Bad Astronomy and Universe Today Forum - View Single Post - Why is there a tidal bulge on the far side of the Earth?

Pinemarten · #2 (**permalink**) 23-September-2003, 09:52 AM

I remember making an 'accelerometer' in school.

It was just a jar with a tight fitting lid, a cork, and a string.
Attach the cork to the string, attach the other end to the inside of the lid at the center. Fill the jar with water, screw the lid on, and flip it upside down.
What you should have is the cork floating at about the center of the jar, and totally under water.
When you move the jar, the cork will swing toward the direction of acceleration. If you put it on the dash of a car, it will move forward when you speed up, backward when you brake, and stay centered when you are going a constant speed.
We used it to prove that centripetal force is to the inside, and centrifugal force is a 'feigned' force.

I assume this is how the earth reacts to the gravitational force of the moon. The water goes away from the direction of the force.