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The Earth and Moon comparison conundrum.
#41
Ah, I finally see the light -

The problem you are having is because the moon rotates exactly one time during each complete Earth orbit.

If the moon were rotating even slightly faster - say two times during an orbit, you'd probably not have any problem seeing it, and if the moon were rotating even slightly slower - say one rotation every two orbits, you'd probably not have any problem seeing it.

Oh, and you can do the math - the moon rotates about 13.3 times in one Earth year.
I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#42
(08-21-2011, 11:56 AM)Derek Wrote: The moon is constantly turning a corner, making an orbit, not being dragged about by a finger.

You are combining two different things and calling it one. Turning a corner is in fact rotation. It can be nothing else, hence the use of the word turning. Orbiting is the motion around a central point.

The moon turns the corner or rotates at exactly the same time it orbits. It takes the same amount of time to make one complete rotation as it does to complete one orbit.

If you take two children, one playing the Earth, spinning in place and one playing the Moon. Have the Earth child hold the hand of the moon child and spin. The moon child is now orbiting the earth child keeping one face always facing the Earth child. Now if you remove the earth child but have the moon child continue to turn at the same speed but this time without orbiting, you can see the axis rotation.
(08-21-2011, 11:56 AM)Derek Wrote: 2) How many times does the earth rotate upon it's own axis every orbit of the sun it completes?
I have always assumed the same as the number of days and nights in a year.
BUT, if the moon supposedly rotates once per orbit of the earth, as seems to be being argued by some here, then,
applying the same logic to earth would mean there is a 1 day and night difference between
the number of revolutions the earth completes upon it's own axis and the number of days and nights in a year...........
This is I simply can not see. I'll stand corrected, and humbly so, if this is a well known astronomical "fact" I am not aware of.

If you apply the concept of tidal lock to the Earth/Sun relationship, then it would take the Earth 365 "days" to complete one axis rotation, the same amount of time it takes to complete one orbit of the sun. This would cause the same side of the Earth to always face the sun and the planet would lose its current day/night cycle. But it would still be rotating just a heck of a lot slower.

Derek, do you drive? Ever driven on an icy road? Turning a corner or curve is rotation on your axis. Take a corner on an icy road. If you lose traction you will spin out. Why? because you are already rotating. The friction with the road keeps your rotation slow until you lose traction. Your rotation speed increases and you spin out.
“We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to inquire. We know that in secrecy error undetected will flourish and subvert”.J Robert Oppenheimer.
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#43
The replies are so "good", I had stickied the thread to highlight it.

For clarity my position is -
The moon's axis of rotation is traveling in an elliptical orbit around earth.
Just as the earth's axis of rotation is traveling in an elliptical path around the sun.

The earth spins upon it's axis whilst orbiting the sun, hence we have day and night.
The moon does not spin upon it's own axis of rotation whilst orbiting earth,
hence, we only ever see one face of the moon from earth.

As my plots posted earlier clearly depict.
If the elipse that the axis of rotation of the moon is traveling in is straightened out into a straight line then
the moon is clearly not spinning upon it's own axis at all.
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
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#44
(08-22-2011, 11:46 AM)Derek Wrote: The earth spins upon it's axis whilst orbiting the sun, hence we have day and night.
The moon does not spin upon it's own axis of rotation whilst orbiting earth,
hence, we only ever see one face of the moon from earth.

I know it is difficult for you to admit you are wrong, however, based on just this quote of yours, you should re-think this.

The moon in fact does spin upon it's own axis of rotation and, if you were on the moon, you also would have day and night. (Remember, it is the Sun that makes day and night.) Moon day lasts about 14 Earth days and Moon night would last about 14 Earth days. (Actually since the moon rotates once every 27.322 Earth day, a Moon day or night is half of that, or 13.661 Earth days.) Of course, this is not considering the times when the Earth is all or partially between the Sun and the Moon which, while still technically part of a Lunar day, would obscure either all or part of the Sun's light.


It is interesting that we say we never see the "Dark side of the Moon", but that is not technically correct - we see most of the "side that is dark" during the "New Moon" phase. At that time, the side of the Moon receiving illumination is the side that is opposite of Earth. So, more correctly I suppose, the side of the Moon we never see isn't the "Dark Side", it is the "Back Side" (assuming the "Front Side" is the side facing Earth). This begs the question: Would we see the Man on the Moon's backside if we saw the other side?

Smile

(Just kidding - because we have seen the entire surface of the moon, or at least virtually all of it, thanks to the Lunar Orbiter missions.)
I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#45
Actually the dark side of the moon means the back side.
Decided to look for some youtubes. maybe they will help.







