[rmolnav]

I can argue that the centripetal component is the part that would make the planet follow a circle rather than an ellipse.

In the singular case of a circular orbit same principles necessarily apply ... In this case gravitational pull keeps constantly perpendicular to the orbit, and therefore its "tangential" component is always null. Velocity vector doesn´t change in size, only in direction, due (as when an elliptical orbit) to the gravitational pull, whose "function" keeps now being 100% as centripetal force (what, together with the somehow initially given velocity, originates that "uniform circular movement", as it is called in this case) !
There are no different Physics whatsoever, as you have argued several times (not finding other "arguments" ...). Same basic Physics laws applied to different circumstances ... That simple !

[RobC]

This thread is almost as long-winded as the MH370 disappearance on the pilot's forum.

[rmolnav]

5)
A centripetal force (Fc) is the force that makes a moving object change direction
is not a particular force, but the name given to whatever force or combination of forces is responsible for a centripetal acceleration ( Centripetal Force - Summary – The Physics Hypertextbookhttps://physics.info/centripetal/summary.shtml )

When I chose that definition to include on my post #413, I didn´t realize that the inclusion of "or combination of forces" alludes to cases such as farther from the moon high tide.
At earth CM, moon´s pull vector and centripetal force required for earth´s revolving are equal: 100% of that gravitational pull exerts the function of centripetal force.
But at farthest hemisphere moon gravitational is smaller, there is a deficit (compared to required centripetal force) and an additional pull in the same sense is necessary to "combine" with moon´s pull to counter the deficit. That pull, on any considered portion of earth stuff, only can be exerted by the rest of our planet.
That additional pull is exerted both through contiguous material (especially on solid earth), and by own earth gravity.
Where solid earth, opposite pulls appear (exerted by the considered portion on the rest of the planet, through contiguous material), according to 3rd Newton´s Motion Law. All those internal stresses stretch solid earth.
On the oceans, as water follows its curved path (its revolving around the barycenter) partially due to its own weight, its inertial tendency to follow the tangent kind of diminishes (though very slightly) its weight, and water moves towards where that weight is smaller, and the farthest bulge builds.
In that last detail is where the phenomenon is very similar (though much, much smaller) to equatorial bulge formation, as far their causes (mentioned inertial effect) are concerned.
In both cases that "diminishing" of water weight can also be called a centrifugal force, because it is equivalent to a force vector, opposed to own earth´s pull on the water ...   
 

[David Cooper]

This thread is almost as long-winded as the MH370 disappearance on the pilot's forum.

I hope you didn't wade through the whole thing. Maybe a warning needs to be added at the top to guide people to the right answer and away from centripetal farce explanation.

[David Cooper]

NONE  of your posts reveals any "arbitrary" division point of me !
Please kindly tell us where do I "argue" what quoted. And don´t reply you have no time to look for it ...
It´s you who don´t understand, or don´r read carefully!

If you want to claim that I misrepresented your position, that's fine - it's hard to work out exactly what your position is when your wording of everything is so weird, all built into bloated masses of messy text decorated with bold print and exclamation marks, but your situation is hopeless. There is an arbitrary choice to be made as to how much of the force should be counted as centripetal depending on whether you consider it to be the amount that would result in a circular orbit or if you consider it to be the amount that maintains the elliptical orbit at any point in time, and whichever one you choose, you'd be allocating different amounts of the lifting of material further out to centrifugal force. Your artificial division point is arbitrary. That provides two rival proposed mechanisms (both of which are equally wrong), and it doesn't matter which of them you decide is yours.

I said what follows months ago. I´m afraid your so frequent errors are due not only to rather poor knowledge on physics Science, but also on Philosophy and Logics, or simply on the use of your own language: in your "arguments", you have been mixing the concepts of "essence" and "function" for months (at least) !

The errors are yours, darling. You're the one mauling the physics over and over again while believing that you understand it on the basis of your faulty application of half-learned rules.

When a tennis ball hits the net, does the force of the collision cause movement of the ball that leads to the collision?

Please kindly, when discussing physics (as a Science), use clearly identifiable terms. Otherwise confusion is almost unavoidable ... What do you exactly mean with "the force of the collision" ??

