Why dosent ? the moon rotate

B

buddieboy

Registered Senior Member
I take it the moon is heavier: on the side closest to the earth:...? so .....
that would possibly slow it to a non rotation dew to rotation balance
ok ? but why hasnt it been started rotating by asteroid collision?
shouldnt the moon rotate? it cetainly must have rotated when forming from
molton magma to have formed so round is the center of the ,moon cold /solid
if so then then shouldnt the earths rotatoin spin the moon i dont know but
this seems weird wealways see the same side of the moon but i dont think thar is a one sided answer as to why the moon dosent rotate as well as revolve
 
You're not right at all which is probably why your thread is here in Pseudoscience. The moon does rotate, just not on it's axis. The moon is in orbit with the earth, we might well see one side constantly because of the Gravitational effect of both the moon and earth combining, however if you were to observe the moon from another planet, you'd probably see 3/4's of it's surface as it rotates from it's orbit.

To my knowledge (obviously feel free to surf the internet to check on it), the reason that it doesn't spin on it's axis is because of it's size. Since it's small it's cooled relatively quickly compared to the earth, this means that it's core isn't as molten as the earth, therefore gravity is effecting a mostly solid mass rather than a solid crust and molten core. I guess you could say the earth spins because it has both a moon and magma flow.
 
buddieboy said:
I take it the moon is heavier: on the side closest to the earth:...? so .....
that would possibly slow it to a non rotation dew to rotation balance
ok ? but why hasnt it been started rotating by asteroid collision?
shouldnt the moon rotate? it cetainly must have rotated when forming from
molton magma to have formed so round is the center of the ,moon cold /solid
if so then then shouldnt the earths rotatoin spin the moon i dont know but
this seems weird wealways see the same side of the moon but i dont think thar is a one sided answer as to why the moon dosent rotate as well as revolve
Click to expand...

Without going into any of the details at all, it's actually quite easy to tell that the Moon does rotate. If it didn't, we'd see the back and sides as it revolved around the Earth.;)
 
Stryder said:
To my knowledge (obviously feel free to surf the internet to check on it), the reason that it doesn't spin on it's axis is because of it's size. Since it's small it's cooled relatively quickly compared to the earth, this means that it's core isn't as molten as the earth, therefore gravity is effecting a mostly solid mass rather than a solid crust and molten core. I guess you could say the earth spins because it has both a moon and magma flow.
Click to expand...

Hi, Stryder,

Just a minor point of correction. The Moon and magma flow has nothing to do with causing Earth to rotate. It began rotating as it was formed from an accretion disk due to conservation of angular momentum. (That's why all the planets and even the Sun rotates.)
 
Stryder said:
To my knowledge (obviously feel free to surf the internet to check on it), the reason that it doesn't spin on it's axis is because of it's size.
Click to expand...
Wrong. It does spin on its axis, it's just that its rate of spin coincides with the time it takes to revolve around the Earth (as ReadOnly has pointed out.) This is due to tidal locking between the Earth and the moon.
 
Read-Only said:
Hi, Stryder,

Just a minor point of correction. The Moon and magma flow has nothing to do with causing Earth to rotate. It began rotating as it was formed from an accretion disk due to conservation of angular momentum. (That's why all the planets and even the Sun rotates.)
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But then you have to explain why Venus and Uranus have retrograde rotation.
 
Ophiolite said:
Wrong. It does spin on its axis, it's just that its rate of spin coincides with the time it takes to revolve around the Earth (as ReadOnly has pointed out.) This is due to tidal locking between the Earth and the moon.
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Ophiolite, In honesty if you were to model it's spin it wouldn't be on it's axis, it's spin would actually be on the earth's axis at least from 3D modelling. (actually to be honest, it's axis, the earths axis, even the suns axis wouldn't be a static point of pivot, but it's all relative really) Although to be perfectly honest, as I statement in my initial message "surf the internet yourself", it's not up to me to give a correct definition, it's up to the original OP to search out other evidence and come to a conclusion. (considering most people post here without references we'd be Third-person or worse evidence, notoriously unreliable.)
 
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I think it rotates with the Earth because it came from the Earth. If it was a separate body captured by Earth's gravity, it would have it's own rotational speed, independent of our's.
 
buddieboy said:
shouldnt the moon rotate?
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The moon is rotating with respect to inertial an inertial reference frame, one revolution per sidereal month.

The moon isn't rotating from the perspective of an Earth-fixed observer because it is tidally locked with respect to the Earth.

spidergoat said:
I think it rotates with the Earth because it came from the Earth.
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This is not the consensus view. It flies in the face of observed data and common sense. Latter problem first: What could have made the Earth rotate so fast as to split off a piece of itself to form the Moon? The other problem: The Moon's orbit is not in the Earth's equatorial plane.

