The Flat Earth Society

Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: GreatATuin on April 25, 2020, 10:48:30 PM

Title: Comet Shoemaker–Levy 9
Post by: GreatATuin on April 25, 2020, 10:48:30 PM
In 1993, a comet was discovered (https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9). Calculations showed that it would collide with Jupiter in July 1994.

As the fragments of the comet collided with the planet between July 16 and July 22, even amateur astronomers with small telescopes could see the effects of the impact, which were at least as visible as the famous "red spot" (https://link.springer.com/article/10.1007%2FBF00612878).

How could such a prediction be made, more than a year before the event (https://www.nature.com/articles/363492a0), without very precise knowledge of the orbits of Jupiter and the comet? How does that fit with a flat Earth view claiming that little is known about the celestial bodies and their distances, and predictions are only based on patterns? This collision was the first one ever observed between two bodies of the Solar System, it's hard to find a pattern when there's a single occurrence.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 25, 2020, 11:59:41 PM
(https://ase.tufts.edu/cosmos/pictures/Chapter14/Fig14_2.jpg)

It was discovered March 1993 and it appears to have been predicted to impact Jupiter in May or June 1993. Not even a complete orbit. They predicted a partial orbit.

I can't find the method used to predict the orbit, but I would bet that it's probably the epicycle method of prediction used elsewhere in astronomy. (https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns)
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on April 26, 2020, 01:16:14 AM
It was discovered March 1993 and it appears to have been predicted to impact Jupiter in May or June 1993. Not even a complete orbit. They predicted a partial orbit.

I can't find the method used to predict the orbit, but I would bet that it's probably the epicycle method of prediction used elsewhere in astronomy. (https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns)

It was discovered on March 24, 1993 and on May 22, 1993 a prediction was published (http://www.cbat.eps.harvard.edu/iauc/05800/05800.html) indicating it was likely going to hit Jupiter on July 25, 1994.

It hit Jupiter between July 16 and 22, 1994.

They were only three days off, 14 months in advance, a month after discovering it.

This is extremely strong evidence that the calculations used in modern astronomy work.

Calling them "patterns" with no knowledge of how they were actually made or any references is not evidence at all.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 26, 2020, 02:50:18 AM
It's only a segment of an orbit, regardless of whether it took 14 months.

Did I call them patterns or did I say that I would bet that a method was similar to another method?
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 26, 2020, 03:27:59 AM
(https://ase.tufts.edu/cosmos/pictures/Chapter14/Fig14_2.jpg)

It was discovered March 1993 and it appears to have been predicted to impact Jupiter in May or June 1993. Not even a complete orbit. They predicted a partial orbit.

I can't find the method used to predict the orbit, but I would bet that it's probably the epicycle method of prediction used elsewhere in astronomy. (https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns)

I'm not sure what a partial orbit versus a complete orbit has to do with anything. In any case, you are wrong in terms of it probably being an epicycle prediction. Yeomans, D. K. & Chodas are the ones who calculated just when the fragments and which ones would impact Jupiter and where on Jupiter. There's this:

(https://i.imgur.com/OcKrEcT.png)
http://adsabs.harvard.edu/full/1994BAAS...26R1022Y

Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 26, 2020, 03:42:20 AM
I clicked on your link and saw that the first page described how it was using perturbative analysis, which are epicycle methods.

"The equations of motion include perturbations due to all nine planets"

Perturbations = The modern epicycles with a gravitational twist
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 26, 2020, 04:01:07 AM
I clicked on your link and saw that the first page described how it was using perturbative analysis, which are epicycle methods.