I'm asking you if the force from the collision between ball and net causes the ball to hit the net (which would be reversed causality) or if the ball hitting the net causes the collision and generates the forces. The point here is that you somehow imagine that forces cause movement and that movement can't cause forces, but the consequence of that would be that in a case where a tennis ball is heading for a net, no forces can be generated by any collision between the two because you demand that the force happens first.

Take another case. In snooker, one ball is moving and another is stationary. The first ball hits the second one and stops, setting the other ball moving. I say that the movement of the first ball leads to a force being generated when the two balls collide, and that the force transfers the energy to the other ball, causing it to move. Movement causes a force and the force causes further movement. If you never have the original movement, the force is never generated. Quite why you need this explained to you is a mystery, but you've somehow become stuck in a place where you don't understand that movement can generate forces, thinking instead that it only works the other way round. It's a symmetric process.

[David Cooper]

To clarify the arbitrary divide further, in the case the centrifugal force making the material at the equator rise, we call it centrifugal force because there is movement away from the centre. With a moon moving away from the barycentre (because it's on an elliptical orbit rather than a circular one), when we use this same definition of centrifugal, we must regard the movement of the centre of mass of the moon away from the centre of the system as being driven by centrifugal force rather than having that description apply solely to the material further out than the centre of the moon, so the amount of declared centrifugal force depends on whether you start it at zero for the centre of mass or if you give it a positive value there, in which case there may sometimes be centrifugal force applying to every particle of the moon. At another point of the orbit where the moon's getting nearer to the barycentre rather than further away, the zero centrifugal point moves the other way from the centre of mass, and in some cases there may be no centrifugal force applying to any particle of the moon at all. This means that in some cases the tidal forces across the entire moon are presumably "explained" by differential gravity dictating how much centrifugal force applies at any point, while in other cases they are "explained" by differential gravity dictating how much negative differential centrifugal force applies at any point.

If we only start counting it as centrifugal force from the centre of mass, again it is differential gravity that dictates how much centrifugal and negative centrifugal force is in play at any given point, and it should be obvious to anyone that the whole business of counting up the centrifugal force is entirely superfluous, having absolutely no role in the mechanism.

[rmolnav]

As  yesterday, I won´t waste too much time trying to make you understand many things you say are utterly wrong. I know it´d be to no avail ...
Just one thing, relative to one of the main reasons of your quite erroneous stand, that could help others learn that (just in case somebody doesn´t have it clear yet).

... your situation is hopeless. There is an arbitrary choice to be made as to how much of the force should be counted as centripetal depending on whether you consider it to be the amount that would result in a circular orbit or if you consider it to be the amount that maintains the elliptical orbit at any point in time

"An arbitrary choice" when deciding "how much of the force should be counted as centripetal ...?" :
NOT AT ALL.
What quoted shows, once again, your really low education in Physics and Maths.
A much simpler case:
If we throw upwards and vertically a stone, all Physics variables will always have same vertical direction (speed, gravitational force, acceleration ...). Speed vector changes in size, but not in direction. Not necessary, I hope, to elaborate any further ...
But if we throw the stone with some inclination, earth´s gravitational pull vector (logically always vertical as before) produces two quite different effects: it changes speed size (as in above case), and also its direction.
It can easily be deduced that the trajectory will be parabolic, thanks to basic mathematical analysis, considering (at any point) separately the effect of the component of the weight in the direction of speed vector (which changes the size of the later), and the effect of the component perpendicular to the speed (which bends the trajectory).
That last component exerts what is called a centripetal force on the stone, because in an infinitesimal lapse of time any curved line is an infinitesimal arc of a circle, with same curvature as the line at that point ...
As somebody could not clearly understand that concept of “curvature” (most probably, you one of them):
"Curvature, in mathematics, (is) the rate of change of direction of a curve with respect to distance along the curve. At every point on a circle, the curvature is the reciprocal of the radius; for other curves (and straight lines, which can be regarded as circles of infinite radius), the curvature is the reciprocal of the radius of the circle that most closely conforms to the curve at the given point (see figure)”.
(Encyclopedia Britannica).
So, there is no arbitrary choice whatsoever, because it´s not me who choses "how much of the force should be counted as centripetal depending on whether you (I) consider ..."
It is just a rational way to analyze a physical phenomenon, really simple but not just "gravity" that only could be considered as a whole.
Educated adults learnt that as early as when teenagers !!
Whose situation is hopeless ??

