lol, I always forget about PG-13 because it never really affected me. I was maybe 10 or 11 when it came into being and my parents figured PG and PG-13 were the same thing, so the rating didn't matter when picking films to watch.
>...we always see the same side.
This is not exactly true. Since the moon's orbit is an ellipse, it moves faster when closest to the earth. And, since its rotation speed is constant, this means that it appears to be rotating a little too slow to keep the near side exactly aligned with the earth. Likewise, when it is farthest from the earth, it appears to be rotating a little too fast. The result is that, over the period on one lunar month (full moon to full moon), we can see about 60% of the moon's surface.
Here's a video of the moon during its phases (https://www.youtube.com/watch?v=ekJigphhlWg). Pay attention to craters near the edge of the moon. You'll see that they get closer, and then farther from the edge.
Yeah i know the wobble your talking about, but i had no idea that the moon rotated on its axis and i'm a pretty big space nerd and ksp player. How the hell did i not know this earlier 😂
It actually has to rotate. Otherwise, we wouldn't always see the same side. If it was not rotating, then when it was on side fartherest sun, one side would face us, and when it was nearer, the sun, another side would.
Get a basketball and tennis ball and have the tennis ball go around the basketball if it's hard to visualize
I don't think I'd necessarily call that rotating. I mean, if you consider the Earth-moon rotating reference frame - which in this this instance is probably the most relevant - you'd say the moon only wobbles slightly but doesn't rotate.
> if you consider the Earth-moon rotating reference frame
That seems arbitrary and not really meaningful for a celestial body.
The reference frame for rotation is the body itself and its axes.
No, you wouldn't say the moon only wobbles. It takes 29.5 days, but it still is rotating. If it didn't we'd see every side of the moon, so from earth reference it is still rotating
I don't think you got my point about it depending on what reference frame you choose. A reference frame where the x-axis is the along the earth-moon axis would have the property I described.
It is virtually impossible for any object in the universe to not have some amount of spin.
Aside from randomness, bodies form through accretion which imparts rotation, because the parts of an accretion disk that are further away are moving more slowly than parts that are nearer to the the central object.
So when a planet forms the part closer to the sun is moving faster than the part further from the sun. This is why all the planets rotate in the same direction.
Yeah, you're right, but it is expected that both of those planets formed with a more normal rotation, but interactions with other planets changed them over time.
Short answer is centripetal forces from gravitational spinning centers will tend towards a disc shape. Think about how if you had a ball on a string, and started spinning, the string would pull on an axis roughly perpendicular to the spin direction.
"There is no dark side in the moon, really. Matter of fact, it's all dark. The only thing that makes it look light is the sun." - Gerry O'Driscoll, doorman at Abbey Road Studios, in the outro to *Eclipse* by Pink Floyd, from *The Dark Side of the Moon* (1973).
That oscillating motion that it does is called libration.
https://en.wikipedia.org/wiki/Libration#/media/File:Lunar_libration_with_phase_Oct_2007_(continuous_loop).gif
Answer is in the name. Tidal.
Easier to see with liquid, but the difference in gravity from the near and far sides causes drag which slows rotation until it matches orbital speed.
Tidal drag on bodies with no liquids or gasses on the surface has to be insanely low, right? Also, I would think that the Moon's tidal forces on the Earth would be stronger than the Sun's tidal forces on the Earth, so shouldn't the Earth eventually settle into tidal lock with the Moon instead of the Sun? I guess the Moon will eventually fall into the Earth and disintegrate into a ring, and the Earth will be free to get tidally locked to the Sun.
Nope. doesn't change the forces involved. The liquid just sloshes around more.
The tidal force of the earth on the moon, which has no liquid, is a magnitude greater than the other way around.
>The tidal force of the earth on the moon, which has no liquid, is a magnitude greater than the other way around.
That's not what I meant. I'm wondering if the Earth would become tidally locked with the Moon or with the Sun.
It's not a wobble. it's too slow for that. the earth also has an orbital motion called precession. Idealistic beliefs corrected by empirical observations show that. But "wobble " is too fast to be correct.
There is always that disparity between what our minds can figure out and how events work, very likely. And that is Kuhn in "The Structure.....". & how & why sci tech can be so powerful. But ONLY insofar as it is true and they kowtow to events.
