Could Mountains Act as Wheel Weights for Earth's Rotation?

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Mountains could theoretically influence Earth's rotation by affecting its mass distribution, similar to how wheel weights balance a car's rotation. However, the Earth inherently rotates around its center of mass, which prevents violent shaking during rotation. Earthquakes can shift the planet's rotation axis, demonstrating that mass distribution changes can impact rotation. The Earth primarily rotates around the center of mass of the Earth-Moon system, with various orbital cycles influencing its motion. Overall, while mass distribution affects rotation, the Earth's rotation remains stable despite these changes.
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Hello there!

Car wheels need some little sticky wieghts to ajust their moment of inertia in such way its rotation gets balanced.
As for the Earth since it's not uniform in mass, could the presence of mountains play the same role as wheel weight in ajusting Earth's rotation axis with its principal axis of inertia, lest our planet can shake violently while it's spinning?
 
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The reaon that car wheels etc shake when spinning is because they are forced to rotate about a fixed axis (the axle of the wheel). The purpose of the balance weights is to move the center of mass to the same place as the axis of rotation.

A free body in space like the Earth always rotates about its own center of mass, wherever that happens to be inside the body. So it will never "shake violently" while rotating, whatever shape it is.
 
true, but earthquakes have been known to shift the rotation of the planet. Let's not forget though, that the Earth rotates around the COM of the earth-moon system for the most part.
 
Thank you for your answers!


AlephZero,
what you state implies that if something somehow managed to shift Earth's axis of inertia (by a sudden bad mass distribution), our planet rotation-axis would ajust itself to make the Earth spin around its new axis of inertia?
 
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That's correct. Earthquakes are an example of that.
 
EinsteinKillr said:
Let's not forget though, that the Earth rotates around the COM of the earth-moon system for the most part.
What is "the most part"? :smile:

The Earth spins in 24h periods around its own COM, which orbits in 28day periods around the the COM of the earth-moon system, which orbits in 1year periods around the sun, which orbits around the center of tha galaxy...
 
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