"The equations of motion include perturbations due to all nine planets"

Perturbations = The modern epicycles with a gravitational twist

With a relativistic twist and supported by data from the 4 Galilean satellites. And don't forget the use of the disruption model developed by Sekanina, Zdenek; Chodas, Paul W.; Yeomans, Donald K:

Tidal Disruption and the Appearance of Periodic Comet Shoemaker-Levy 9

A unified model is presented that quantitatively interprets the observed characteristics of the nuclear train, the two dust trails, and the tail region of P/Shoemaker-Levy 9 in terms of a collisionally modified rotation velocity distribution of the comet's debris.

https://trs.jpl.nasa.gov/handle/2014/36567

Calculated and predicted through modern means, not just perturbations. And they were spot on.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on April 26, 2020, 04:26:22 AM
I clicked on your link and saw that the first page described how it was using perturbative analysis, which are epicycle methods.

"The equations of motion include perturbations due to all nine planets"

Perturbations = The modern epicycles with a gravitational twist

Im not certain that equal sign is right. I found this:

https://arxiv.org/abs/0807.2708

This article derives Copernicus epicycles from Newtonian gravity using linear algebra. It shows that by taking a perturbed circular orbit (from weak gravitational effects) Newtonian gravity can explain the observations made by early astronomers.

This sounds like a good thing for Newtonian gravity: it is consistent with observations.

So it doesn’t appear from this that perturbations are re-vamped epicycles, but instead that Newtonian gravity has the power to explain even very old observations.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 26, 2020, 05:03:02 AM
Dr. Gopi Krishna Vijaya says that astronomers are really using epicycles with a gravitational disguise.

Replacing the Foundations of Astronomy - .pdf (https://archive.org/download/replacing-the-foundations-of-astronomy-vijaya-gopi-krishna-2/Replacing%20the%20Foundations%20of%20Astronomy%20%28Vijaya%2C%20Gopi%20Krishna%29%20%282%29.pdf)

Epicycles Once More

“ Following the Newtonian era, in the 18th century there were a series of mathematicians – Bernoulli, Clairaut, Euler, D’Alembert, Lagrange, Laplace, Leverrier – who basically picked up where Newton left off and ran with it. There were no descendants to the wholistic viewpoints of Tycho and Kepler, but only those who made several improvements of a mathematical nature to Newtonian theory. Calculus became a powerful tool in calculating the effects of gravitation of all the planets upon each other, due to their assumed masses. The motion of the nearest neighbor – the Moon – was a surprisingly hard nut to crack even for Newton, and several new mathematical techniques had to be invented just to tackle that.

In the process, a new form of theory became popular: Perturbation theory. In this approach, a small approximate deviation from Newton's law is assumed, based on empirical data, and then a rigorous calculation of differential equation is used to nail down the actual value of the deviation. It does not take much to recognize that this was simply the approach taken before Kepler by Copernicus and others for over a thousand years – adding epicycles to make the observations fit. It is the same concept, but now dressed up in gravitational disguise: ”

(https://i.imgur.com/KiTaMfy.png)

“ In other words, the entire thought process took several steps backwards, to redo the same process as the Ptolemaic - Copernican epicycle theory, only with different variables. The more logical way of approach would have been to redirect the focus of the improved mathematical techniques to the assumptions in Newton’s theory, but instead the same equations were re-derived with calculus, without examining the assumptions. Hence any modern day textbook gives the same derivation for circular and elliptical motion that Newton first derived in his Principia. The equivalence of the epicycle theory and gravitational theory has not been realized, and any new discovery that fits in with the mathematical framework of Newtonian gravity is lauded as a “triumph of the theory of gravitation.” In reality, it is simply the triumph of fitting curves to the data or minor linear extrapolations – something that had already been done at least since 2nd century AD. Yet the situation is conceptually identical. ”
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on April 26, 2020, 07:13:51 AM
Are you arguing they couldn't make the prediction they did make?

Do we, or do we not, know the orbit of Jupiter precisely enough to predict more than one year in advance, not only that a comet will hit it, but also where on the planet it will hit?

Is that compatible with not knowing the distances between celestial bodies?
Title: Re: Comet Shoemaker–Levy 9
Post by: Pete Svarrior on April 26, 2020, 11:12:11 AM
Please try to post in the correct board in the future.

