Maybe some one can answer this question.

I am sure it has been solved many many times before.

Simpy put:
Why doesn't the moon rotate on an axis?
Why is it's face always pointed to earth? ( I am correct in this statement ...I hope?)

Maybe some one can answer this question.

I am sure it has been solved many many times before.

Simpy put:
Why doesn't the moon rotate on an axis?
Why is it's face always pointed to earth? ( I am correct in this statement ...I hope?)

Actually you asked two questions. :D

Which one do you want answered? HeHe.

In reality one answer is for both questions. It does rotate on its axis once per lunar orbit around the earth.

Your question should be why is the moons orbit and rotation synchronized as it is.

I don't have that answer.

hmmmmmm ok let me rephrase the question...hmmmmm
"why is the moons orbit and rotation synchronised as it is? (ha)

hmmmmmm ok let me rephrase the question...hmmmmm
"why is the moons orbit and rotation synchronised as it is? (ha)

It's due to tidal force. I suggest you to look up the information in the Internet. You will surely find a lot of information.

The earth rotates 356.25 times per obit of the sun.
Why does the moon only rotate once and not more?

Why would tidal force stop the moon from rotating more than once per orbit of the earth on an axis of it's own?

Is the moon heavier on the face thats constantly "looking " at us?

The moon rotates once every 28 days or so - the same time it takes to go around the Earth.

The tidal force of the Earth on the moon causes the moon to "bulge" a little towards the Earth, so that instead of it being spherical, the moon is more of an ellipsoid. In the past, the moon rotated faster than it does today, and the tidal bulge was therefore a little ahead of the imaginary line joining the centre of the Earth to the centre of the Moon. The gravity of the Earth therefore tended to pull backwards on the bulge, which meant the rotational rate of the Moon gradually decreased until the bulge was aligned. This is why the Moon always points the same side towards Earth.

The same general process tends to cause "tidal locking" of the rotation rates of all solid orbiting bodies, given a long enough period. For example, if the Earth lasted long enough, eventually it would end up with one side always facing the Sun.

The Moon is not heavier on one side than the other.

do other moons studied within the solar system also rotate once per orbit?
(BTW thanks James)

Yes, there are a few, QQ.

One example, I think, is Jupiter's moon Io, which is the closest of the four "Galilean" moons to the planet.

do other moons studied within the solar system also rotate once per orbit?
(BTW thanks James)

Yes, 24 are known to, and 3 are known not to. For the rest (the majority), we don't have enough info to determine rotational rates yet.

the moon's core and the mantle is off-centre facing the earth.

http://www.olemiss.edu/courses/astr103/Topics-Solar/Moon-N.html

Interesting, Boris2. But which came first - the tidal locking or the off-centre core? I think probably the tidal locking.

Pluto and Charon are tidally locked to each other.
The same face of Pluto always faces Charon, and vice versa.

>> the moon's core and the mantle is off-centre facing the earth.

yep this is the reason IMO.... tidal locking is crap.

Because the Moon is relatively close to Earth its field is very oblate, creating pronounced uneven forces. I suspect that travelling to the Moon is much more difficult that travelling to Mars.

However I suspect magnetism has a profound effect as well.

the moon's core and the mantle is off-centre facing the earth.
This is what I meant by asking
Is the moon heavier on the face thats constantly "looking " at us?

It seemed to me that this would be the most obvious answer, in that the mass distribution within the moon creates a situation where by the moon fails to rotate other than by the effect of orbiting the earth.
The face or heavier side constantly facing the earth due to graviational values given.

Zarkov,

Nobody cares about your opinions, unless you can support them in some way.

There are plenty of moons in the solar system with off-centre centres of mass which do not have the same side constantly facing their primary planet.

>> Nobody cares about your opinions, unless you can support them in some way.

Sorry ???? I can support my assertions mathematically, but you, JR are closed minded.
Bye

In other words what we are really saying here is that we really don't know?

James, from a casual perpective it would be fair would it not, to assume that the rotation of a body, be it a moon or a planet would in some way be influenced by where it's center of mass is? As it would be to consider tidal lock also?

Does the moon wobble as it orbits the earth? or is it's orbit really smooth and consistant, being free of "wobble"?

