EMILY KWONG, HOST: Hey, everybody. Emily Kwong here. Today we're going back to school, where we revisit something you may have learned in science class and go a bit deeper with it. Joining me in this is science correspondent Geoff Brumfiel. GEOFF BRUMFIEL, BYLINE: And today, Emily, I've got a good one for you. It's one of the most mysterious forces in the world, but you can find it on your fridge. I'm talking about magnets and magnetism, which is a fundamental force of nature. It can feel a little bit like magic. KWONG: Yeah. BRUMFIEL: But how it works is really interesting. And I'm going to tell you something else. We all should know how magnets work, Emily, because magnets matter.