Answer: Sun and Moon on the Earth
Notes: The slythmic side and fall of ocean water twice in a day is called a Tide. Tide-generating forces (TGF) are a result of the gravitational attraction between the earth, the sun, and the moon and the centrifugal force due to the relative motions of the moon around the earth, and the earth around the sun. While these forces exactly balance on average, the local mismatch at the earth's surface creates a horizontal force directed towards the surface points closest and farthest from the moon.
