# Stuff and Things > HISTORY, veterans & science >  When did the Earth start spinning and rotating around the Sun?

## Fall River

Did it start spinning and rotating before it was formed or after it was formed?  


And, either way, what was the motivating force that acted upon it to start it rotating and spinning so as to maintain orbit.



If gravity was the motivating force, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.



P.S. Thanks to Jen for giving me this idea

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Foghorn (07-15-2021),Northern Rivers (07-16-2021),Quark (07-15-2021),Swedgin (07-15-2021)

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## Captain Kirk!

Yeah, why doesn't it just sit in space unmoving? It must have something to do with angular momentum but how? What? Why? What force acted upon it to cause it to try and move away from the sun?

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Fall River (07-15-2021),Foghorn (07-15-2021)

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## Authentic

Gravity.

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Foghorn (07-15-2021)

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## Captain Kirk!

> Gravity.


'Splain that Lucy.

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Fall River (07-15-2021)

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## Canadianeye

Too many drinks. Everything starts spinning after too many drinks. It's settled science.

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Fall River (07-16-2021),Foghorn (07-15-2021),MedicineBow (07-15-2021),Northern Rivers (07-18-2021)

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## Oceander

> Did it start spinning and rotating before it was formed or after it was formed?  
> 
> 
> And, either way, what force acted upon it to get it up to speed to start its orbit around the sun?
> 
> 
> 
> If it was gravity, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.
> 
> ...


Because the Earth and the Sun (and all the other planets, plus asteroids, meteorites, and etc) all formed from a giant interstellar gas cloud that collapsed.  The cloud of gas had momentum and, since momentum is conserved in a closed system (the gas cloud was, for practical purposes, a closed system), that momentum was preserved, including rotational momentum.  As a result, the collapse was not simply centripetal, but tangential in part, and since the system conserved momentum, component parts that collapsed into solid(ish) bodies rotated.

So, the rotation arose long before either the Earth or the Sun were formed.

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Big Bird (07-16-2021),Foghorn (07-15-2021),Quark (07-15-2021),UKSmartypants (07-16-2021)

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## Captain Kirk!

> Because the Earth and the Sun (and all the other planets, plus asteroids, meteorites, and etc) all formed from a giant interstellar gas cloud that collapsed.  The cloud of gas had momentum and, since momentum is conserved in a closed system (the gas cloud was, for practical purposes, a closed system), that momentum was preserved, including rotational momentum.  As a result, the collapse was not simply centripetal, but tangential in part, and since the system conserved momentum, component parts that collapsed into solid(ish) bodies rotated.
> 
> So, the rotation arose long before either the Earth or the Sun were formed.


You got a video, right? lol, IMO, no one knows what happened, it's all speculation.

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Fall River (07-15-2021),Foghorn (07-15-2021)

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## Fall River

I forgot to ask for an understandable explanation.  What good is an explanation if no one understands it?  Do you really understand it or are you just repeating something you read?

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Captain Kirk! (07-15-2021)

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## Frankenvoter

> Yeah, why doesn't it just sit in space unmoving?


And @Fall River it's because space itself is moving as it's being stretched out after the initial big bang, you can think of why the whirlpool starts in a toilet as it flushes, the Earth is spinning and so the ground below the water is moving just slightly as compared to the water molecule and so it's "dragged" by gravity around a central point.

It's why people get the spins when drunk @Canadianeye , the Earth is spinning at 1,000MPH (thereabouts) while rotating around the sun at 67,000MPH (a second force acting on you) while the solar system as a whole is moving through space at 1.3 million miles per hour (a whole other force acting on you and why it's easier to just fall flat on your face than stand up sometimes).

Anyway the primordial solar system was moving through space as opposed to being fixed in space and the different masses of the ingredients were allowed to start orbiting around and running in to each other over time (this is just my theory, I'm not a degreed PhD even though I do play one while teaching my trade to people entering the field).

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Big Bird (07-16-2021),Canadianeye (07-15-2021),Foghorn (07-15-2021),Quark (07-15-2021)

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## Canadianeye

See! Settled science.

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Foghorn (07-15-2021),Quark (07-15-2021)

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## Fall River

> And @Fall River it's because space itself is moving as it's being stretched out after the initial big bang, you can think of why the whirlpool starts in a toilet as it flushes, the Earth is spinning and so the ground below the water is moving just slightly as compared to the water molecule and so it's "dragged" by gravity around a central point.
> 
> It's why people get the spins when drunk @Canadianeye , the Earth is spinning at 1,000MPH (thereabouts) while rotating around the sun at 67,000MPH (a second force acting on you) while the solar system as a whole is moving through space at 1.3 million miles per hour (a whole other force acting on you and why it's easier to just fall flat on your face than stand up sometimes).
> 
> Anyway the primordial solar system was moving through space as opposed to being fixed in space and the different masses of the ingredients were allowed to start orbiting around and running in to each other over time (this is just my theory, I'm not a degreed PhD even though I do play one while teaching my trade to people entering the field).


At the moment of the Big Bang, everything would have been propelled straight out into space. At what point would everything start spinning and rotating?  What would cause that?

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Foghorn (07-15-2021)

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## fmw

The entire galaxy spins.  There is a super massive black hole in the center of the galaxy and the stuff of the galaxy rotates around it like water circles a drain.  Sometimes things will collide with each other.  Sometimes they will be flung away from each other. Sometimes they will orbit each other.  It is all about motion and, as mentioned above, gravity.

To help you understand how an orbit works, imagine a planet moving relatively near a star.  The stars gravity pulls on the planet but can't attract it straight on because it continues to move forward.  The satellite is always falling toward the larger object but is still moving forward as well.  The orbit occurs when the forward motion of the satellite  and the inward tug of the larger body result in a a stable path.

Simple enough to understand?

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Foghorn (07-15-2021)

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## fmw

> At the moment of the Big Bang, everything would have been propelled straight out into space. At what point would everything start spinning and rotating?  What would cause that?


Gravity.  Sorry I couldn't resist.  Understand that the Big Bang is a theory and not settled science. See my post above.

