Expert: Tom Whiting - 1/12/2011

Question
Why do , at first place ,

a)things start orbiting around the earth (means under what circumstances/influence of forces and why this orbiting starts) when sent in space just like moon around earth and earth around sun?

a1)why do electrons revolve around nucleus?

b)why do earth revolves on its own axis?

c)why orbits are elliptical?

Answer
Why (and Who?) are philosophical, or theological questions;  Why is Saturn here? Why are we here?
Who put us here? Who put Saturn here? Why is the Earth here?
Science answers the questions... How? What? And especially, by what process? or by what mechanism?  Science does not answer the "Why and Who?" because those questions are out of our field; you'll have to ask your Religious Leader for answers to those questions... of Why? and Who?

We in science stay out of 'their territory' and hopefully, they stay out of our territory, like how, or by what process, did we get here? (By process of Big Bang and Evolution.)  Sometimes they don't stay out of (or overlap into) our territory... so anytime either side crosses over from their own expertise, there is always big trouble and fireworks. So we in science don't answer the questions, who and why... as that is THEIR field. If we stay out of their field, maybe they will some day, give us the courtesy of staying out of our territory also.... the how, what, and especially... by what process... science only, questions.
Besides, One could always answer all your 'why' questions with.... "Why Not?; you got a better idea?"
Clear Skies,
Tom Whiting
Erie, PA USA
PS...Oh, and by the way, the Earth 'rotates' on it's axis. Revolution is motion of one body around another body, like around the sun... the Earth revolves around the sun, but it ROTATES on it's axis. Normally there is no difference, but in astronomy (and physics also) there is a big difference to those separate words. Rotation is motion around an axis.

The planets are as they are because some 4.6 - 5 billion years ago, they condensed and contracted out of a spinning interstellar cloud that already had rotation around it's center as it began to collapse. Thus as the matter coalesced into planets, the planets simply continued with that revolution around the sun, and a spin on their axes. The spin presumably developed as eddies and currents in the primordial cloud developed, and the planets just continued with that rotational speed around their axis at their formation. Meanwhile the central sun captured 99.86% of the matter in the newly developed Solar System, Jupiter grabbed 0.1%, and all the other stuff, including the Earth, make up the lowly 0.04% of the mass of the Solar System, that remained.