[David Cooper]

As  yesterday, I won´t waste too much time trying to make you understand many things you say are utterly wrong. I know it´d be to no avail ...

You are the one who needs to understand them, but you're not open to learning.

"An arbitrary choice" when deciding "how much of the force should be counted as centripetal ...?" :
NOT AT ALL.
What quoted shows, once again, your really low education in Physics and Maths.

You may be right, but if so, that just makes it all the worse that you keep pushing the wrong answer on this issue while I was able to identify the right one for myself (differential gravity) without even researching it. They didn't teach much about centrifugal force though because they didn't regard it as a real force, so it should be no surprise if I make some mistakes in analysing your fake physics and your terrible wording used to describe it. I now realise that even when the moon is following part of its elliptical orbit where it's moving closer to the Earth, you probably still imagine centrifugal force to be acting on it, whereas I was thinking you counted it as zero at the centre of mass of the moon, but I suspect now that you don't. If you place the moon at the same distance from the Earth in part of its orbit where it's moving further out rather than further in, you presumably assert that there's the same amount of centripetal force in both cases, but this time you'll have a greater amount of centrifugal force, and that's where I see an arbitrary division point being selected. I may not have found the right way to explain how there is a difference here that leads to you making an arbitrary divide, but I can see very clearly that you are making an arbitrary divide there, so I'll have another go:-

In cases where the moon is maintaining distance from the Earth rather than moving further in or out, the two forces (centripetal and centrifugal) will be in balance (from the rotating frame's perspective). What's happening then when the moon's moving out and the two forces aren't in balance at the moon's centre of mass? Why would you chose the centre of mass as your division point for your artificial divide between the two mechanisms when the forces are no longer in balance there? If the centrifugal force is stronger than the centripetal force at this centre of mass, it is also stronger than the centripetal force nearer to the Earth than the moon's centre of mass, and this must apply to the entire moon, so it seems odd to make a distinction between the two halves of the moon. In this particular situation, you could assert that centrifugal force wins out over centripetal force all the way through rather than just from the centre out to the far side. In the opposite case where the moon is moving closer to the Earth, you would likewise have to say that centrifugal force is losing out to centripetal force the whole way through the moon and not just from the centre to the near side. In one case, the tidal forces would then be explained in their entirety by centrifugal force out-gunning centripetal force and doing so more strongly further out, so you don't need the near side to be lifted at all as the centre of the moon is being lifted away from it in the opposite direction. In the other case, the tidal forces would need to be explained in their entirety by the Earth's stronger pull closer to it, which is differential gravity. What you're doing though is locking the division point to the centre of mass, but what justification do you have for putting it there rather than cutting the cake the way I've just outlined where the whole thing can be accounted for by centrifugal force out-powering the centripetal force in some parts of the orbit and the whole thing being accounted for by differential gravity at other parts of the orbit? Both ways of cutting the cake are equally valid (and they're both equally wrong as mechanistic explanations of events).

So, there is no arbitrary choice whatsoever, because it´s not me who choses "how much of the force should be counted as centripetal depending on whether you (I) consider ..."
It is just a rational way to analyze a physical phenomenon, really simple but not just "gravity" that only could be considered as a whole.
Educated adults learnt that as early as when teenagers !!
Whose situation is hopeless ??

I was imagining before that you were giving different values to the size of the centripetal force in two cases where the moon is at the same distance form the Earth but in one case moving away and the other case moving nearer, and the reason I thought you were doing that is that you always make your divide at the centre of mass of the moon. Now, I assume that you aren't asserting different amounts of centrifugal force for those two cases, but that makes your division point questionable. There remains room for a rival place to cut the cake which renders your chosen place for doing it arbitrary.

Imagine three objects replacing the moon such that they aren't gravitationally tied together, one of them at the centre of mass, another at NE (nearest the Earth) and the third at FE (furthest from the Earth). A different amount of centrifugal and centripetal force should be applied to each rather than applying the CoG's value of centripetal force to all three - to apply the CoG's value to NE and FE is clearly wrong in this new situation. If you make this sudden replacement (replacing the moon with these three objects), you might find that the centripetal force is stronger than the centrifugal force for NE while the centrifugal force is stronger than the centripetal force for FE, but if you do it at other points of the moon's orbit, there will be times when the centrifugal force is stronger than the centripetal force for both FE and NE, or the opposite.