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## nonsqtr

> I forgot to ask for an understandable explanation.  What good is an explanation if no one understands it?  Do you really understand it or are you just repeating something you read?


It's not an easy answer.

I tend to agree with what @Oceander said, the rotation came first.

You were asking about orbits - and here is the closest thing I can find, that paints the conceptual picture.

Limit cycle - Wikipedia.

You'll notice in the first pic, it's showing you the concept that if the orbit deviates, it tends to return to it's original equilibrium.

And that's the key word, "equilibrium". An orbit has a radius and a speed, so why that particular stable configuration, instead of any other? The math is kinda complicated, it has to do with differential equations, but the simple view is, there's a 'preferred' orbit, and if you deviate too far from it your moon will fly off into space, or go crashing into the earth, but if you only deviate ("perturb") a tiny bit, the system finds the preferred equilibrium again.

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## Frankenvoter

> At the moment of the Big Bang, everything would have been propelled straight out into space. At what point would everything start spinning and rotating?  What would cause that?


I think that's a question for the higgs boson to answer, your question is logical from an idea of looking at an explosion in the way we see a detonation where everything goes everywhere equally but Science! (I'm mocking them) says something "slowed down" certain particles over others acting as a "screen" the way the one in a window allows air though, but still holds some molecules back as they interact with the material making up the grid of the screen which causes the initial turbulence and orbital mechanisms to start that movement is at least the current theory on why.

I'd think @nonsqtr would know for sure this stuff seems right up his alley he might be sitting back letting me dig a deeper hole because this is all stuff I'm pulling out of the I rememebr reading it somewhere file.

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## Captain Kirk!

> And @Fall River it's because space itself is moving as it's being stretched out after the initial big bang, you can think of why the whirlpool starts in a toilet as it flushes, the Earth is spinning and so the ground below the water is moving just slightly as compared to the water molecule and so it's "dragged" by gravity around a central point.
> 
> It's why people get the spins when drunk @Canadianeye , the Earth is spinning at 1,000MPH (thereabouts) while rotating around the sun at 67,000MPH (a second force acting on you) while the solar system as a whole is moving through space at 1.3 million miles per hour (a whole other force acting on you and why it's easier to just fall flat on your face than stand up sometimes).
> 
> Anyway the primordial solar system was moving through space as opposed to being fixed in space and the different masses of the ingredients were allowed to start orbiting around and running in to each other over time (this is just my theory, I'm not a degreed PhD even though I do play one while teaching my trade to people entering the field).


The aliens have a planetary radar gun to measure those speeds?

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Foghorn (07-15-2021),Frankenvoter (07-15-2021)

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## Foghorn

The Earth doesn't really spin, it's an illusion.

The Universe rotates around us.



 :Happy8:

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Canadianeye (07-15-2021),Fall River (07-16-2021)

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## Fall River

> The entire galaxy spins.  There is a super massive black hole in the center of the galaxy and the stuff of the galaxy rotates around it like water circles a drain.  Sometimes things will collide with each other.  Sometimes they will be flung away from each other. Sometimes they will orbit each other.  It is all about motion and, as mentioned above, gravity.
> 
> To help you understand how an orbit works, imagine a planet moving relatively near a star.  The stars gravity pulls on the planet but can't attract it straight on because it continues to move forward.  The satellite is always falling toward the larger object but is still moving forward as well.  The orbit occurs when the forward motion of the satellite  and the inward tug of the larger body result in a a stable path.
> 
> Simple enough to understand?



Your explanation always starts with the assumption that the planets are already formed.  Also, you assume the star is going slower than the planet, so that the planet is gaining on the star.

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## Oceander

> At the moment of the Big Bang, everything would have been propelled straight out into space. At what point would everything start spinning and rotating?  What would cause that?


(a) Not true.  The "Big Bang" was not some big explosion that threw stuff out the way that, say, a dynamite explosion would; it was an expansion of space itself, which carried stuff along with it;

(b) The collapse was of only a very, very, very, very, .... very small portion of the total amount of matter in the universe.  So even if the universe as a whole did not have any angular momentum, that does not mean that the portion that collapsed to form the Solar System did not have net angular momentum.

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## Authentic

Trust the science.

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Fall River (07-16-2021)

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## Captain Kirk!

> The entire galaxy spins.  There is a super massive black hole in the center of the galaxy and the stuff of the galaxy rotates around it like water circles a drain.  Sometimes things will collide with each other.  Sometimes they will be flung away from each other. Sometimes they will orbit each other.  It is all about motion and, as mentioned above, gravity.
> 
> To help you understand how an orbit works, imagine a planet moving relatively near a star.  The stars gravity pulls on the planet but can't attract it straight on because it continues to move forward.  The satellite is always falling toward the larger object but is still moving forward as well.  The orbit occurs when the forward motion of the satellite  and the inward tug of the larger body result in a a stable path.
> 
> Simple enough to understand?


Sorry, but you're just stating one unprovable idea. As stated, NO one knows what happened.

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Authentic (07-15-2021),Fall River (07-16-2021)

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## Fall River

> It's not an easy answer.
> 
> I tend to agree with what @Oceander said, the rotation came first.
> 
> You were asking about orbits - and here is the closest thing I can find, that paints the conceptual picture.
> 
> Limit cycle - Wikipedia.
> 
> You'll notice in the first pic, it's showing you the concept that if the orbit deviates, it tends to return to it's original equilibrium.
> ...


But I wasn't asking how a moon gains or maintains "equilibrium".  Did the earth form first and then start orbiting?  That seems impossible.   Or was everything orbiting first as the earth was forming. That seems equally impossible.

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## Oceander

> But I wasn't asking how a moon gains or maintains "equilibrium".  Did the earth form first and then start orbiting?  Or was everything orbiting first as the earth was forming.  Either way it seems like there are problems.


Why are there problems?

The local gas cloud that collapsed to form the Sun and the Earth had net angular momentum as it started to collapse.  Since that momentum must be conserved, it resulted in the compact objects rotating both around their own poles as well as in orbit around the Sun.

