Why does the same side of the Moon always face the Earth? The Moon has synchronous rotation: it's rotation period is the same as its period of revolution. Earth image credit: NASA
It's hard to understand because they are lying to you abut the moon spinning, it does not spin. Simple as that. Observation shows that , so they have to come up with nonsense explanations as to how it really does spin. Those nonsense explanations are what causes the confusion. It's very simple, if the moon spun on an axis we would see the whole thing from earth over a 29 day period, but we don't, because it's not spinning. They lie to us about a lot of things.
*imnotabotrlyimnot* ///"It's hard to understand because they are lying to you abut the moon spinning, it does not spin. Simple as that. Observation shows that , so they have to come up with nonsense explanations as to how it really does spin. Those nonsense explanations are what causes the confusion. It's very simple, if the moon spun on an axis we would see the whole thing from earth over a 29 day period, but we don't, because it's not spinning. They lie to us about a lot of things."/// While I agree with you, THEY don't consider it to be a LIE since they were taught synchronous theory nonsense in Astronomy 101, so it must be TRUE! Synchronous theory MUST be true since it would be so embarrassing for them if it weren't true and they failed to spot the theory's many problems themselves. The only TRVTH here is that my comments will be soon removed by our Fascist AstroGurl since "They" don't want a fair debate on the issue, because their synchronous theory nonsense is patently absurd, and it's also been disputed for hundreds of years by people such as Tesla, the genius who made their computers even possible.
zooxanthus: The reason orbiting bodies become tidally locked is due to gravitational pull between those objects. In the case of the Earth-Sun system, the Sun's gravity is pulling on the Earth in the opposite direction that we are rotating, causing the rotation to slow down. This is why we add leap seconds to our clock time. Our rotation rate slows by about a second every year or two. The Moon has already become tidally locked and so its orbit is now stable (no longer slowing). Hope that helps!
even though the earth spinning , it wont changes the truth that the moon always facing the earth with the same side (red side on the video) , the one who will changes is the side of the earth which is facing the moon ( sry bad english)
This would only complicate the driving cause of why our moon always faces us. I'm no expert, but I know gravity extends out from the center of a mass regardless of its rotation. My guess is when the moon tugs on our ocean the center of earth's mass is slightly shifted. I agree it would be cool to see, but it gets confusing for educational purposes!
It takes 28 days for the moon to orbit the earth. So that means the earth, in the video, would have to complete 28 rotations in the same time the moon goes around the circle once. It would look burred and barely recognizible as much more than a blue-green spinning wheel.
SelfReflective The moon doesn't rotate on it's axes, like the earth does, it just travels around the earth with only one side that always faces the earth.
thank you for this excellent and informative animation! this concept is difficult to visualize, and further complicated by the popular use of 'dark side' of the moon -- it's just the 'far side' but we only see the 'near side' from earth; (I also think it's pretty cool that water has been detected at one of the moon's polar areas, in places that are in perpetual shadow) ~
So if we only see one side of the moon then it means that it's not rotating around its axis, its just revolving around Earth. Because it shows in the video that the moon rotates on its axis then that would mean we'll see both sides of the moon, right?
@@paulmerritt8593 Astro-Physics Community (with 12,541 likes) has now given the following three writings the thumbs up. TOTAL PERFECTION: E=MC2 AS F=MA CLEARLY PROVES (ON BALANCE) WHY AND HOW THE PROPER AND FULL UNDERSTANDING OF TIME (AND TIME DILATION) UNIVERSALLY ESTABLISHES THE FACT THAT ELECTROMAGNETISM/ENERGY IS GRAVITY: A PHOTON may be placed at the center of what is THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the speed of light; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Indeed, the stars AND PLANETS are POINTS in the night sky. E=mc2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. Time DILATION ULTIMATELY proves ON BALANCE that ELECTROMAGNETISM/energy is GRAVITY, AS E=mc2 IS F=ma. Indeed, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=MC2 IS F=MA. Great. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. (Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black.) BALANCE and completeness go hand in hand. It ALL CLEARLY makes perfect sense. I have mathematically unified physics/physical experience, as I have CLEARLY proven that E=mc2 IS F=ma in what is a truly universal and BALANCED fashion. By Frank DiMeglio Mr. Boris Stoyanov is a super bright and an HONEST physicist. He has agreed that the following post is "crystal clear": ELECTROMAGNETISM/energy is gravity. This is proven by F=ma AND E=mc2. Accordingly, gravity/acceleration involves balanced inertia/inertial resistance; as ELECTROMAGNETISM/energy is gravity. "Mass"/energy involves balanced inertia/inertial resistance consistent with/as what is balanced ELECTROMAGNETIC/GRAVITATIONAL force/energy, as electromagnetism/energy is gravity. Gravity IS electromagnetism/energy. That objects fall at the same rate (neglecting air resistance, of course) PROVES that ELECTROMAGNETISM/energy is gravity. Think about it. By Frank DiMeglio THE SIMPLE, PROPER, FULL, AND BALANCED UNDERSTANDING OF THE SHAPE, FORM, AND RELATIONAL MOTION OF WHAT IS THE MOON IN UNIVERSAL ACCORDANCE WITH THE FACT THAT E=MC2 IS F=MA: What is THE MOON is moving AND not moving IN BALANCED RELATION to the Earth AND the Sun AS a linked AND BALANCED opposite in accordance with the UNIVERSAL fact that E=mc2 IS F=ma. THEREFORE, the rotation of WHAT IS THE MOON necessarily matches it's revolution; AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the shape AND form of the Moon is basically constant or invariant. The Moon is a BALANCED MIDDLE DISTANCE manifestation or form that is in fundamental accordance with the Earth/Sun BALANCE pursuant to the fact that E=mc2 IS F=ma. GREAT !!! Therefore, the Moon is electromagnetically/gravitationally extended AND contracted ON BALANCE in true agreement with the fact that E=mc2 IS F=ma. Gravitational force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. It ALL CLEARLY makes perfect sense. Gravity IS ELECTROMAGNETISM/energy. By Frank DiMeglio
James If you're claiming our moon has a 360˚ polar axial rotation along with its 360˚ orbit around the Earth (*synchronous rotation*), then please note that this picture of an orrery (a sun-Earth-moon model) DOES NOT REQUIRE ANY GEARING TO ROTATE THE MODEL MOON 360˚ while keeping one (1) face pointed at Earth: onedrive.live.com/redir?resid=e71a54cd3b075a15!147&authkey=!AP06TNc8WDdXEcM&v=3&ithint=photo%2cjpg If you try to devise an actual model of the Earth and our moon with a moon that actually has polar axial rotation (along with its 360˚ orbit around the Earth), then that moon will quickly start showing all sides to the center! *Synchronous rotation* is a MYTH! If you disagree, then post your proof of *synchronous rotation* here - let's see your logic in action.
