Why are there ebbs and flows?

Because the earth and the moon are in constant motion, and the relative positions of the earth, the moon and the sun change periodically, the tidal force also changes periodically, which makes the tidal phenomenon happen periodically, which is the reason for the tidal fluctuation.

The seawater is also rotating with the rotation of the earth, and the rotating object is subjected to centrifugal force, which makes it tend to leave the center of rotation. At the same time, seawater is also attracted by celestial bodies such as the moon and the sun. Because the moon is closest to the earth, it is more attractive. In this way, seawater forms the tidal force under the combined action of these two forces.

The moon, commonly known as the moon, also known as the lunar moon and the mysterious rabbit in ancient times, is the only natural satellite on the earth and the fifth largest satellite in the solar system.

The sun is the central celestial body of the solar system, accounting for 99.86% of the total mass of the solar system.

Earth (English name: Earth; Terra (Latin) is the third planet closest to the sun and the only celestial body known to breed and support life.