Now imagine more than just three objects on our straight line - we could have an infinite series of them all the way from just above the Earth to far out beyond the moon. In every case, there will be one object which has a match between the centripetal and centrifugal forces that apply to it, and that  object is in the correct location for making your artificial divide. It is not the same as the centre of gravity of the moon, so we have two rival places for making an artificial divide, and our decision to choose one over the other is arbitrary.

[rmolnav]

What a confusing and misleading exposition !
And you even told me:

... it's hard to work out exactly what your position is when your wording of everything is so weird, all built into bloated masses of messy text ...??

Surely my expositions could be better. In your case it is much worse... After all, English is your mother tongue, but not mine !
Later on another post I´ll try and explain, especially for others who may be interested, the singular case of the rotation of the moon around earth-moon barycenter  Compared to earth´s revolving, there are some differences, and I want to elaborate them on with more time. I´ll make an effort to put it as concise and clear as possible ...

[rmolnav]

In cases where the moon is maintaining distance from the Earth rather than moving further in or out, the two forces (centripetal and centrifugal) will be in balance (from the rotating frame's perspective). What's happening then when the moon's moving out and the two forces aren't in balance at the moon's centre of mass? Why would you chose the centre of mass as your division point for your artificial divide between the two mechanisms when the forces are no longer in balance there? If the centrifugal force is stronger than the centripetal force at this centre of mass, it is also stronger than the centripetal force nearer to the Earth than the moon's centre of mass, and this must apply to the entire moon, so it seems odd to make a distinction between the two halves of the moon. In this particular situation, you could assert that centrifugal force wins out over centripetal force all the way through rather than just from the centre out to the far side

Inertia (and its manifestation as centrifugal force), especially when elliptical orbits, is rather tricky to grasp. And you often mix up forces with "movements", what doesn´t make things any easier ...
In the first place, some "singularities" of our moon are:
1) It´s center of mass it is not located where its geometric center (if it were perfectly spherical, the center of the sphere). Visible part of its crust is slightly denser than the rest, and the center of mass is some 2km closer to earth than the geometric center.
2) That center of mass would also be the center of "gravity", if in relation to a uniform gravitational field. That would "almost" be the case if the celestial object causing the gravitational field were a far distant star ... But, leaving aside sun´s gravity, earth is sufficiently close to the moon to cause a varying pull, with a negative gradient in relation to distance.
Therefore, the earth-related center of gravity is even a little closer than above mentioned 2 km.
3) And that doesn´t change in time, whatever the movement of the moon, precisely because it is tidal locked to earth.
When considering moon´s dynamics and saying closer/farther hemispheres, to be 100% precise we should say e.g. "moon´s parts closer/farther than that earth-related CG). But the differences are relatively very small, it would make difficult the exposure ... and nobody does.
THAT SAID, for the sake of simplicity, let us now suppose moon´s orbit were a perfect circle.
It is actually at mentioned "earth-related center of gravity" were gravitational pull per unit of mass:
- GM/d² (Gravitational universal constant, earth´s Mass and distance to earth´s CM)
and centrifugal force per unit of mass:
- ω²r (angular speed ω and distance to barycenter r)
are in balance with each other.
On moon´s farther parts not only gravity is smaller: centrifugal force, on the contrary, is bigger.
And on moon´s closer parts gravity is bigger, and centrifugal force is smaller.
On farther parts centrifugal forces prevail, and on closer parts gravitational pulls prevail.
That is why moon got stretched long ago ...
As the post is already rather long, I´ll leave the actual case of an elliptical orbit for another post.
 
 

[rmolnav]

In cases where the moon is maintaining distance from the Earth rather than moving further in or out, the two forces (centripetal and centrifugal) will be in balance (from the rotating frame's perspective). What's happening then when the moon's moving out and the two forces aren't in balance at the moon's centre of mass? Why would you chose the centre of mass as your division point for your artificial divide between the two mechanisms when the forces are no longer in balance there? If the centrifugal force is stronger than the centripetal force at this centre of mass, it is also stronger than the centripetal force nearer to the Earth than the moon's centre of mass, and this must apply to the entire moon, so it seems odd to make a distinction between the two halves of the moon. In this particular situation, you could assert that centrifugal force wins out over centripetal force all the way through rather than just from the centre out to the far side.