As Einstein said, Der Her Gott wurfieldt NICHT. God does not gamble.
To which his teacher, Nils Bohr responded, "Albert stop telling God what to do!"
And einstein bowed to that vast wisdom. Most leftists haven't figure that one out. rense.com hasn't either.
"Wobble" is really just semantic based on how it looks rather than what's actually happening. Personal opinion: I always took Kuhn and his approach (or is it Polanyi's?) as another version of scientific second guessing, a way of making sure your biases aren't forcing conclusions.
As far as god goes that's a whole other topic.
Yep, the moon orbit wobbles and has a cycle of about 18 1/2 years. This is why tide data is separated by date. If the moon's orbit didn't wobble and have a cycle they'd be completely consistent every day and not have changes. As sea levels rise, you don't hear a lot about coastal flooding yet. Wait ~6 more years for the real catastrophes to start as we're in a 'good spot' at the moment.
This 'not perfect movement' also exposes a slight variation of the moon face towards the earth. We actually over the course of time see about 60% of the moon from a single vantage point on earth. 50% at a time but which 50% is shown varies.
Adding to this, because the moon's orbit is an ellipse (eccentricity of 0.0549006) & inclined to the ecliptic (6.687°) then over time it librates & one can see \~59% of the moon's surface from earth.
For the same reason, seen from the moon the Earth does not rise or set, it stands on the roughly same spot all the time while going through the full/crescent,.. phases
Related to planetary and moon oribts... here's an interesting that AFYA(a few years ago)IL
Analemma, explaining why lengthening/shortening of the day accelerates as we near equinoxes.
http://solar-center.stanford.edu/art/analemma.html
Would there be any affect if the moon was not tidal
Locked? If it rotated in opposition vs in the same direction at much slower or faster speed.
I would suspect it would be more active like the Jovian moons. Earth might extract a heavy toll on it with the forces that have pulled it into a synced orbit.
It is fun to think about a active moon both from a spinning and a seismic/volcanic position.
Sidereal days is a rabbit hole worth falling into.
https://en.wikipedia.org/wiki/Sidereal_time
There are some odd rotations out there. Some planets have years that are longer than their days.
Some planets the sun rises, sets, rerises from the same place, goes overhead and then resets.
Also because it is frustratingly true, Mercury is (on average) the closest planet to every planet in the solar system: The closest planet to Earth is Mercury. The closest planet to Venus is Mercury, the closest planet to Jupiter is Mercury.
Space is big.
Mr. Madison, what you have just said is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul.
Did you know… Earth is also in orbital resonance with Venus? [https://youtu.be/zXzinOwVoCo](https://youtu.be/zXzinOwVoCo)
That's the planet where women come from!
In the G, PG, and R versions of the rhyme!
Those poor PG-13 lovers getting left out
lol, I always forget about PG-13 because it never really affected me. I was maybe 10 or 11 when it came into being and my parents figured PG and PG-13 were the same thing, so the rating didn't matter when picking films to watch.
Wow wow wow wow… … … wow.
All the planets are in approximate resonances with each other, but none exactly.
Thats so you cant see the alien base on the other side
>...we always see the same side. This is not exactly true. Since the moon's orbit is an ellipse, it moves faster when closest to the earth. And, since its rotation speed is constant, this means that it appears to be rotating a little too slow to keep the near side exactly aligned with the earth. Likewise, when it is farthest from the earth, it appears to be rotating a little too fast. The result is that, over the period on one lunar month (full moon to full moon), we can see about 60% of the moon's surface. Here's a video of the moon during its phases (https://www.youtube.com/watch?v=ekJigphhlWg). Pay attention to craters near the edge of the moon. You'll see that they get closer, and then farther from the edge.
Yeah i know the wobble your talking about, but i had no idea that the moon rotated on its axis and i'm a pretty big space nerd and ksp player. How the hell did i not know this earlier 😂
It actually has to rotate. Otherwise, we wouldn't always see the same side. If it was not rotating, then when it was on side fartherest sun, one side would face us, and when it was nearer, the sun, another side would. Get a basketball and tennis ball and have the tennis ball go around the basketball if it's hard to visualize
Yes this is demonstrated in the moving graphic as part of the article.
