Making tides

[Duyz72]

OK here goes

Imagine the Earth as a round ball surrounded by a nice layer of water (which happily it just happens to be).
NOW imagine the Earth as a metal ball, and the water as mercury. #Both will be attracted to a magnet (the Moon).
So you have the moon attracting the water and the Earth at the same time.

In the pic below:
1. #There are no tides and no attraction because no moon.
2. #The attraction is strongest closest to the moon (top) and gets weaker the further you go. #So firstly the water closest to the moon is attracted making a high tide.
3. #The Earth surface closest to the moon is also attracted [but not so strongly as the water] so it too moves slightly closer. #Since the Earth is solid it all moves.
4. #The water on the opposite side is attracted the least so is left behind making another high tide.

The water at the sides is what fills the bulges making a low tide.
Since the Earth rotates once every 24 hours any point on the Earth will pass through 2 high and 2 low tidal effect areas.

This is fairly simple explanation because
a) the Earth's axis is tilted around 23.5 degrees (tides are bigger around 23.5 degrees from the Equator)
b) the Earth is spinning (causing a drag effect)
c) the moon is rotating around the Earth (so we get changes in tide times)
d) and all of this is rotating around the sun (so we get spring tides etc)

(Side note :if the Earth was on it's own and just spinning, there would be a constant high water mark at the equator, and low water mark at the poles. #This effect can be seen with the rings of saturn or the spiraling arms of a spiral galaxy)

[gogecko]

Gee Duyz, youve gone to so much effort, I do appreciate it. Im still stumped on this. I do have good knowledge of basic astrophysics, and I do mean basic.

Are these your own concepts or can you quote a source/website? Ive researched this problem before, and I never came across this concept.

heres a few points I need clarified;

"3. The Earth surface closest to the moon is also attracted [but not so strongly as the water] so it too moves slightly closer. Since the Earth is solid it all moves."
- surely you are not suggesting the moon pulls the earth off course? Your diagram seems to be saying so. The earth does not move, except around the sun. Orbit is the net result of 2 forces, and the earths gravitation is stronger than the moons. Isnt the distance between the earth and moon CONSTANT? ie Geostationary orbit....The moon does NOT pull the earth towards it resulting in a suction effect. The earth exerts a gravity force on the moon that stops the moon spinning off into hyperspace. There is a big difference.

"a) the Earth's axis is tilted around 23.5 degrees (tides are bigger around 23.5 degrees from the Equator) "
- surely the earth is only tilted at the solstice in winter and summer? In Spring and Autumn we get the equinox, and no tilt? We still get 2 tides a day.

If the moon was causing the earth to move, then we would never have been able to navigate by stars, everything in the sky would be moving. Do I understand you correctly? Im not trying to have a go at you. If you can explain this to me , I will be very grateful. As you can tell, I enjoy physics, and Ive been trying to understand this problem for years.

regards
Andrew

[Duyz72]

Pictures were a simplistic exaggeration of what happens.
A simple google search should help you out.
Here are just a few links.

http://www.faqs.org/faqs/astronomy/f...ection-17.html
http://csep10.phys.utk.edu/astr161/lect/time/tides.html
http://www.mesa.edu.au/friends/seash...idal_zone.html
http://science.howstuffworks.com/fra...oon/Tides.html
http://www.vskc.org.au/stories/two_tides.htm

Another way to explain using Axial forces.
http://www.quoddyloop.com/tides.htm

Plus the Earth 'wobbles', called the Chandler wobble, once about every 1.2 years.
http://www.crystalinks.com/earthswobble.html
http://www.sciencedaily.com/releases...0717123812.htm

Plus every 26000 years or there abouts the axis plane does a complete rotation too.
http://www.uccs.edu/~tchriste/course...ecmotions.html

Also, the moon's orbit is increasing slowly each year, eventually it will leave the gravitational pull of the Earth and go somewhere else.

So there is a lot going on just with our own Planet, let alone the rest of the Universe.

Happy Googling

[webby]

To put it simply the spinning and rotation causes gravity, which creates gravitional pull and the moon tries to pull on anything on the eaarth to bring it closer, but the earth is able to hold onto everything but the water.
Since the water is always moving the earth cannot hold on to it and the moon is able to pull on it.
Tides are not caused by the direct pull of the moons gravity, the moon is actually pulling upwards on the water while the earth is pulling downwards, but the moon has that slight advantage due to the massses of water.
The gravational force of the moon is 1 ten-millionth that of earth, but when combined with other forces such as the earths centrifical force created by its spinning you get tides.
The suns gravitional force on the earth is only 46% of the moon.
Making the moon the single most important factor for the action of tides.
Twice a month new/full the sun-moon-earth line up, which creates the greatest pull.
The rising tide is slower then the ebb.
regards

[CHRIS_aka_GWH]

just for the kids so we keep the science right....

gravity - the force between two masses, any two masses they do not have to be in motion (spinning, rotating etc) - its #an attraction - almost all objects in the universe are falling toward another - that merry dance is what started the whole spinning orbit thing

centrifugal force - the force that "throws" something outward when its in circular motion. It is if fact an inertial force - the thing thrown outward just wants to keep travelling in a straight line but its on a ride that constantly changing direction to stay in a circular path.

centripetal force - it has to be there or circular motion could not exist. For every action there is an equal and opposite reaction. It is the force that acts back toward the centre. It isn't gravity. On an aside though centifugal forces & other inertial forces are used to imitate gravity.

to put simply what webby said simply #

one object (a fluid that is distendible - water) attracted by 3 others all in motion of their own & in relation to their own attraction to each other. The strongest (closest to the fluid) the earth holds the water in place the others stretch it around the earth, but the earth holds a thick layer on the side furtherest away - there is distortion at the sides. # that was simple ?!