Why Is The Moon Not Spinning Then?

[StrangerInAStrangeLa]

Am I in the Twilight Zone???

[Vkothii]

If you are sitting right on the nose of the man in the moon and looking at earth, you would see the earth rotating, but it would never be out of your sight.

How would you explain the apparent progression of the sun, as you sat on the moon?
The fact that it would appear to follow the same path across the sky, behind the earth and back, once for every 29 or so apparent rotations of the earth?

[James R]

I understand what you are saying about relative motion, but my answer would be no.

If you are sitting right on the nose of the man in the moon and looking at earth, you would see the earth rotating, but it would never be out of your sight.

Yes. But the only way it can do that is if the moon rotates relative to the distance stars.

[common_sense_seeker]

I agree with one_raven. That's a great statement you make. The Moon is not spinning about it's own axis in a single direction only. I propose that this would be the case if it was gaining angular momentum from the Earth, which is spinning about it's own axis in a single direction.

Therefore the theory that the Earth is simply losing gravitational field strength seems the likeliest explanation in my mind, and so the Moon's orbit would increase slightly.

Is the velocity of the Moon increasing? Can that be determined by the laser reflector measurements?

AL

[Steve100]

If the moon was not rotating about its own axis, it would look to us as if it were rotating.

[common_sense_seeker]

Yeah, well my head's startin' to spin.

Do you think that the Moon's speed has increased with it's increase in orbital distance?

[Captain Kremmen]

Common Sense Speaker. I hope you are not being disingenuous and asking naive questions to which you know the answer. People here will gobble you for breakfast.

Here's an explanation of why the moon is rotating by Rosanna Hamilton:

The Moon is 384,403 kilometers (238,857 miles) distant from the Earth. Its diameter is 3,476 kilometers (2,160 miles). Both the rotation of the Moon and its revolution around Earth takes 27 days, 7 hours, and 43 minutes. This synchronous rotation is caused by an unsymmetrical distribution of mass in the Moon, which has allowed Earth's gravity to keep one lunar hemisphere permanently turned toward Earth. Optical librations have been observed telescopically since the mid-17th century. Very small but real librations (maximum about 0°.04) are caused by the effect of the Sun's gravity and the eccentricity of Earth's orbit, perturbing the Moon's orbit and allowing cyclical preponderances of torque in both east-west and north-south directions.


I think I can explain this more simply:
The moon both rotates and always keeps the same face pointing towards the earth. To understand this, draw a large circle (earth) on a piece of paper, then take a smaller circular object (moon) with a mark to one point of the edge. Move the "moon" around the "earth" so that the mark always faces the "earth". You will see that in one full rotation around the earth, the mark has itself made one rotation. If you can imagine the moon without the earth, on its own and centred in a single space, it is spinning.

btw
Has any astrologer worked out a chart for a child born on the moon?
What are the key astrological effects of the earth?

[common_sense_seeker]

I am being serious, alright. My science is fundamentally rusty, I agree, since it's been over 12 years since I was involved with science research.

I'm never going to convince Standard Model devotees over night, I know that. The simple question of why gravitational fields don't decay naturally still stands. It's a good solution.

[AlphaNumeric]

I am being serious, alright. My science is fundamentally rusty, I agree, since it's been over 12 years since I was involved with science research

Bull. You've never been involved in physics research.

[common_sense_seeker]

No need to get personal. Incidentally, anybody with common sense can see that modern physics is floundering.

[Ophiolite]

Bull. You've never been involved in physics research.

Perhaps he means psychic research.

common sense seekeer, the current explanation for the moons orbit, orbital variations and progressive movement away from the Earth are all wholly consistent with observations and standard gravitational theory. There are no paradoxes or enigmas to explain. Your explanation is an unnecessary addition, that offers nothin and likely generates contradictions for other situations.

[Janus58]

The natural decline of the Earth's gravitational field strength is a simple and elegant solution.

AL

So was phlogiston. It was also completely erroneous.

[Janus58]

I'm not claiming to be an expert. Perhaps you can summarise the models for me?

