Magnet Science - How Magnet Works
How Magnets Work - The Science Behind One Of Nature's Fundamental Forces
How Magnets Work
Magnets have the ability to either attract or repel each other due to a significant number of unpaired electrons aligning their spins in one direction - this condition is known as ferromagnetism.
Each magnet features both north and south poles. When forces form around a magnet, they usually follow a specific path from one pole to the other - typically starting from the northern end and entering through its southern side.
The Electrons
Magnets have long been known to attract or repel certain metals, but how exactly do they do this? To understand, one needs to delve into the atomic level; all matter is composed of protons, neutrons and electrons which act as building blocks in our universe. Electrons orbit each atom's nucleus quickly in circular orbits known as shells. Each shell can only contain a certain number of electrons: two in the first shell, eight in the second shell and up to 18 electrons in the third. The spin of electrons gives each atom magnetic properties, acting like a miniature magnet with north and south poles. Magnets of opposite polarity attract each other; when like-polarity magnets are separated they repel each other; when we place a magnetic field near iron objects it attracts them due to unpaired electrons aligning themselves with this field forming multiple mini magnets into one massive one.
Magnets differ significantly from most objects. Most materials feature balanced atoms whereby electrons at either end spin in opposite directions - this cancels out their magnetic forces; but in magnets all of the electrons align evenly along their north and south poles, producing an intense magnetic force.
Stroking iron can turn it into a magnet without magnetic fields being present - electrons in its core align into one big magnet with north and south poles that is easily detectable. Iron is considered a paramagnet as its magnetic moment comes from quantum mechanical spin of unpaired electrons in its atoms, and thus becomes magnetic when stroked.
Most magnets possess an intrinsic magnetic moment as well, though its strength is much weaker. Most diamagnetics lack any magnetic force at all - instead they exhibit diamagnetism - however when heated or cooled to specific temperatures this aligns the magnetic moments within its atoms creating permanent magnets with distinct poles of attraction (a north and a south pole).
The Protons
Magnets need protons and electrons in order to attract each other. Protons possess positive electric charges that naturally repel similar charges; however, their strong nuclear forces over very short distances (such as within an atom), completely overpower electromagnetic forces and draw protons together; this mechanism forms the nucleus of an atom as well as contributing to processes such as star fusion.
All matter is composed of atoms. Each atom features a nucleus with protons and neutrons and an electron cloud surrounding it, known as an electron shell. Most materials feature pairs of electrons whose opposite polarities cancel each other out, rendering the material non-magnetic. But some metals feature domains with magnetic properties; when unmagnetized these domains jiggle about randomly without aligning themselves - preventing it from adhering to itself or other pieces of iron.
But when combined together to form a magnet, their similar poles cause them to attract. Their magnetic fields will align with each other and with that of Earth; hence the magnetic properties of magnets stick so securely together; paperclips too stick strongly onto steel or iron objects.
Magnets can be re-magnetized by rubbing them against another magnet or simply wood. As electrons from one piece of metal transfer their spin energy to the other piece, this causes it to become magnetized as well.
Magnets also create their own magnetic fields by constantly emitting invisible virtual particles which communicate to other magnetic particles to move away or gather closer, giving magnets the power of action at a distance.
The Domains
If you're curious as to why magnets attract or repel one another, the answer lies at an atomic level. Any material with magnetic energy -- known as domains -- contains small bits that act like tiny bar magnets; for instance, consider how compass needles point north because their domains align with Earth's magnetic energy source.
Domains tend to point in opposite directions when side-by-side; when they line up end-to-end they line up and strengthen each other, which explains why most ordinary magnetic materials such as chunks of iron or alphabet magnets on your refrigerator have multiple domains rather than just one unified magnetic field. But once heated to its Curie point, ferromagnetic materials become saturated with magnetic energy and all their domains reorganize into one unifying field; at which point the material becomes permanent magnetic material which no longer attracts or repel other magnets!
Permanent magnets may lose their magnetism if their electrons don't spin in an orderly fashion; when this happens, their magnetic fields cancel each other out; when trying to hold two such magnets together without their electrons aligning perfectly together they will repel each other and lose magnetism altogether.
A magnet's North and South Poles determine whether it attracts or repels other magnets. When aligned correctly, magnetic field lines run straight between them for maximum attraction; otherwise they resist each other and repel one another.
Magnets have the ability to attract or repel one another from a distance, depending on their poles. This occurs because adjacent magnetic fields angling together create push or pull effects between them according to magnetic induction principles; closer their magnetic field lines are, the stronger this effect becomes; hence why fridge magnets tend to stick directly on metal cabinet doors rather than directly to their surfaces.
The Fields
Magnetic force, like gravitational force that causes apples to fall from trees and determines planet orbits around the Sun, is a fundamental interaction. While gravity and electromagnetism were mostly understood by 17th-century scientists (Isaac Newton explained gravitational force; James Clerk Maxwell developed electromagnetic theory), many aspects of magnetism remain largely unexplained today.
Magnets work on the basic premise that like metals attract, while unlike metals repel. Therefore, metals like iron have natural magnetism which makes them attract other metals; this magnetic property of metals - also referred to as magnetism - can be exploited in many different ways.
Large scale magnetism results from electromagnetic fields produced by electrically charged particles found within atoms, radiating outward like electromagnetic rays from an antenna. The direction and strength of these fields is determined by how magnetically charged each electron in a material is; hence their relative strengths depend on this factor.
Physics experts now recognize that electromagnetic fields possess other properties, including energy content and momentum that were once unaccounted for. Thus, modern scientific framework for fields includes the concept that they are physical entities which can be altered just like particles can.
When two magnets come into close proximity, their electrons experience a Lorentz force from each magnet's magnetic field that causes their electrons to reorient themselves, aligning themselves along one side or another of each magnet and producing a magnetic field with both north and south ends, like poles on any magnet would do. This creates an electromagnetic field resembling its own poles.
Certain materials are ferromagnetic, meaning their electrons tend to align themselves with the magnetic field of a magnet. Non-ferromagnetic materials have atoms which do not respond to magnetic fields and remain randomly distributed; when moved closer, however, these non-ferromagnetic materials will rearrange themselves to align with its magnetic domains and stick more securely than ever to it.