Perpetual motion accepted in astronomy - why ?

[bojan]

Alan,
From "The Cambridge Companion to Newton" provided here by Stephen, it is visible Newton "experimented" (mathematically) with movement of bodies influenced by central force between them that has various dependency on distance r between them. We would say today he played with different math models of orbital motion, by varying the value of exponent to "r" (distance between bodies) in his equations.

Basically, he concluded then that gravitational force obeying only inverse square law (1/r^2) results in stable elliptical orbit (circular is a special case of ellipse where eccentricity is zero), which corresponded with observations.

If gravitational force obeyed for example 1/r^3 law, the orbit would have been inward spiral (I don't remember which type of spiral exactly, it could be Archimedes' ?)... resulting in collision of two bodies. BTW, spiral (and unstable) orbit results from any value of exponent >2.
If exponent applied to r is less than 2, then spiral would have been "open", resulting in increasing separation of bodies (and escape).
Remember, this was happening in times physicists did know how gravity force behaves with distance... hence the discussion.. involving mathematical details... So, apart from historical insight, it is irrelevant to our discussion here.

However, my question to you was:
"why and how spiral motion causes precession".

[spaceout]

Allow me to throw a wrench into this discussion.


Rather then discussing solid bodies, or jelly filled bodies might I remind you of the electrical/magnetic interaction that probably has a lot to do with the alignment of planetary orbits.



Do we think it's a coincidence that the top and bottom of the earth are also it's north and south magnetic poles?
How do you think this aligns with the suns magnetic poles?


Seems like a planet has no choice but to fall in line, or be obliterated or expelled. The orbital disc is determined primarily by magnetic equilibrium for lack of a better term.



As a footnote I might remind you that Archimedes math for infinity is still obscured in a Palimpsest. Everything cited since then, including Newton may be dealing with incomplete information. For better or worse.

[bojan]

Originally Posted by spaceout

... might I remind you of the electrical/magnetic interaction that probably has a lot to do with the alignment of planetary orbits.

I have to inform you that, contrary to all EU believers, electromagnetic interaction has nothing to with "alignment" of celestial bodies.


In our discussions on this forum, we are trying to be scientific.

That means, every claim or statement anyone writes here has to be backed with evidence.

[Dove (Alan)]

Originally Posted by spaceout

Perpetual motion could be philosophically accepted in space, simply because you cannot find a single item at rest.


Find something in the universe that doesn't move, then you can prove that perpetual motion is impossible.




Perpetual motion is a misnomer that shouldn't be given much thought.



The term is usually used and convoluted with free-energy machines, but the term is not exclusive to gypsy science.



To deny perpetual motion is to infer the age of the universe and how long it will last. How can something perpetual exist in a finite theater?

Space out

Hello
You should find the topic of great interest it is surprising how many people unwittingly accept the medieval notion of perpetual motion within the solar system.

Alan D

[Dove (Alan)]

Originally Posted by bojan

Alan,
From "The Cambridge Companion to Newton" provided here by Stephen, it is visible Newton "experimented" (mathematically) with movement of bodies influenced by central force between them that has various dependency on distance r between them. We would say today he played with different math models of orbital motion, by varying the value of exponent to "r" (distance between bodies) in his equations.


However, my question to you was:
"why and how spiral motion causes precession".

Hello bojan,
Bojan,

Yes we can see that the protection of the medieval perpetual solar system notion has got deeper and deeper and more complex since the 17th century . I take it this is your reply to my question, that “if you consider there is no such thing as spiral planetary motion, what do you think the motion is? Then your response now is that, there is such a thing as spiral planetary motion, “open and closed” spirals but that spiral motion, is a highly complex motion. Well at least you have answered the question, you believe there is such a thing as spiral planetary motion.

Your question to me was for an explanation.

I have posted the first part of my explanation to you and will continue probably today.

As I see it, the situation at the moment has advanced, most agree that there is such a thing as spiral planetary motion. The difference of opinion now lies in whether it is a relatively simple movement of our spheres or; is a highly complex movement, a movement that prevents science discerning whether our planet is moving progressively and continuously, albeit slowly changing our angle of obliquity.
That then is your task, to maintain this situation of no advance beyond the medieval notion of an ‘invariable’ solar system; that our axis is merely wobbling back and forth over a 2.4 degrees cycle over 14 thousand years. Over the past 360 years there has built up a vast array of ‘proof’ to defend this. You have plenty of ammunition, we know.

