# Nature of this pristine force

## Main Question or Discussion Point

What is the nature of this rotational force that affects all celestial bodies? What was the initial impetus? How does physics explain it?

Thank you,
ion

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mathman
I think you should try to clarify the term "rotational force". However rotations and revolutions of celestial bodies are in general a combination of inertia and gravity. In some extreme cases (e.g. our moon), the rotation and revolution periods are locked, so we always see the same face.

I know what you mean, I've been trying to figure this out as well.

I've come across this site which details the rotation time of each planet on it's axis plus the revolution time around the sun. The revolution time of each planet is as expects ie it increases the closer a planet is to the sun. Check this site out for exact figures
http://www.marsdenshs.qld.edu.au/subjects/science/junior_science/astro/solar.html [Broken]

Also another thread that might interest you is
[URL]https://www.physicsforums.com/archive/topic/1689-1.html

Hopefully someone might be able to give us a full explanation. At best I would guess a planets rotation was initiated/set by the rate of impacts on the planets surface during the creation of our solar system.

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I know what you mean, I've been trying to figure this out as well.

.......... At best I would guess a planets rotation was initiated/set by the rate of impacts on the planets surface during the creation of our solar system.

The above is very true. Many people's idea of the formation of the solar system is of 9 planets forming simply from a cloud of swirling gas orbiting the Sun. However, the system was much more dynamic than this, with proto planets colliding, enormous collisions with other large masses etc. The rotational period of a planet reflects their development history, as well as, in the case of the Earth, the effect the moon has slowing us down.
Venus was tipped almost upside down in its early history and spins very slowly the opposite way to all the other planets! Uranus is on its side too, due to collisions.

Venus was tipped almost upside down in its early history and spins very slowly the opposite way to all the other planets! Uranus is on its side too, due to collisions
Just out of interest how do astronomers know what the original axis of the planet was?