Please not that this is not the right board for asking entry-level FET questions. If your post starts with "I'm new and I just wanted to ask" or "The Earth can't be flat because of this concept", you're in the wrong place and should probably be looking at the Flat Earth Theory (https://forum.tfes.org/index.php?topic=10088.0) board (and the FAQ).
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on April 26, 2020, 01:16:54 PM
Please try to post in the correct board in the future.

Please not that this is not the right board for asking entry-level FET questions. If your post starts with "I'm new and I just wanted to ask" or "The Earth can't be flat because of this concept", you're in the wrong place and should probably be looking at the Flat Earth Theory (https://forum.tfes.org/index.php?topic=10088.0) board (and the FAQ).
It didn't look particularly "entry-level" to me, it's not addressed in the FAQ and doesn't even directly deal with the shape of the Earth: it's about our knowledge of the position and movement of celestial bodies.

But well, your forum your rules, I'm fine with either board.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on April 26, 2020, 01:17:00 PM
It's only a segment of an orbit, regardless of whether it took 14 months.

Did I call them patterns or did I say that I would bet that a method was similar to another method?

Don't be disingenuous.  Your only actual reference to these "similar methods" was your Wiki page titled "Astronomical Prediction Based on Patterns" so don't claim patterns had nothing to do with your answer. 

The prediction worked, it was extremely accurate, it shows that the math and theory is correct and we understand how planets and comets and bodies move, and even collide.

And that segment was 14 months of an 18 month orbit, very nearly a full orbit. 

Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on April 26, 2020, 03:12:50 PM
Dr. Gopi Krishna Vijaya says that astronomers are really using epicycles with a gravitational disguise.

Replacing the Foundations of Astronomy - .pdf (https://archive.org/download/replacing-the-foundations-of-astronomy-vijaya-gopi-krishna-2/Replacing%20the%20Foundations%20of%20Astronomy%20%28Vijaya%2C%20Gopi%20Krishna%29%20%282%29.pdf)

Epicycles Once More

“ Following the Newtonian era, in the 18th century there were a series of mathematicians – Bernoulli, Clairaut, Euler, D’Alembert, Lagrange, Laplace, Leverrier – who basically picked up where Newton left off and ran with it. There were no descendants to the wholistic viewpoints of Tycho and Kepler, but only those who made several improvements of a mathematical nature to Newtonian theory. Calculus became a powerful tool in calculating the effects of gravitation of all the planets upon each other, due to their assumed masses. The motion of the nearest neighbor – the Moon – was a surprisingly hard nut to crack even for Newton, and several new mathematical techniques had to be invented just to tackle that.

In the process, a new form of theory became popular: Perturbation theory. In this approach, a small approximate deviation from Newton's law is assumed, based on empirical data, and then a rigorous calculation of differential equation is used to nail down the actual value of the deviation. It does not take much to recognize that this was simply the approach taken before Kepler by Copernicus and others for over a thousand years – adding epicycles to make the observations fit. It is the same concept, but now dressed up in gravitational disguise: ”

(https://i.imgur.com/KiTaMfy.png)

“ In other words, the entire thought process took several steps backwards, to redo the same process as the Ptolemaic - Copernican epicycle theory, only with different variables. The more logical way of approach would have been to redirect the focus of the improved mathematical techniques to the assumptions in Newton’s theory, but instead the same equations were re-derived with calculus, without examining the assumptions. Hence any modern day textbook gives the same derivation for circular and elliptical motion that Newton first derived in his Principia. The equivalence of the epicycle theory and gravitational theory has not been realized, and any new discovery that fits in with the mathematical framework of Newtonian gravity is lauded as a “triumph of the theory of gravitation.” In reality, it is simply the triumph of fitting curves to the data or minor linear extrapolations – something that had already been done at least since 2nd century AD. Yet the situation is conceptually identical. ”

Hmm, I see your point. One can draw many parallels as this author has done. But this description does not gel with the history of science. It is almost as though the author comments on the intention of those who developed the subject. Epicycles fell out of favor because it was descriptive rather than explanatory. Newton provided the explanation.