I do wonder how any modern astronomer can be happy with the accepted theory of the ‘invariable’ solar system without question

Can you explain what a ‘closed spiral’ looks like please. A simple sketch would be better.

Alan D.

[morls (Stephen)]

Alan,

You say "most agree that there is such a thing as spiral planetary motion".

You are not being specific, you are not providing evidence, and you are not backing up these blanket assertions with any published literature. The challenge for you is to do so.

I suspect you aren't because you cannot. I suspect there is no published literature from the last 100 years supporting a theory of spiral planetary motion.

Please prove me wrong.

[spaceout]

Originally Posted by bojan

I have to inform you that, contrary to all EU believers, electromagnetic interaction has nothing to with "alignment" of celestial bodies.


In our discussions on this forum, we are trying to be scientific.

That means, every claim or statement anyone writes here has to be backed with evidence.

Science is not a democracy, I do not acknowledge your insulting demands rather ask that you first practice what you preach.

[spaceout]

Originally Posted by Dove

Space out

Hello
You should find the topic of great interest it is surprising how many people unwittingly accept the medieval notion of perpetual motion within the solar system.

Alan D

Alas the topics of such interest are the source of the great frustration.



I long for the days to be able to have these conversations with "peers", however I always regret it. It's akin to talking politics or religion, the worst is when they think they know something.



History repeats itself in ironic ways with the antagonists cheering on protagonists of the past.

[morls (Stephen)]

Spaceout, Bojan's is not an insulting demand, but a call for intellectual rigour. Without rigour there is the risk of prejudice, bias and emotion to cloud discussion.

We are all human and subject to human frailty. I believe that by acknowledging that every idea has a history, and referring to this history openly and diligently when involved in debate, we can avoid many pitfalls.

[bojan]

Heh, this is getting interesting :-)

First, reply to Alan:
What I wrote was, if gravitational force were not obeying the inverse squared law (1/r^2), the motion would have been spiral.. which is contrary to observation. Observational results (measurements) suggest orbital motion of planets are along ellipses. Which means the gravity obeys 1/r^2 (inverse square) law.
Using that law, today we can calculate the positions of planets with sufficient accuracy, which is the proof the concept is valid.
To achieve better accuracy (and to explain fully the precession of Mercury orbit) we have to use General Relativity.

Interesting fact is, GR does predict the spiral motion of two bodies in extremely strong gravitational field (for example two neutron stars or two black holes in close orbit), and that motion results in crash or fusion. This kind of motion I called (possibly clumsy) "closed spiral" because orbital distance becomes smaller with time... my term "open spiral" suggests orbital distance increasing with time).
Please note, systems like the one described above were observed, and the measurement results of decreasing orbital distance exactly follows the GR.
However, for some reason I feel this is not the proof for whatever you are trying to suggest.
BTW, have a look at this link, discussion of Arcimedean spiral:
https://gamedev.stackexchange.com/qu...constant-speed





To Spaceout:
?
Well, of course I agree, the science is not democracy.

It is not democracy precisely because the outcome is not based on opinions, wishes/feelings and power games between individual scientists (of course there are always elements of those factors because science is human activity, but we have peer review process in place to eliminate those un-scientific factors).
Science is based on facts, than can be confirmed, measured and obtained (at lest in theory) repeatably by anyone whenever needed/wanted.

What was my "insulting" demand?

And I do not understand your suggestion ("practice what you preach"), could you please be more specific and let me know exactly where I do not practice what I preach? I do not preach.. I am just trying to guide this discussion so we could come to result we can all agree on.

[spaceout]

Bojan rather then dwell on the past lets have a look at the link you have with the Archimedian spiral.



Where is the Z axis?


What is the reason for omitting the third axis in a 3-dimensional equation?



I could tell you that the planets are not orbiting, so much as they are chasing the sun through space. That is why I am not offended by those that suggest the earth is spiraling toward the sun. They aren't really wrong, if the sun is moving away.



I could also suggest the direction the sun is traveling based upon the right hand thumb rule, (Perpendicular to earths orbit) but alas I would have to try prove it.