James I had posted: ///KEN: "If you're claiming our moon has a 360˚ polar axial rotation along with its 360˚ orbit around the Earth (synchronous rotation), then please note that this picture of an orrery (a sun-Earth-moon model) DOES NOT REQUIRE ANY GEARING TO ROTATE THE MODEL MOON 360˚ while keeping one (1) face pointed at Earth: onedrive.live.com/redir?resid=e71a54cd3b075a15!147&authkey=!AP06TNc8WDdXEcM&v=3&ithint=photo%2cjpg “/// ///*James Just:* "It is not my claim although I am happy with the explanation. The claim is the current model accepted by science. Debate it with the Astronomers and Wiki. I have never claimed to be a scientist or astronomer of any kind.”/// *KEN:* So then, your only claimed “logic” used in this matter is that you blindly accept what astronomers claim, which is that our moon requires *synchronous rotations* in order to keep one face pointed at Earth? To be clear, astronomers are claiming the two (2) 360˚ spins required would be the moon's 360˚ polar axial *rotation* in the CCW direction (around an internal axis), while at the same time also *revolving* CCW 360˚ around the Earth (around a 2nd external axis). Did you look at the picture of this orrery: www.curiousminds.co.uk/image/cache/data/Edu-Lab/151-425x425.jpg Do your really see the moon in that model rotating 360˚ around its internal axis as the orrery’s moon *revolves* (orbits) 360˚ around the Earth in the center? James, those of us opposing *synchronous rotation* theory fully realize the expert opinion on the matter, which as that orrery proves, is clearly WRONG! We have other proofs, such as the FACT that the moon’s longitudinal librations occur midpoint between our moon’s apogee and perigee, which is NOT consistent with *synchronous rotation* theory. Indeed, google around for explanations on longitudinal librations and you will see that astronomers are all over the place when using *synchronous rotation* theory to describe what causes our moon’s longitudinal librations. There are two ways to look at revolving objects, from the center-point perspective (i.e., from Earth, the sun, etc), or from the outside (sidereal) perspective, and these two perspectives clearly differ by one (1) *apparent* rotation, as explained here: www.aoc.nrao.edu/~smyers/courses/astrolabs/navigation.html As astronomer Steve Myers explains, from the sidereal perspective our Earth has 366 (*apparent*) rotations per year, while from the center-point perspective of our sun, our Earth has 365 polar axial rotations per year. From our perspective here on Earth, or from the sun’s center-point perspective, our Earth has 365 polar axial rotations per orbit, with each rotation 24 hours long. However, from the sidereal (outside) perspective, Earth *appears* to rotate 366 times, with each rotation 23 hours, 56 minutes long. That extra 366th *apparent* sidereal rotation is merely the Earth’s one (1) 360˚ orbit being aggregated with the Earth’s 365 polar axial rotations -- that’s what the sidereal perspective does, it combines two very different types of spins together and treats them the same. From the center-point perspective here on Earth, our moon has zero (0) polar axial rotations, but from the sidereal perspective our moon *appears* to have one (1) rotation, but that single rotation is just its 360˚ orbit around the Earth and is NOT a polar axial rotation. The sidereal (outside) perspective gets even more confusing when it comes to orbiting objects that have a CCW orbit and a retrograde CW polar axial rotation, such as Venus has. From the sidereal (outside) perspective, Venus *appears* to rotate .92 times (less than one) around its polar axis, which is why a lot of your “experts” claim that a Venusian day is longer than a Venusian year, which is wrong since Venus actually has 1.92 polar axial rotations per orbit, thus nearly 2 days per each orbit. Many astronomers are clearly confused by the sidereal perspective. Don’t believe me? Google around and you will find that some “experts” say a Venusian day is shorter than a Venusian year, while other “experts” get it right. In short, your claim that it’s “logical” to rely on ‘expert’ opinion is not as logical as you may think since your ‘experts’ are clearly divided on the causes for longitudinal librations, as well as for the length of a solar day on Venus. *KEN:* These two perspectives would be easier for you to grok if you try doing this simple demonstration of "SPIN" using any round object, such as a can of tuna. Your body would represent the Earth and the can of tuna in your outstretched palm would be the moon. You need to actually get and do this for these spatial relationships to actually sink in -- don't worry, it only takes a minute to do. *EXPERIMENT #1* -- Place a can of tuna in your outstretched right palm, and with your left hand rotate the tuna-can both counter-clockwise (CCW) and clockwise (CW) - clearly, when you do that the tuna-can is rotating around its center of mass (CM) and its label would face (in turn) all four walls in the room. Now that you understand what it means for an object to rotate around its own center mass, let’s proceed. *EXPERIMENT #2* -- Place a can of tuna in your outstretched right palm, then turn your entire body 360˚ CCW - clearly, when you do that the can is now revolving around your body's center of mass (CM) and its label would again face (in turn) all four walls in the room, but it does that with no need to reach out with your hand to spin the can around its center mass (your body will now be the can’s exterior spin axis). This is what our moon is doing, and it’s also consistent with the moon in that orrery. *EXPERIMENT #3* -- Next, with the can of tuna in your outstretched right palm, turn your body CCW 360˚ again and give the can a single CCW 360˚ spin around its CM - that can (moon) would have TWO *apparent* rotations from the sidereal perspective (a 2:1 rate). Have a friend observe (from the sidereal perspective) and count, and they will see the label twice, while you in the center only see the can’s label once. Clearly, your friend would count two (one more then you) since your friend will see the can make one 360˚ orbit (around an exterior axis) and one 360˚ spin around the can's center mass, and two 360˚ spins = 2 spins from the sidereal perspective. *EXPERIMENT #4* -- Next, with the can of tuna in your outstretched right palm again, turn your body CCW 360˚ again, and with your left hand try to keep the can's label pointed to one wall - to do so, you will be forced to rotate the can CW 360˚ as you spin your body 360˚ CCW - i.e., the tuna can (moon) would have zero sidereal rotation (0:1). Venus is fairly close to doing that right now. -/-- After conducting *EXPERIMENT #4*, go back and watch AstroGirl’s above video, and with a fresh mind, look at her supposedly “Zero Rotating” moon and note how her moon is clearly ‘rotating’ clockwise (CW) 360˚ as it orbits 360˚ in the opposite counter-clockwise direction. Two 360˚ turns, one around an internal axis, and the 2nd 360˚ turn around an external axis, these two 360˚ turns in opposite directions cancel each other out. It’s as simple as that.
