How Does Magnetism Work?
The invisible force that makes compass needles spin, holds photos on your fridge, and powers electric motors.
An Invisible Push and Pull
You've probably played with magnets before — sticking them to a fridge, feeling them snap together, or pushing them apart when they resist. That push or pull is magnetism, an invisible force that can act across a distance without touching. Unlike gravity, which only pulls, magnetism can both attract (pull together) and repel (push apart).
But what causes this force? It all comes down to what's happening inside the atoms of certain materials.
Atoms Are Tiny Magnets
Every atom has electrons spinning around its nucleus. These moving electrons create tiny magnetic fields — invisible areas of magnetic force surrounding the electron. In most materials, the electrons spin in random directions, so their tiny magnetic fields cancel each other out. The material isn't magnetic.
In magnetic materials like iron, nickel, and cobalt, groups of atoms naturally align their magnetic fields in the same direction, forming small regions called domains. When you magnetize a piece of iron, you cause all these domains to line up, pointing the same way. Their tiny forces add up into one strong magnetic field — and you have a magnet.
North and South Poles
Every magnet has two ends called poles — a north pole and a south pole. The fundamental rule of magnetism is simple: opposite poles attract, and like poles repel. Hold two magnets with their north and south poles facing each other, and they'll snap together. Flip one around so two north poles face each other, and they'll push apart — you can feel the resistance even though nothing visible is between them.
You can never have a magnet with only one pole. If you break a magnet in half, each piece becomes a complete magnet with its own north and south poles. You'd have to break it down past the atomic level to separate them — and that's not possible with ordinary tools.
Magnetic Fields
The area around a magnet where its force can be felt is called a magnetic field. You can't see magnetic fields with your eyes, but you can make them visible by sprinkling iron filings near a magnet. The tiny iron pieces arrange themselves along the field lines, forming beautiful curved patterns that arc from the north pole to the south pole. The closer the lines are to each other, the stronger the magnetic force in that area.
Electromagnets — Magnets You Can Switch On and Off
Here's where magnetism and electricity connect. When electric current flows through a wire, it creates a magnetic field around the wire. If you coil the wire into loops and wrap it around an iron core, you create an electromagnet — a magnet that works only when electricity flows through it. Turn off the current, and the magnetism disappears. Electromagnets are incredibly useful because you can control them: they power electric motors, MRI machines, speakers, and the giant magnets used in junkyards to lift cars.
Earth Is a Giant Magnet
Earth itself has a magnetic field, generated by the movement of liquid iron in its outer core. This field extends far into space and creates the magnetosphere, which shields us from harmful solar radiation. It's also why compasses work — a compass needle is a tiny magnet that aligns with Earth's magnetic field, always pointing roughly toward the magnetic north pole.
Some animals can sense Earth's magnetic field and use it for navigation. Sea turtles, salmon, honeybees, and many migrating birds have built-in "compasses" that help them travel thousands of kilometers without getting lost. Scientists are still studying exactly how this ability works, but it may involve tiny magnetic crystals inside their cells.
Last reviewed: April 2026