AL

Okay:

The Moon, due to the differential of its gravitional effect across the diameter of the Earth, raises two tidal bulges on the Earth. Ideally, these bulges would be in line with the line joining the center of the Moon adn the center of the Earth.

The Earth, however rotates, and there is a friction between the bulges and the main rotating Earth. As a result, the Earth tries to drag the bulges along wth its rotation. The Moon, on the other hand, tries to keep the Bulges aligned with itself. This results in a tug of war between the Earth and the Moon which ends in a "tie" where the tidal bulges don't rotate with the Earth, but don't stay aligned with the Moon either. Instead, they "lead" the Moon by a slight amount.

This leading the Moon by the bulges, alters the line of gravitational force between the bulges and the Moon. It no longer acts on a line going through the center of the Earth. Instead, it works on a slight angle which pulls forward on the Moon in its orbit and backwards on the bulges with respect to the Earth's rotation. These pulls act to increase the orbital energy of the Moon while decreasing the rotational energy of the Earth. greater oribital energy results in a higher orbit and lower rotational energy means a slower rotation.

One aspect of this mechanism is that if the satellite orbit retrograde or directly but with a shorter period than it take the planet to rotate, then the tidal bulges lag behind the satellite and pull backwards on the satellite in its orbit, robbing it of orbital energy and drawing it into a lower and lower orbit.

This is what is happening to Mars' moon Phobos, which orbits faster than Mars rotates.

It also explains why the majority of Jupiter's outer moons are retrograde. These bodies are captured asteroids, and since a retrograde satellite will be drawn in towards the planet and prograde ones ejected, It is easier to capture and hold bodies into a retrograde orbit.

Your explaination of decreasing gravitational strength, on the other hand, would have all satellites receding from their planet regardless of the type of orbit, and this does not match what we actually see in practice.

[common_sense_seeker]

Your explaination of decreasing gravitational strength, on the other hand, would have all satellites receding from their planet regardless of the type of orbit, and this does not match what we actually see in practice.

Thanks for the reply in general, I'll look into it a bit more. As to the last statement, we only know that the Moon is moving away from the Earth due to precise laser reflector measurements. So how would we know whether other natural satellites are receding from their parent planet or not?

[AlphaNumeric]

No need to get personal.

There's nop need for you to lie. If you didn't lie about having done aeronautical research, that doesn't mean you've done physics research. My father has worked with Lockheed, Boeing, Airbus, the development team for the Eurofighter and even the supersonic car. He doesn't know the first thing about theoretical physics research. Doesn't even know the concepts in it!

Incidentally, anybody with common sense can see that modern physics is floundering.

How so? You don't even know modern physics, you're making mistakes in this forum which are on material taught to people doing GCSEs and A Levels. I did circular orbital velocities when I was 16 or 17. You claim to have a degree in astronomy and you don't know about orbital velocities? I teach people doing degrees in astronomy and they know about such things!

So either you lied about your degree or you have forgotten so much of it you effectively don't have a degree in anything but in paper form only.

So how would we know whether other natural satellites are receding from their parent planet or not?

We don't, not to the level of accuracy we know the Moon is. But given places like Io experience even more tidal interactions with their parent planet than our Moon does with the Earth and all models of Newtonian and Einsteinian gravity predict such behaviour and we have not found any reason to doubt such results yet, the models are not invalidated.

We have yet to even see you provide a single quantitative model for your work.

[StrangerInAStrangeLa]

Does the moon spin on its axis?

[James R]

Try reading the thread.

[StrangerInAStrangeLa]

I'd like a simple civil yes or no answer.

[Vkothii]

Try really hard to imagine looking at the moon and not the earth, so just the moon.

If you watched it from say, a point several hundreds of thousands of Km 'above' the plane of the ecliptic, would it rotate around an axis, as well as orbiting a "non-existent" earth?
(Answer: yes, it would, just like holding a string with a ball at the end of it, and 'swinging' it around a centre means the ball rotates around it's axis as it orbits the centre).

[StrangerInAStrangeLa]

Is it possible for an orbiting body to not rotate?