***** *Libration of the Moon* ///*James Just:* "And for the record, the only claim I make in this thread is that it does spin (rotate). I said nothing about all the bullshit you're on about. “Read the original comment to see mine in the proper context. Logic lol”/// *KEN:* I fully groked your original context, which is that you were accepting “Expert” opinion on this matter despite the many inconsistencies in that ‘Expert’ opinion. Clearly, you were spouting off about a topic you admittedly knew nothing about, which was obvious. Not exactly a stellar moment for you. You may feel blindly accepting “Expert” opinion is logical, but in areas where “Expert” opinion is at odds with other “Expert” opinion, or illogical on its face, I consider that to be sloppy thinking instead of “logical” thinking, as you had initially claimed when putting down another poster who had expressed legitimate doubts about "Expert" opinion on the matter. In any event, a very good PROOF that our moon no longer rotates would be the timing of our moon’s longitudinal librations, which occur midpoint between apogee and perigee. If our moon did *rotate* 360˚ around its polar axis as our moon simultaneously *revolved* 360˚ around an exterior axis (its barycenter), then can anyone here explain why maximum lunar longitudinal librations occur midpoint between its apogee and perigee? James, I fully realize that this topic is way over your head, so I'm not expecting an intelligent comment from you about lunar libration. “Expert” opinion is divided on the timing of our moon’s longitudinal librations, with some claiming it happens at perigee and apogee, and others claiming (correctly) that maximum lunar longitudinal librations occur midpoint between our moon’s apogee and perigee, but then they fail to explain why their supposedly rotating moon would be most out of sync while orbiting at the moon’s mean orbital speed. This first citation correctly states maximum lunar longitudinal librations occur midpoint between its apogee and perigee: --snip-- *Libration of the Moon* The apparent periodic pendulum-like oscillations of the moon at its center, as a result of which the spots on the lunar disk seen by an observer on the earth appear to shift slightly first in one direction and then in the other. Optical (geometric) libration and physical libration are distinguished. Optical libration in longitude occurs because the moon revolves about the earth non-uniformly while it rotates about its axis at a constant angular velocity. Figure 1 depicts an elliptic lunar orbit; Figure 1. Libration in longitude: img.tfd.com/ggse/32/gsed_0001_0014_0_img3447.png T is the earth (at the focus of the ellipse). When the moon is at position A (perigee), let some point a on its surface be visible at the center of the disk. After a quarter of a month, the moon will be at point B and will have turned about its axis one-fourth of a revolution, that is, 90°. The point a observed from the earth will no longer be visible at the center of the disk but will have shifted to the east. At position C (apogee), the point a again coincides with the center of the disk. At the end of the third quarter, the point a will lie to the west of the center at position D. The largest libration in longitude is 7°45″. encyclopedia2.thefreedictionary.com/Libration+of+the+Moon *KEN:* I’ve added some arrows and text to their graphic to better explain why maximum lunar longitudinal librations occur midpoint between our moon’s apogee and perigee: onedrive.live.com/view.aspx?cid=E71A54CD3B075A15&resid=E71A54CD3B075A15%21142&app=WordPdf Twice each orbit, our NON-ROTATING (despun) moon is simply facing the ‘Empty Focus’ of its elliptical orbit at ‘B’ and ‘D’ in that graphic. All elliptical orbits have two focus points, one occupied by the primary the body is rotating around, and the 2nd focus point is empty -- *all “Experts” agree with that*. *KEN:* This next *“Expert” opinion* incorrectly states that maximum lunar longitudinal librations occur when our moon is at its apogee and perigee: --snip-- There are four types of librations. The first is libration in longitude. It is a side-to-side wobbling of the Moon like it is saying no. Rotation of the Moon equals its revolution period around the Earth. The rotation around its axis is constant but the speed with which it orbits the Earth is not. This is a consequence of Kepler’s second law. The Moon’s orbit is not a perfect cycle but an ellipse. Therefore the speed around apogee is slower than the mean speed and quicker around perigee. For instance around apogee, its orbital speed is a little bit slower than that the Moon rotates along its axis. Therefore the western limb of the Moon is turned a little bit towards the Earth. At perigee, its orbital speed is a little bit quicker than that the Moon rotates along its axis and the western limb of the Moon is turned a little bit away from the Earth. As a consequence we experience a better look of the eastern limb. Figure 1.1 Around perigee, the Moon is closer to the Earth and its orbital speed is therefore larger. The opposite happens around apogee. At perigee the distance Earth-Moon is about 363263 km and at apogee about 405547km (National Maritime Museum, Royal Observatory Greenwich) [Their graphic on page 3 of this PDF]: users.telenet.be/lunar/jpeg/libratieboek.pdf *KEN:* Here we have two ‘Expert” opinions about how *synchronous rotation* affects our moon’s position at maximum longitudinal librations, and those two “Expert” opinions are 90˚ apart with no clear consensus. So much for “Expert” opinion.
***** ///*James Just:* "Seriously if you think I am going to read 113 lines you are a bloody idiot." *KEN:* No, I never thought you would read it, and even if you did read it you wouldn't understand it since you were obviously spouting off on a topic you were totally ignorant about, so I was never expecting an intelligent comment from you. Go back to sleep!
***** ///*James Just* (@ Ken Dine): "hmmm, whilst I am at it. If you were on the moon, it would be roughly 29 Earth days to one Luna day. It takes that long therefore to experience 1 day on the Moon.)"/// Not sure why you would be directing that apparent correction at me since earlier, when correcting the Lunatic-rotator Dudev (who wrongly claimed it was 27.3 days), I correctly had posted that a lunar day was instead 29.5 Earth days long. Were you trying to correct Dudev's erroneous 27.3 day posting?
For anyone else who might be struggling with this at 3 am instead of sleeping. What helped me picture the actual rotation of moon on its axis, was making the orbit smaller, making earth negligent in size and also taking the tilted axis of the moon into account.
I agree! At the beginning of the animation, moon without any rotation, it would be clearer if they wrote "...without rotation relative to the sun". At the end of the animation where the sun is included one can see that that there is rotation of the moon relative to the sun.
@@td866 without rotation relative to the sun is a given. The earth rotates around the sun and the moon rotates around the earth. So it appears as if the moon isn't moving because we are rotating around the same time.