Therefore, the earth-related center of gravity is even a little closer than above mentioned 2 km.
3) And that doesn´t change in time, whatever the movement of the moon, precisely because it is tidal locked to earth.

Minutes ago I happened to be ruminating on that, and I realized that it is not fully correct: in the actual case of elliptical orbit, things change (though very, very slightly).
The center of mass (as referred to on point 1 of my last post) is not always exactly at its closest to earth´s location.
Moon´s tidal locking was asymptotical: its previous spinning angular speed got its actual value (2π radians/some 28 days) at an ever smaller pace, partially due to the high moon´s angular momentum.
And, as far as I can understand, same reason doesn´t let earth-related tidal effects to change significantly that angular speed in only weeks ...
That must be one of the reasons of moon´s relative wobbling (the visible part of the moon is not always exactly the same) ...
I´ll think it over a little longer. In any case, I´m afraid I´m trying to be too precise, just to refute a kind of bizarre argument of D.C. If, in a certain moment, the exact area where earth´s pull and centrifugal forces balance each other is a little closer or farther, that has no importance for the validity of "my" model ... Closer and farther "hemispheres" (where either gravitational pulls or centrifugal forces prevail) would be slightly bigger or smaller. But that doesn´t invalidate the model whatsoever !
There wouldn´t be any "arbitrary" election whatsoever, just a lack of information and mathematical tools to be "almost 100%" precise !!
You seem to be running out of "arguments".

[David Cooper]

Running out of arguments? Hardly. Your model's already been disproved in multiple ways (such as in cases where the actual acceleration's acting in the opposite direction to the one where you supposedly have centrifugal force working, and in straight-line cases where there is no centripetal force). What I'm doing now is looking at your broken argument and finding an arbitrary aspect to it (quite in addition to its well-established brokenness).

On moon´s farther parts not only gravity is smaller: centrifugal force, on the contrary, is bigger.
And on moon´s closer parts gravity is bigger, and centrifugal force is smaller.
On farther parts centrifugal forces prevail, and on closer parts gravitational pulls prevail.

You assert that for one side, centrifugal force wins out over gravitational force, while at the other side it loses out to it, but if you cut the cake in a different way, you could say that centrifugal force wins out the whole way through on some occasions, while on other occasions it loses out the whole way through. The chosen location of the point beyond which winning turns to losing is arbitrary - you always seem to put it in the middle, but it could be further in or further out than the whole moon (or planet, if you'd rather work the other way round - they both follow the same shape of orbit, so whatever applies to one of them in relation to this point also applies to the other).

For a correct analysis of what's going on, you should be looking at the amount of gravitational pull (from the other body) applying at any given point and going by that alone - considering the centrifugal force is then superfluous as it doesn't change the result, but you're determined to include it. The only way you can make the centrifugal force appear relevant is by fiddling the amount of gravitational force that you're counting as centripetal force at different distances from the source, and then by using that artificial value instead of using the actual gravitational force (so that the net effect is the same as you get just by considering the gravitational force alone). We already know that you're making an artificial division in this way and that your explanation is broken, but I'm now pointing out that you're doing it in an arbitrary way too (in terms of where you cut the cake).

[rmolnav]

You assert that for one side, centrifugal force wins out over gravitational force, while at the other side it loses out to it, but if ... The chosen location of the point beyond which winning turns to losing is arbitrary - you always seem to put it in the middle, but it could be further in or further out than the whole moon (or planet, if you'd rather work the other way round - they both follow the same shape of orbit, so whatever applies to one of them in relation to this point also applies to the other).

The scientifically "chosen location", obviously matches with basic Physics laws: it is where
 

...gravitational pull per unit of mass:
- GM/d² (Gravitational universal constant, earth´s Mass and distance to earth´s CM)
and centrifugal force per unit of mass:
- ω²r (angular speed ω and distance to barycenter r)
are in balance with each other.

