Moon and tides?

Question

If the moon goes around the would once every month, why do the tides go out twice a day all over the earth?

Answer 1

I am sorry but there is still something missing in the three answers you've got so far:

The moon account for about 70% of the tide and the sun for about 30%. The tide calculation is something very complex - I know, I have programmed it years ago, on my navigation tool.

The position of the moon and sun at any given moment are the most important factors influencing the tide. But there are also things like the sun's declination, the moon's declination, the relation between both ... in fact the tide is calculated as the sum of up to 40 components, each adding or subtracting a bit of the expected tidal height. It is the configuration of all those components that make one tide higher than another. Some components only affect the calculation in a cycle of 4.5 years. This may cause exceptional great tidal difference (a.k.a. spring tide) or small (neap tide).

The tide is the greatest when the moon and sun are either in the same direction (new moon) or opposite (full moon). The greatest tidal difference registered is in the bay of Fundy (between US and Canada) but those in the English channel aren't bad either. I have personaly sailed around the British Channel island and experienced in the French port of Paimpol a tide of 11 meters.

Answer 2

Because, the moon also moves closer and farther away from the earth as it rotates. The closer it comes to earth, the higher the tide.

Answer 3

Tides are created because the Earth and the moon are attracted to each other, just like magnets are attracted to each other.

Tides are periodic rises and falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day.

Answer 4

Due to gravitational pull of the moon,the places facing the moon as well as the places which are exactly on the other side of the earth, both will have tides( high) at the same time.As the earth spins once in each day,each place will be facing the moon once and will be on the other side at another time within a period of 24 hours.Hence tides(either high or low) occur twice a day.