ocean tides - Moonstick Information Site

How the Moon Creates Ocean Tides

Of course, one of the most imposing symptoms of the moon phase is the ocean tides. "What causes ocean tides?" you may ask. Let me explain. The moon hovers 250,000 miles above the Earth. So why doesn't it fall to the Earth? Well, it actually does; it just never hits the Earth. Equally true, the Earth hovers 250,000 miles above the surface of the moon. Why doesn't the Earth fall to the surface of the moon? As you may have guessed, it actually does, but never manages to hit the moon. So the Earth and moon are in a constant fall and miss, round and round relationship. You may already know the following, but if you don't, you will need to accept it as fact. (I don't have the patience to explain it in detail.) Objects fall faster, closer to the surface of the Earth (or moon). (Sounds reasonable, doesn't it.) So as the Earth falls toward the moon, the moonward side of the Earth falls a little bit faster, and the opposite side falls a little bit slower. Kind of like how Wile E. Coyote falls off a cliff (stretches out from top to bottom as he begins to fall). Now, every reasonable person knows that the Earth does not stretch out as it falls toward the moon. Oh, but it does. The relatively inflexible body of the Earth stretches about 10 inches (25 cm) as it falls. The much more flexible, moveable oceans gladly stretch several feet toward and away from the moon as we all fall down (toward the moon). So as the Earth turns, and your town swings around to the moonward side of the Earth, you should notice that your sea level stretches several feet farther than your ground level. In fact, it will look a lot like the tide has come in.