... as I already said yesterday. You didn´t even read it, did you ??
Once again, on farther and closer parts that balance can´t exist (basic Maths):
- On farther parts centrifugal force prevails.
- On closer parts gravitational pull prevails.
NOW IT IS YOUR TURN:
Please kindly give us an example of location (and "occasions") where ...
 

... you (could) cut the cake in a different way,  (and) you could say that centrifugal force wins out the whole way through on some occasions, while on other occasions it loses out the whole way through.

... and explain your "reasons" !!
Otherwise, anybody could tell you just "invent" false scenarios due to your "hopeless situation" ...

[rmolnav]

A couple of days ago I started a post saying::

As  yesterday, I won´t waste too much time trying to make you understand many things you say are utterly wrong. I know it´d be to no avail ...
Just one thing, relative to one of the main reasons of your quite erroneous stand, that could help others learn that (just in case somebody doesn´t have it clear yet).

Another of the main reasons of your quite erroneous stand is the "bizarre" and erroneous relation you suppose between force and movement, as when you say, e.g.:

Take another case. In snooker, one ball is moving and another is stationary. The first ball hits the second one and stops, setting the other ball moving. I say that the movement of the first ball leads to a force being generated when the two balls collide, and that the force transfers the energy to the other ball, causing it to move. Movement causes a force and the force causes further movement. If you never have the original movement, the force is never generated. Quite why you need this explained to you is a mystery, but you've somehow become stuck in a place where you don't understand that movement can generate forces, thinking instead that it only works the other way round. It's a symmetric process.

What in bold is correct, but not the rest. As I´ve told you several times, you not only have serious problems with Physics: neither Logics is your forte ...
One thing is to be one of the "necessary conditions" for something to happen, and another to be the "cause".
One of the conditions required for me to run is, e.g., to be able to breath. If I couldn´t breath it´d be impossible for me to run ...
But we couldn´t say that breathing is what causes me to run !!

[David Cooper]

The scientifically "chosen location", obviously matches with basic Physics laws: it is where
 

...gravitational pull per unit of mass:
- GM/d² (Gravitational universal constant, earth´s Mass and distance to earth´s CM)
and centrifugal force per unit of mass:
- ω²r (angular speed ω and distance to barycenter r)
are in balance with each other.

... as I already said yesterday. You didn´t even read it, did you ??

I read it, but something doesn't add up for me which has been blocking my ability to take it in properly, but perhaps you can help by explaining what I'm missing. Your first partial equation suggests that the centripetal force is the same for two cases where the Earth-moon separation is the same but with them in one case moving closer together and in the other case moving further apart. Your second partial equation suggests that the centrifugal force is the same in both cases too (if the angular speed means the component of speed perpendicular to the centripetal force), in which case it doesn't matter whether they're getting closer or moving further apart because the outward acceleration is the same for both cases - in one case it leads to an inward deceleration and in the other to an outward acceleration. That would indeed put your division location in the centre of the moon (or Earth) if these forces always match. But I'm puzzled by this, because if the centrifugal force and centripetal force are always equal there, I can't see any mechanism to accelerate the two bodies further apart and then have them accelerate closer together again. For two things to move further apart, then stop moving apart, then move closer together, then stop moving closer together and then move further apart again, you need a changing acceleration with the centrifugal force sometimes being stronger than the centripetal force and sometimes being weaker than it, but you can't have any such variation if I'm understanding your equations correctly - if one of the forces changes, the other changes to match, so if the moon is moving further away, it should spiral further and further out on every orbit, or if it's moving closer to the Earth, it should spiral inwards. I'd like to understand how you prevent that.

NOW IT IS YOUR TURN:
Please kindly give us an example of location (and "occasions") where ...
 

... you (could) cut the cake in a different way,  (and) you could say that centrifugal force wins out the whole way through on some occasions, while on other occasions it loses out the whole way through.

... and explain your "reasons" !!
Otherwise, anybody could tell you just "invent" false scenarios due to your "hopeless situation" ...

The way I see it, you need to have times when the centripetal and centrifugal force don't balance for the centre of the body, because that's necessary if it's to follow an ellipse rather than a spiral path - this can move the point of balanced forces a long way away from that centre of mass. If we take a nearly-straight-line case with the moon falling almost directly towards the Earth (though still following an elliptical orbit and avoiding a collision), the centripetal force is clearly stronger than the centrifugal force, so they are nowhere close to being in balance at the centre of the moon, or indeed anywhere inside or near it.

