Gravity and the Tides

Okay, you know that gravity is the stuff that keeps your feet on the ground, but did you know that the Moon's gravity is the reason we have ocean tides?  What would all the surfers do without the moon?  The weather forecasters wouldn't even be able to report high tide and low tide times for the fishermen and women.  At first it's kind of hard to understand, but if you think carefully, you'll get it.

The moon pulls on the Earth because of gravity, right?  The water on Earth gets pulled easier than the land.  That makes sense.  It's easier to pour water than peanut butter.  So as the moon's gravity pulls on the Earth, it makes bulges and we get tides.  That's a pretty simple explanation, but we hope you get the idea.  See our links page for some more sites that explain tides.

That's not it though.  The hard part is that the Earth bulges on opposite sides at the same time.  If the gravity of the moon is pulling on one side, how does it bulge on the other?  Think about this, have you ever seen a cowboy swing his lasso?  Well, it is sort of the same thing.  You know how the lasso stays in an oval shape or a circle?  It's called centrifugal force.  The Earth spins so fast that is has centrifugal force.  If it bulges on one side, then it has to bulge on the other.