Of course, since both involve circular geometry, it is not a surprise that one can find mathematical transformations between the two. But over interpreting that would be a mistake.

At any rate, it is clearly confirmed from the article I posted that the mathematical theory (which is what matters in the end) predicts epicycles, and not the other way around.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 27, 2020, 12:45:31 AM
Dr. Gopi Krishna Vijaya says that astronomers are really using epicycles with a gravitational disguise.

Replacing the Foundations of Astronomy - .pdf (https://archive.org/download/replacing-the-foundations-of-astronomy-vijaya-gopi-krishna-2/Replacing%20the%20Foundations%20of%20Astronomy%20%28Vijaya%2C%20Gopi%20Krishna%29%20%282%29.pdf)

I read Dr. Gopi Krishna Vijaya’s paper. Interesting until I got to who he recommends as far as researchers in this space - One recommended individual, Miles Mathis, stood out as I have read his work before. Dr. Gopi writes:

"Miles Mathis has independently detected both the problems with the conventional explanations for orbital motion as well as the need for an outward force against gravity, and has also, among other things, shown how Lagrange implicitly assumed it in his equations.

Miles Mathis is the same guy who claims Pi = 4, from his paper:

Abstract: I show that in all kinematic situations, π is 4.

And has page after page of what he considers fake, just a smattering of Mathis’ work:

PAPER UPDATE, added 3/11/20, The Lincoln Assassination. I show that we now have the grand slam: Lincoln was a gay Jewish actor who faked his death. See p. 29.
NEW PAPER, added 10/10/19, The 22 July Massacre in Norway was Fake, part 1. This is the Breivik event, where 77 people were allegedly killed. You probably already know it didn't happen, but here I do the world the favor of proving it. I also tie it to many other events and people.
NEW PAPER, added 4/17/15, Stephen Hawking died and has been replaced. I show lots of photographic evidence that Hawking died in 1985 and has been played by an impostor since then.
NEW PAPER, added 9/29/17, Looks like the Bushes are Jewish, too. Another big day at the genealogy sites and the peerage.

Mathis is a crackpot and Dr. Gobi cites him as "Other researchers (who) have shed additional light on these phenomena. Sullies the whole thing with the credibility meter plummeting.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 27, 2020, 01:09:10 AM
Physics hero Issac Newton believed in alchemy, young earth creationism, and made end-of-the-world predictions. That doesn't make everything Newton ever wrote to be wrong or uncitable, however. People can cite Newton without believing his other stuff. He believed in that other stuff, yet is somehow called the 'greatest physcist to have ever lived'. Vijaya is referencing something because he thinks it's correct.

By your posting you appear to be saying that you believe that this paper debunks you, and so you need to somehow discredit the author. And, desperately, you are telling us about something that someone else believes, who is not the author, that is unrelated to astronomy.

You can find several celestial mechanics experts calling perturbation theory to be based on epicycles as well - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns
 
Gravitation Vs. Relativity
Charles Lane Poor, Ph.D.
Professor Emeritus of Celestial Mechanics,
Columbia University