Imagine You and your girlfriend (gf) in a childrens' park. You are at the centre of a roundabout. Imagine for now that you don't move. Now your gf is sitting on one of the seats, and she's moving with the roundabout. Every time she completes a round, you see her facing you. Now imagine you had an eye in the back of your head. You will still see her facing you when she reaches your back. This means that an observer, anywhere from earth(similar you your in this example) will see one the moons front face(gf face in this example).
Not quite true about Mercury since it isn't tidally locked to the sun. Mercury has indeed been tidally braked by the sun, but due to Mercury's highly eccentric orbit, Mercury actually does a cute little 180 degree back-flip each orbit, which is called a 3:2 spin resonance.
The shadow of the moon crosses the USA from west coast to east coast. If the earth is spinning 28 times faster counter clockwise (seen from top of north pole), shouldn't the moon's shadow go from east coast to west coast? The solar eclipse is a whole three hour process. The earth can't be slowing down for 3 hours.
No. As light travels pretty much in straight, parallel lines from the sun (at our distance anyway), what is important is the linear speed. The moon is travelling much faster than Earth and thus so is its shadow.
Nope. For the most part they are in parallel lines. There is a small variation due to the size of the sun, but not as much as they appear to diverge. It is only those who see it and don't understand perspective that think it is a pyramid shape. You know, the kind of people that would look at train tracks and say they are closer together when further away. Crepuscular rays are parallel. Just like all parallel lines do, they appear to converge as they get further away. Some times this can make the sun appear to be just behind a tree. At other times, it makes the sun appear as if it is inside Earth.
It looked like it wasn't rotating when you said it was. If it rotates then it goes around once, then at one point in it's orbit it should show the other side somewhere on earth. Either I don't understand the word synchronous or just can't picture the rotation spatially.
Thank you for this animation. I read a few different explanations of synchronous rotation, but only after seeing the animation did it become clear to me.
And the servants of the Most Merciful are those who walk upon the earth easily, and when the ignorant address them [harshly], they say [words of] peace, Qur'an 25:63
So the same side of the moon always faces the earth, and the moon is exactly the same size relative to distance from the earth as the sun. Conclusion: there's something fkn weird about the moon.
Or many statistically unlikely events occurred and we need to believe that. What are the chances that by random chance this happened? It fell into perfect orbit so we only see one side of it. /scratches head/
theskateboardfan the moon is heavier on one side, so earth's gravity pulls the heavier side of the moon towards it. i honestly felt like a fool for not realizing how simple it was on my own
Damien Perry Hi Damien, It's not quite that simple since our moon's heavier side is the far-side of our moon. Gravity is still not fully understood, but what's clear is that our moon is trapped within Earth's gravity well, and Earth and our moon are also both trapped within our sun's gravity well. However, even though astronomical bodies can be trapped within a larger body's gravitation well, gravity still doesn't act like a tractor beam to FORCE a portion of a trapped body's heaviest side to face inwards to its primary that it's orbiting around. PROOF? During each orbit about Earth that our moon makes, our moon is actually pointing away from Earth more than our moon points directly towards Earth, which is called "longitudinal librations". How could that happen if Earth's gravity acted like a tractor beam on our moon's nearside? That's not to say that Earth's gravity didn't pull at our moon's tidal bulges as Earth's gravity slowly despun our moon billions of years ago, so I'm just saying that the tidal braking process is very slow and it takes many hundreds of millions of years for tidal braking friction to slowly despin a moon. While Earth's gravity can slightly tug at our moon's nearside each orbit to try and pull it to face us, that tugging force is so slight (per each orbit) that it's inconsequential in the short time frame of our moon's orbit each month, so mostly (over 50% of the time) our moon faces the empty focus of its elliptical orbit rather than facing directly at Earth.
Ken Dine I incorrectly made that conjecture on my own, after discovering the moon was "lopsided" for lack of a better word. I assumed that the heavier side was toward earth and incorrectly put 2 and 2 together. We definitely agree that gravity has some role in synchronizing the moon's axial rotation with its orbit, though. I don't intend to jump to conclusions, but we all falter, I guess
"Hi -- Our moon isn't always the perfect size to cause a total eclipse of the sun." I think that's a minor technicality. It's still an incredible coincidence. So... Why has the moon already stopped spinning beyond following it's own elliptical trajectory, but the earth hasn't? Is it the size difference (which isn't THAT big)? Is it actually an effect of the earth's gravity that the moon has slowed, or could it be... friction?
i get that it looks like its rotating on the true example, but its like swinging a ball out at arms length. the side the ball is tied to the string will always face you, but its not rotating... from a distance it could look like it, but from your POV, like earths POV, it isnt rotating at all. just being pulled by centrifugal force
This is an excellent representation of the synchronous rotation of the moon. I was able to do a simple experiment to confirm it. This can be a tricky concept to understand so it helps to do an experiment in three dimensional space. 1) I simply took a tennis ball to represent the moon and marked an X on the face of one side to represent the side of the moon we always see. 2) I then began rotating this tennis ball in my hand as I moved my hand around another tennis ball sitting stationary on the center of a table to represent the Earth. 3) Once I rotated the ball representing the moon at the same rate that I was circling the center ball (Earth), I was able to make one complete rotation of the moon tennis ball in my hand every time I completed a revolution around the center tennis ball (Earth). 4) I observed that the X side of the tennis ball representing the side of the moon we see was always facing the center tennis ball (Earth). My conclusion? Not surprisingly, the moon does rotate on its axis as it orbits the Earth. The timing of the rotation of the moon on its axis and its orbit around the Earth are synchronized so there is an illusion from our perspective that the moon does not rotate at all. Try it!
