| MadSci Network: Astronomy |
Hi Ankur,
Why does the earth spin on it's own axis? Well, it is spinning because it was formed long ago from a large disc of matter orbiting the new sun. And the net effect of all of those pieces coming together was a net angular momentum (i.e. spin). And of course it spins on its own axis... an axis by definition is the imaginary line around which a rotating body turns.
As to your second question, general relativity is the theory of gravitation developed by Albert Einstein.. So the force you are looking for is gravity, although it is more accurate to say that in Einstein's theory, mass warps spacetime, and the effects of gravity are due to this warping.
Hope this helps!
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