The momentum that was conserved, and that resulted in the rotation and orbiting of the planets around the Sun was already in existence prior to the collapse of the gas cloud, and therefore the rotation, if you will, preceded the existence of the Earth.

Very simple.

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Quark (07-15-2021)

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## Authentic

> Why are there problems?
> 
> The local gas cloud that collapsed to form the Sun and the Earth had net angular momentum as it started to collapse.  Since that momentum must be conserved, it resulted in the compact objects rotating both around their own poles as well as in orbit around the Sun.
> 
> The momentum that was conserved, and that resulted in the rotation and orbiting of the planets around the Sun was already in existence prior to the collapse of the gas cloud, and therefore the rotation, if you will, preceded the existence of the Earth.
> 
> Very simple.


Were you there?

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Captain Kirk! (07-15-2021),Fall River (07-16-2021)

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## Oceander

.

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## Authentic

> Sorry, but you're just stating one unprovable idea. As stated, NO one knows what happened.


That is why they are called theories.

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Captain Kirk! (07-15-2021),Fall River (07-16-2021)

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## Foghorn

There is a great series out there called _The Planets_ on some of the streaming apps.

The first episode goes into this very question.  It is a very well done series in my opinion.

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Canadianeye (07-15-2021),Captain Kirk! (07-16-2021)

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## Fall River

> (a) Not true.  The "Big Bang" was not some big explosion that threw stuff out the way that, say, a dynamite explosion would; it was an expansion of space itself, which carried stuff along with it;


So it was an expansion of space that carried stuff along with it.




> (b) The collapse was of only a very, very, very, very, .... very small portion of the total amount of matter in the universe.  So even if the universe as a whole did not have any angular momentum, that does not mean that the portion that collapsed to form the Solar System did not have net angular momentum.


What collapse?  Collapse of what? How?  Angular momentum?  What the heck is that all about?  I didn't ask how the solar system formed.

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Captain Kirk! (07-15-2021)

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## Authentic

> You have a better explanation?  One that doesn't require jimquackery by some half-assed deity?


No jimquackery and He is a full deity. I refer you to Genesis 1.

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## Oceander

> So it was an expansion of space that carried stuff along with it.
> 
> 
> 
> What collapse?  Collapse of what? How?  Angular momentum?  What the heck is that all about?  I didn't ask how the solar system formed.


Yes you did, indirectly.  Furthermore, the answer to your question derives from how the Solar System formed.

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## Captain Kirk!

> No jimquackery and He is a full deity. I refer you to Genesis 1.


Jimmy quack corn, I don't care.

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## nonsqtr

> But I wasn't asking how a moon gains or maintains "equilibrium".  Did the earth form first and then start orbiting?  That seems impossible.   Or was everything orbiting first as the earth was forming. That seems equally impossible.


It's not just the earth or the moon, it's anything and everything. Everything obeys the laws of physics, even a gas cloud.

The answer is, it depends how the moon was formed. If it got carved off the earth in a big chunk (like,another planet hit it, or a huge meteor or something), and it went flying wildly off into space, surely part of that wildness included rotation.

And same for a gas cloud, if you have zillions of particles flying all over the place inside the cloud, at some point somewhere there will be a collision and angular momentum will be a part of it.

A rotational solution to the physical equations is what they call "modes". You can have rotational modes, vibrational modes... all these are "permissible" solutions to the differential equations. If something collides (or more generally in spacetime, "interacts") with something else, which way the energies go depends on the exact conditions of the interaction.

At the quantum level, when the planet and moon get real small, we have to integrate over 'all possible paths' to get the right answer. Which means, we have to consider all the different ways a collision (interaction) might occur.

The point being, the modes are math, they're solutions to differential equations. They "always" apply, no matter what. To anything and everything. Regardless of whether any matter existed or what form it was in, the modes were there first.

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Quark (07-15-2021)

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## nonsqtr

> But I wasn't asking how a moon gains or maintains "equilibrium".  Did the earth form first and then start orbiting?  That seems impossible.   Or was everything orbiting first as the earth was forming. That seems equally impossible.


You're asking how the earth was formed? 

When you say "everything" orbiting first, are you envisioning the earth condensing from a gas cloud?

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## nonsqtr

Here - "modes".

Modes and the Characteristic Equation | Unit II: Second Order Constant Coefficient Linear Equations | Differential Equations | Mathematics | MIT OpenCourseWare

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## nonsqtr

In quantum-land, we basically sum over "all possible modes".

But in the material world, an orbit is only ONE specific mode. It's the 'preferred' mode, the one the system tries to return to.

Because it's in equilibrium that way.

You can look at it like a "lowest energy state".

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## Authentic

> Here - "modes".
> 
> Modes and the Characteristic Equation | Unit II: Second Order Constant Coefficient Linear Equations | Differential Equations | Mathematics | MIT OpenCourseWare


You don't have to enroll at MIT to go to MIT?

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## Authentic

Is there an ideal gas cloud?

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## nonsqtr

> So it was an expansion of space that carried stuff along with it.
> 
> 
> 
> What collapse?  Collapse of what? How?  Angular momentum?  What the heck is that all about?  I didn't ask how the solar system formed.


It sounds like you're asking about the basic structure of spacetime, which is the differential equations themselves, as distinct from any behavior that may result from them.

In our ordinary 3+1 dimensional spacetime, that answer is provided by general relativity. Those are the equations that determine the permissible modes.

Beyond that, honestly, it's anyone's guess at this point. If you're UKSmartypants and you believe in a 12-dimensional Calabi-Yau manifold, that thing has so many modes it boggles the mind.

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## Authentic

Interesting course in the MIT history department.

How to Stage a Revolution | History | MIT OpenCourseWare

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## Authentic

> It sounds like you're asking about the basic structure of spacetime, which is the differential equations themselves, as distinct from any behavior that may result from them.
> 
> In our ordinary 3+1 dimensional spacetime, that answer is provided by general relativity. Those are the equations that determine the permissible modes.
> 
> Beyond that, honestly, it's anyone's guess at this point. If you're UKSmartypants and you believe in a 12-dimensional Calabi-Yau manifold, that thing has so many modes it boggles the mind.