“We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to inquire. We know that in secrecy error undetected will flourish and subvert”.J Robert Oppenheimer.
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#46
If the moon didn't spin on its axis as it orbited the earth we would see the whole surface of the Moon as it orbited the earth.

As the moon's rotates in the same time it takes to make one orbit of th earth, we only ever see the one side of the moon. the Moon keeps once one face to us by rotating and orbiting at the same rate.

It is quite simple really.
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#47
Wiki, NASA, wow, they are stacked up against me....

OK, the earth spins upon an axis that is not exactly perpendicular to the sun.
Does that also revolve once per orbit the earth makes of the sun????

Or does earth's axis of rotation travel in a circular path, so
the earth always spins in relatively the same way to the sun?

If it does, then I am correct.
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#48
sigh rotation and orbit are two separate things. Now you have added precession. The Earth is tilted on its axis. I can't remember which planet it is but one planet is completely laid over on its side.
“We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to inquire. We know that in secrecy error undetected will flourish and subvert”.J Robert Oppenheimer.
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#49
Also, it doesn't matter whether an object is rotating in the direction of its orbit (prograde) or opposite of the direction of its orbit (retrograde) - it is still rotating.

I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#50
Post #45,first video convincingly shows that the moon rotates.That is why we see one side all the time.
It is our attitude toward free thought and free expression that will determine our fate. There must be no limit on the range of temperate discussion, no limits on thought. No subject must be taboo. No censor must preside at our assemblies.

–William O. Douglas, U.S. Supreme Court Justice, 1952
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#51
The videos in Post 45 show exactly the same things as my apparently, as described by Scpg02 "worthless plots" do, but interprets them differently.
This is interesting because we now get to the numb of "the problem" here.
I think on this thread in particular, and many other threads recently, it is obvious how difficult, even impossible, discussion is between different paradigms.

The "discussion" on this thread is now "off topic" as for the original intended subject of the thread, but
it has become more useful as it is now effectively and plainly a discussion between two paradigms.
Paradigm 1, effectively the "consensus paradigm" says,
the moon's axis of spin does not change whilst the moon orbits earth, ie, it always faces the same way.
Paradigm 2 is my position, that the moon's axis of spin is following a circular path around earth, because of gravity, ie tidal lock, that "powers" the moons orbit around earth.

I have given many examples that I hope people can relate to easily.
A ball in the hand of your outstretched arm being probably the simplest for most to understand and be able to replicate for themselves.

" sigh rotation and orbit are two separate things. "

Yes, that is exactly my point really....Paradigm 1 adds them together, Paradigm 2 separates them.

Idea - Not being a mathematician, I do not know, but, I assume the way angular momentum is calculated
could throw some light on this subject or rather discussion between paradigms.
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#52
Derek -

You still do not address the fact that the Moon has both day and night.

This makes the rotation easy to perceive when viewed from the Sun.

Even the "ball in hand of an outstretched arm" will show all of it's sides to a third party watching. If you think of this as a large disc around a person with a radius equal to an outstretched arm you would surely say the entire disk is rotating, would you not? The arm and ball is just a small, very thin "slice" of that disk.

The only reason this analogy is even being considered is because the moon's rotation exactly matches its orbit and it keeps the same side facing the Earth. If the moon's rotation was even just slightly slower or faster this perceived lack of rotation would not be confusing to some.

I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#53
JohnWho Post 52 - I did address the fact the moon has day and night in plot 2 of 4.
Moon day being yellow, and moon night being black.

What that has to do with whether the moon is spinning upon it's own axis of spin, or not, is lost on me.

You are correct in that,
" The only reason this analogy is even being considered is because the moon's rotation exactly matches its orbit "

The point is, does "exactly" mean 1 spin or no spin?
It could mean either, depending upon how you view it...
Later edit - From now on I am going to use rotation to mean turning a corner, or orbiting and
spin to mean spinning upon it's own axis of spin.


If there is a question not being addressed by the "consensus" so far it is that;-
Does the moon's axis of spin travel in a circular path, or does it always face the same way?
I have seen that "it faces the same way" has been asserted several times on this thread so far, but with no proof to date.
The penny example is inappropriate because what "powers" the movement of the penny (your finger)
is not the same as what powers the moon's orbit around earth, ie gravity and tidal lock. As "shown" in the ball in hand example I have given.
Are there any other examples please, the "consensus" can give of such movements, from the real world, as the inappropriate penny example?

All the examples I have given on this thread show the axis of spin is traveling in a circular path,
ie, in particular the ball in the hand, and the Wonder Waltzer fairground ride.
These examples show the moon is not spinning upon it's own axis of spin.

Hence my position or paradigm that, "exactly" = No spinning upon it's own axis.
Incidentally, I agree that ANY deviation from "exactly" = Spinning upon it's own axis.
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#54
(08-24-2011, 06:11 AM)Derek Wrote: JohnWho Post 52 - I did address the fact the moon has day and night in plot 2 of 4.
Moon day being yellow, and moon night being black.

