How does a compass use Earth's magnetism to point north?
Needle's Quiet Handshake
How does a compass use Earth's magnetism to point north?
You hold a little disc in your palm, and no matter how you turn, the needle inside swivels back to the same spot like it's stubborn about something. North, it insists. Always north. How does a sliver of metal know which way the planet is facing?
Here's the secret: the needle is a tiny magnet. And the whole Earth, all eight thousand miles of it, is a giant magnet too. The needle isn't pointing at a place. It's quietly answering a much bigger magnet's invisible pull.
