Well, perhaps in the spirit of fighting my ignorance, you will indulge me, and explain what I said that was wrong. But before you do, please understand that I and others here are using very specific definitions for the words rotate and revolve.
From wiki:
It is for this reason I say that the moon rotates on its axis, and revolves around the earth. The period of time for both is the same, but they are independant motions and should be considered as such.
If you believe the moon rotates around the earth’s axis, you must believe the earth rotates around the sun’s axis. If not why?
It would only rotate around the Sun’s axis in that sense if the Earth were tidally locked to the Sun. Instead it would be some axis between the Earth and the Sun. (At a guess, at a distance of about 1/365th of an AU from the Earth’s center towards the Sun.) [/aside]
It’s not really the tidal locking that’s important, it’s that for the axis to be at the Sun, the same part of the Earth would need to be “aimed” at the Sun over the coarse of its orbit. I was using “tidally locked” as shorthand for that.
I’m not so sure… If you could “magically” blink the earth away in an instant – “I Dream of Jeannie” style – then the moon’s path from that point forward would depend on where it was in the course of the month. If it were during a full moon, then the moon would swing outward away from the sun into an elliptical orbit of more than 1AU semi-major axis. If it happened during a new moon, then the moon would fall inward (a little) toward the sun, into an orbit of slightly less than 1AU semi-major axis.
(Varying cases in between.)
I guess I am actually agreeing with you, and just quibbling over the word “nearly” in your post!
re which axis of rotation, aren’t we falling into the classical trap of accelerating frames of reference? To a person living on the moon, yeah, it pretty much feels as if the moon is rotating on its own axis. Sun rises, sun sets. Earth rises, earth sets. Venus, Mars, Rigel, Deneb, all rise and set. But from this selenocentric viewpoint, the sun is accelerating back and forth, going farther away, coming nearer, like a bloomin’ yo-yo! The moon only “rotates about its own axis” in a powerfully accelerating frame of reference.
There’s nothing wrong with using accelerating frames of reference, save only that they can generate spurious and illusory forces. They can simplify calculations – if I’m a rocket scientist and trying to put a satellite up into orbit around the moon, you bet I’m gonna use the frame of reference of the moon spinning about its own axis! I’m also likely to use a frame of reference where the moon doesn’t rotate, at least in some calculations, to make the math even easier.
(Same reason no-one, so far, has insisted on correcting for the solar system’s motion with respect to the galaxy!)
I think I probably just didn’t understand you then.
As far as I can see, the rotation of a body such as the moon around the earth can be legitimately dissected into orbital and rotational components*, the rotational component will then be about the axis of the moon. I don’t think it makes any difference whether the moon is tidally locked to the earth.
*(in the same way that the rotational component of the Earth is a day and the orbital component is a year - you could magic away either component without affecting the other)
If that’s not anything to do with what you said, I apologise for talking at cross purposes.
" the moon does not rotate about its own axis" Yes it does says all the astronomers, scientists and probably 99.99 percent of the people on this planet because the revolution around the sun counts as one rotation in relation to the sun and to any distante point in space.
Myself I say: The moon does not spin on its axis and thank god i’m not smoking what the are smoking
Pormitsu917, we generally allow revival of old threads in General Questions only to add new factual information. Since these appear to represent your personal opinions rather than facts, I am closing this.