This illustrates how the Moon causes tides on the Earth.
The Moon’s gravity pulls on each piece of the Earth, but the attractive force is a little stronger on the side facing the Moon, and a little weaker on the side opposite the Moon. The average force is the force at the center of the Earth.
The arrows at each point show how much the attractive force differs from the average as the Moon circles the Earth. These are the tidal forces
, and the result is a bulge in the ocean on opposite sides of the Earth. Earth rotates under these bulges, resulting in about two high tides each 24 hours.
Source: WolframAlpha demonstrations.#gravity #astrophysics