"[Bleeping] magnets: How do they work?" That's the question that rappers Insane Clown Posse posed in their single "Miracles" a few years back, which led those snarkmeisters at "Saturday Night Live" to ridicule them unmercifully. And that was unfortunate, because it's a perfectly reasonable thing to ponder. A magnet is any object or material that has a magnetic field -- that is, a bunch of electrons flowing all around it in the same direction. Now, electrons -- like rappers from Detroit who wear clown masks, curse a lot, and drink Faygo Cola -- like to hook up in pairs, and iron has a lot of unpaired electrons that are all eager to get in on the action. So, objects that are solid iron or have a lot of iron in them -- nails, for example -- are going to be pulled toward a sufficiently powerful magnet. The substances and objects attracted to magnets are called ferromagnetic substances [source: University of Illinois].
Humans have known about the phenomenon of magnetism for a long, long time. There are naturally occurring magnets, such as lodestone, but medieval travelers figured out how to rub steel compass needles against those stones so that they picked up electrons and became magnetized, which means that they developed their own magnetic fields. Those magnets weren't particularly durable, but in the 20th century, researchers developed new materials and charging devices that enabled them to make more powerful permanent magnets [source: Stupak]. You can actually create a type of magnet, called an electromagnet, from a piece of iron by wrapping an electrical wire around it and then connecting the ends to the poles of one of those big batteries with the clips on top [source: University of Illinois].