I suppose if I was to believe in the big bang, I could use that to back up my claim that the sun is moving in a linear direction, however opportunistic uncorrelated correlations are a pet peeve of mine. Until then I will have to wait with baited breath for confirmation that the Earth's orbit is slightly "below" the center of the sun.

[bojan]

Originally Posted by spaceout

Allow me to throw a wrench into this discussion...
... Do we think it's a coincidence that the top and bottom of the earth are also it's north and south magnetic poles?
How do you think this aligns with the suns magnetic poles?.

Well, don't you think labels/names for magnetic "North" and "South" poles are just conventions? Same as "up" or "down".. where is 'up'?


Magnetic field of the planets are thought to be caused by movement in the liquid iron core (dynamo effect). Earth's magnetic poles are moving but did not flip for quite some time, see here:
https://www.space.com/43173-earth-ma...lips-when.html



As for Sun, have a look here:
https://www.nasa.gov/content/goddard...about-to-flip/ It flips every 11 year cycle.

[mynameiscd (Andy)]

Doesn't Mars have a small core so the corolus effect is so small it doesn't have a magnetic field but is still in alignment with the other planets?
I think magnetic fields have little to do with planar alignment but that's my opinion.
Cheers
Andy

[bojan]

Originally Posted by spaceout

Bojan rather then dwell on the past lets have a look at the link you have with the Archimedian spiral.
Where is the Z axis?.

Hmm... this link I provided to Alan only to help defining what we mean by term "spiral", because I think he needed that definition.



As to clarification you gave to motion of planetary system, we can call orbits "coils", right? Well, yes of course that is right, if we assume Milky Way is "fixed" (which it is not of course) and Sun (with planets) moves relative to Galactic coordinate system.



Actually so far I do not see we have any disagreement of the issue...

However, this is OT.. the thread is about Alan's "spiral motion" and precession of nodes..

Let's stick to that until the issue it resolved.

The orientation of rotational axes of Sun and Planets are caused by total angular momentum of the primordial cloud of gas and dust from which the Solar system formed.. not much to do with its original magnetic field (however there may be some remnants of it still present on planets and Sun magnetic fields).

[Dove (Alan)]

Originally Posted by morls

Alan,

You say "most agree that there is such a thing as spiral planetary motion".

You are not being specific, you are not providing evidence, and you are not backing up these blanket assertions with any published literature. The challenge for you is to do so.

I suspect you aren't because you cannot. I suspect there is no published literature from the last 100 years supporting a theory of spiral planetary motion.

Please prove me wrong.

I am putting my explanation posts to bojan to save repeating for simplicity I hope you don't mind.

Alan D.

[morls (Stephen)]

Originally Posted by Dove

I am putting my explanation posts to bojan to save repeating for simplicity I hope you don't mind.

Alan D.

So you don't have any evidence to support your assertion? The challenge I put to you was to provide evidence, which it seems you cannot do.

Originally Posted by bojan

The orientation of rotational axes of Sun and Planets are caused by total angular momentum of the primordial cloud of gas and dust from which the Solar system formed.. not much to do with its original magnetic field (however there may be some remnants of it still present on planets and Sun magnetic fields).

Do all planets rotate in the same direction?
Is it always (WRT the line of travel) right side (outside of orbital path) moving in same direction as orbital path?

edit: for some reason I assume both planetary rotation and orbit are clockwise. Interesting...

[Dove (Alan)]

Originally Posted by bojan

Hmm... this link I provided to Alan only to help defining what we mean by term "spiral", because I think he needed that definition,

Actually so far I do not see we have any disagreement of the issue...

However, this is OT.. the thread is about Alan's "spiral motion" and precession of nodes..

Let's stick to that until the issue it resolved.

Bojan, thank you for your patience.

Hello bojan,

Here is part two of my explanation of the spiral orbit of Earth about the Sun, producing the precession of the equinoxes, as requested by you. But first, a little of how Newton had to deal with the facts of planetary motion, he had to exercise great care not to openly give recognition to the spiral nature of planetary motion, his whole future could be in jeopardy.


Produced 7 years after Hooke’s death we have Newton’s definition in:
The ‘Principia’. Book 1. The Motion of Bodies, Basic Concepts: Definitions and Axioms.

