You may think that this article isn’t relevant to you; Perhaps you have some refrigerator magnets or your kids play with magnets, but you don’t exactly have household magnets laying around. You’re completely wrong.
Magnets and magnetism are integral to the functioning of every single appliance in your house that uses a motor; that means everything from your food processor to your ceiling fan contains magnets and uses them to get work done. This article will cover the basics of how they work and how they can be put to work.
Magnets have been a recent development in terms of the history of human technological advancement, and they have opened up the door to a rapid change in pace and mindset the likes of which our species has never seen.
The reason they weren’t put to use sooner is that naturally occurring magnets are extremely weak. Lodestone is the strongest naturally-occurring magnet and can only attract tiny metal objects like paper clips and staples.
By the 12th century, people had figured out that they could use lodestone to magnetize small pieces of iron, leading to the invention of the compass. Compasses were created by repeatedly rubbing lodestone along an iron needle in one direction. The iron would then become magnetized and align itself in a north-south direction when suspended on an axis. Scientist William Gilbert figured out that this happened because the earth itself was a giant magnet and had north and south poles with which the compass would align itself.
This particular process by which metal is turned into a magnet involves the microscopic regions known as magnetic domains. Magnetic domains make up a part of the physical structure of ferromagnetic materials like iron, cobalt and nickel. Each domain is basically just a tiny, self-contained magnet with its own north and south pole. However, in these circumstances “north” and “south” are actually misleading terms, because the magnetic domains all point in different, random directions. The magnetic domains that are opposite directions simply cancel each other out, so the material does not produce a net magnetic field.
Here’s the most important aspect of magnets: Each domain’s magnet field extends from its north pole into the south pole of the domain ahead of it. This is why breaking a magnet in half creates two smaller magnets, each of which containing their own north and south poles. It also shows why opposites attract; the magnetic fields of the two magnets are locking into place, making one larger magnet with the same northern and southern ends. Like ends repel each other because their lines of force are traveling in opposite directions, making them clash against each other.
Using only these simple observations, the potential to create and manipulate electricity was discovered. From compasses to cars, magnetism has served humans very well.