We know there is less gravity on the moon but why the moon gravity effect on the sea?

Question

We know there is less gravity on the moon but why the moon gravity effect on the sea?

Answer 1

......you might want to check out this entirely different take on the tides and how, or if, gravity plays a role.....

I'm still milling it around, but it makes some sense.

Answer 2

Less gravity, therefore, smaller effedt.

Answer 3

well cause the moon and the sun both a gravitational pulls on earth,  wen there both on seperate sides of earth they both have pulls going different ways.

i think

Answer 4

Every planet,moon or star has a gravitational effect. The Moon has a small effect on the earth which we all can see; the oceans.

The Moon is also moving away from the earth. In the distant future the Moon will be too far away to have an effect on our oceans and planet.

Answer 5

The moon is less massive than the Earth so it has less gravitational pull on its surface than the Earth does. And less gravity doesn't mean no gravity. The moon is more than three times more massive than all the water on Earth (and Earth has a lot of water). The gravitaniol pull it has on the Earth might not be felt by you and me, but when you have huge oceans the affect builds up and affects the water levels. I think its surprising such a huge object as the Moon only moves the oceans the few meters it does.

Answer 6

Basically, even though the gravity is weaker, it isn't negligible.  The sun tugs on you, too.  So do the other planets, but the force is so negligible as to be unnoticeable.  Basically, it's a property of the moon's gravity, and its distance.

Answer 7

What causes the tide is the difference in the force of gravity.  The near side of the Earth is closer to the Moon than the far side.  The moon pulls a bit more on each molecule of water on the Moon side than it does on the Earth's centre.  So the water nearer the Moon tries to "fall" towards the Moon (of course, because of Earth's gravity, it never makes it very far).  The coast is attached to the crust, which sits on the mantle, etc.  It would try to rise but it will go less far than the water.  That is why there is a cyclical difference between the level of the coast (which we perceive as unchanging) and the level of water (which we see as rising).

The water on the other side is less pulled by the Moon.  It will not "fall" toards the Moon as fast as the rest of Earth (including the coast).  But, instead of perceiving the coast as going down, we perceive the water as going up.

That is why we get two tidal bulges, one on the Moon side and one on the opposite side.

(Same thing applies to the Sun's tidal effect, but it is much weaker because the Sun is further out:  Earth's diameter, relative to the Sun's distance, is a lot less than Earth's diameter relative to the Moon's distance.

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The Moon's tidal effect does slow down Earth's rotation and we could imagine that one day, when our rotation has stopped relative to the Moon, there will no longer be a lunar tide.  However, this will take too long.  The Sun will have gone through its red giant phase (in 5 billion years) before we get "spin-locked" with the Moon.

Answer 8

The moon also affects the ground, too.  Studies show that there is a tidal effect on solid ground.  It moves up and down about 6 inches.

The water moves more than the ground because it can move.  It's liquid, so it flows very easily.