Why do we have tides


Planet Earth is surrounded with interesting facts and unexplained theories. Starting from Earth’s evolutionary history to its life sustaining features like water, oxygen, balanced temperature etc, everything has fascinated scientists and aroused curiosity among millions. One vital fact that has been enthralling people all over the world is the origin of tides. Have you ever wondered what cause tides in the sea? Check out the amazing phenomenon.

The main reason behind origination of tides is the gravitational pull from moon and sun. But if you are thinking that the gravitational pull from moon and sun just pull out water that causes tides, then that’s not the case. Earth’s own gravitational pull is evenly distributed everywhere on its surface causing no tides but the gravitational pull from moon and sun is relatively strong to disrupt the gravitational center of the earth causing tides.

Earth and moon are both heavenly bodies orbiting a huge center of mass. The orbital motion causes centrifugal force on earth that is away from the moon and it also forces the ocean to move in opposite direction. The moving away of ocean because of centrifugal force cause high tides to a point and the gravitational pull from the moon cause another high tide. So, Earth experiences one high tide when moon is at closest location and the other one right after 12 hours when it is on the other side of the earth from the moon.

Now, if moon is the only one exerting gravitational pull then the intensity of high tide must be same over the entire time, but there is tidal difference cycle every 28 days and that’s because of the gravitational pull of the sun. The sun’s gravitational pull is weaker than moon because of far distance from earth but strong enough to cause a change in the tidal cycle. When the moon and sun are working together with respect to earth it causes the strongest tide (spring tide) and when they are working opposite then that causes weakest tide (neap tide) in the ocean.