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The Earth and Moon comparison conundrum.
#21
Ok, Scpg02 let me put it like this.
Imagine you are on a children's roundabout, and you are facing towards it's center.
If the roundabout is spinning are you spinning on your axis?
No, you are stood perfectly still.
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
#22
(08-18-2011, 10:45 AM)Derek Wrote: Ok, Scpg02 let me put it like this.
Imagine you are on a children's roundabout, and you are facing towards it's center.
If the roundabout is spinning are you spinning on your axis?
No, you are stood perfectly still.

No you aren't. Using your analogy if you look over at the swing set you will see that you are rotating. If you were not rotating you would always be facing the swing set as the roundabout goes round. You would still be orbiting but you would not be rotating. The person sitting on the swings sees you rotating as well as orbiting.

Here is a thread that deals with this issue.
“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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#23
The point or question was and is -
Is the moon rotating upon it's own axis?
It is not, not a jot.

If you were spinning on your toes on the childrens spinning roundabout 365 1/4 times per revolution of the roundabout then
you would be earth, orbiting the sun.
ie, traveling in a "circle" whilst also rotating upon your own axis.
But, if your stood still on the roundabout then you are the moon orbiting the earth.
ie, traveling in a circle whilst NOT spinning upon your own axis, not a jot.
Like driving a car around a roundabout, you would not describe yourself as spinning,
you would describe yourself as driving (traveling in a circle) around the roundabout.

It is just that the moon orbits around the earth once, in tidal lock,
whilst the earth spins on it's own axis 27.322 times.
ie,
" the moon fully revolves on it's own axis once every 27.322 days,
and,
the moon fully orbits earth once every 27.322 days.
"

So, we are observing the moon from a position of mixed perspective/s.
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
#24
the moon does rotate on its axis. So does the child on the merry-go-round. The axis also moves in space, that is the nature of orbiting.

  • If you were spinning on your toes on the childrens spinning roundabout 365 1/4 times per revolution of the roundabout then
    you would be earth, orbiting the sun.
    ie, traveling in a "circle" whilst also rotating upon your own axis.
    But, if your stood still on the roundabout then you are the moon orbiting the earth.
    ie, traveling in a circle whilst NOT spinning upon your own axis, not a jot.

you would be spinning faster while on your toes but nothing else changes. If you were not spinning on your axis you would always be facing the swing set not the center of the merry-go-round.

does the swing set go around you? in front at one point, behind at another? then you are spinning. and it doesn't matter if you are spinning fast on your toes or slow in tidal lock. you are also orbiting the center of the merry-go-round. Because you are spinning at a slow rate, the same rate you are orbiting you are in tidal lock with the merry-go-round. But you can tell you are spinning because the swings move.
“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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#25
(08-19-2011, 12:59 AM)Scpg02. Wrote: If you were not spinning on your axis you would always be facing the swing set not the center of the merry-go-round.

Sorry Scpg02 I have to disagree. Please see the below and
substitute the view of the swing set for the sun view of the moon.
(The Moon is depicted orbiting the earth anti clock wise in this illustration)
[Image: Slide4.jpg]
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
#26
LOL sorry Derek, you illustration is worthless. It shows the moon standing still, not rotating. The moon rotates as well as orbits. If you could hold a pencil and draw a line in the air while you are on the merry-go-round you would see it. I don't know how to explain it to you more simply than I have.
“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.
Reply
#27
" If you could hold a pencil and draw a line in the air while you are on the merry-go-round you would see it. "

" The moon rotates as well as orbits. "

OK, take two steps towards the center of the merry go round.
Hold your pencil aloft. Spin the merry go round.
Your pencil has drawn a (perfect) circular orbit.
Note, no circle upon a circle, just a single circle.
Take a step back, repeat, you draw another slightly bigger (perfect) circle.
Take a second step back, repeat again.
You have 3 perfect circles, all equally distant from each other,
you have driven round the roundabout 3 times,
etc, etc, etc.
Take another step back, fall off roundabout, then it hits you,
not the ground, but it will anyways, but that,
the moon is NOT rotating upon it's own axis, not a jot.