[Note for those reading this who are interested in reality: bear in mind that centrifugal force only provides the illusion of existing in rotating frames while it doesn't exist in the real universe, so if something is moving round the centre at a fixed distance, the two apparent forces must match exactly for the rotating frame to maintain the same separation of the objects (or to maintain the rate at which they're moving together or apart). In reality, there is no centrifugal force and the only force acting is gravity - if there were two actual forces in balance, the moon would move in a straight line and not orbit the Earth at all. But let's return to the rotating frame: for centrifugal force to be used in a calculation, the centripetal force that's calculated to go with it will presumably need to be stronger than the actual amount of gravity involved in order to compensate for this imagined force outwards. If I've got this right (and I may not have - I'm no expert in the rules of rotating frames), that means that the way this centripetal force is divided into non-centripetal force and centripetal force is not the way I have been picturing up until now - the non-centripetal component of gravity must be negative rather than positive, and part of the centripetal force is therefore not gravity, but another imaginary force invented to balance the imaginary centrifugal force.]

[David Cooper]

Another of the main reasons of your quite erroneous stand is the "bizarre" and erroneous relation you suppose between force and movement, as when you say, e.g.:

Take another case. In snooker, one ball is moving and another is stationary. The first ball hits the second one and stops, setting the other ball moving. I say that the movement of the first ball leads to a force being generated when the two balls collide, and that the force transfers the energy to the other ball, causing it to move. Movement causes a force and the force causes further movement. If you never have the original movement, the force is never generated. Quite why you need this explained to you is a mystery, but you've somehow become stuck in a place where you don't understand that movement can generate forces, thinking instead that it only works the other way round. It's a symmetric process.

What in bold is correct, but not the rest.

All of it was correct. If you think otherwise, you clearly don't understand very much physics at all.

As I´ve told you several times, you not only have serious problems with Physics: neither Logics is your forte ...

Logic is my speciality - your problem is that you don't understand any logic, and that affects your ability to tell correct physics from voodoo.

One thing is to be one of the "necessary conditions" for something to happen, and another to be the "cause".

Having an ability to move is not the same as actually moving. If the ball has an ability to move but isn't moving, it isn't going to collide with the other ball and no forces will be generated by the collision that doesn't happen. I can assure you that the first ball actually moves quite in addition to being capable of moving, and that specific movement causes the collision in a way that it's mere ability to move does not cause the collision.

One of the conditions required for me to run is, e.g., to be able to breath. If I couldn´t breath it´d be impossible for me to run ...
But we couldn´t say that breathing is what causes me to run !!

Being able to breathe does not cause you to run, and being able to move does not cause the ball to move. If you run, your running causes you to breathe more, and if the ball moves, it is carrying momentum which can be transferred to something else via a force. The movement causes the force. You really ought to consider studying logical reasoning so that you have some kind of clue as to how to apply it.

[rmolnav]

I am utterly baffled ...
Somebody who tells me:

Logic is my speciality - your problem is that you don't understand any logic, and that affects your ability to tell correct physics from voodoo.

... and who had also previously told me (in relation to the snooker case):
 

... you've somehow become stuck in a place where you don't understand that movement can generate forces, thinking instead that it only works the other way round. It's a symmetric process.

[/b]
(by the way, Isaac Newton did "agree with me" regarding that; did he also become "stuck in place"?)
... yesterday, among many other bizarre things, he also said:

Your second partial equation (?) suggests that the centrifugal force is the same in both cases too (if the angular speed means the component of speed perpendicular to the centripetal force), in which case it doesn't matter whether they're getting closer or moving further apart because the outward acceleration is the same for both cases

What I had said was:

It is actually at mentioned "earth-related center of gravity" where gravitational pull per unit of mass:
- GM/d² (Gravitational universal constant, earth´s Mass and distance to earth´s CM)
and centrifugal force per unit of mass:
- ω²r (angular speed ω and distance to barycenter r)
are in balance with each other.