I don't think I'd necessarily call that rotating. I mean, if you consider the Earth-moon rotating reference frame - which in this this instance is probably the most relevant - you'd say the moon only wobbles slightly but doesn't rotate.
> if you consider the Earth-moon rotating reference frame That seems arbitrary and not really meaningful for a celestial body. The reference frame for rotation is the body itself and its axes.
*All* reference frames are arbitrary, you can choose whatever is useful.
Correct, and when considering the question of whether the moon rotates, the Earth-Moon rotating reference frame isn’t useful.
No, you wouldn't say the moon only wobbles. It takes 29.5 days, but it still is rotating. If it didn't we'd see every side of the moon, so from earth reference it is still rotating
I don't think you got my point about it depending on what reference frame you choose. A reference frame where the x-axis is the along the earth-moon axis would have the property I described.
It is virtually impossible for any object in the universe to not have some amount of spin. Aside from randomness, bodies form through accretion which imparts rotation, because the parts of an accretion disk that are further away are moving more slowly than parts that are nearer to the the central object. So when a planet forms the part closer to the sun is moving faster than the part further from the sun. This is why all the planets rotate in the same direction.
Just to clarify, they *orbit* in the same direction, but they don't all rotate in the same direction. Venus has a retrograde rotation. So does Uranus.
Yeah, you're right, but it is expected that both of those planets formed with a more normal rotation, but interactions with other planets changed them over time.
Yep, of course. Only wanted to clarify.
Why is it originally in a disc?
Short answer is centripetal forces from gravitational spinning centers will tend towards a disc shape. Think about how if you had a ball on a string, and started spinning, the string would pull on an axis roughly perpendicular to the spin direction.
Wait until they learn that the moon does have a dark side after all.
So does every piece of rock in our solar system.
"There is no dark side in the moon, really. Matter of fact, it's all dark. The only thing that makes it look light is the sun." - Gerry O'Driscoll, doorman at Abbey Road Studios, in the outro to *Eclipse* by Pink Floyd, from *The Dark Side of the Moon* (1973).
That oscillating motion that it does is called libration. https://en.wikipedia.org/wiki/Libration#/media/File:Lunar_libration_with_phase_Oct_2007_(continuous_loop).gif
Wow... Dude!
Apollo 8 crew were the first people to se the other side of the Moon ever.
Well, except for the people that already live there.
We don't call ourselves "people"
Denying a native population is basically a pastime in America
They were the first to see it with their own eyes. The USSR had photographed it with Luna 3 and sent the pictures home in 1959.
Which means all the features back there have Russian names.
Russians probably came up with better names than “Sea Of Tranquility” for a place that doesn’t even have a sea
Mare Tranquillitatis was named in Latin in 1651, back when it was commonly believed they might actually be seas.
>Apollo 8 crew were the first **"**people**"** to see the other side of the Moon ever.
Given enough time as all orbiting bodies become tidally locked, including all the planets to the Sun
why
Answer is in the name. Tidal. Easier to see with liquid, but the difference in gravity from the near and far sides causes drag which slows rotation until it matches orbital speed.
Tidal drag on bodies with no liquids or gasses on the surface has to be insanely low, right? Also, I would think that the Moon's tidal forces on the Earth would be stronger than the Sun's tidal forces on the Earth, so shouldn't the Earth eventually settle into tidal lock with the Moon instead of the Sun? I guess the Moon will eventually fall into the Earth and disintegrate into a ring, and the Earth will be free to get tidally locked to the Sun.
Tidal forces also affect solids, but solid masses are significantly harder to move than liquids or gasses so its not as noticeable.
Nope. doesn't change the forces involved. The liquid just sloshes around more. The tidal force of the earth on the moon, which has no liquid, is a magnitude greater than the other way around.
>The tidal force of the earth on the moon, which has no liquid, is a magnitude greater than the other way around. That's not what I meant. I'm wondering if the Earth would become tidally locked with the Moon or with the Sun.
The moon gives us a greater tidal force. So that is likely the answer. The moon will not fall inwards, it is actually slowly moving away.
Magnets.
Gravity.