The moon's axis is orbiting the earth, ie you drive round a roundabout in a car,
which is not the same thing as the moon spinning upon it's own axis.
It might help to straighten out the moons orbit into a straight line, in your own mind.
("green line" in below plot)
[Image: Slide1.jpg]
See, the moon is not spinning upon it's own axis. Not a jot.
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
#28
(08-19-2011, 08:44 AM)Derek Wrote: " If you could hold a pencil and draw a line in the air while you are on the merry-go-round you would see it. "

" The moon rotates as well as orbits. "

OK, take two steps towards the center of the merry go round.
Hold your pencil aloft. Spin the merry go round.
Your pencil has drawn a (perfect) circular orbit.
Note, no circle upon a circle, just a single circle.
Take a step back, repeat, you draw another slightly bigger (perfect) circle.
Take a second step back, repeat again.
You have 3 perfect circles, all equally distant from each other,
you have driven round the roundabout 3 times,
etc, etc, etc.
Take another step back, fall off roundabout, then it hits you,
not the ground, but it will anyways, but that,
the moon is NOT rotating upon it's own axis, not a jot.

The moon's axis is orbiting the earth, ie you drive round a roundabout in a car,
which is not the same thing as the moon spinning upon it's own axis.
It might help to straighten out the moons orbit into a straight line, in your own mind.
("green line" in below plot)
[Image: Slide1.jpg]
See, the moon is not spinning upon it's own axis. Not a jot.

yes it is and your illustration this time proves it. See the 1 going around? You can't hold the pencil straight up you have to hold it out away from your center. It will draw circles. You mean to tell me you can't see the one going around the center of the moon. first it is pointing south then east then north then west. it IS spinning as well as orbiting.
ok let's try this. put a penny on the table re represent the moon. now put your finger on the penny so it can't turn. now orbit it around something. notice how the penny doesn't turn and the same side is not always facing what you orbit.

Now orbit the penny keeping the same side pointed at your "earth". see how you have to spin the penny in order to keep the same side facing the earth? The penny is turning. you can't keep your finger on it and keep the same side facing the earth at the same time.

“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.
Reply
#29
It is the "off moon" view point you are using that is confusing the issue for you Scpg02.

Which was really the whole point from the off.
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
#30
Let's be sure we are saying the same thing, based on the illustration above -

the moon is rotating once every 27.322 Earth days.

If it did not, it could not keep the same side facing the Earth.

Stop the moon's rotation, and we Earth folks will get to see all sides of the moon as it goes around us.

In the roundabout example, someone standing in the exact center of the roundabout will also not appear to be spinning to any of the other children on the roundabout, but certainly will be spinning to anyone not on it.

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!


Reply
#31
(08-19-2011, 10:38 AM)Derek Wrote: It is the "off moon" view point you are using that is confusing the issue for you Scpg02.

Which was really the whole point from the off.

I'm not confused at all. View point is not the issue. The moon rotates around its axis. That's a fact plain and simple.



“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.
Reply
#32
Does the Moon Rotate?

Quote:Well, the Moon does rotate. In fact, the Moon takes 27.3 days to turn once on its axis. But the Moon also takes 27.3 days to complete one orbit around the Earth. Because the Moon’s rotation time is exactly the same amount of time it takes to complete an orbit, it always presents the same face to the Earth, and one face away.

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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#33
Even Wikipedia gets it: Moon.
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!


Reply
#34
The moon does rotate once in a month.But orbits Earth once a month too on the very same time frame.

Just as the Moons orbital distance from Earth is in the right distance to barely cover the Suns disk for those spectacular solar eclipse events.

But millions of years ago.It did not happen the way it does now.

The moons rotation rate was different.

The moon used to be closer to Earth.

In the future it will be different from what it is now.
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
Reply
#35
(08-19-2011, 07:05 PM)Sunsettommy Wrote: The moon does rotate once in a month.But orbits Earth once a month too on the very same time frame.

Just as the Moons orbital distance from Earth is in the right distance to barely cover the Suns disk for those spectacular solar eclipse events.

But millions of years ago.It did not happen the way it does now.

The moons rotation rate was different.

The moon used to be closer to Earth.