Motion of the Planets p.132

  “ The deviations from the “ideal” in the elements of a planet’s orbit are called “perturbations” or “variations”.... In calculating the perturbations, the mathematician is forced to adopt the old device of Hipparchus, the discredited and discarded epicycle. It is true that the name, epicycle, is no longer used, and that one may hunt in vain through astronomical text-books for the slightest hint of the present day use of this device, which in the popular mind is connected with absurd and fantastic theories. The physicist and the mathematician now speak of harmonic motion, of Fourier’s series, of the development of a function into a series of sines and cosines. The name has been changed, but the essentials of the device remain. And the essential, the fundamental point of the device, under whatever name it may be concealed, is the representation of an irregular motion as the combination of a number of simple, uniform circular motions. ”
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 27, 2020, 01:57:43 AM
Physics hero Issac Newton believed in alchemy, young earth creationism, and made end-of-the-world predictions. That doesn't make everything Newton ever wrote to be wrong or uncitable, however. People can cite Newton without believing his other stuff. He believed in that other stuff, yet is somehow called the 'greatest physcist to have ever lived'. Vijaya is referencing something because he thinks it's correct.

By your posting you appear to be saying that you believe that this paper debunks you, and so you need to somehow discredit the author. And, desperately, you are telling us about something that someone else believes, who is not the author, that is unrelated to astronomy.

You can find several celestial mechanics experts calling perturbation theory to be based on epicycles as well - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns
 
Gravitation Vs. Relativity
Charles Lane Poor, Ph.D.
Professor Emeritus of Celestial Mechanics,
Columbia University

Motion of the Planets p.132

  “ The deviations from the “ideal” in the elements of a planet’s orbit are called “perturbations” or “variations”.... In calculating the perturbations, the mathematician is forced to adopt the old device of Hipparchus, the discredited and discarded epicycle. It is true that the name, epicycle, is no longer used, and that one may hunt in vain through astronomical text-books for the slightest hint of the present day use of this device, which in the popular mind is connected with absurd and fantastic theories. The physicist and the mathematician now speak of harmonic motion, of Fourier’s series, of the development of a function into a series of sines and cosines. The name has been changed, but the essentials of the device remain. And the essential, the fundamental point of the device, under whatever name it may be concealed, is the representation of an irregular motion as the combination of a number of simple, uniform circular motions. ”

Simply, I just find your source material subject as stated before. And your reference on 'perturbations' is lovely, but the fact remains that these astronomers found, derived, calculated, and predicted a collision with Jupiter, when it would occur, and where it would occur on Jupiter's surface. And it was witnessed.

Now, how does FET account for that? Can FET make such a prediction? I think not. If and when FET can do all that, post it, in the mean time keep searching for how RE doesn't 'fit' observation. I'm looking forward to how FET can or does. Lay it on us how FET could make such a prediction.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on April 27, 2020, 04:28:04 AM
Physics hero Issac Newton believed in alchemy, young earth creationism, and made end-of-the-world predictions. That doesn't make everything Newton ever wrote to be wrong or uncitable, however. People can cite Newton without believing his other stuff. He believed in that other stuff, yet is somehow called the 'greatest physcist to have ever lived'. Vijaya is referencing something because he thinks it's correct.

By your posting you appear to be saying that you believe that this paper debunks you, and so you need to somehow discredit the author. And, desperately, you are telling us about something that someone else believes, who is not the author, that is unrelated to astronomy.

You can find several celestial mechanics experts calling perturbation theory to be based on epicycles as well - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns
 
Gravitation Vs. Relativity
Charles Lane Poor, Ph.D.
Professor Emeritus of Celestial Mechanics,
Columbia University

Motion of the Planets p.132

  “ The deviations from the “ideal” in the elements of a planet’s orbit are called “perturbations” or “variations”.... In calculating the perturbations, the mathematician is forced to adopt the old device of Hipparchus, the discredited and discarded epicycle. It is true that the name, epicycle, is no longer used, and that one may hunt in vain through astronomical text-books for the slightest hint of the present day use of this device, which in the popular mind is connected with absurd and fantastic theories. The physicist and the mathematician now speak of harmonic motion, of Fourier’s series, of the development of a function into a series of sines and cosines. The name has been changed, but the essentials of the device remain. And the essential, the fundamental point of the device, under whatever name it may be concealed, is the representation of an irregular motion as the combination of a number of simple, uniform circular motions. ”

I’m confused. How can a paper “debunk” me? This isn’t personal. I’m offering different perspectives to further the discussion.