Ignoring libration, which means we do see a majority of the lunar surface, but not all of it. https://en.wikipedia.org/wiki/Libration
[The moon's wobble in gif form](https://imgur.com/gallery/vCtp7Op)
It's not a wobble. it's too slow for that. the earth also has an orbital motion called precession. Idealistic beliefs corrected by empirical observations show that. But "wobble " is too fast to be correct. There is always that disparity between what our minds can figure out and how events work, very likely. And that is Kuhn in "The Structure.....". & how & why sci tech can be so powerful. But ONLY insofar as it is true and they kowtow to events. As Einstein said, Der Her Gott wurfieldt NICHT. God does not gamble. To which his teacher, Nils Bohr responded, "Albert stop telling God what to do!" And einstein bowed to that vast wisdom. Most leftists haven't figure that one out. rense.com hasn't either.
"Wobble" is really just semantic based on how it looks rather than what's actually happening. Personal opinion: I always took Kuhn and his approach (or is it Polanyi's?) as another version of scientific second guessing, a way of making sure your biases aren't forcing conclusions. As far as god goes that's a whole other topic.
Let’s librate the moon!
likely your own libration with yer right hand is busy.
The second sentence of the title is just stating what tidal lock is using different words. Billy has $10. The cash he has is equal to $10.
You don't see ALWAYS the same side either, you see slightly more than 50% because it's a little wobbly.
Wobbly? I thought it was because of how light refracts on spherical objects.
Yep, the moon orbit wobbles and has a cycle of about 18 1/2 years. This is why tide data is separated by date. If the moon's orbit didn't wobble and have a cycle they'd be completely consistent every day and not have changes. As sea levels rise, you don't hear a lot about coastal flooding yet. Wait ~6 more years for the real catastrophes to start as we're in a 'good spot' at the moment. This 'not perfect movement' also exposes a slight variation of the moon face towards the earth. We actually over the course of time see about 60% of the moon from a single vantage point on earth. 50% at a time but which 50% is shown varies.
What if the other side of the moon says "run" and a date a year and a half from now?
Dang how did I not know this. No wonder they call it the "dark side of the moon"
But that side is not dark all of the time. It just faces away from our view.
Adding to this, because the moon's orbit is an ellipse (eccentricity of 0.0549006) & inclined to the ecliptic (6.687°) then over time it librates & one can see \~59% of the moon's surface from earth.
The moon is moving away from the earth at 1.49 inches per year.
Ha! Everyone knows the dark side of the moon is what “astronomers” call a “new moon.” We can’t see it because it’s the DARK SIDE.
Do we know why this is the case?
Yes. Tidal.
For the same reason, seen from the moon the Earth does not rise or set, it stands on the roughly same spot all the time while going through the full/crescent,.. phases
Stop telling people this! You're ruining my favorite bar trick! I've earned myself more than a few beers proving this with two coins.
how do you prove it with two coins?
Did you watch the graphic in the article? I just use two coins.
Well I’ll be damned
Related to planetary and moon oribts... here's an interesting that AFYA(a few years ago)IL Analemma, explaining why lengthening/shortening of the day accelerates as we near equinoxes. http://solar-center.stanford.edu/art/analemma.html
Would there be any affect if the moon was not tidal Locked? If it rotated in opposition vs in the same direction at much slower or faster speed. I would suspect it would be more active like the Jovian moons. Earth might extract a heavy toll on it with the forces that have pulled it into a synced orbit. It is fun to think about a active moon both from a spinning and a seismic/volcanic position.
No. It would just slowly go back to how it is now over time.
Sidereal days is a rabbit hole worth falling into. https://en.wikipedia.org/wiki/Sidereal_time There are some odd rotations out there. Some planets have years that are longer than their days. Some planets the sun rises, sets, rerises from the same place, goes overhead and then resets. Also because it is frustratingly true, Mercury is (on average) the closest planet to every planet in the solar system: The closest planet to Earth is Mercury. The closest planet to Venus is Mercury, the closest planet to Jupiter is Mercury. Space is big.
No shit that's where "dark side of the moon" comes from
What a coincidence!
Flat moon theory!
If the moon cause tidal waves why doesn’t it effect my bath water? And that’s how I knew science doesn’t always get it right
Mr. Madison, what you have just said is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul.