Surfers have taken to the ocean for centuries. Ancient Polynesian civilizations were surfing as far back as 2,000 BC, and there is evidence of wave riding in 12th-century Hawaii. Of course, back then, ...

They roll toward the beach, burst into foam, then retreat only to return again. But where do waves come from? It's not the sea "breathing," nor a giant blowing on it... The answer is both simple and ...