In the future it will be different from what it is now.

The Earth's rotation is slowing and we will eventually be in tidal lock with the moon, always showing the same side. But the moon is also receding which will cause the Earth's wobble to become increasingly unstable. I was told which one would happen first but I can't remember.

“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.
Reply
#36
I'll repeat for clarity.
(08-19-2011, 08:44 AM)Derek Wrote: The moon's axis is orbiting the earth, ie you drive round a roundabout in a car,
which is not the same thing as the moon spinning upon it's own axis.
It might help to straighten out the moons orbit into a straight line, in your own mind.

The straightening the orbit into a straight line is why I did the plots as I have.
To illustrate what is happening from different view points.

Think about the earth orbiting the sun, the earth spins on it's own axis whilst orbiting the sun.

The moon patently does not spin upon it's own axis, whilst orbiting earth,
hence we always see the same "face" of the moon,
otherwise,
you would not be able to drive around a roundabout in a car....
But you can drive a car around a roundabout because
the car DOES NOT spin upon it's own axis whilst orbiting the roundabout.
Just like the moon does not spin upon it's own axis, not a jot, whilst the moon and it's axis of rotation is orbiting earth.

Another (and probably final attempt by me to explain this), way to see what I mean.
Hold a ball in your hand with an outstretched arm. Please spin yourself slowly, keeping your arm outstretched.
What do you see?
Do you see the same side of the ball all the time?
Note the ball does not rotate a single iota.
It stays in exactly the same position in your hand.
The ball is not spinning upon it's own axis whatsoever.
This is what the moon does orbiting earth.

Now try to repeat this with the ball spinning in the palm of your hand.
What do you see?
Do you see the same side of the ball, all of the time?
No.
Because the ball is now spinning upon it's own axis.
This is what the earth does orbiting the sun.
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
#37
(08-20-2011, 12:46 PM)Derek Wrote: I'll repeat for clarity.
(08-19-2011, 08:44 AM)Derek Wrote: The moon's axis is orbiting the earth, ie you drive round a roundabout in a car,
which is not the same thing as the moon spinning upon it's own axis.
It might help to straighten out the moons orbit into a straight line, in your own mind.

The straightening the orbit into a straight line is why I did the plots as I have.
To illustrate what is happening from different view points.

Think about the earth orbiting the sun, the earth spins on it's own axis whilst orbiting the sun.

The moon patently does not spin upon it's own axis, whilst orbiting earth,
hence we always see the same "face" of the moon,
otherwise,
you would not be able to drive around a roundabout in a car....
But you can drive a car around a roundabout because
the car DOES NOT spin upon it's own axis whilst orbiting the roundabout.
Just like the moon does not spin upon it's own axis, not a jot, whilst the moon and it's axis of rotation is orbiting earth.

The car does spin so does the moon. You didn't do that penny thing did you?
“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.
Reply
#38
Unbelievable, I give up.
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#39
Don't give up, Derek, but try this:

Do your graphic again (Post #27 among others)

only this time, put the Moon in the middle.

You'll see that it rotates quite easily then, I hope.
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!


Reply
#40
I only meant giving up trying to explain to those participating here.

The earth spins on it's own axis, the moon does not. It really is that simple.
Oh, just a couple of final examples.
1) I remember one of my favorite fairground rides as a child was the Wonder Waltzer, does anyone else remember that fairground ride?
Those cars spinning on their own axis as they orbited the center of the ride.
If the car did not spin on it's own axis, it would of been a very boring ride,
and you would only see one side of the car from the center of the ride...

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.

BTW - The penny "thing" is an inappropriate example (I genuinely would call it a misdirection), infact it is completely different.
The moon is constantly turning a corner, making an orbit, not being dragged about by a finger.
The difference being, the moon's axis of rotation is following a circle the same size as it's orbit.
When this is visualized, then it is obvious the moon is not spinning upon it's own axis.

This thread was originally about trying to get to a better earth / moon comparison,
this "sideline" has killed any chance of that.
We have not a chance of agreeing, even the basics.

A close friend of mine years ago told me that, in respect of girlfriends,
"If she holds you back, move on, and don't look back".

I think that applies here.
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


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