"Wobble" means partial rotation on an axis say 1 or 2 degrees in a form of oscillation.

Post your maths here, Zarkov.

QQ:

Yes, the rotation is influenced by the location of the centre of mass as well as by tidal effects.

I'm not sure about wobbles of the moon. I suspect that it doesn't wobble.

>> Nobody cares about your opinions, unless you can support them in some way.

Sorry ???? I can support my assertions mathematically, but you, JR are closed minded.
Bye

Zarkov, I agree with your assessment, this comment is blatantly close minded however what I think was intended would read more like:
"the seriousness that we take to your opinion is based on how it is supported"

Maybe you and James have duelled before......?

QQ:

Zarkov and I have had extensive interactions on another forum. Zarkov's standard tactic is to post unsupported assertions that accepted science is wrong. He also pretends to have an alternate theory of gravity, which is really nothing more than a disguised form of Newtonian gravity, with a few unsupported assertions about magnetism thrown in to confuse the unwary.

19] Secondary Field Systems

The reported gravity on the moon is about 1 / 6 Earth gravity so a rough estimate of.

Gcentral spin-moon = 9.81 / 6 X 10^-3 X R2

= 4.9 X 10^3 km3 sec-2

For the Earth-Moon system L1 = 71,880 km

L2 = 114,821 km

The equipotential points L1 and L2 define the inertial field density around an orbiting
body. A body orbiting the Moon would have an eccentric inertial orbit.

Mass of the Moon = Gcentral spin-moon / Gnewton

= 4.9 X 10^3 / 6.667 X 10^ -20

= 7.35 X 10^22 kg

The calculated value for mass of the Moon employing Gcentral spin and Gnewton, and the published value for the mass of the Moon are in good agreement.

Moon parameters using Gcentral spin-moon equal to 4.9 X 10^3 km3 sec-2

Earth-moon distance =384,400 km
Radius of Moon = 1,736 km
Earth field velocity at L1 = 1.13 km sec-1
Earth field velocity at L2 = 0.89 km sec-1
Effective radius (L1 X L2 ) = 90,848 km
Moon field velocity, L1 - L2 = 0.24 km sec-1
Surface field density-moon = 9.4 X 10^-7 field units / km2
( ~61% of Earth's value )

Theoretical SGV-moon = 1.74 km sec-1
Theoretical gravity-moon = 1.74 m sec-2
Theoretical radius = 1,699 km
( using B = 10^-7 field units km-2 for the calculation of theoretical radius)
Geomagnetic mass induces the same field conditions in a secondary poloidal field as it does in a primary toroidal field.

Normalised radius of Moon = conversion constant X Normalised g
= 664 X ~2.23

= 1481 km.

the mass of the Moon = Volume X Normalised density

= 4/3 π r^3 X 55 X 10^11

= 7.48 X 10^22 kg

The value for the mass of the Moon calculated from Gnewton as a field constant is in good agreement with the calculated result using Gcentral spin with Gnewton as a mass constant. For the calculations involving mass, Gnewton is pivotal to the calculations, however the use of Gnewton may be flawed, since we can only know mass as a resistance to applied non-inertial force.

Gnewton is the inertial field-mass constant of the Universe, a constant universal coupling ratio between mass and the field it induces, and it is valid in both toroidal or primary and poloidal or secondary spin frames of reference. The value of Gnewton and mass are both derived values.

Zarkov:

How is any of that relevant to your statement:

yep this is the reason IMO.... tidal locking is crap.

?

And show me how you derive Gnewton from your theory, while you're at it.

You would have to read the whole paper.
I am not posting it all.

Gravity is a PUSH, therefore no "tidal locking"

I leave you here high on your rock
bye

So, you admit that the extract you posted above is actually irrelevant. I thought so.

>> So, you admit that the extract you posted above is actually irrelevant.

Eyes wide shut, JR.... I refuse to discuss, only because you are obnoxious

Just as an aside, the magnetic nature of the Moon is observed in the repulsive effect it has on Earth's oceans, seen as tides.

For those that are open minded, a careful analysis of the section I posted re secondary field systems, will show that this IS NOT Newtonian gravitation theory, however the mechanics of the system analysed is based upon Newtonian mechanical principles.