I believe your experiment is flawed, try it again but this time stand on the axis of the orbit or your earth ball (as I believe you should when studying orbits) and rotate about that axis, you will see it is now not necessary to rotate your moon ball on it's axis. Imagine a car traveling around a circular track, from outside of the track you will see both sides of the car during one orbit. Move to the inside of the track and you will only ever see 1 side of the car. In neither case does the car rotate about it's axis, yet it appears to do so if viewed from outside the system and it appears not to do so when viewed from inside the system!. Look again at this video and it actually explains very well why the moon does not rotate about it's axis. Look from 00:30 where the moon is rotating about it's axis several times per orbit.(Now at all times watch ONLY the moon and its axis..the earth and the edge of your RU-vid screen has nothing to do with it. )Imaging you break the white circle representing a plot of the moons axis and straighten it out, notice the red 1/2 crosses to the other side of the axis during each revolution.Now watch the orbit that supposedly shows synchronous rotation. Do the same thing imagine you stretch the white circle into a line...the moon does NOT cross to the other side of its axis plot in fact it does not move the slightest bit on it's axis..how can bending the axis plot back into a circle magically make the moon start spinning? I am not 100% convinced the moon does not rotate on it's axis, but I lean towards thinking that it does not and would be glad to hear any argument you have to prove it does as I enjoy being wrong, it means I have learnt something new :-)
Tony Carlaw I appreciate your admission and willingness to be proven wrong. First of all, while this is not proof that the moon rotates, it is worth mentioning. You will not find a single educated astro physicist in the entire world that would agree with an assertion that the moon does not rotate. Either you know something they don't know - which is unlikely (no offense intended), or they are all lying. If you are right, which is it? Second, rotation is rotation. Rotation is simply a change in orientation about an axis. Does the moon do this or not? The best way to tell this is to determine if the moon changes its orientation relative to a fixed reference frame. Unfortunately, there is no such thing. However, for our purposes we can define one. The moon's rotational period according to science is about 28 or 29 days. The distant stars - while not stationary - are for all intents and purposes stationary. They do not move relative to the Earth in a 28 or 29 day span far enough for there to be confusion about whether the moon rotates about an axis - or the distant stars rotate around the moon in that same span. The fact is, if you were standing on the surface of the moon, the sun would rise and set - the distant stars would rise and set - every 29 days or so. There are only two possible explanations for this. Either the sun and the stars are orbiting the moon, and completing an orbit every 29 days - - - - or the moon is rotating and its rotational period is 29 days. The same applies to the Earth. The sun and the distant stars orbit the Earth every 24 hours (relative to the Earth). There are only two explanations for this. Either the Earth is stationary and the sun and stars all orbit the Earth every 24 hours - - - - - or the Earth rotates and its rotational period is 24 hours.
Willoughby Krenzteinburg Hi, I am afraid I disagree with your claim that scientific consensus is proof of anything, there are many many cases where the consensus was later proven to be wrong. I feel that "consensus science" is a major stumbling block to science today, I disagree also with there only being 2 options for astro physicists , there is the 3rd possibility that they are not lying but simply mistaken or are victims of an optical illusion. I do however agree with you in that it is unlikely I know something they don't and took no offense at all at you suggesting same :-) I believe your assumption that you can acuratly observe an orbit from a stationary point outside the orbit is possibly incorrect and the explanation to this conundrum. When observing an orbit , I follow this rule. "You must observe an orbit from the axis or move with the orbiting object and view it along a line of the axis and the object" Place a mug on a microwave with the handle facing away from you and towards the axis. At 180% rotation the the handle is now pointing towards you..how can this be as clearly the mug has NOT changed it orientation about its axis? Now also move your point of view 180% around the microwave and the handle is now pointing away from you as it should be if the mug is not rotating on its axis.Of course you will have to cut the back off your microwave to see this, but fortunately it is easily imagined :-) If I stand at the same observation point as the mug orbits, it will see me rise and set just as the moon sees the sun and distant stars rise and set in your example, yet in my opinion the mug does not rotate about it's axis. This whole conundrum comes down to whether you think the mug does or does not rotate about its axis as it orbits, and I would be very pleased to know your opinion . This is a win win argument , if you convince me to change my mind, I have learned something new and that's always a win. Mind you, you will never change my mind on concensus science :-) .Thanks for taking the time to reply.
Tony Carlaw What you said, " I am afraid I disagree with your claim that scientific consensus is proof of anything" I did not assert or imply that it was proof of anything, and I explicitly stated this What I said, "while this is not proof that the moon rotates, it is worth mentioning. You will not find a single educated astro physicist in the entire world that would agree with an assertion that the moon does not rotate." So, I acknowledged that it was not proof of anything; just worth mentioning. "At 180% rotation the the handle is now pointing towards you..how can this be as clearly the mug has NOT changed it orientation about its axis? " Either you don't understand what an 'axis' is or you do not understand what 'rotation' is. If either of those are the case, then we have a long way to go. "Now also move your point of view 180% around the microwave and the handle is now pointing away from you as it should be if the mug is not rotating on its axis.Of course you will have to cut the back off your microwave to see this, but fortunately it is easily imagined :-)" And you would have to constantly be changing your frame of reference to make this happen. That is an invalid frame of reference from which to base your conclusions. Let's just use measurable data. Any object that is rotating about its axis will have measurable angular momentum. This is the case with the moon. It has been measured, and it is consistent with an object with the mass of the moon with a rotational period of about 29 Earth days. There is a measurable amount of centrifugal force that exists on the moon that counters the gravity of the moon, and once again - this has been measured and is consistent with an object with the mass of the moon with a rotational period of about 29 days. I'm not sure what your goal here is. What are the consequences to you personally if you are wrong (because you ARE wrong)? The only thing you have demonstrated is that from a reference frame that is constantly changing, a mug in a microwave does not rotate about its axis. That's thin at best (and actually obvious if you control that change)- - - if you can't see that, then I'm not sure what you are after here. Rotation is accelerated motion. It is not relative. Relativity only applies to inertial motion. There are experiments and observations that can be made that can determine rotation. Like I said, there are only two possible explanations for the observation one would make from the moon. Either the stars are orbiting the moon, or the moon rotates. If you can name a third, I'm all ears.
Tony Carlaw If someone wants to feel like they are a self-important independent thinker by going against all scientific data there is nothing to stop them. Sometimes people are motivated to have contrary opinions regardless of the overwhelming evidence proving them wrong. Some people are driven by ego others because they seek drama and intrigue where none exist. The idea that there is a grand and meticulously orchestrated conspiracy to lie about the actual mechanics of the moon's orbit in an attempt to keep the masses in the dark is laughable at best. I think that Ockham's Razor applies here: 1) is it likely that there is a grand orchestrated conspiracy by all educated astrophysicists around the world to fool people? 2) is it likely that all educated astrophysicists around the world are wrong? 3) are you simply wrong? I think I will put my bet on #3. Although my observation here does not "prove" that the moon orbits around its axis, it does shed some light on a possible reason for your belief other than the moon actually being stationary on its axis.
Makes more sense if someone says it does not spin. I've had my telescope on the moon for hours and I have never ever detected ANY spin. I believe what I see not what I'm told. If I believed what I was told, then I would be praying to god right about now.
