The Giant Jigsaw Under Your Feet

Theory of plate tectonics

If we drain the oceans, the jagged cracks between Earth's puzzle pieces become obvious. Take the North American Plate—it stretches halfway across the Atlantic. Meanwhile, the Pacific Plate is mostly underwater, edged by a fiery ring of volcanoes. Seven major giants like these make up the map.

But here's the strange part... these plates aren't just sitting there. They are constantly jostling for space, moving at about the speed your fingernails grow.

Where they pull apart, new crust is born. Where they crash together, mountains rise. This slow-motion demolition derby is what shapes the world we live on.