The model is also based upon electrodynamic theory to provide a classically unexplained spin (orbital motion) and also explains why all the bodies in the Solar System are moving away from each other, explains the size of planets and so much more.

You refuse to discuss because you have nothing worth discussing.

If the moon affected the Earth magnetically to such an extent as to cause tides, our magnetic compasses would not point North all the time. Instead, they would move around as the moon moved around the Earth. This is not observed, so your magnetic theory of gravity cannot be correct.

>> You refuse to discuss because you have nothing worth discussing.
In your opinion, why are you the ears of others.

Plasma physics is unfolding and all your classical physics is up for grabs. Newton was wrong, Gr is wrong.... what have you got left?
QM is electrodynamic, and correct, as at this date.

I do understand why you are worried, Pope.

QM is relativistic, which is why it is correct.

Your saying that GR is wrong is just another unsupported assertion of yours. Or rather, merely the same one you've repeated for years.

I also post to this other forum, same one as JR and Zarkov. I would side with JR. Not that my opinion is worth much.

I'm not sure about wobbles of the moon. I suspect that it doesn't wobble.

The moon does wobble back and forth slightly. I can't seem to find a reference now, but I think we can actually see something like 60% of it's surface over one entire wobble. It's still slowing down I guess.

edit- found my reference, "The Moon Book", Kim Long. It says at any one point in time we can see 41% of the moons surface (not 50% since it's curved), but the wobbles (fancier technical name-librations) let us see almost 59%.

so that reads a wobble of about 5-8%...if I am not mistaken...that is amazing......

Hi, I added an edit with a bit more information above. Not all of the 59% comes from wobbling back and forth, apparently it's orbit is also tilted with respect to the earth, so we see higher and lower latitudes on the moon depending on where in it's orbit it is. We also see some added bits as the moon rises and sets.

The "wobbles" add about 8 degrees in either direction. These aren't really wobbles, but caused by the moons slightly elliptical orbit. It's rotation is constant, but it's orbit speed isn't (like all elliptical orbits). This is what makes it's rotation slightly out of sync with it's orbit.

Does the moon wobble as it orbits the earth? or is it's orbit really smooth and consistant, being free of "wobble"?

"Wobble" means partial rotation on an axis say 1 or 2 degrees in a form of oscillation.

It certainly appears to wobble as viewed from Earth...

http://aa.usno.navy.mil/graphics/Moon_movie_small.gif

(Found at US Naval Observatory - Astronomical Applications (http://aa.usno.navy.mil/faq/docs/moon_phases.html))

This is not a real wobble, however. It's an optical effect, due to the Moon's spin axis being tilted, and due to its elliptical orbit.

There is a real wobble (change in rotation rate with respect to the stars), but it is very small. The Moon has a pretty big moment of inertia - it takes a lot of torque to change its spin rate, even slightly.

Thanks guys for all that insight

Hi, I added an edit with a bit more information above. Not all of the 59% comes from wobbling back and forth, apparently it's orbit is also tilted with respect to the earth, so we see higher and lower latitudes on the moon depending on where in it's orbit it is. We also see some added bits as the moon rises and sets.

The "wobbles" add about 8 degrees in either direction. These aren't really wobbles, but caused by the moons slightly elliptical orbit. It's rotation is constant, but it's orbit speed isn't (like all elliptical orbits). This is what makes it's rotation slightly out of sync with it's orbit.

All these "wobbles" are called "librations".

The tilt of the moon's axis causes the libration of lattitude.
The eccentricity of its orbit causes the libration of longitude.

The difference in viewing angle between moonrise and moonset is the diurnal libration.

These librations make up the vast majority of the "wobble" we see.

There is are actual physical librations, caused by the fact that the Moon is not quite spherical. Tidal forces try to make the long axis of the moon align with the Earth. The above mentioned librations cause this to not always be the case. during these times the Earth tugs on the Moon trying to force it into alignment. This cuases the moon to physically wobble back and forth. But this libration amounts to a small fraction of a percent.

Well, that seems to wrap up the "wobble" issue nicely. Thanks guys.

actually you would expect some form of "wobble" given the uneven distribution of mass on the earth..this would have to effect the way the moon orbited and ha..."wobbled" ( as Janus has suggested )