@@rawwad That is not a spin god damn it ! Jaj. Spinning is in the same place. This video thing is just moving around the earth. Otherwise earth would be spinning in his axis and another spinning around sun. Thats ridiculus.
I almost lost my mind I was trying to debunk flat earthers when i had this in my mind! what if they asked me why we only see the same side of the moon! I really was freaked out so I had to research It said it rotates same speed as it goes around earth didn't get it at all so I saw this vedio and bam simple as it gets I really see how it works now!
if the moon were rotating equivalent to its complete orbit around the earth, the red half depicted in this video would be have rotated 180° half way through its orbit. That is not the case here.
+myviews Why, because the moon is what astronomers call "Tidally Locked" to the earth. As it rotates on it's own axis it presents only the locked side to the earth. If it didn't rotate we would see all sides as the two coin demo proves and as countless other videos and demos prove. Perhaps MVK needs an eye exam because he is blind to the truth or maybe just stupid. I'll go with stupid.
+myviews the moon is aparently denser on the side that faces us hence there is more gravitational pull on that side according to modern physics anyway.
+AdmiralBird +Alex ander Magnetic field is (basically) an effect of the speed of the rotation of the core, and the Moon doesn't have much of an active core or convection, so its field comes from a combination of off-axis movement between the mantle and core. The moons magnetic field is quite unrelated to the gravitational effect it might have, though. When the Moon was settling, Earths gravitational pull dragged on the Moons molten iron core forcing it upward but only on the near side to the Earth; indeed making the Moon 'lopsided'. It's not visible from the outside, but it's a fact. The crust on the Earth side is about half as thick as the far side because the core is sitting up there. The density on this side results from the Earths gravitational pull, rather than the gravitational pull being stronger because the Moon is more dense on this side. Source - studying astrophysics at AZU
+Jorge Macias Look up at the "clouds" they're spraying just about every day now. Especially at sunset. The colors from all that aerosolized barium, aluminum, etc., are breathtaking.
This has always been somehow out of my ability to visualize. Thank you so much for this. Now when I look at the moon in its phases, it will make sense to me.
why can everyone claim to have the answer to the Moon's rotation, but cannot get "it's" and "its" right. "It's" is short for "it is" and "its" is the possessive. As far as the Moon's rotation goes, it depends on which reference system you use. It appears to rotate from our point of view. From its point of view it is travelling in a straight line through space which is curved from the Earth's gravity.
I love to see a fellow pedant - but, no, the Moon appears NOT to rotate from our point of view, as we always see the same face, so I don't know where you got that from, but, wrong! And the reason being, that it DOESN'T ROTATE, see above! (ref; billymodo, Jinga etc)
If something rotates on its axis EVER, you will see the other side of it eventually. In this scenario, the moon is not rotating at all. The act of it rotating and the act of it revolving still have two different meanings. They should just say the moon has no axis rotation because it is not rotating.
This, by definition is NOT I REPEAT IS NOT a rotation...smh Im starting to think that the moon is a projection of some sort. If you cannot see the back of something at some point in the revolution then it does not rotate on its axis... simple. Now someone please tell us whats really going on.
///“Brent Fisher:* “This, by definition is NOT I REPEAT IS NOT a rotation…smh Im starting to think that the moon is a projection of some sort. If you cannot see the back of something at some point in the revolution then it does not rotate on its axis... simple. Now someone please tell us whats really going on.?”/// *KEN:* What’s going on here is an ‘*Argument from Authority*' -- hey, we’ve all used it and we’ve usually been right when we do use that argument, but in this one instance, the authorities are WRONG ….embarrassingly, WRONG! Most astronomy websites today do spout synchronous rotation nonsense, but their flawed 'theory' simply CANNOT be modeled! Nevertheless, students tend to believe what their teachers say, which is good since they mostly teach things which are true, but sadly, not in this instance. This dispute has actually raged for hundreds of years. Several hundred years ago after debating it the Royal (British) Astronomical Society put it to a vote, and most astronomers back then agreed that our moon had no polar axial rotation left (their debates prior to the vote are online and interesting to read). Nevertheless, you can’t keep a fanatical lunatic rotator down for long, so today they teach synchronous rotation theory as fact, despite their theory’s obvious flaws. An enterprising psych major should do a paper on how this mass delusion came into being and lasted for so long.
I wish I knew... it does not make sense, that if the moon orbits the Earth, and the Earth orbits the Sun, then the moon would appear in the day time often and sometimes not at all in the night because it would be on the otherside of the Earth right? its confusing, I will keep looking up videos until I get my answer
That's why you have new moon, full moon, and lunar eclipse. Moon does show up at day time (near equator, sometimes you can see it in a clear morning during dry season) but usually it's overpowered by the light reflection from earth.
The moon's rotation on its axis matches the time it takes for it to complete one orbit around the Earth. That's why the far side of the moon does not ever face the Earth. Furthermore, other planets are said to be tidally locked to their companions. Now that Ken brought up a good point, I will search if there is any evidence behind this. I wanted to know how anyone came to this conclusion. I don't see why the moon would be a projection considering that we have visited our moon as well other moons exist in our solar system. If it is a projection, we will need a projector.
From 0:58, the moon IS NOT rotating around his own axis. I am the moon, the red part is my face, the grey part is my ass, in the center there is a friend of mine with eyes all around his head (so his rotation now doesn't really matter, he can always look at me), if i start rotating around my axis sooner or later he's gonna look at my ass...doesn't matter how fast i rotate, his thousands eyes are always watching me so sooner or later he's going to see my ass. But with the moon that doesn't happen because it rotates around earth's axis not his own... At 0:58 the god damn moon is rotating around earth's axis NOT his own... I'm not Einstein, Galileo or Copernico but hey..that's pretty clear.
