Does the Moon Rotate?

Beyond the boundaries of established science an avalanche of exotic ideas compete for our attention. Experts tell us that these ideas should not be permitted to take up the time of working scientists, and for the most part they are surely correct. But what about the gems in the rubble pile? By what ground-rules might we bring extraordinary new possibilities to light?

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D_Archer
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Re: Does the Moon Rotate?

Unread post by D_Archer » Tue Oct 01, 2013 1:13 am

After my post i started doubting again and was thinking about this the whole evening, i even said in my post that the moon did rotate around this 'virtual axis' and when i visualized a non rotating moon it was not what we see in reality.

So i would now agree with Chrimony and Viscount Aero.

The proof would be 'libration' as forwarded by Chrimony.

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Daniel
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Re: Does the Moon Rotate?

Unread post by viscount aero » Tue Oct 01, 2013 10:55 am

Yes I hadn't thought about this issue very much until a thread was created about it. It got me intrigued a great deal because the Moon is in our lives daily and visible most of the time. It is there and close yet possesses great mysteries. I wanted to demystify at least something about it--its rotation. "On the surface" it looks like it doesn't rotate. So that it does rotate on axis is somewhat of an optical illusion because its rotation is non-traditional. It seems counter-intuitive that it would rotate. To wrap one's head around it can be confusing.

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Re: Does the Moon Rotate?

Unread post by viscount aero » Tue Oct 01, 2013 12:06 pm

jtb wrote:The moon revolves--changes direction--but does not rotate.

A person at the center of an oval track (earth) racing CW will see the right side of a horse (moon) in every direction.

A person anywhere in the bleachers (external view) will see the right side of the horse at the farthest point of the track, the head when approaching, the left side when closest, and the tail when departing. One rotation per revolution. However, common sense tells us the horse is changing direction, not rotating. The same can be said for the moon.
jtb
This is an interesting perspective and illustration. Being that the Moon does rotate that would follow, too, that the horse is also rotating about an axis. Although we would not consider this example "rotation" as the horse is terrestrial and on the ground running, were you to put an axis through the horse you would find that the horse's body rotates about it as it runs through the circular track. If the track has straightaways then it is at these moments that the horse ceases to rotate. When he rounds a curve, he begins rotating again :lol:

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Re: Does the Moon Rotate?

Unread post by jtb » Sat Oct 05, 2013 12:39 am

If the moon were to stop in its orbit, would it continue to rotate in place? If a horse running on an oval track were to stop, would it continue to rotate in place?
jtb

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Re: Does the Moon Rotate?

Unread post by chrimony » Sat Oct 05, 2013 7:13 am

jtb wrote:If the moon were to stop in its orbit, would it continue to rotate in place?
You don't specify how it would be "stopped in its orbit". However, if the gravity of the Earth and Sun were to magically disappear, yes, it would still be rotating without orbiting. Of course it would also continue moving in a straight line relative to its previous orbit.
If a horse running on an oval track were to stop, would it continue to rotate in place?
Instead of continuing to come up with bad analogies and new questions that don't share the characteristics of bodies in space, how about instead you address the counter-arguments already given?

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Re: Does the Moon Rotate?

Unread post by viscount aero » Sat Oct 05, 2013 1:51 pm

jtb wrote:If the moon were to stop in its orbit, would it continue to rotate in place?
The plot thickens :) That's a great question! In my knee jerk reaction I'd say no, it would no longer rotate because the motion of its orbit is the mechanism behind its rotation. Or is it?

However to conserve angular momentum the answer would be "yes" it continues to rotate on its axis. That is the answer I would ultimately support were it a test question.
jtb wrote:If a horse running on an oval track were to stop, would it continue to rotate in place?
jtb
No because the horse is on terra firma. Its momentum is absorbed and halted by the friction of the ground it stands on. Whereas in space the Moon has no such friction to impede its rotation were it to somehow stop orbiting the Earth.

This raises more questions however. Why does Earth's Moon have an exact 1:1 lock with 1 orbit per axial rotation? What has caused this?

If the Moon's rotation were just a hair slower or faster we on Earth would perceive this rotation as "rotation" in the traditional sense. But the Moon is locked 1:1. Why?

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Re: Does the Moon Rotate?

Unread post by chrimony » Sat Oct 05, 2013 2:23 pm

viscount aero wrote:This raises more questions however. Why does Earth's Moon have an exact 1:1 lock with 1 orbit per axial rotation? What has caused this?
Tidal locking. It's already been mentioned twice in the thread, though not in hyperlink format. Of course it wouldn't have been hard to Google and find the answer, either.
If the Moon's rotation were just a hair slower or faster we on Earth would perceive this rotation as "rotation" in the traditional sense.
If you took the time to understand libration (what finally convinced D_Archer), you would know that we can already perceive this rotation. The moon's rotation is constant, but its orbital velocity around the Earth is not.

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Re: Does the Moon Rotate?

Unread post by nick c » Sat Oct 05, 2013 8:16 pm

Note to Viscount Aero and Chrimony,
Several of your posts had to be deleted because they contained ad hom remarks or quotes containing ad hom remarks from a previous post.
Please review the forum Rules and Guidelines.
Specifically:
Personal or ad hominem attacks will not be tolerated, under any circumstances. If you disagree with something which has been posted, address the post, not the poster.
That includes quoting someone's ad hom attack. If you come across such a violation do not respond, because that tends to make things more complicated. Click the red exclamation mark (report this post) which will call it to the attention of a moderator.

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Re: Does the Moon Rotate?