Not to mention nodes.

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## Canadianeye

> There is a great series out there called _The Planets_ on some of the streaming apps.
> 
> The first episode goes into this very question.  It is a very well done series in my opinion.


Seen it. Saved it. Watch it everyone now and then. Yes, great series.

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## Dan40

> Did it start spinning and rotating before it was formed or after it was formed?  
> 
> 
> And, either way, what was the motivating force that acted upon it to start it rotating and spinning so as to maintain orbit.
> 
> 
> 
> If gravity was the motivating force, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.
> 
> ...


After the 10th beer.

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Fall River (07-16-2021)

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## Big Dummy

> Gravity.


Magnetic fields.

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## Big Dummy

> It's not just the earth or the moon, it's anything and everything. Everything obeys the laws of physics, even a gas cloud.
> 
> The answer is, it depends how the moon was formed. If it got carved off the earth in a big chunk (like,another planet hit it, or a huge meteor or something), and it went flying wildly off into space, surely part of that wildness included rotation.
> 
> And same for a gas cloud, if you have zillions of particles flying all over the place inside the cloud, at some point somewhere there will be a collision and angular momentum will be a part of it.
> 
> A rotational solution to the physical equations is what they call "modes". You can have rotational modes, vibrational modes... all these are "permissible" solutions to the differential equations. If something collides (or more generally in spacetime, "interacts") with something else, which way the energies go depends on the exact conditions of the interaction.
> 
> At the quantum level, when the planet and moon get real small, we have to integrate over 'all possible paths' to get the right answer. Which means, we have to consider all the different ways a collision (interaction) might occur.
> ...


The moon is the only body in the solar system not to have rotation. It revolves around the earth, but does not spin.

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## nonsqtr

> The moon is the only body in the solar system not to have rotation. It revolves around the earth, but does not spin.


Does the moon rotate? | Space

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Quark (07-15-2021)

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## Big Dummy

> Does the moon rotate? | Space


Although you can't see the back side of the moon from Earth, NASA and other space agencies have glimpsed it with satellites.

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## Quark

> Too many drinks. Everything starts spinning after too many drinks. It's settled science.


 :Smiley ROFLMAO:

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## Quark

> Although you can't see the back side of the moon from Earth, NASA and other space agencies have glimpsed it with satellites.


Actually, you can see the backside of the Moon during the day at the right times and under the right conditions.

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Big Dummy (07-15-2021),Fall River (07-16-2021)

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## Quark

The reason the Earth rotates is one day I had a bad case of flatulent while flying my spaceship. I stuck my butt up to a spaceport and let it rip. Now you know the rest of the story.  :Smiley ROFLMAO:

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Fall River (07-16-2021)

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## Trinnity

> Did it start spinning and rotating before it was formed or after it was formed?  
> 
> 
> And, either way, what was the motivating force that acted upon it to start it rotating and spinning so as to maintain orbit.
> 
> 
> 
> If gravity was the motivating force, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.
> 
> ...


No.

Gravity.

Gravity + centrifugal motion.

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## Trinnity

> Does the moon rotate? | Space


No.

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Big Dummy (07-15-2021)

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## nonsqtr

> No.


Heh heh - the moon rotates exactly once, every time it circles the earth.

You must read my long diatribes on "reference frames" elsewhere and elsewhen on this forum.

It's even weirder than that - the moon actually "wobbles" in its orbit. The lefties are all over this particular piece ...

NASA: Moon "wobble" in orbit may lead to record flooding on Earth - CBS News

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## Northern Rivers

> Did it start spinning and rotating before it was formed or after it was formed?  
> 
> 
> And, either way, what was the motivating force that acted upon it to start it rotating and spinning so as to maintain orbit.
> 
> 
> 
> If gravity was the motivating force, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.
> 
> ...


It appears Earth was clobbered by something big, long ago. Some posit that it was what we now call Mars and the debris made the moon. BTW: Mars rotates about the same day length as we do. Why?

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## Physics Hunter

> Did it start spinning and rotating before it was formed or after it was formed?  
> And, either way, what was the motivating force that acted upon it to start it rotating and spinning so as to maintain orbit.
> If gravity was the motivating force, why wouldn't it just be pulled into the sun rather than rotating and revolving around the sun.
> P.S. Thanks to Jen for giving me this idea


Some pretty simple answers:

A) If the mass of stuff that is now the earth did not move tangent to the Sun (thus establishing an orbit as a collection of cosmic junk), and came close, and too slowly, it would be part of the Sun and not earth

B) What caused this tangent motion is impossible to theorize.  As the earth is made of many light and heavy elements it is clearly a collection of literal cosmic garbage from early cosmos (Hydrogen, Helium...) and late in life star deaths (heavy metals and radioactive stuff), and everything in between.
It is clear that the early earth was bombarded by many different types of these chunks of junk.  Any of them could have struck at an angle imparting rotational momentum on the earth.  The largest of these, as one compelling theory has it, is that a relatively large and energetic (fast moving) object hit the earth at an angle ejecting something like 1/5-1/6 of the earth to form our Moon.  There is a computer simulation of this out there and it is cool in a geeky way.

C) As to why would all that cosmic junk not just run straight toward the Sun and fall in...?  Don't forget that everything in the visible universe is in motion. The Sun is moving through space around the Milky Way galaxy center, the MW galaxy is moving around other centers of mass on a poly galactic scale, and everything is expanding outward, making more "space" all the time.
Stars grow old and die and explode, propelling stuff this way and that.  Passing massive bodies attract other massive bodies, sometimes colliding, forming temporally stable rotational relationships, massive things get attractive to solar sized objects, but miss and get whipped out into larger space...

D)  That is just a taste.  In summary, I am really disappointed in all the uniformity arguments that the universe origin theorists seem to love, explosions are messy, often Chaotic (that is a science term).  No reason to go back to origins that we can only theorize about.  We can simply observe the universe that we see and know that it is a messy Chaotic soup with stuff regularly starting to move every which way, upsetting the current order.  (Think Dino destruction by asteroid...)

