When you are by the sea, you can see something strange. Sometimes the water is much higher and sometimes the water recedes a bit for a longer period of time. This is called ebb and flow.
What does ebb and flow mean?
The terms ebb and flow describe the condition and height of seawater. At low tide the water recedes and you can walk further out onto the mudflats. At high tide the water comes back and sometimes even rises a little above the normal level.
What does this have to do with
This phenomenon of the sea moving to such an extent is due to gravity. This gravity keeps us humans and other objects on the ground and prevents us from floating through the air. This gravity does not exist in space, which is why astronauts float in space. Also, gravity causes the earth and moon to attract each other.
The water of the seas and oceans is also influenced by this attraction. The water that is on the side of the earth that faces the moon is attracted to the moon. This is noticeable to us as a flood. The position of the sun and the moon in relation to each other play an important role here. If they are in line with the earth, then a spring tide occurs. This is higher than a normal tide. When the sun and moon are at right angles to the earth, a neap tide occurs. This is lower than a normal tide.
The lunar gravitational pull is so strong that it is felt even on the far side of the earth. However, one should actually experience an ebb on this side. Surprisingly, however, this is not the case. There is high tide both on the side of the earth that faces the moon and on the side that faces away from the moon. Many scientists explain this with the centrifugal force.
The centrifugal force
The centrifugal force can be explained most easily with an example. When you sit in a chairoplane and reach a certain speed, your body will be pushed outwards, away from the center of the carousel. This force is called centrifugal force. When the earth rotates, this is exactly the force that is created. But we don't notice it because the earth's gravitational pull keeps us on the ground.