Why is the earth and other planets rotating ?
347321
On themselves? Because of the original rotation the gigantic clouds of dust that condensed to fom galaxies had, which is probably a leftover from the Big Bang. In fact, stars rotate too, and so do galaxies and everything else.
438984
Minimally, 2.  Depending on how simplisticly we are thinking about the problem.\n\n1) the Earth rotates around it's axis\n2) the Earth revolves (orbits) around the sun\nhttp://www.ucolick.org/~bolte/AY4_00/week1/motionsC.html\n\nMaximally: ???\n3) the Earth and Moon really form a system together which revolves around the sun so there is the wobble attributable to that interaction.\nhttp://search.yahoo.com/search?ei=utf-8&fr=slv1-&p=earth%20moon%20system%20motion\n\n4) the Earth precesses about it's axis changing the tilt relative to the orbital plane\nhttp://csep10.phys.utk.edu/astr161/lect/time/precession.html\n\n5-14) Perturbations in Earth's motion due to gravitational pull from other planets (Mercury, Venus, Mars, Jupiter, Saturn, Neptune, Pluto, UB313).\n\n15) Solar system motion through the Milky Way galaxy which brings the Earth along with it\n\n16) Motion of Galaxy through the universe bringing along the solar system and earth.\n\n17) Changes in motion due to sloshing of the oceans and earthquakes.\n\n...
745488
Your presumption is entirely likely my friend.  Things in the Universe that have mass and hence gravity, tend to rotate around something else.  All plants spin on their axis, all planets orbit around the Sun, the Sun rotates around the center of our Milky Way galaxy, our galaxy rotates around other galaxies in the local cluster of galaxies, the local cluster rotates around other clusters and so on right up to the Universe itself.
736239
rotation of earth causes days and nights and also effect in high tides and low tides across the seas.\n\nrevolution of earth result into years and centuries.\n\none rotation of earth take  24hrs=1day\none revolution takes 365 days
465388
The Earth is round for the same reason that things don't fall off it.  Gravity is a force in the universe that attracts all forms of matter equally, this means that pieces of matter will eventually move together and form clumps, if this is happening from every direction then the most likely shape it will form is a sphere.\n\nThis gravitational attraction is pretty small.  However, the Earth is pretty big, so the combined effect of all that gravity is just enough to keep your feet firmly planted on the surface :)\n\nThere are a few other related effects that come into play, such as centrifugal force, which keeps everything spinning and moving.
1037575
The Earth is about 12,750 kilometers (km) in diameter.\n\nHere are some answers to some more of your questions:\n\nHow old is the earth?\nThe earth is about 4.5 billion years old. That is 45,000,000,000 years. The sun, the moon, the planets, and nearly everything in our solar system was formed at the same time, so they are all 4.5 billion years old. \nHow does the earth spin?\nIf you look around at planets, stars, and galaxies in the universe you will see that EVERYTHING spins! This is because planets like Earth (and stars and galaxies) formed from a large cloud of gas and dust. As gravity pulled the cloud together, any little bit of spin gets multiplied. This is known to scientists as the Conservation of Angular Momentum. You can try this out yourself. Find a chair that spins easily and sit on it. Start out by spinning with your arms outstretched, then pull them in to your body. Did you notice that the chair started to spin faster when you pulled your arms in? The same thing happens as the planet forms — as its gas, dust, and rocks fall together the planet spins up faster and faster. Later other things can affect the spin. Earth and the moon pull on each other, affecting both their spins and the orbit of the moon. It's quite a dance! \n\nHow fast is the earth spinning and why can't we feel it spin?\nThe circumference of (distance around) the earth is 2 x PI x radius, which turns out to be about 24,000 miles. Since the earth turns once per day (or 24 hours), that is 1,000 miles per hour! We don't feel that because everything else is moving with us and because the motion is very, very smooth. It's kind of like sitting in a car and reading a book or playing a game. If the car is going very smoothly, with no stops or bumps, and you don't look out the window, you wouldn't know you were moving. The only reason we know the earth is turning is because the sun and stars move across the sky. \n\nWhat is the exact tilt of the earth? How much does it change throughout the year?\nThe tilt of the earth is 23.45 degrees. This is measured as the tilt of the earth's equator compared to its orbit around the sun. The amount of the tilt doesn't change with time, but the direction that the earth's poles are pointed does. This is called precession. It is just like the wobbling of a spinning top. The direction that the North Pole (and South Pole) is pointed moves in a circle in the sky very slowly, completing each circle once every 26,000 years. \n\nWhy does only Earth have so much oxygen?\nThat's a very good question — no other planet in the solar system has so much oxygen. The answer is — life! Earth did not originally have a lot of free oxygen in the atmosphere. The oxygen was mostly combined with other elements to make carbon dioxide, water, or in rocks. But as early life evolved, especially plants, well they give off oxygen. So the reason we have so much oxygen in our atmosphere — and we are here and can breathe it! — is due to plant life on the earth! \n\nHow can rockets get through the earth's atmosphere, but comets can't?\nObjects hitting our atmosphere usually burn up because they are hitting it so fast. Usually they are moving at hundreds or thousands of miles per second. Rockets and the shuttle move more slowly (although pretty fast compared to cars on the highway). Here's a comparison. If you jump into a swimming pool from the high board and hit the water really hard, it stings and you make a big splash. But if you step into the water slowly, it feels fine and you make only a little ripple. The same thing happens to meteors — they hit the earth's atmosphere real hard and go splat! \n\nIf a comet hit the earth, what would happen?\nIt could cause a big explosion. The nucleus of a comet is thought to be a mile or two in size. The nucleus is made up of ice and rock, but we aren't sure how solid it is. Something that big hitting the earth from space would be bigger than
596684
The correct option is 'rotation of the earth'. When earth revolves, some part of it is directly facing the sun, and the other part is not. That explains the presence of day in one part of the world, and night in the other.
