Tides

Have you ever sat on a sandy beach, building a magnificent castle with tall towers and a deep moat? You look away for a little while, and when you look back, the ocean has crept closer, tickling the edges of your creation with foamy water. Or maybe you've found a beautiful seashell far up on the sand, and wondered how it got there. The ocean seems to breathe, taking a long, slow breath in, and then an even slower breath out. This magical movement, this gentle back-and-forth, is me. I am the way the ocean rises and falls each day, visiting the shore and then pulling back again to reveal hidden treasures. I am a slow, silent dance that happens all over the world, every single day. Hello. I am the Tides.

For thousands of years, people who lived near the sea watched me. They knew I came and went with a steady rhythm, like a sleepy giant sighing. They built their homes and planned their fishing trips around my daily visits. An ancient Greek explorer named Pytheas, who sailed the seas way back in the 4th century BCE, was one of the very first people to write down that I seemed to be connected to the Moon. He saw that when the Moon was high in the sky, I was high on the shore. It was a wonderful clue, but for a very long time, no one knew why. It was a big mystery. Then, a super smart scientist named Sir Isaac Newton figured it out. On July 5th, 1687, he shared his discovery of an invisible force called gravity. The Moon, even though it is so far away, has enough gravity to gently pull on the Earth’s oceans. This pull creates a little bulge of water, like a tiny hill in the sea. As the Earth spins around, this bulge of water travels across the globe. That's me. I am like a giant, slow-motion wave caused by a secret handshake between the Moon and the ocean.

My daily dance is very important. Sailors and the captains of big ships look at my schedule to know when the water in a harbor will be deep enough for their boats to sail in and out safely. Fishermen know that my movements bring different kinds of fish closer to the shore, so they know the best times to cast their nets. I even help people in a very modern way. In some places, my powerful currents are used to spin special machines called turbines to create clean electricity. This is called tidal power. I am a beautiful reminder that our big planet Earth, the glowing Moon, and the deep blue oceans are all connected in a wonderful rhythm. The next time you visit the beach and see the water line moving up the sand, you can look up at the sky, wave to the Moon, and know that you are watching our special, secret dance together.