Super Nova But it doesn't rotate around his own axis, at 0:58 it's rotating around earth axis, which is different. "An unalterable rotational velocity thru all phases of planetary evolution is manifestly impossible. The truth is, the so-called “axial rotation” of the moon is a phenomenon deceptive alike to the eye and mind and devoid of physical meaning. The moon does rotate, not on its own, but about an axis passing thru the center of the earth, the true and only one.” -Nikola Tesla
Super Nova ///*Super Nova:* "Think again. Didn't you see the first example when he shows the moon without any rotation?"/// *KEN:* You are wrong and you have obviously been deceived by the above video! The supposedly zero-rotation moon in the above video would be easier to grok if you try this simple demonstration of "SPIN" using a can of tuna - your body would represent the Earth and a can of tuna would be the moon. You need to actually get up and do this for these spatial relationships to actually sink in - don't worry, it only takes a minute to do. Any round object will work, but when you use a can of tuna you can eat the experiment when you're done. If nothing else, do #4 below: ---snip--- *EXPERIMENT #1* -- Place a can of tuna in your outstretched right palm, and with your left hand rotate the tuna-can both counter-clockwise (CCW) and clockwise (CW) - clearly, when you do that the tuna-can is rotating around its center of mass (CM) and its label would face (in turn) all four walls in the room. Now that you understand what it means for an object to rotate around its own center mass, let’s proceed. *EXPERIMENT #2* -- Place a can of tuna in your outstretched right palm, then turn your entire body 360˚ CCW - clearly, when you do that the can is now revolving around your body's center of mass (CM) and its label would again face (in turn) all four walls in the room. This is what our moon does. *EXPERIMENT #3* -- Next, with the can of tuna in your outstretched right palm, turn your body CCW 360˚ again and give the can a single CCW 360˚ spin around its CM - that can (moon) would have TWO *apparent* rotations from the sidereal perspective (a 2:1 rate). *EXPERIMENT #4* -- Next, with the can of tuna in your outstretched right palm again, turn your body CCW 360˚ again, and with your left hand try to keep the can's label pointed to one wall - to do so, you will be forced to rotate the can CW 360˚ as you spin your body 360˚ CCW - i.e., the tuna can (moon) would have zero sidereal rotation (0:1). Venus is fairly close to having a zero-rotation rate (from the sidereal perspective) right now. -/-- After conducting *EXPERIMENT #4*, go back and watch AstroGirl’s above video, and with a fresh mind, look at her supposedly “Zero Rotating” moon and note how her moon is clearly ‘rotating’ clockwise (CW) 360˚ as it orbits 360˚ in the opposite counter-clockwise direction. Two 360˚ turns, one around an internal axis, and the 2nd turn around an external axis, cancel each other out. It’s as simple as that. If you need further proof, then they’ve been making orreries (sun-Earth-moon models) for hundreds of years, and any orrery can prove that our moon doesn’t require polar axial rotation to keep one face pointed inwards:: onedrive.live.com/redir?resid=e71a54cd3b075a15!147&authkey=!AP06TNc8WDdXEcM&v=3&ithint=photo%2cjpg Do you really see that moon model rotating 360˚ about its metal support spindle? I don’t see that moon rotating 360˚ about its metal support spindle, and miraculously, that model moon in the orrery still manages to show only one face inwards towards the Earth model, and the only 360˚ ‘spin’ I see in that orrery is its moon's 360˚ ‘REVOLUTION' (orbit) around the Earth. Can you provide a model of *synchronous rotation* to prove that our moon still retains one last 360˚ rotation around its polar axis?
I'm having a hard time grasping this concept as well. Check out this link. After watching over 20 videos, surprisingly this was the most helpful out of them all. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LFsE6ugEN7U.html
Kitana (Goharik) That video is just another penny-around-the-quarter parlor trick, so don't be deceived by the differences between the outer (sidereal) perspective versus the center-point perspective.
This is a great and accurate video. I was looking for a good video of synchronous rotation of the Moon to show to my class, and I will use this one. Thank you!
Why don't you model it with the earth spinning too...lolKind of isn't a model unless you show how it works in supposed reality..Shame we don't have any videos or photos of the earth from 5 moon missions for reference...I wonder why that is?...:)
There are photos of the Earth from the moon. The demonstration in this video is only addressing the moon's rotation. Having an accurately rotating Earth does not add to or take away from this demonstration in the least. If you are concerned with that, then you are missing the point.
Total bunk. Just admit it doesn’t rotate. If I tie a washer to the end of a string and twirl it with my finger, is the washer spinning? Nope. It’s remaining stationary. It’s path though is rotating around the central axis, in this case, my finger. One fixed side of the moon always faces the earth. Period. That’s all you need to know. As a body it rotates around the earth as an axis point, but no, not around its own axis.
One, not sure why you are so worked up about this. Two, the washer in your example is indeed rotating on a central axis. You can deny this all you wish, and at the end of the day, it's really a trivial thing. You seem to think there is some giant conspiratorial push to make you think it rotates when it does not, and it's just laughably asinine to consider that a viable possibility. If you were standing on the surface of the moon, the sun would rise and set; the stars would rise and set. Because the moon is rotating on a central axis. If you take a point located on the side of the moon facing the Earth, a second point located at the center point of the moon, and a third point on the far side of the moon - all of which lie upon a straight line from the center of Earth to - and through - the center of the moon, you would find each of these points make a virtual circle in their paths around the Earth. One bigger than the next. Obviously, each of these points make their trek around Earth in the same amount of time - so necessarily, the point farthest from Earth must necessarily be travelling faster to make its larger circle in the same amount of time. If you transfer the coordinate system such that the center point of the moon is the origin, you would find that the other two points would be traveling at the same speed - in opposite directions - about the central point of the moon - ergo demonstrating that the moon is undoubtedly rotating about a central axis. Once again, you can put your fingers in your ears and deny this all you wish; it doesn't change the nature of our universe. You are mistaken. Period.
@OmegaGenesisTrueEarth globetard? Your insults are both juvenile and uneffective. You're insulting yourself when you make an attempt to insult an intelligent person. The moon is tidally locked with the Earth - meaning its ROTATIONAL period matches its orbital period. That's why we always see the same side. It orbits the earth every month (it's where we get months from by the way), and rotates once a month. The moon always shows the same side to Earth ---- the moon must necessarily rotate in its orbit to make this possible. It's just that after billions of years, it becomes locked. It's still rotating, but it's rotation was slowed to match its orbit around Earth. The moon rotates, and you're an idiot.
wow, i finally understand this. thank you. so many large documentaries dont cover what may be considered super simple. if this had music or sound it would have even more views, very nice
The tidal lock is the consequence of the effect of the gravity gradient which itself comes from the fact that it is the heavier side of the moon which faces us.
That is incredible, how we find that planets and moons are rotating not only around their axis but around each other, and the stars are also spinning around the center of the galaxy which is so very massive, but invisible so we can't see it.
You don't understand. Anyway anyone ever tried to describe this process to me never made sense in my head. I've tried watching other videos and reading about the process and simply didn't get it. Then I saw this and the entire process made 100% sense. Thank you SO Much.
Steve's comment ending w/ gravity over time is pretty cool because it makes me think that the lowest energy state of a satellite would be a synchronous rotation with its heaviest side towards the larger body.