Taken as a great machine the Universe is both awesomely beautiful and horribly terrifying.  Kind of like the True God that I am convinced created it.

That was fun for me, hope others enjoy it.   :Smiley20:

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Quark (07-16-2021)

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## UKSmartypants

> You got a video, right? lol, IMO, no one knows what happened, it's all speculation.


Its not 'speculation', idiot, its maths' The physics of planets, stars, gas clouds, black holes and anything else you find out in space are governed by  a set of well known, we defined and long proven set of mathematical laws, including Lagrangian Functions, the Poisson equation, the Boltzman equation, Kepler's Laws of Planetary Motion, etc. 

Helmholtz Contraction, for example, is a phenomenon well-defined by maths, demonstrating exactly how low pressure contraction of a cloud. or system of particles. by the force of gravity, is retarded by outward gas pressure and the limited rate at which radiation can escape, whereas The law of Conservation of Angular Momentum tells us that as the gas cloud shrinks, it preserves its angular momentum by causing successive out bands to rotate faster than inner bands. Thus the entire system tends to turn into disc of rings rotating at different speeds, and then the rings tend to accrete into single bodies. We can look round the Universe and see all of this happening before our eyes, and as maths predicts - the orbital times and spacing of the planets in the Solar System obey exactly the Titus Bode Law, (1715) as corrected by Blagg and Richardson (1913).  Gas clouds in space obey precisely the same physical laws as pools of water or cups of coffee.



The Titius-Bode law was regarded as interesting, but of no great importance until the discovery of Uranus in 1781, which happens to fit into the series nearly exactly. Based on this discovery, Bode urged his contemporaries to search for a fifth planet. Ceres, the largest object in the asteroid belt, was found at Bode's predicted position in 1801.Even the moons of planets such as Jupiter and Saturn obey Bodes law in their orbital spacings

If we didnt know how bodies in space behaved we wouldnt have got to the Moon, or Mars,  no GPS satellites would be in orbit and the Voyagers wouldnt have been able to do the Grand Tour.

THIS 2008 paper

On the gravitational collapse of a cold rotating gas cloud | Mathematical Proceedings of the Cambridge Philosophical Society | Cambridge Core

goes into extreme mathematical detail of how  gas clouds in space collapse into stars and planets.



Or this one


Collapse of Rotating Gas Clouds and Formation of Protostellar Disks: Effects of Temperature Change during Collapse - IOPscience


or this one on the effects of angular momentum on gravitationally collapsing gas clouds


Teach Astronomy - Angular Momentum in a Collapsing Cloud




Honestly, of all the daft anti-science posts you make, this one is a humdinger.

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Quark (07-16-2021)

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## Physics Hunter

> Its not 'speculation', idiot, its maths' The physics of planets, stars, gas clouds, black holes and anything else you find out in space are governed by  a set of well known, we defined and long proven set of mathematical laws, including Lagrangian Functions, the Poisson equation, the Boltzman equation, Kepler's Laws of Planetary Motion, etc. Gas clouds in space obey precisely the same physical laws as pools of water or cups of coffee.
> 
> 
> If we didnt know how bodies in space behaved we wouldnt have got to the Moon, or Mars,  no GPS satellites would be in orbit and the Voyagers wouldnt have been able to do the Grand Tour.
> 
> THIS 2008 paper
> 
> On the gravitational collapse of a cold rotating gas cloud | Mathematical Proceedings of the Cambridge Philosophical Society | Cambridge Core
> 
> ...



Before we criticize, we need to need to acknowledge the ragged edges of science such as dark matter and (potentially?) dark energy.  We theorize a lot but saying that we truly understand them is at best a stretch.

In Cosmology there is more that we don't know than we do.

You will note that my post 54 is from first principles, as a Physicist should.

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Quark (07-16-2021)

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## UKSmartypants

> The moon is the only body in the solar system not to have rotation. It revolves around the earth, but does not spin.



Yes it does, but its gravitationally locked to face the earth. it does exactly one daily rotation in the same time as one yearly rotation (ie one earth month)

Gravitational locking is not uncommon and in fact most rotating two body systems end up gravitationally locked -  mercury is gravitationally locked to the Sun.  Its a mathematical function of the mass of the two bodies, the strength of their gravitational fields, and the angular momentum of the two bodies. And its  governed by Lagrangian Functions.  This entire thread's subject matter is all about maths.


The fact that the rotational period of the Moon and the orbital period of the Earth-Moon system are of the same length is not an accident. This was not always true, but over billions of years the gravitational coupling of the Earth and the Moon has led to this synchronization. In the case of the Earth-Moon system the synchronization is not yet complete. The Earth is slowly decreasing its rotational period and eventually the Earth and Moon will have exactly the same rotational period, and these will also exactly equal the orbital period. At the same time, the separation between the Earth and Moon will slowly increase in just such a way as to conserve angular momentum for the entire system.



Thus, billions of years from now the Earth will always keep the same face turned toward the Moon, just as the Moon already always keeps the same face turned toward the Earth, ie the Moon will become stationary in the sky over some part of the earth

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Big Dummy (07-16-2021),Quark (07-16-2021)

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## UKSmartypants

Jeez theres  several people in this thread need to go read a book on basic astrophysics and astronomy, so much uninformed bollox posted.

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## UKSmartypants

> Before we criticize, we need to need to acknowledge the ragged edges of science such as dark matter and (potentially?) dark energy.  We theorize a lot but saying that we truly understand them is at best a stretch.
> 
> In Cosmology there is more that we don't know than we do.
> 
> You will note that my post 54 is from first principles, as a Physicist should.



The conversation isnt about dark matter or black holes, its about we well documented and totally understood maths and physics of cold rotating gas clouds in zero gravity.

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## Physics Hunter

> The conversation isnt about dark matter or black holes, its about we well documented and totally understood maths and physics of cold rotating gas clouds in zero gravity.



Scientists know how to take criticism on their limits.

Eh?