I cited a published paper of physics which shows the mathematical formalism. It stands for itself, and clearly details that Newtonian mechanics predicts epicycle observations. Do you wish to challenge the formalism?

From your reply, you appear to try to poison the well by discussing Newton’s failed ideas. That is irrelevant here. Also, I have never heard him called the greatest physicist. That’s a new one to me!

Next, you cite an opinion of a retired physicist, which is fine. Everyone may have their opinion. But the argument offered by him is best placed in an editorial - not a scientific journal. In fact, he ends the passage with a statement that confirms the formalism - obviously one can represent Newtonian mechanics by performing linear transformations on circles - the Newtonian gravitational force law has this embedded within it. And this comes as no surprise to anyone who understands it.

I hesitate to place much credence in TFES wiki sources, since I have found several instances throughout the fora of those sources being pseudoscience, along with evidence to support those statements.

In the end, any scientist may have their opinion on the philosophical implications of what the formalism shows. That is their prerogative. But that opinion should not be confused with the science - which are models themselves.

And the Newtonian model unequivocally demonstrates that epicycles follow as an observational consequence. And that fact can only be impeached by those who do not understand it.

But perhaps you see something in the math that they have all missed. I think that would be interesting to hear about!
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 28, 2020, 11:39:52 PM
How is a Columbia University Professor Emeritus of Celestial Mechanics an invalid source? I doubt that your credentials are as good to tell us how this works.

From the paper you posted (https://arxiv.org/pdf/0807.2708.pdf), in the summary and conclusion section:

Quote
In this paper, we derived the Copernican system of epicycles from Newton’s gravitational force law in vector form
via linear perturbation theory in Clifford (geometric) algebra Cl2,0 of the plane.

It says that they derived Copernicus's epicycles with the Newtonian perturbation theory, which we had learned were also epicycles with a gravitational disguise.

Ptolmy's epicycle theory is described as follows (https://books.google.com/books?id=aXU2AAAAQBAJ&lpg=PT38&ots=zNE0nJr1Qw&pg=PT37#v=onepage&q&f=false):

  “ The circle is the geometric figure possessing perfect symmetry, so Ptolemy and earlier Greek astronomers began with the intuition that celestial bodies orbit in circles at uniform speed. Observations then determined the deviations from the ideal, which Ptolemy modeled using mathematical contrivances unrelated to physical principles (deferents, epicycles, and equants).

...Ptolemy’s science was superficially anti-Platonic in that he emphasized the role of careful observation. However, at a deeper level, his science was a logical application of Platonism; in astronomy and in optics, he started with the “perfect” model and then merely described without explanation the inherently unintelligible deviations from it. ”

Charles Lane Poor says:

"The deviations from the “ideal” in the elements of a planet’s orbit are called “perturbations” or “variations”.... In calculating the perturbations, the mathematician is forced to adopt the old device of Hipparchus, the discredited and discarded epicycle."

Dr. Vijaya said earlier:

"In the process, a new form of theory became popular: Perturbation theory. In this approach, a small approximate deviation from Newton's law is assumed, based on empirical data, and then a rigorous calculation of differential equation is used to nail down the actual value of the deviation. It does not take much to recognize that this was simply the approach taken before Kepler by Copernicus and others for over a thousand years – adding epicycles to make the observations fit. It is the same concept, but now dressed up in gravitational disguise"

Sounds pretty clear what the Newtonian Perturbation Theory is to me.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 28, 2020, 11:56:27 PM
How is a Columbia University Professor Emeritus of Celestial Mechanics an invalid source? I doubt that your credentials are as good to tell us how this works.

Sounds like a smart guy, but he is beside the point. The point is, these astronomers found, derived, calculated, and predicted a collision with Jupiter, when it would occur, and where it would occur on Jupiter's surface. And it was witnessed.