What that has to do with whether the moon is spinning upon it's own axis of spin, or not, is lost on me.

And that is exactly where you fail, Derek.

We must use some reference point to determine whether an object such as the moon is spinning or rotating, and within the Solar System that reference is usually the Sun (although a distant "Zodiac" set of stars or another galaxy could also be used). If the moon were not spinning relative to the sun, it would still experience day/night, but it would be exactly one day/night period for each orbit around the sun. Since it gets a little over 13 "day/night" periods for each orbit of the Sun, we know that it is rotating on it's axis at least 13 plus times a year (the Lunar year and the Earth year are very close to the same amount of time).

Unless, of course, the Moon's axis was exactly pointing toward the Sun, in which case only either the northern or southern hemisphere of the Moon would get light from the Sun. In this case, though, according to where one was standing on the Moon, they would watch the Sun make circles in the Lunar sky as would the stars.

Maybe that is the way you need to look at this - view it all from a distant star. You will get a constantly changing view of the Moon depicting its rotation.

I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#55
JohnWho my viewpoint is from the object in question.

How could it possibly be from any other view point, that seems absurd to me.
Almost as if your paradigm's view is limiting your understanding of what we observe. ie, reality...

" If the moon were not spinning relative to the sun, "
Almost beggars belief, except, I have "discussed" with you before.
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#56
Quote:JohnWho my viewpoint is from the object in question.

And, as I said, if you were standing on the Moon now, you would see the stars, galaxies, constellations, etc. move across the Lunar sky.

Another fact you choose to ignore.

What appears to me, Derek, is that you seem to be unable to grasp the scientific fact that the moon is rotating on its axis.

All the scientific sources are wrong, and only you are right.

All the experts are wrong, and only you are right.

I see now why others have abandoned attempting to have rational discussion with you

and on this topic, I'm joining them.

I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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#57
(08-24-2011, 11:51 AM)JohnWho Wrote: What appears to me, Derek, is that you seem to be unable to grasp the scientific fact that the moon is rotating on its axis.

All the scientific sources are wrong, and only you are right.

All the experts are wrong, and only you are right.


and on this topic, I'm joining them.

I have given relevant examples, that have not been answered.
Therein lies the rub for you, not me.

Rational discussion, really, from you, I had not noticed that.
Assertions I must say, plenty of them.
Peculiar view points I must also say, a few of them as well, and, of course,
by others plenty of appeals to higher authorities. Wiki and NASA to name just two.
I think this is because in several areas we hold to different paradigms.
You have been using phrases as,
" where you fail, Derek. "
" I know it is difficult for you to admit you are wrong, "
" you'd probably not have any problem seeing it. "
because I do not agree, or rather I am questioning the paradigm you believe to be correct.
It should be clear by now that I do understand the paradigm view you prefer.
I am not aware that because I do not agree with the paradigm you agree with,
that is reason for you to use the above phrases in rational discussion.
It appears if I do not agree with you, you feel justified in using the above types of phrases, is that rational discussion?


" I'm joining them. "
Well, actually, I asked you politely to do this a bit back by PM, but you pointedly refused my request.
I explained at the time it was because we seem to view "things" from different paradigms, and,
that I wanted to build up this part of the forum as being from a different to most peoples at present paradigm / understanding / view point.

The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#58
saying 2 + 2 = 5 is not questioning a paradigm, it is just flat wrong. The moon rotates on its axis. This is a provable fact. The moon is also in tidal lock with the Earth. Also a provable fact. ANYTHING that turns a corner is rotating on its axis, kid on a merry-go-round or car on a roundabout. you can't change physics.
“We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to inquire. We know that in secrecy error undetected will flourish and subvert”.J Robert Oppenheimer.
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#59
" saying 2 + 2 = 5 is not questioning a paradigm, it is just flat wrong. "
I think that is a "strawman". ie, a debating tactic, not normally used in rational discussions....
Remembering "debate" = winning by any means is acceptable.
To be fair to Scpg02, " 2 +2 = 5 " could be (and is actually) the difference between the paradigm views we have, so
it is yet another example of what I have been saying,
discussion between paradigms is all but impossible.

" The moon rotates on its axis. This is a provable fact. "
Which I have asked for proof of, so far, none has been given.
I am talking about spin, not rotation, please see " Later edit " in Post 53.
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#60
Hey scpg02 -

If you Google "Does the moon rotate on its axis"

you'll get a paltry 1.1 million plus hits.

Oddly, "2 + 2 = 5" gets over 3.3 million!

Interesting, eh?
I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!


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