Why would you want to detect metal? Oh, I don’t know … maybe you want to find some gold in the ground. You could dig up ALL the dirt, or you could find the location that has the gold before you dig. Or maybe you’re looking for buried metallic meteorites. You could even use a metal detector to find that ring you lost at the beach. These devices are quite useful.
But do you know how they work? Aha! When you think about it, it’s not obvious. There are different types of detectors, but they all draw on the same cool physics of electric and magnetic fields. Let’s take a