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## UKSmartypants

dupe, delete

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## Physics Hunter

Yeah, I don't put up with bullies.  My post to the OP was all Newton and sub-atomic physics in stellar phenomena.

Grow a pair and represent.

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## UKSmartypants

[QUOTE=Physics Hunter;2807004]
D)  That is just a taste.  In summary, I am really disappointed in all the uniformity arguments that the universe origin theorists seem to love, explosions are messy, often Chaotic (that is a science term).  No reason to go back to origins that we can only theorize about.  We can simply observe the universe that we see and know that it is a messy Chaotic soup with stuff regularly starting to move every which way, upsetting the current order.  /QUOTE]

because the explosions you are talking about are  miniscule on the scale of the universe. On a large scale the Cosmic Background Radiation appears to show that the universe is pretty much homogenous and isotropic in substance and composition, apart from the fact galaxies in one direction are moving faster away from us than galaxies in the opposite direction (which is odd)

if it wasnt, the distribution of Galaxies wouldnt be so uniform.

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Quark (07-16-2021)

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## Fall River

> You got a video, right? lol, IMO, no one knows what happened, it's all speculation.


Good point, and you have a cosmologist, Richard Preston, on your side. He said, "We cannot say exactly how our universe formed."

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Captain Kirk! (07-16-2021)

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## Captain Kirk!

> Although you can't see the back side of the moon from Earth, NASA and other space agencies have glimpsed it with satellites.


Neil armstrong and crew saw it first hand.

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Big Dummy (07-16-2021)

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## Captain Kirk!

> Its not 'speculation', idiot, its maths' The physics of planets, stars, gas clouds, black holes and anything else you find out in space are governed by  a set of well known, we defined and long proven set of mathematical laws, including Lagrangian Functions, the Poisson equation, the Boltzman equation, Kepler's Laws of Planetary Motion, etc. 
> 
> Helmholtz Contraction, for example, is a phenomenon well-defined by maths, demonstrating exactly how low pressure contraction of a cloud. or system of particles. by the force of gravity, is retarded by outward gas pressure and the limited rate at which radiation can escape, whereas The law of Conservation of Angular Momentum tells us that as the gas cloud shrinks, it preserves its angular momentum by causing successive out bands to rotate faster than inner bands. Thus the entire system tends to turn into disc of rings rotating at different speeds, and then the rings tend to accrete into single bodies. We can look round the Universe and see all of this happening before our eyes, and as maths predicts - the orbital times and spacing of the planets in the Solar System obey exactly the Titus Bode Law, (1715) as corrected by Blagg and Richardson (1913).  Gas clouds in space obey precisely the same physical laws as pools of water or cups of coffee.
> 
> 
> 
> The Titius-Bode law was regarded as interesting, but of no great importance until the discovery of Uranus in 1781, which happens to fit into the series nearly exactly. Based on this discovery, Bode urged his contemporaries to search for a fifth planet. Ceres, the largest object in the asteroid belt, was found at Bode's predicted position in 1801.Even the moons of planets such as Jupiter and Saturn obey Bodes law in their orbital spacings
> 
> If we didnt know how bodies in space behaved we wouldnt have got to the Moon, or Mars,  no GPS satellites would be in orbit and the Voyagers wouldnt have been able to do the Grand Tour.
> ...


Why didn't someone tell me I was an idiot? And I haven't even voted for Biden. 

Seriously, Very few lay people understand math on the level that you reference. Also, I don't think that any math can sufficiently explain what happened millions of years ago. Just my opinion. And my posts aren't really anti-science they are anti scientist. Big difference.

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Fall River (07-16-2021)

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## Fall River

> Some pretty simple answers:
> 
> A) If the mass of stuff that is now the earth did not move tangent to the Sun (thus establishing an orbit as a collection of cosmic junk), and came close, and too slowly, it would be part of the Sun and not earth
> 
> B) What caused this tangent motion is impossible to theorize.  As the earth is made of many light and heavy elements it is clearly a collection of literal cosmic garbage from early cosmos (Hydrogen, Helium...) and late in life star deaths (heavy metals and radioactive stuff), and everything in between.
> It is clear that the early earth was bombarded by many different types of these chunks of junk.  Any of them could have struck at an angle imparting rotational momentum on the earth.  The largest of these, as one compelling theory has it, is that a relatively large and energetic (fast moving) object hit the earth at an angle ejecting something like 1/5-1/6 of the earth to form our Moon.  There is a computer simulation of this out there and it is cool in a geeky way.
> 
> C) As to why would all that cosmic junk not just run straight toward the Sun and fall in...?  Don't forget that everything in the visible universe is in motion. The Sun is moving through space around the Milky Way galaxy center, the MW galaxy is moving around other centers of mass on a poly galactic scale, and everything is expanding outward, making more "space" all the time.
> Stars grow old and die and explode, propelling stuff this way and that.  Passing massive bodies attract other massive bodies, sometimes colliding, forming temporally stable rotational relationships, massive things get attractive to solar sized objects, but miss and get whipped out into larger space...
> ...


It was very refreshing to read an explanation that I can understand.  Especially, "No reason to go back to origins that we can only theorize about."

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Physics Hunter (07-16-2021)

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## UKSmartypants

> Why didn't someone tell me I was an idiot? And I haven't even voted for Biden. 
> 
> Seriously, Very few lay people understand math on the level that you reference. Also, I don't think that any math can sufficiently explain what happened millions of years ago. Just my opinion. And my posts aren't really anti-science they are anti scientist. Big difference.



It does.
You can make a mathematical model of a gas cloud in space, based entirely on the rules we know, run it forward and viola, you get what we see with our eyes in real life, showing the model is correct. The same laws are  the ones keeping satellites and airplanes in the air and making the planets go round in well-defined and understood ways.   And you can run the models backwards to the big bang.  Theres no real guesswork in this, until you get to about 370k years after  the big bang, then different physics starts to apply.

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## Trinnity

> Heh heh - the moon rotates exactly once, every time it circles the earth.


You know he meant does the moon spin. No, it's tidally locked. Carry on...

