Why does the Earth spin on its axis?

Answer 1

The answer depends on how one reads your question.

The spin creates the axis. First the Earth spins. The imaginary line down the center of the spin is the axis.

Or, I could read the question as asking why the Earth spins.

The earth and othe planets were formed from the huge mass of materials and gasses that gathered around the sun. The huge mass of the sun's gravity attracted this material. The sun, and neighboring stars all spin and orbit aroung this galaxy's central mass.

As the material around our sun continued to gather and spin around the star, the spin tended to flatten the material into a vaguely disc form. The bigger pieced attracted othe pieces and continued to spin, gathering even more and more material. As the pieces grew larger, the gravitational pull of each peice grew stronger. The more mass, the more stable the spin.

Billions of years and the planets continue to spin around each of their own axes.

Try this experiment. Take a large bucket or tub of water. Swirl your and around the inside in one direction. Start the water spinnin around in the tub. Drop in a few flower petals, or small leaves. Watch them float around the center of the water and see if they remain stable, or if they begin to spin while they go around.

Answer 2

CONSERVATION OF ANGULAR MOMENTUM

There is a physical quantity, called angular momentum. It measures how, from a given fixed point, something else appears to be rotating around that point.

Angular momentum is conserved--that means if you start with some, no matter how you rearrange your system of particles, the angular momentum remains the same.

So, as you know by now, the earth condensed out of a primordial dustty cloud--along with the rest of the solar system. This dust cloud had some net rotation, about the eventual center of mass of the earth, and the earth, being just a rearrangement of these primordial particles, must exhibit their angular momentum.

There are some complications due to the fact that the earth is not really isolated from the other bodies of the solar system, so that these can exchange angular momentum by exerting torques on each other, but this is the basic idea.

Answer 3

It's kind of been said already, but just to make it clear, the Earth does NOT need to be spinning for it to have gravity. All it depends on is its mass.

Answer 4

Before there was a star here, there was a big cloud of dust. The Sun and all the planets condensed from it. The cloud of dust was rotating, and the law of conservation of angular momentum made that motion carry into all of the objects that formed out of that cloud.

That cloud of dust was the stellar nebula of a star that went supernova around this area. Because the cloud of dust was rotating, so was the star that it exploded from.

The galaxy is rotating.

Most likely, the original singularity from which the Universe exploded, the source of the Big Bang, was rotating, and all angular rotation is a remnant of that.

The Universe itself is probably rotating.

Now to find a place to stand to watch it.

Answer 5

According to an old song "it's love that makes the world go round"

Answer 6

um
because if it spun on a point in the world we would spin round randomly and we would have weird light and seasons!!

Answer 7

the sun gravity

Answer 8

The universe cannot be rotating because theres no "space" for it to be rotating in...

Answer 9

To create gravity.

Answer 10

so that it stays in one place