An excellent illustration. Now I understood why we see only one(same) side of the moon although I was trying hard to understand this for last 25 years ! Nevertheless I am happy today. Harish
Every night we see that the earth spins from *West to East* direction, but we see the moon moves from *East to West direction* as we're standing on North America. Why don't both move in the same direction from West-to-East direction?
Umm. If the Earth moves toward the east, things in the sky will move toward the west. Isn't this common sense? Face North. Hold your hand in front of your face. Move your head toward the east. Your hand will appear to move toward the west.
Hi Cecilia, AstroGirl's video is clearly wrong, so don't be duped by her video. Go back and look at the beginning of the above video that AstroGirl has labeled “Zero Rotation” and you will see that her supposedly zero rotating moon is in fact *’REVOLVING’* 360˚ CCW around an exterior axis (the barycenter within the Earth), as her moon *’ROTATES’* 360˚ CW around its interior polar axis. When an object has two 360˚ spins (in opposite directions) around two different axes, when viewed from the sidereal (outside) direction, that object will *’appear’* to have zero rotation since the two opposite 360˚ spins cancel each other out. An astronomical body with zero *’apparent’* rotations (from the sidereal perspective) is certainly possible since CW rotating Venus is approaching that so-called zero-rotation state. However, when Venus reaches zero rotations, like the moon in AstroGirl’s video, Venus will still have one remaining CW polar axial rotation to lose, so Venus (as with other astronomical bodies before it) will pass thru this transitory 'zero' state until Venus is fully locked to the sun, just as our moon is now locked to the Earth. Once a moon's surface stops moving in relation to the planet it's orbiting around, tidal braking friction ceases to work since the moon (or Venus) would be fully despun. Go back again and look at the beginning of the video that AstroGirl has labeled “Zero Rotation” and you will clearly see that her moon's surface is still moving in relation to the Earth in the center; consequently, that CW rotating moon is not yet fully despun. As any orrery proves, our moon only needs to *’REVOLVE’* 360˚ around an exterior axis, which is the barycenter within the Earth. If the moon had a 2nd 360˚ spin around its polar axis, then the moon would no longer present only one side to us. Please note that this picture of an orrery (a sun-Earth-moon model) DOES NOT REQUIRE ANY GEARING TO ROTATE THE MODEL MOON while keeping 1 face pointed at Earth: onedrive.live.com/?cid=e71a54cd3b075a15&id=e71a54cd3b075a15%21147&v=3&ithint=photo,jpg&authkey=!AP06TNc8WDdXEcM The above video, and the penny-around-the-quarter trick (etc), are all designed to distract you from what's really happening. As the coin experiment goes (in its various forms), place a quarter and a penny on a table and the quarter in the center will be the Earth, and the penny will be the moon. As you move the penny CCW AROUND the quarter, you are told to keep Lincoln's head on the penny facing towards the quarter, and you'll thus be forced to rotate the penny 360˚ to keep it facing the quarter - PROOF THE MOON ROTATES!!! planetarium.madison.k12.wi.us/files/planetarium/mooncal/coinrotation.jpg planetarium.madison.k12.wi.us/mooncal/moonfaq.htm As Hector noted in another thread, tape a penny to the top of the orrery's moon, and that penny will clearly not have polar-axial rotation. Our moon simply DOES NOT rotate around its polar axis, nor has it done so in over 3 billion years!!! Ken
Your example of a ball attached to a string actually describes the Moon's motion very well. The point of the ball to which the string is attached always faces the centre point of the rotation. From the point of view of an observer outside the orbit, the ball *is* rotating around its own centre. If you observe the ball when it is on the far side you see the point where the string is attached. When you see the ball on the near side you will see the other side of the ball.
i just finished my 8th grade school year and our 4th qtr.subject was astronomy. we went over this material in clss..(Why we always see one side of the moon.) And during the school year while we were studying it, i could never understand why. the explination was that the moon rotates on its axis as the same speed as earth does..something like that..but only now, halfway into my summer break, i finally understand! ^^i also won the science award because i was my teachers fav.&exceptional student!
You need a little lesson on the gravity gradient: When an object comes closer to the earth, the gravity pull increases with the square of the distance to the earth's center, while the centrifugal force increases only with the simple distance to the earth's center (because of the increase of angular velocity), and that's what makes the heavier side of the moon turn toward the earth. There is a such thing as the gravity gradient, and it is even used by some satellites.
Moon’s center of gravity is not the same as its center of mass because it has dense areas called “mascons”. This was discovered by early moon missions, and provides a gravitational handle for the near side of the moon.
The Moon revolves around with Earth in a common axis WHILE the Earth revolves on its axis. The Moon has no rotation axis because it is a dead rock in space. Published 1919 Tesla about the Moon rotation energy : ".. there is not enough energy in the moon to run a delicate watch."
Hmm that didn't come out as I wrote it. It was supposed to say " which is why the moon's entry and exit point on on the the horizon changes but because the moon does not spin/rotate, it's face remains the same.
heres why..... when the earth and moon were cooling down the gravity from the earth pulled alot of the moons molten core towards the earth. one side ofnthe moon is much denser then the other and therefore gravity from the earth keeps this side pulled towards it resulting in a locked rotation. hope this helps
Thanks for this!! I could never picture how it worked that the moon rotates but the same side faces earth. I knew it principle, but I couldn’t quite grasp the mechanics (and it really bugged me).
@wiseyeffect Actually in the first case the Moon has no rotation around its own axis with respect to the background stars. In the other cases the Moon does have rotation around its own axis with respect to the background stars. I'm not sure if this answers your question, but the two cases are definitely different. No BS physics necessary.
Hi there. The moon does this as a result of tidal forces between the Earth and Moon. If it were not in synchronous orbit, these forces would gradually remove energy from the rotation of the Moon until its rotation period equals its orbital period (synchronous). Basically, nature likes state of lowest energy; and in this configuration, no extra energy is being removed from the Moon's rotation. All major satellites in our solar system do this.
this the BEST video I have seen on youtube concerning the moon's orbit and phases! if you could add music it would be sick, and would probably get more hits. someone needs to because this is the most accurate presentation of the moon's orbit i have seen and was extremely helpful in getting me to understand the complex and multiple motions going on in lunar rotation and phases.
In this movie, the third case is shows *synchronous rotation*, which is actually how the moon moves. Its rotation period exactly matches its period of revolution. So from the Earth's point of view we always see only one side, which I have coloured red in this case (purely for illustrative purposes).
