Why does the earth not rotate around its own axis at the same speed as it revolves around the sun?
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Smaller bodies are more readily affected than are larger bodies, and closer bodies are more readily affected than farther bodies.  Many of the moons in the solar system are locked to their planets in much the same way that our moon is locked with earth.  Pluto and its moon Charon are thought to both be locked to each other.  The constant pull of our moon is actually slowing the earth down slowly but surely with every tide.  It will take billions of years, and the sun will likely burn us to a cinder before we get locked in with the moon, but it is happening.  As for why the sun doesn't lock us in, well, the moon kind of saves us from that.  If we were spinning more slowly than the moon was rotating around us, it would try to pull us faster to reach equilibrium (though the earth would succeed in slowing its rotation down (and into an ever deteriorating orbit...probably why we don't see any examples of this in nature) more than it would succeed in speeding us up).  In fact, we are slowly imparting more speed to the moon with every rotation, and the moon is expanding its orbital radius in every rotation as a result.  Given enough time, it would escape.\n     If we had no moon to keep us "spun up", the sun would  probably have a little more effect on us.  Mercury, though not locked with the same face towards the sun, is rotating very very slowly, likely due to the same forces that we are talking about.  Venus is rotating even more slowly than Mercury...and in retrograde (some believe as a vestige of some primordial collision).  Again, given enough time the sun would probably succeed in locking both Venus and Mercury...but time is not on the sun's side.  It will likely reach it's red giant stage (vaporizing both Mercury and Venus as well as Earth) before it succeeds in "locking them in".
168503
Finally, the gravitational pull between the Earth and Sun causes the Earth to travel around, or "orbit", the Sun at a velocity of 29.8 km/sec. At the same time, the Earth also turns on its axis causing the daily cycle of day and night. This "rotational velocity" is approximately .47 km/sec. That means that at the same time we're hurdling through space at nearly 67,000 mph, we're also spinning around in circles at over 1000 mph! Whew! Almost makes you dizzy, doesn't it?
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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.
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The Earth rotates counter-clockwise when viewed from above the North Pole. \n\nThe rotation causes a centrifugal force, which causes the bulge of the equator, and a coriolis force, which is important in determining the flow of jet streams in the atmosphere and currents in the ocean.
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Consider that the Earth moves around the Sun because of gravity, like a ball on a rope moves around your hand when you swing it.\n\nNow, consider some of the laws of gravity (in english):\nCloser objects = more gravity to eachother\nBIGGER objects = more gravity to them\n\nThe Earth is 1/100000(lots of 0's, maybe more) the size of the Sun, so we really don't affect it much, but it keeps us going around it like nuts! (once a year, right?)\n\nThe Moon, however, is not sooooo different from the size of the Earth (yes it's smaller, but not 1/10000etc(like the Earth vs. Sun thing), AND it's CLOSER to the Earth than the Sun is (WAY CLOSER)!\n\nSo because it's kindda nearer to our size, and it's kindda close, it's got 2 big check-marks for LOTS-O-Gravity!
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Earth revolves around the sun because the giant nebula out of which the solar system formed was spinning and the angular momentum is conserved, and earth spins because of the initial config. Why it revolves in an ellipse, see this\nexplanation at http://www.mathsnet.net/cabri/feynman.html
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It is more like falling around the Sun. Earth is always falling into the Sun, but it's sideways orbital speed keeps moving Earth to the side of it's direction of fall. So the direction it would have to fall to hit the sun is different and Earth has to start over to get up speed falling in the new direction. This just keeps going on forever, falling toward the Sun but always missing it to one side. Of course, this takes enormous speed on the part of the Earth, about 66,000 miles per hour sideways all the time.
876446
The sun rotates on its own axis that what causes the gavational pull to keep the planets moving around it.
467215
Spin relative to what?\n\nThe spin of the Earth about its own axis causes day and night but only because the spin is not synchronised with the orbit of the axis around the sun.  Mercury spins once on its axis for every orbit and so always has the same face to the sun.  It could be said in this case that Mercury does not spin, but that is only relative to the orbit of Mercury.\n\nImagine a frame of reference that is fixed in space like the grid lines on a map.  If a planet did not spin on its axis relative to this reference, then it would have a day/night cycle that took one orbit to complete (this would be one year for the Earth).\n\nIt is also believed that the spin of the Earth contributes to the generation of the magnetic field, so if the spinning stopped or slowed (relative to any reference) we could loose the magnetic field and thus be exposed to higher radiation levels from the sun.