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## Oceander

> You know he meant does the moon spin. No, it's tidally locked. Carry on...


Actually, for it to be tidally locked, it must spin, just at a rate that keeps the same side pointed at the Earth all the time.

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## Trinnity

No. That's just playing with words. Tidally locked is tidally locked.

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## East of the Beast



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## Dan40

Our moon DOES rotate on its axis. Slowly but it does.

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## Authentic

> No. That's just playing with words. Tidally locked is tidally locked.


I missed a word game?

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## nonsqtr

> No. That's just playing with words. Tidally locked is tidally locked.


No. Try it yourself. You can do it with an apple and an orange. 

The moon is the apple, because it's easy to distinguish one end from another, therefore easy to orient a reference frame. Let's say we point the apple in the "direction" of the stem.

The orange will be our earth, and let's say the navel of the orange is "tidally locked" to the stem of the apple.

Now rotate the apple around the orange (you can rotate the orange too if you wish, to ensure it remains "tidally locked" with the apple). You'll find, that to remain tidally locked, the apple has to spin around its own axis.

If it "weren't" tidally locked, you could rotate the apple in such a way that the stem always points in the same direction. But if it's tidally locked, you can't do that.

To remain locked, the apple has to rotate around its own axis exactly once, during the period of the full rotation of the orange. The two rotations have to match for tidal locking.

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Trinnity (07-16-2021)

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## Physics Hunter

[QUOTE=UKSmartypants;2807042]


> D)  That is just a taste.  In summary, I am really disappointed in all the uniformity arguments that the universe origin theorists seem to love, explosions are messy, often Chaotic (that is a science term).  No reason to go back to origins that we can only theorize about.  We can simply observe the universe that we see and know that it is a messy Chaotic soup with stuff regularly starting to move every which way, upsetting the current order.  /QUOTE]
> 
> because the explosions you are talking about are  miniscule on the scale of the universe. On a large scale the Cosmic Background Radiation appears to show that the universe is pretty much homogenous and isotropic in substance and composition, apart from the fact galaxies in one direction are moving faster away from us than galaxies in the opposite direction (which is odd)
> 
> if it wasnt, the distribution of Galaxies wouldnt be so uniform.


Yeah, but in going there you cheated on the OP's question, by zooming out so far.  That level of aggregate average mass/energy distribution in the universe has little to do with micro questions about planet/solar formation.  As you know, solar systems are all over the place in size, composition, energy...

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## UKSmartypants

> No. Try it yourself. You can do it with an apple and an orange. 
> 
> The moon is the apple, because it's easy to distinguish one end from another, therefore easy to orient a reference frame. Let's say we point the apple in the "direction" of the stem.
> 
> The orange will be our earth, and let's say the navel of the orange is "tidally locked" to the stem of the apple.
> 
> Now rotate the apple around the orange (you can rotate the orange too if you wish, to ensure it remains "tidally locked" with the apple). You'll find, that to remain tidally locked, the apple has to spin around its own axis.
> 
> If it "weren't" tidally locked, you could rotate the apple in such a way that the stem always points in the same direction. But if it's tidally locked, you can't do that.
> ...



No no it doesnt  Im sure ive explained this once.

The moon is tidally locked to the earth, but the earth isnt tidally locked to the Moon. 

A definition ort two first:

a 'day' is when an object performs one revolution round its own axis
a 'year' is when a body performs one revolution round the body it is orbiting
'tidal locking' or gravitational locking' is when a body always has the same face pointing  at the object its orbiting, or the objecting orbiting it

The moon's 'day' and its  'year'  are the same length, one earth month, this is because its tidally locked to the Earth, hence it keeps one side always facing the earth.Thus when you stand on the Moon, the earth always occupies the same place in the sky, never moving. This situation was caused by the drag from the earth's much larger gravitational field slowing the rotation of the moon on its own axis

The earth is not tidally locked to the Moon, because we do not keep the same side of the Earth facing the moon - the Moons 'year is one Earth month and the Earths day is 24 hours. They have to be the same for tidal locking of the Earth.. Thats why the moon rises and sets every day, from any earth observers point of view. However, the  gravitational drag from the moon is much smaller, and so the moon will take much longer to slow the rotation of the earth down until its tidally locked, and then the  same face of the earth will always faces the moon.  This will take about another billion years. At that point the moon will stop moving in the sky, and hang permanently in the sky over some part of the earth, just as the earth hangs permanently in the sky over a part of the moon

One consequence of the earth slowing down is that to preserve the  angular momentum of the Earth-Moon system , the moon will move to a further out orbit, and thus look smaller. thus, in about half a billion years total eclipses of the sun will cease to happen, because the moon will be visually too small to totally cover the sun.

Now can we cut the bollox about tidal locking?

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## UKSmartypants

[QUOTE=Physics Hunter;2808059]


> Yeah, but in going there you cheated on the OP's question, by zooming out so far.  That level of aggregate average mass/energy distribution in the universe has little to do with micro questions about planet/solar formation.  As you know, solar systems are all over the place in size, composition, energy...



Nope, exact;ly the same maths applies in the way the gas distributes. we have built phenomenally detailed models that produce universes with exactly the same type of filaments , void and galaxy clusters we see in our universe.


The point is, to get back to page one of this thread, is that the entire system is pretty much 98% mathematically predictable, based on know proven maths, whether we are talking about how solar systems from, or how galaxies form, or how the mass of the galaxies formed and distributed out the  fireball. Even the ratio of Hydrogen to Helium after the Epoch of the Last Scattering is precisely defined by the maths. 


its all known, predictable maths from 1 second after the big bang. The universe is ruled by maths, to be accurate, by 16 known constants that existed at the moment 3D space popped out.

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## Authentic

> No. Try it yourself. You can do it with an apple and an orange. 
> 
> The moon is the apple, because it's easy to distinguish one end from another, therefore easy to orient a reference frame. Let's say we point the apple in the "direction" of the stem.
> 
> The orange will be our earth, and let's say the navel of the orange is "tidally locked" to the stem of the apple.
> 
> Now rotate the apple around the orange (you can rotate the orange too if you wish, to ensure it remains "tidally locked" with the apple). You'll find, that to remain tidally locked, the apple has to spin around its own axis.
> 
> If it "weren't" tidally locked, you could rotate the apple in such a way that the stem always points in the same direction. But if it's tidally locked, you can't do that.
> ...