Definition V
‘Centripetal force is that by which bodies are drawn or impelled, or anyway tend, towards a point as to a centre.
Of this sort is gravity, by which bodies tend to the centre of the Earth; magnetism, by which iron tends to the lodestone; and that force, Whatever it is, by which the planets are continually drawn aside from the rectilinear motions, which otherwise they would pursue, and made to revolve in curvilinear orbits.
………... And the same thing to be understood of all bodies, revolved in any orbits. They all endeavour to recede from the centres of their orbits; and were it not for the opposition of a contrary force which restrains them to, and detains them in their orbit, which I therefore call centripetal, would fly off in right lines, with a uniform motion.
And after the same manner that a projectile, by the force of gravity, may be made to revolve in an orbit, and go round the whole Earth, the Moon also, either by the force of gravity, if it is endued with gravity, or by any other force, that impels it towards the Earth, may be continually drawn aside towards the Earth, out of the rectilinear way which by its innate force it would pursue; and would be made to revolve in the orbit which it now describes; nor could the Moon with out some such force be retained in its orbit. If this force was too small, it would not sufficiently turn the Moon out of a rectilinear course; if it was too great, it would turn it too much, and draw down the Moon from its orbit towards the Earth. It is necessary that the force be of a just quantity, and it belongs to the Mathematicians to find the force that may serve exactly to retain a body in a given orbit with a given velocity; and vica versa to determine the curvilinear way into which a body projected from a given place, with a given velocity, may be made to deviate from its natural rectilinear way, by means of a given force.'

End quote.

Terms from the above we have:

Centripetal force - tending to a centre, = spiral motion.

Of this sort is Gravity, Bodies tending to the centre of the Earth = spiral motion.

Planets continually drawn aside from rectilinear motion = spiral motion

The same of all bodies revolved in any orbits = spiral motion

They all endeavour to recede from the centre = restrained linear motion.

Centripetal = a restraining force, gravity’.
Also,
Moon - retained in its orbit - restrained by some such force not too great and not too small, = a circular orbit.
The latter is an assurance to the governing religious authorities, Moon is not getting closer to Earth.

Newton’s lifesaving statement ; ‘ it belongs to mathematicians to find the force to retain a orbiting body in a given orbit. Very clever, he knew there was no such force, he just passed the buck on.

Newton had side - stepped the issue of perpetual motion implied in retaining an orbiting body in a given orbit.

And who could blame him, or Hooke who had walked away from recognition of spiral motion? They both knew that Gallileo had recanted his works when he was threatened with torture, only 40 years earlier. That is how things were in the 17th century.

Of course, there is more to tell, that was 350 years ago but still today, astronomy kow - tows to the church.

Even so, my faith is in the masters of astronomy right up to Newton and Hooke., who acted within the limits imposed on them during their time. I respect their judgement, they had their necks to lose.
The next step forward for the science of astronomy, in recognising the spiral mode pf planetary motion, will keep for a bit longer it seems.

With this historical background presented, I will explain my view of the cause of the precession of the cause of the equinoxes as requested. It is based on Newton’s explanation and is to my mind, a perfect one, consistent with the law of spiral planetary motion.

His definition is subject to the necessary constraints on him, not to openly recognise the spiral nature of planetary motion, which he dared not venture into. His explanation we recall was delivered in the ‘Principia’. Which we can examine in next post. I will post again soon.

Alan D. 2/11/19

PS I will try to send a graphic that will greatly in my explanation

[bojan]

Alan,

I think your detailed explanation will not be necessary, now I know exactly what you have in mind, and I am sure other do as well. Please leave it for some other times.

[morls (Stephen)]

Thanks for the detailed post Alan.

[JohnF (John)]

Originally Posted by Dove

Hello guys,

seriously, why is it accepted that the Earth's obliquity is unchanging apart from a wobble caused by the perturbations of our sister planets?

It is clearly asserted that our axis movement, a decrease of 47" of obliquity per century, will remain wobbling 2-3 about our present obliquity. That is a notion of perpetual motion of Earth's axis if there ever was.

Any one like to check it out ? There is ample evidence for the assertion available on record.

Cheers, Alan.

Omission to last post.

read. 2-3 degrees

Alan.

Who says it is due to "the perturbations of our sister planets?" There is Archaeology Evidence that tells us that the wobble is not constant over the Centuries, but has been decreasing, however slowly.