Should I laugh? ... Should I cry? ... Should I "throw the towel ??
Where is the global moderator? Should he, at least, suggest him to start some new threads such as "What is angular speed?", or "What is movement?", or "What is a force?" ...? (though, I´m afraid, to no avail ...).
But, watch out! Just that measure wouldn´t avoid that, eventually,  could get next level of Naked Scientists Forum GOD !!
Would that be good for our forum ? Or, even more important, is it good for our forum to have in this thread such a lot of ideas contrary to basic Physics principles, and repeated time and again ? 
I also wonder, where are other members who used to send comments?? Do they agree with all that rubbish, or are they just fed up and don´t want to waste any more time ??

[Le Repteux]

Should I laugh? ... Should I cry? ... Should I "throw the towel ??

I think you should call for a pause and say that time will tell. I'm pretty sure David would accept that kind of compromise.

[David Cooper]

Should I laugh? ... Should I cry? ... Should I "throw the towel ??

If you think I'm not understanding the symbols you're throwing at me, why not try illustrating their usage with actual numbers and clear descriptions.

Should he, at least, suggest him to start some new threads such as "What is angular speed?", or "What is movement?", or "What is a force?" ...? (though, I´m afraid, to no avail ...).

All you have to do is tell my what I'm misunderstanding. Is that really too difficult for you? (I looked up angular speed to check it's meaning and it appeared to mean what I said.) Or are you just running away from a problem you can't fix and engaging in diversion tactics to hide it?

Here's the point: if the centripetal force is always equal to the centrifugal force for the moon as a whole (or Earth, or anything else), you have no mechanism for keeping it in an elliptical orbit because it will either spiral out and never come back or spiral in collide with the other body.

Why don't you respond to that issue and explain how the position of equality of centripetal and centrifugal force remains at the middle of the body instead of varying in the manner it would need to to support an elliptical orbit.

Or, even more important, is it good for our forum to have in this thread such a lot of ideas contrary to basic Physics principles, and repeated time and again ?

This forum is a place that helps educate people. You are pushing fake physics and that needs to be challenged. I may be getting some things wrong here and there, and I expect people to point that out so that I can improve my understanding of things. I actually learn from that and gain, correcting any mistakes that I've been making. You don't though - you just keep on pumping out the same old bilge over and over again. There is no such thing as centrifugal force - it's an illusion. (There is a reactive centrifugal force which does exist, but it is completely absent in cases involving gravity.)

I also wonder, where are other members who used to send comments?? Do they agree with all that rubbish, or are they just fed up and don´t want to waste any more time ??

You may have forgotten now, but you spent a long time talking to yourself early on (after the thread had reached its natural conclusion and found the right answer) - no one wanted to engage with your bloated drivel so they kept out of it and simply left you to it after that. You annoyed people though (myself included) because everyone who's ever posted in this thread got a notification every time you added another chapter to your dismal book of warped physics. It eventually occurred to me though that you might be an interesting subject of study because it's important to understand how people think, and to see how flexible/inflexible they are in that regard. Can you recognise your mistakes? How much work does it take to get you to recognise any of them? I decided to turn an irritation into a learning opportunity by studying your mind. It's also been an opportunity to learn more physics though at the same time, and I've gained a lot by thinking through different aspects of the tides along the way. What have you gained though? You don't learn - you just go on and on being wrong long after being proved wrong, and you keep rejecting lots of correct physics that I provide, writing it all off as rubbish. You have absolutely no idea what's good physics and what's rubbish because your judgement is nowhere near up to the task.

One of my opponents from another forum found this thread and told you that he agreed that the correct answer is differential gravity. You then started treating him the same way as you treat me, throwing bold print and exclamation marks at him as if he was a moron. Why do you think he stopped engaging with you? He's one of the sharpest minds posting on this forum, and he knows a lost cause when he encounters one. You are incapable of learning.

[Le Repteux]

You are incapable of learning.

He looks intelligent, so he's probably able to learn, but as I always say in this case, he can no more change his mind instantly than a ball can accelerate instantly. The problem is not intelligence, thus conscious thinking, but unconscious one. We unconsciously resist to change ideas because our memory is about keeping our ideas the same. Our ideas change by chance, not by will, and not because they are exposed to others ideas if those ideas are too far from ours. Our ideas change with time the same way it takes time for chance to produce any durable thing.