You're comparing apples to oranges?

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## Fall River

> You're comparing apples to oranges?


Ahh, fruit,  this is what they call a healthy discussion.

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## Frankenvoter

> No no it doesnt  Im sure ive explained this once.
> 
> The moon is tidally locked to the earth, but the earth isnt tidally locked to the Moon. 
> 
> A definition ort two first:
> 
> a 'day' is when an object performs one revolution round its own axis
> a 'year' is when a body performs one revolution round the body it is orbiting
> 'tidal locking' or gravitational locking' is when a body always has the same face pointing  at the object its orbiting, or the objecting orbiting it
> ...


Nope, because the way I understand it is thus: 

The moon rotates, but at a speed to which it matches it's "new moon" and "full moon" sequences to which side is facing us so the side with "the man in the moon" will always be facing us during full moon, the "dark side" does face us but during times of new moon meaning it's still unseeable to us even though it is facing us during that time and when the aliens who inhabit that side get thier most observation time in.

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## nonsqtr

> No no it doesnt  Im sure ive explained this once.
> 
> The moon is tidally locked to the earth, but the earth isnt tidally locked to the Moon. 
> 
> A definition ort two first:
> 
> a 'day' is when an object performs one revolution round its own axis
> a 'year' is when a body performs one revolution round the body it is orbiting
> 'tidal locking' or gravitational locking' is when a body always has the same face pointing  at the object its orbiting, or the objecting orbiting it
> ...


None of that contradicts anything I said.

Like you keep saying, it's math. It only works one way.

And like I said, TRY IT YOURSELF. You will see with your own two eyes, that it only works one way.

Cut the conjectural crap, and TRY IT.

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## UKSmartypants

> Nope, because the way I understand it is thus: 
> 
> The moon rotates, but at a speed to which it matches it's "new moon" and "full moon" sequences to which side is facing us so the side with "the man in the moon" will always be facing us during full moon, the "dark side" does face us but during times of new moon meaning it's still unseeable to us even though it is facing us during that time and when the aliens who inhabit that side get thier most observation time in.



the dark side of the moon never faces us, this is clearly obvious by simply looking at  the moon every night for a month.

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## Frankenvoter

> the dark side of the moon never faces us, this is clearly obvious by simply looking at  the moon every night for a month.


It is facing us during new moon which would be while it's between us and the sun.




> New moon: This is the first phase of the moon when the moon is between the sun and the earth. During this phase the moon is not seenas the dark side of the moon is facing the earth. Waxing crescent: This is the second phase which occurs after a few days of the new moon.

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## nonsqtr

Sigh. Will you people just try it please?

You'll see exactly how it works, you'll see it with your own two eyes.

I do this stuff every day, I work with reference frames in animation, cameras moving around scenes and stuff like that. All you have to do, to see what's going on, is attach a reference frame to your object, and watch what happens as it moves around.

If the stem of the apple points at the earth, then it is plainly obvious that when the apple's on top the stem is pointing down, whereas when the apple's on the bottom the stem is pointing up.

Ergo, a rotation has occurred.

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## Physics Hunter

[QUOTE=UKSmartypants;2808263]


> Nope, exact;ly the same maths applies in the way the gas distributes. we have built phenomenally detailed models that produce universes with exactly the same type of filaments , void and galaxy clusters we see in our universe.
> 
> 
> The point is, to get back to page one of this thread, is that the entire system is pretty much 98% mathematically predictable, based on know proven maths, whether we are talking about how solar systems from, or how galaxies form, or how the mass of the galaxies formed and distributed out the  fireball. Even the ratio of Hydrogen to Helium after the Epoch of the Last Scattering is precisely defined by the maths. 
> 
> 
> its all known, predictable maths from 1 second after the big bang. The universe is ruled by maths, to be accurate, by 16 known constants that existed at the moment 3D space popped out.


I avoided cosmology/astronomy in my Physics study, as it did not seem useful or practical.
I have read in in the intervening years out of sheer personal interest.

What I said was absolutely correct and does not buck the theoretical models that you speak of.

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## nonsqtr

> Nope, exact;ly the same maths applies in the way the gas distributes. we have built phenomenally detailed models that produce universes with exactly the same type of filaments , void and galaxy clusters we see in our universe.
> 
> 
> The point is, to get back to page one of this thread, is that the entire system is pretty much 98% mathematically predictable, based on know proven maths, whether we are talking about how solar systems from, or how galaxies form, or how the mass of the galaxies formed and distributed out the  fireball. Even the ratio of Hydrogen to Helium after the Epoch of the Last Scattering is precisely defined by the maths. 
> 
> 
> its all known, predictable maths from 1 second after the big bang. The universe is ruled by maths, to be accurate, by 16 known constants that existed at the moment 3D space popped out.


No, and no.

Your so-called phenomenally detailed models depend on a plethora of unproven assumptions, like dark matter and such. You clowns can't even agree on the cosmological constant!

The problem is, the field theories predict a huge value, it's off by 120 orders of magnitude if your models are going to work!

But we're talking apples and oranges.

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## Authentic

Is the dark side of the moon racist?

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## Physics Hunter

> Is the dark side of the moon racist?


No, it's oppressed!

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Authentic (07-18-2021)

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## nonsqtr

> Is the dark side of the moon racist?


It's black, how can it be racist?

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## UKSmartypants

> It is facing us during new moon which would be while it's between us and the sun.


 Consecutive hotographs of the moon taken every 4 days over a period one month. Notice the same face is always shown, even some of it is in shadow/ At no point does it appear to rotate on its own axis.



This ofc can be observed with your own eyes.  This is Tidal Locking in practice.

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## Authentic

> It's black, how can it be racist?

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## Authentic

John Wiley Price is known to Metroplexans as "our moron downtown".

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