each piece has a north and a south pole. We know the secrets of making electricity with them, can damage electronic devices and what surprises us the most: they are capable of working at a distance without touching each other. How is this possible? Can two objects communicate without touching or exchanging something?
Be that as it may, magnets attract each other, especially their opposite poles, and the closer they are, the stronger they attract. The opposite happens at the same poles, with north pushing north farther away, preventing them from touching, moving us so strongly that the magnets are closer together. They follow an inverse square law, that is: the further apart they are, the interaction between the two magnets decreases exponentially. Where’s the catch? As some physics textbooks say, action at a distance is impossible. For example, light travels between the source and the light in the form of particles, which we call photons. What is happening to him? Magnetism?
In fact, it is not entirely true that physics has problems with actions at a distance. It is true that relativity has changed the way we see them, not because they are no longer possible, but because they cannot be immediate. There are several conclusions that can be drawn from Einstein’s famous theory of relativity, one of which is that nothing accelerates to the speed of light in a vacuum. Or as popularly simplified: nothing can travel faster than light. That means if you put a magnet in the middle of a room full of spoons, they won’t be immediately attracted, it will take a while for the magnet to exert its force, depending on how far away it is. spoon
That kind of action at a distance does not counter the locality that we posit that relativity theories make sense. AndAlthough we may reject them at some point, for now it’s comfortable to be okay with them. So, starting from this point, what we have to ask ourselves is how two separated objects, apparently, nothing travels, come into contact. The key lies in a somewhat complex concept, but one we’ve been intuitively aware of for centuries: fields.
Magnets are named after Magnesia, the place where the Greeks discovered magnetite, a rock with ferromagnetic properties. Even before that, we humans were already experimenting with these strange properties, perhaps even discovering magnetic field lines. If we put an object attracted by magnetic fields on a sheet of paper, place a magnet under it, and shake the sheet slightly, we find that the files are arranged in curved lines to enter a pole. Others. This means that at each location around the magnet, a different intensity of the magnet is experienced in a different direction. This concept makes the magnetic field very simple: the values ​​the magnetism takes at every point in space around an object. For some they are a very useful mathematical tool for working with forces such as electromagnetism. For others it is a different matter. In fact, it all depends on what we understand by field.
Magnetic field lines are not our invention, so even though the concept of the field is a bit, it accounts for something real and measurable. To that extent, it stands alone outside of mathematics. We may be hard to imagine and rightly so. This is not a simple concept, although we are used to hearing it for gravity, where we refer to it as a canvas that sinks more or less depending on the mass of objects in this gravitational field. In this way, the curvature of the canvas stabilizes the movement of the objects. We can imagine magnetism and electricity as similar, although the difference is that only attraction is attractive, while electricity and magnetism are either repulsive or attractive. So no, there aren’t particles traveling between poles or invisible elves moving magnets, they’re fields and thanks to them, we’ve innovated the technology we enjoy.
Don’t get it:
- In fact, when we talk about the gravitational field, we are talking about the geometry of spacetime, and quantum field theory is one of the most accurate we’ve ever developed, and although it posits fundamental forces as excitations of different fields, it’s not. It means that we are in front of us, the same mechanisms that govern gravitational fields. The existence of these concepts beyond their mathematical application is an open question in the scientific world, and we must wait until our knowledge of these matters advances to know to what extent the concept transcends theory.
Notes (MLA):
- Rahman, Wajeeh. Electromagnetism University of Cambridge Part IB and Part II Mathematical Tripos. Academia.edu, 1.