Unread post by viscount aero » Sat Oct 05, 2013 8:34 pm

My apologies. I will abstain from such behavior hereafter and quit this thread.

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Re: Does the Moon Rotate?

Unread post by jtb » Sun Oct 06, 2013 4:56 am

Sorry guys for not commenting to your posts. I will eventually.

I have another question: If a horse ran 1 mile east, then 1 mile south, then 1 mile west, then 1 mile north, is it changing direction or rotating?

An issue I have with tidal locking is that it requires billions (not thousands or millions) of years to achieve. A lot of things can change in several billion years. If space weather is anything like Earth weather, it can be pretty chaotic and unpredictable. Tidal locking assumes no changes in distribution of mass. If Venus was once a comet entering the solar system as Velikovsky theorizes, wouldn’t it disrupt the formula for tidal locking for the satellites of all the planets? How could they have synchronized so soon after that event?

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Re: Does the Moon Rotate?

Unread post by chrimony » Sun Oct 06, 2013 5:26 am

jtb wrote:Sorry guys for not commenting to your posts. I will eventually.

I have another question: If a horse ran 1 mile east, then 1 mile south, then 1 mile west, then 1 mile north, is it changing direction or rotating?
I don't see the point in answering questions like these while you still haven't addressed analogies that closely match what we see in space.
An issue I have with tidal locking is that it requires billions (not thousands or millions) of years to achieve. A lot of things can change in several billion years. If space weather is anything like Earth weather, it can be pretty chaotic and unpredictable. Tidal locking assumes no changes in distribution of mass. If Venus was once a comet entering the solar system as Velikovsky theorizes, wouldn’t it disrupt the formula for tidal locking for the satellites of all the planets? How could they have synchronized so soon after that event?
I don't put much stake in Velikovsky, but if you want an answer to such a question you'd have to run the numbers or even better run a simulation. I don't know of any EU theorist who has run planetary simulations. If they did, it would add some credibility to the fantastic planet dance that supposedly occurred within human memory.

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Re: Does the Moon Rotate?

Unread post by jtb » Mon Oct 07, 2013 5:47 am

Chrimony, I tried your experiment with the bowls. The center bowl (Moon) did not rotate when I revolved the larger bowl. It always pointed in the same direction, even when I walked in different directions. It always faced the same direction. It did not rotate.

The water in both bowls did not rotate either. I put bits of toothpicks in the water to observe their motion--there was none.

Moving in a circle with the larger bowl, it revolved (changed direction), but did not rotate. I put the large bowl on a lazy Susan and spun it simulating rotation and got the same results. The only difference was that the toothpick bits near the edge of the larger bowl began to revolve (orbit) very fast when I slowed the lazy Susan. The center bowl (Moon) remained stationary. It did not rotate.

For tidal locking to occur the rotation and revolution of the satellite must be in the same direction. For example, the rotation and orbit of the satellite must both be CCW.

I will address the other comments another day.
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Re: Does the Moon Rotate?

Unread post by jtb » Mon Oct 07, 2013 9:17 am

by viscount aero » Sat Sep 28, 2013 12:03 pm
If you had a wooden ball with a fixed and static rod through its axis on ball bearings (like a wheel and axle) and then mimicked the orbit and fixed face of the Moon around the Earth you would find that the rod wouldn't have moved but the wooden ball would have. The ball would make exactly one revolution around the fixed rod in one orbit around the Earth. Therefore the Moon rotates around a central axis. The periodicity of this one full rotation, however, is locked in phase within one complete orbit around the Earth in a 1:1 ratio of rotation to orbit.
Viscount aero, It's raining so I have a little time to answer another comment. Tidal locking requires the moon to rotate CCW ~90 degrees for every CCW ~90 degrees of orbit. With one marked side of a wooden ball facing you, rotate it CCW ~90 degrees then revolve in your orbit CCW to the ~90 degrees position. The mark on the ball no longer faces the center. The moon does not rotate. The same applies to the finger in the fist comment.
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Re: Does the Moon Rotate?

Unread post by viscount aero » Mon Oct 07, 2013 11:46 am

jtb wrote:
by viscount aero » Sat Sep 28, 2013 12:03 pm
If you had a wooden ball with a fixed and static rod through its axis on ball bearings (like a wheel and axle) and then mimicked the orbit and fixed face of the Moon around the Earth you would find that the rod wouldn't have moved but the wooden ball would have. The ball would make exactly one revolution around the fixed rod in one orbit around the Earth. Therefore the Moon rotates around a central axis. The periodicity of this one full rotation, however, is locked in phase within one complete orbit around the Earth in a 1:1 ratio of rotation to orbit.
Viscount aero, It's raining so I have a little time to answer another comment. Tidal locking requires the moon to rotate CCW ~90 degrees for every CCW ~90 degrees of orbit. With one marked side of a wooden ball facing you, rotate it CCW ~90 degrees then revolve in your orbit CCW to the ~90 degrees position. The mark on the ball no longer faces the center. The moon does not rotate. The same applies to the finger in the fist comment.
jtb
jtb, rotation of the Moon has long been established as a fact. It does seem counter-intuitive but lots of things in science are. A rotation does not always look like a basketball spinning around someone's finger. Rotations take many forms, the Moon being one of them.

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Re: Does the Moon Rotate?

Unread post by jtb » Wed Oct 09, 2013 4:22 am

Viscount aero, If you look closely at my last post you will notice that I accidentally proved your point. I haven't changed my view, but it shows how confusing an issue this is.
jtb

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