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Earth orbits in a counterclock wise direction around the sun.\nIt takes approximately 365.25 days do orbit around the sun.\nThe gravitational forces between the sun and earth and the resulting centripetal and centrufugal forces makes the earth go around.
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That's because the Earth's spin is caused by electromagnetics.  Something about the electrical properties of these gasses in our atmosphere causes them to be spun around faster than the rest of the Earth.
20798
The Earth spins from west to east at about 900 mph. Looking from above the Earth's North Pole, the Earth rotates counter-clockwise around the Sun.
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Time is unconnected to the Earth.  The only immediately noticeable differences between normal Earth and a backward rotating Earth (NOT counting the moment during which the Earth stops spinning) is that water will circulate in the opposite direction in the ocean, counterclockwise instead of clockwise, and storms will rotate across the Earth in a different directional tendency.
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There are a lot of variables to consider.  First, lets assume the Earth's rotational axis is a line more or less on the same plane as the Earth's orbit around the Sun instead of the existing axis alignment which is more or less perpendicular to the plane of the Earth's orbit.  Then, lets assume the Earth has the same axial rotation rate it does now, that is, one complete revolution around the rotational axis every 24 hours or so.  Next, lets assume the new rotational axis is fixed.  An easy was to visualize this scenario would be to see the Earth orbiting around the Sun's poles instead of it's equator.  Finally, lets assume you are standing at teh South Pole.  Let's start with the Earth at 12:00, directly above the Sun's North Pole.  The Earth's southern hemisphere would be bathed in sunlight with the South Pole being closest to the Sun.  The Earth's rotational axis would be pointing straight at the Sun from the South Pole.  The Earth's Northern Hemisphere would be in total darkness.  The Earth would still be rotating once about every 24 hours, but at the Earth's South Pole, the Sun would be directly overhead, like at high noon.  It would stay that way for a month, until the Earth moved to 1:00, then the Sun would appear to move about 1/3 of the way down in the sky from high noon to the horizon. and would completely circle the sky every 24 hours, staying at that position all the way around.  It would stay that way for about another month until the Earth moved to 2:00 around the Sun. Then the Sun would appear to be only 1/3 the way above the horizon, and would circle the sky at that level for about another month.   At 3:00 in the Earth's orbit around the Sun, the Earth's rotational axis would be perpendicular to the Sun and parallel with the Earth's orbital path.  Again from the Earth's South Pole, you would have a virtual perpetual dawn with the Sun apparent on the horizon but never quite coming into view.  It would appear that the Sun was circling just below the horizon every 24 hours.  The view from the Earth's North Pole would be the same, except the Sun would appear to be circling the opposite direction just below the horizon.  It would stay this way for about a month, then would reverse the process with the North Pole becoming brighter as the Sun seems to be slowly spiraling up in the sky until the Earth reaches the 6:00 point in it's orbit around the Sun.  At this time, the North pole would be pointing directly at the Sun and it would appear to be high noon at the North Pole for about another month.  The same would happen as the Earth orbits around the Sun from 6:00 to 12:00 only in reverse, with the North Pole getting slowly darker as the Sun appears to slowly spiral down in the sky until it sinks below the northern horizon and starts to slowly spiral back up the sky in the southern hemisphere.  Of course, summer at either of the Earth's poles would be a real scorcher, especially as the Sun climbed high into the sky for months at a time.  The opposite effect would occur on the other side of the Earth, as things started getting colder, until the Sun just disappeared for about 6 months at a time.  \n\nFor folks on the Earth's equator, the Sun would appear to be standing still just below the southern horizon at Earth's 12:00 position in orbit around the Sun.  As the Earth moved in orbit around the Sun, the Sun's rising and setting arc would rise every day until the Earth reached 3:00 in it's orbit around the Sun, then the Sun would be rising and setting in an arc directly overhead and appear much as it does today in mid summer, with 24 hour days and a sunrise and sunset every day.  \n\nProbably the best bet for human survival in such conditions, people would need to be nomads and travel between the equator and the Earth's 30th parallels north and south, following the Sun as it moves over the sky.  Probably wouldn't be much water
739091
because the earth rotates on an axis
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Yes, as long as definitions are consistent.\n\nThe Moon rotates from west to east, the same direction that it revolves around the earth. At its equator, the Moon rotates at a speed of about 10 miles (16 kilometers) per hour. \n\nThe Earth rotates on its axis from West to East with its axis in the North/South direction.\n\nIt is sometimes thought that the Moon does not rotate, because it always presents the same face (roughly) to a point on Earth. However this is because the time it takes to complete one rotation is almost the same as the time it takes to complete one revolution around the earth; not because it does not rotate.