why does the earth spin?

Question

i know why, just is kinda confusing

Answer 1

Philip, that's false information. The fact that one face of the moon is always looking towards the Earth does not mean the moon doesn't spin. The phenomena is called Synchronous Rotation, and it means that a body takes as long to rotate on it's axis, as it takes to rotate arround another body. The same goes for Mercury. In fact, it's extremely rare to find an astronomical object that is not spinning.

And no, Earth rotation was not caused by an asteroid, it is possible that it contributed to our 24 hour period, but that's about it. Also, due to tidal locking, within billions of years one face of the Earth will be looking towards the Sun at all times, but Earth will still be spinning, and will keep doing so until it's evaporated, or loses orbit due to the Sun becoming a Red giant.

Why do objects spin in space?
Answer is simple: Angular Momentum.

In the beggining, there was nothing, then there was the Big Bang, and as a consecuence of the big bang, there was gas and dust spreading through the universe. That means gas and dust were moving everywhere, and since gravity did it's job correctly, particles started condensating into bigger solids. Bigger solids attracted even more dust.

Now, imagine what happens if a comet comes close to Earth? It's motion will be affected due to Earth's gravity, and if we look at it's trayectory, we would see an arc. Well, the very same happens to particles of dust that come accross an object of bigger mass, their trajectory forms an arc when they come close to other objects. If the particles can't scape the gravity field from those bigger objects, then they would stay on a circular motion arround the bigger mass.

With time, the mass of the object the particles were rotatig about got bigger and bigger. That means that due to gravity, the particles that were in orbit started falling towards the cnter of gravity/rotation, in other words the distance from the center of rotation to a particular molecule, got smaller and smaller. Angular Momentum states that if the mass of an object(in this case all the mass from the dust particles rotating around a common origen) get closer and closer to the center of rotation, then the angular momentum increases - meaning, everything starts rotating faster.
The dust particles came so close to the center of rotation, that it was dense enough to form planets, galaxies, etc, and since there was no force stopping those molecules from building angular momentum, then we have spinning stuff all over the universe.

Answer 2

Wow, what a neat question. I think it is related to the effect that
we have seen when a skater who has arms extended and is slowly spinning
suddenly pullls the arms into the body surface. The result is that
spin rate increases. To even spin faster the skater will be standing
straight with the arms up over the head. This makes the distributions
of mass as close toe the spin axis as possible and makes the spin
as large as possible. The main idea is that angular momentum is conseved
, ie, cannot change. Angular momentum is the product of the spin rate
adn the moment of inertia ( a measure of the distribution of the mass about
the axis of rotation) The product is constant. If mass is widely dispersed
as before condensing into a planet, and is very slowly rotating, then
when it condenses into a planet (making a small moment of inertia) the
rate of rotation could be large. So condensing amplifies whatever
rotation there was initially. NOw, what are the chances of something
not rotating exactly before it condenses? Apparently, very small since
everything seems to have some rotation. I am not sure this gets to your
question of why, but it has been a great question to think about

Answer 3

Wow, what a neat question. i think of it is with regards to the end result that we've considered whilst a skater who has hands prolonged and is slowly spinning unexpectedly pullls the hands into the physique floor. the end result's that spin fee will strengthen. To even spin quicker the skater would be status quickly with the hands up over the pinnacle. This makes the distributions of mass as close toe the spin axis as available and makes the spin as large as available. the main theory is that ANGULAR MOMENTUM is conseved , ie, won't be able to alter. Angular momentum is the made from the spin fee adn the 2d of inertia ( a level of the distribution of the mass with regards to the axis of rotation) The product is persevering with. If mass is broadly dispersed as formerly condensing right into a planet, and is amazingly slowly rotating, then whilst it condenses right into a planet (making a small 2d of inertia) the fee of rotation would desire to be large. So condensing amplifies in spite of rotation there became initially. NOw, what are the possibilities of a few thing not rotating precisely formerly it condenses? curiously, very small because of the fact each and every thing seems to have some rotation. i'm uncertain this gets on your question of why, regardless of the undeniable fact that it relatively is been a large question to think of approximately.

Answer 4

Earth spins because of the way it was formed. Our solar system formed about 4.6 billion years ago when a huge cloud of gas and dust started to collapse under its own gravity. As the cloud collapsed, it started to spin. Some of the material within this cloud gathered into swirling eddies and eventually formed into planets. As the planets formed they kept this spinning motion. This is similar to what you see when skaters pull in their arms and spin faster. As material gathered in more closely to form a planet, like Earth, the material spun faster. The Earth keeps on spinning because there are no forces acting to stop it.

Answer 5

Earth spins because of the way it was formed. Our solar system formed about 4.6 billion years ago when a huge cloud of gas and dust started to collapse under its own gravity. As the cloud collapsed, it started to spin. Some of the material within this cloud gathered into swirling eddies and eventually formed into planets. As the planets formed they kept this spinning motion. This is similar to what you see when skaters pull in their arms and spin faster. As material gathered in more closely to form a planet, like Earth, the material spun faster. The Earth keeps on spinning because there are no forces acting to stop it.

Answer 6

Not all planets spin.
Mercury keeps its same face toward the sun at all times, similar to our Moon which keeps its same face toward the earth at all times.
Spinning is NOT a requirement for planets.
The cause of earth's spin and its spin rate is still a debatable issue.
One theory is that the mass of the earth was once much greater and that the Earth was struck by a huge asteroid blasting away a large chunk of the mass. Because of the angle of the imp[act, the force imparted a spin which was initially faster than it is today.
There is also evidence that the rate of spin is gradually slowing, but so gradually that it won't be noticeable within one lifetime.

Answer 7

It spins to sustain equilibrium. That is, to stay revolving around the sun in a stable path.

Answer 8

IT SPINS SO YOU DONT HAVE TO

Answer 9

Mainly because it can't stop.