Sun attracts earth by gravitation. And similarly every heavenly body attracts others. But why are they rotating? The sun is moving in ellipse in the galaxy, the earth is rotating and revolving and same for other planets. Why aren't they stationary?
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Qmechanic
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George carlin
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inertia... This is also the force that keeps the Earth(and other planets in our solar system) from going towards the sun, or whatever they are orbiting. Unless you're talking about why the Earth revolves spins around its axis. – TheGodlyBeast Mar 12 '20 at 04:01
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If they were not orbiting, then they would just drop straight down into each other. The angular momentum is what keeps it all from being just one big lump. As for why the momentum - pick a random clump of matter, it's rotating. Non rotation is a very special and unusual state. – Ponder Stibbons Mar 12 '20 at 04:05
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Possible duplicates: https://physics.stackexchange.com/q/12140/2451 and links therein. – Qmechanic Mar 12 '20 at 06:43
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The rotation of planets comes from the fact that angular momentum is conserved. When the planets are formed the individual parts have some rotation, whose total effect is added up to give the planet some net rotational angular momentum, which is now conserved/it changes very slowly. Now there is a very low chance that the net rotational angular momentum which the planet accumulates as it is formed is zero, hence we find the planets to be rotating.
SK Dash
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Once there is a force, there is also an acceleration (by Newton's second law). Once you have acceleration, you don't expect things to be stationary. After all, acceleration is the second derivative of the position $x$ with time, $d^2x/dt^2$.
Allure
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