29403
The planets were formed by the same cloud of swirling rocks and dust, so when they came together and formed the planets they were all going the same direction. And actually, since the sun was made from the same stuff, it actually rotates in the same direction, though it is hard to tell because there are no surface details to see from earth without assistance to see the movement of the sun. I think astronomers see the rotation of the sun by watching sun spots. \n\nAnd actually they do not all lie in a flat plane. There is actually a small difference between the orbital planes of each of the planets.
1081261
As the earth rotates on its axis, the atmosphere is rotating with it.  Otherwise there'd be a constant wind, like in a fast-moving car on a still day,  as we were dragged through the atmosphere at the speed of the earth's rotation, yes?   And all winds would blow from east to west, and we know that's not the case.  \n\nBut the rotation of the earth does have an important effect on the weather.   A strange thing about rotating a globe is that a point on the equator has to move much faster to make it all the way around the waist of the globe in 24 hours than a point up around the Arctic circle has to move to make it all the way around the Arctic circle in 24 hours. (you can test this with a piece of string: The length of a piece of string wrapped around a globe at the level of New York is much shorter than a piece of string wrapped around the globe at the equator, right?)\n\n  You know that, looking at the globe with the sun behind your back, as the world turns, the continents pass off to the right (the east). New York crosses into the sun at dawn while San Francisco is still on the dark side of the globe.  Because the surface of the earth at the  equator is rotating faster than the surface of the earth 500 miles north of the equator, so is the air above it.  But the air above the equator isn't attached to the air above a point 500 miles north.  So the faster-moving and slower-moving air rub past each other.  This forms a kind of bow wave at the equator, like the wave that peels back from the bow of a boat as it moves through the water. Think of a big arrow pointing to the right and wrapped around  the equator.  So the air peels  back to either side of the equator, and forms a swirling current--curling counter-clockwise above the equator and clockwise below it.  This is called the coriolis wind.  It's one important factor in where weather comes from.
52855
It has to do with the direction the earth rotates on its axis. It rotates once every 24 hours. So, the direction it spins is the direction the sun passes by. The earth would have to completely stop and start to rotate in the opposite direction in order for the sun to rise in the west and set in the east. Hopefully that won't happen any time soon, because it would probably mess gravity all up.
292052
That's a really good question, that doesn't have an answer yet.  The current theory of solar system formation suggests that planets spin in coordination with the orbital spin of the disk of matter that forms the core of the solar system.  The spin of the accretion disk itself is the result of conservation of angular momentum, and can either be clockwise or counter-clockwise, which would be a relatively random process.\n\nThere are 'accidents' however, whereby planets are impacted by other large bodies in random ways and can greatly skew the planetary orbit and/or spin.\n\nSometimes the results are really weird, such as Uranus, which rotates top-to-bottom relative to the plane of our solar system.\n\nFrankly, until we're able to do a survey of planets in our galaxy and a few others, I think it would be hard to guess what the real averages would look like, and whether or not they are random.
515806
The earth rotates on its axis (spins) the same way as the sun does on its axis, since the planets all formed out of the proto-solar disc when the sun was forming.  All of the planets spin the same way, EXCEPT for Venus, which rotates (very slowly, once every 243 days) in the opposite direction.  Some planetary scientists consider this evidence that Venus at one time collided with another large body early in its lifetime, which caused the retrograde rotation.
180154
because of the differing sizes of each planet the time it takes each planet to rotate differs. we also have to factor in the speed at which each planet is rotating.
1015345
The Earth rotates on its access and revolves around the Sun.
314986
To a first-order approximation the Earth is round. This\nis due to gravity. Gravity pulls with equal strength in all\ndirections; therefore any variations from a spherical\nshape will lead to gravitational forces that\nbring the shape back into that of a sphere.\n\nThis is without considering the rotation of the earth,\nhowever. The rotation of the earth adds centrifugal\neffects, which cause the earth to bulge slightly at\nits equator and flatten slightly at its poles.\n(This is like twirling a rock on the end of a string\nand then letting go--the rock flies away from the\ntwirler.) Because of these centrifugal effects, the\ndistance from the center of the earth to the surface\nof the earth is about 0.33% shorter at the poles\ncompared to the equator.
414963
You may be referring to the Coriolis Effect, which governs the rotation of very large fluids (like weather systems on earth), due to differential forces caused by the rotation of the Earth.  In a relatively small object like a pipe (or yes, even a toilet) the direction of rotation is either random or determined by the geometry of the object.
182160
First of, there's no force causing planets to rotate. \n\n"Most of the rotation comes from the conservation of angular momentum. The formula is L=m*w*r2 where m is the mass, w is the angular velocity in radians per second, and r is the radius of the circular motion. Due to conservation of angular momentum, if the radius of the orbit decreases, then its angular velocity must increase (as the mass is constant). \n\nAnyway, the bottom line is that stars like the Sun spin from the original angular momentum that was there in the solar nebula from which it formed. Not only that, all orbital motion of the planets (including the spin) is due to this orginal angular momentum."