If it was a separate body captured by Earth's gravity, it would have it's own rotational speed, independent of our's.
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You are ignoring gravity gradient torque.
 
buddieboy said:
I take it the moon is heavier: on the side closest to the earth:...?
Click to expand...

That is marginally true, I think, but it is not the reason why the moon always faces the same side towards Earth. If anything, it is a consequence of that.

but why hasnt it been started rotating by asteroid collision?
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You'd need a very large asteroid to significantly affect the rotation. And any rotation that started would gradually be damped out again.

shouldnt the moon rotate?
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It does! It rotates about its axis about once a month - the same amount of time it takes to revolve once around the Earth.

The reason for this is that the Earth creates tides on the Moon (tides of land, not water, and not as large as the water tides we see on Earth). These tides tend to slow the Moon's rotation until it is synchronised with its revolution around the Earth.

Stryder said:
The moon does rotate, just not on it's axis.
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It does rotate on its axis (relative to the distant stars) - once every month.

To my knowledge (obviously feel free to surf the internet to check on it), the reason that it doesn't spin on it's axis is because of it's size. Since it's small it's cooled relatively quickly compared to the earth, this means that it's core isn't as molten as the earth, therefore gravity is effecting a mostly solid mass rather than a solid crust and molten core. I guess you could say the earth spins because it has both a moon and magma flow.
Click to expand...

This is wrong. The Moon originally would have rotated faster, but tidal forces have caused its rotation to slow and become locked with its revolution around the Earth. Mars, like the Moon, probably doesn't have a molten core, but it rotates just like the Earth. Rotation has nothing to do with magma flow.

Stryder said:
Ophiolite, In honesty if you were to model it's spin it wouldn't be on it's axis, it's spin would actually be on the earth's axis at least from 3D modelling.
Click to expand...

In astronomy, spin on its axis is called "rotation". Orbiting around another object is called "revolution". The moon both rotates and revolves around the Earth.

spidergoat said:
I think it rotates with the Earth because it came from the Earth. If it was a separate body captured by Earth's gravity, it would have it's own rotational speed, independent of our's.
Click to expand...

For a while, but tidal locking would still apply over time.
 
James R said:
It does! It rotates about its axis about once a month - the same amount of time it takes to revolve once around the Earth.

The reason for this is that the Earth creates tides on the Moon (tides of land, not water, and not as large as the water tides we see on Earth). These tides tend to slow the Moon's rotation until it is synchronised with its revolution around the Earth.
Click to expand...

^ Evidence that the universe tends towards order and not chaos. :cool:
 
buddieboy said:
I take it the moon is heavier: on the side closest to the earth:...? so .....
that would possibly slow it to a non rotation dew to rotation balance
ok ? but why hasnt it been started rotating by asteroid collision?
shouldnt the moon rotate? it cetainly must have rotated when forming from
molton magma to have formed so round is the center of the ,moon cold /solid
if so then then shouldnt the earths rotatoin spin the moon i dont know but
this seems weird wealways see the same side of the moon but i dont think thar is a one sided answer as to why the moon dosent rotate as well as revolve
Click to expand...

it is because the earth and moon are exchanging energy

see casimir

it is the same reason the observations of galaxies show that some stars are moving far too fast on the outer portions, than what the math predicted with a black hole in the middle of the galaxies

The rotation curve of a galaxy can be represented by a graph that plots the orbital velocity of the stars or gas in the galaxy on the y-axis against the distance from the center of the galaxy on the x-axis. Stars revolve around the center of galaxies at a constant speed over a large range of distances from the center of the galaxy. Thus they revolve much faster than would be expected if they were in a free Newtonian potential. The galaxy rotation problem is this discrepancy between the observed rotation speeds of matter in the disk portions of spiral galaxies and the predictions of Newtonian dynamics considering the visible mass. This discrepancy is currently thought to betray the presence of dark matter that permeates the galaxy and extends into the galaxy's halo. An alternative (less favored) explanation is a modification of the laws of gravity
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http://en.wikipedia.org/wiki/Galaxy_rotation_curve

the mass at them close points between the arms is associating (exchanging energy)

the gravity comes from the entangled energy between structures, the more they associate the greater the potential (casimir)

here is science on the subject

http://www.weizmann.ac.il/chemphys/gershon/rand_scat.html
 
James R said:
In astronomy, spin on its axis is called "rotation". Orbiting around another object is called "revolution". The moon both rotates and revolves around the Earth.
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Ty kindly for the correction :)
 
Stryder said:
Ophiolite, In honesty if you were to model it's spin it wouldn't be on it's axis, it's spin would actually be on the earth's axis at least from 3D modelling. (actually to be honest, it's axis, the earths axis, even the suns axis wouldn't be a static point of pivot, but it's all relative really)
Click to expand...
If I stand at the north pole of the moon the stars will turn around me. so the moon does revolve on its axis. The only reference frame that matters for discussing the revolution of a body is one centred on the body.
 
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