Abide With Me, Tis Evenin' Tide

Some times the ocean itself seems alive. Why are there tides and what causes them. It all starts out with gravity. Gravity is not a very strong force, compared to electomagnetic forces, or the strong forces that hold quarks together, but it is a long force. It's amazing how far a field of gravity will reach. Such is the case with the tides. Gravitational forces, pricipally from the moon, and from the sun will pull the ocean closer too it which will pull the water in or out to sea according to the possition of the sun and moon. There are several classifications of tides. A Spring tide is when the tide is higher than average. A Neap tide is lower than average. Tides can also be classified as diurnal or semidiurnal, meaning they occur once or twice a day.