<p>The moon's rotation plane would precess (more) in the same direction as Earth's rotation, if the Earth spun faster.</p>

CC BY-SA 3.0
2014-04-02T11:16:29.983Z
Is the increased precession the only result of increased mass (due to higher kinetic energy)?
frodeborli
CC BY-SA 3.0
2014-04-03T10:43:47.277Z
So, an object that is spinning does not have a higher kinetic energy? And through E=mc^2 you don't get an increase in mass-energy as a result of spin? I will accept your answer if you answer that by editing your answer. :)
frodeborli
CC BY-SA 3.0
2014-04-05T20:38:22.290Z
While the answer does not claim to state that this is the only effect, which I would rely on others to comment on (eg Moon's trajectory, what else besides increased mass contributes to frame-dragging), the answer, I think, stands as an answer to the question about what happens if the Earth spun faster.
Jeremy
CC BY-SA 3.0
2014-03-13T21:15:47.920Z
2014-03-13T21:15:47.920Z
Jeremy
<p>When a planet is spinning around its own axis, it has an effect on the trajectory of its satellites. I believe it is called frame dragging.</p>

<p>Spin increases the kinetic energy of an object, contributing to its mass-energy, but some other effect must come into play as well. </p>

<p>How does one differentiate between spin and orbit velocity?</p>

<p>What is the <em>effect</em> of the spin? Lets say that Earth suddenly started spinning faster, what would happen to the moons trajectory?</p>

CC BY-SA 3.0
2014-01-10T10:27:00.163Z
I don't understand why this was downvoted? I just want to know what the *observed* physical effect of various rates of spin would be, and what causes it.
frodeborli
CC BY-SA 3.0
2014-01-13T00:34:22.473Z
I'd recommend reading http://en.wikipedia.org/wiki/Frame-dragging, http://en.wikipedia.org/wiki/Lense%E2%80%93Thirring_effect, and http://en.wikipedia.org/wiki/Kerr_metric
Gerald
CC BY-SA 3.0
2014-04-05T20:42:21.777Z
It isn't actually clear what question you are asking. Are you asking what causes frame-dragging? ('...but some other effect must come into play...'). Are you asking how to differentiate between spin and orbit velocities? Are you asking what the observable effects are if a body had a different rate of spin?
Jeremy
<rotation><general-relativity>
Rotation and relativity
frodeborli
# Rotation and relativity

(Asked by: username_0 on 2014-01-10)

When a planet is spinning around its own axis, it has an effect on the trajectory of its satellites. I believe it is called frame dragging.

Spin increases the kinetic energy of an object, contributing to its mass-energy, but some other effect must come into play as well.

How does one differentiate between spin and orbit velocity?

What is the *effect* of the spin? Lets say that Earth suddenly started spinning faster, what would happen to the moons trajectory?

**Tags:** rotation, general-relativity

> **Comments:**
> **username_0**: I don't understand why this was downvoted? I just want to know what the *observed* physical effect of various rates of spin would be, and what causes it.  
> **username_1**: I'd recommend reading http://en.wikipedia.org/wiki/Frame-dragging, http://en.wikipedia.org/wiki/Lense%E2%80%93Thirring_effect, and http://en.wikipedia.org/wiki/Kerr_metric  
> **username_2**: It isn't actually clear what question you are asking. Are you asking what causes frame-dragging? ('...but some other effect must come into play...'). Are you asking how to differentiate between spin and orbit velocities? Are you asking what the observable effects are if a body had a different rate of spin?  

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## 1 answers

### Answer by username_2 on 2014-03-13. Score: 1

The moon's rotation plane would precess (more) in the same direction as Earth's rotation, if the Earth spun faster.

> **Comments:**
> **username_0**: Is the increased precession the only result of increased mass (due to higher kinetic energy)?  
> **username_0**: So, an object that is spinning does not have a higher kinetic energy? And through E=mc^2 you don't get an increase in mass-energy as a result of spin? I will accept your answer if you answer that by editing your answer. :)  
> **username_2**: While the answer does not claim to state that this is the only effect, which I would rely on others to comment on (eg Moon's trajectory, what else besides increased mass contributes to frame-dragging), the answer, I think, stands as an answer to the question about what happens if the Earth spun faster.  

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