How does FET account for that? Can FET make such a prediction? If so, how?
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 12:58:03 AM
How is a Columbia University Professor Emeritus of Celestial Mechanics an invalid source? I doubt that your credentials are as good to tell us how this works.

Sounds like a smart guy, but he is beside the point. The point is, these astronomers found, derived, calculated, and predicted a collision with Jupiter, when it would occur, and where it would occur on Jupiter's surface. And it was witnessed.

How does FET account for that? Can FET make such a prediction? If so, how?

FE and RE has nothing to do with it. Astronomers are merely predicting the motion of epicycles. The underlying 'ideal' state on which the deviations differ can be based on anything.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 29, 2020, 01:11:29 AM
How is a Columbia University Professor Emeritus of Celestial Mechanics an invalid source? I doubt that your credentials are as good to tell us how this works.

Sounds like a smart guy, but he is beside the point. The point is, these astronomers found, derived, calculated, and predicted a collision with Jupiter, when it would occur, and where it would occur on Jupiter's surface. And it was witnessed.

How does FET account for that? Can FET make such a prediction? If so, how?

FE and RE has nothing to do with it. Astronomers are merely predicting the motion of epicycles. The underlying 'ideal' state on which the deviations differ can be based on anything.

Wait, so now FET is in agreement with the fact that Jupiter has a diameter of about 88,695 miles which is more than 11 times the diameter of Earth? FET would need to because part of the astronomers' calculations had to take into account the diameter of Jupiter to determine when and where on the planet the debris would hit.

Could FET make the prediction just using an epicycle?
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 01:39:08 AM
Wait, so now FET is in agreement with the fact that Jupiter has a diameter of about 88,695 miles which is more than 11 times the diameter of Earth? FET would need to because part of the astronomers' calculations had to take into account the diameter of Jupiter to determine when and where on the planet the debris would hit.

No, they did not take it into account for any meaningful purpose. Once you start adding epicycles, the underlying model is meaningless.

Here is an orbit in the shape of Homer Simpson, based on the Ptolmy's underlying ideal model of a circle with uniform motion:

https://www.youtube.com/watch?v=QVuU2YCwHjw

Quote
Could FET make the prediction just using an epicycle?

It can be done with any underlying model. FE does not propose a dogmatic underlying 'ideal' celestial model or force that must be justified and adhered to with intellectually wrong epicycles.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 29, 2020, 01:40:24 AM
Wait, so now FET is in agreement with the fact that Jupiter has a diameter of about 88,695 miles which is more than 11 times the diameter of Earth? FET would need to because part of the astronomers' calculations had to take into account the diameter of Jupiter to determine when and where on the planet the debris would hit.

No, they did not take it into account for any meaningful purpose. Once you start adding epicycles, the underlying model is meaningless.

You are wrong. They most certainly took the known size of Jupiter into account. From the paper I cited before, titled 'Tidal Disruption and the Appearance of Periodic Comet Shoemaker-Levy 9', one of just page after page of calculations used to model/predict the collision:

(https://i.imgur.com/SNIRZ3U.png)

Note: R3 is Jupiter’s equatorial radius

And that's just scratching the surface, as it where:

(https://i.imgur.com/xow11EM.png)

https://trs.jpl.nasa.gov/handle/2014/36567

Quote
Could FET make the prediction just using an epicycle?

It can be done with anything, and any underlying model. FE does not propose an underlying 'ideal' celestial dogma model or force that must be justified and adhered to with epicycles.

Wrong again. Read the paper I referenced that describes how it was calculated. A massive undertaking.

Bottom line, FET could not have predicted the collision and modern heliocentric calculation could and did.

So again, if "It can be done with anything, and any underlying model," show us how FET could do it. Prove me wrong.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 01:56:03 AM
I did show you to be wrong. I gave you an epicyclic Homer Simpson. The layered corrections made the underlying model of a circle with uniform motion meaningless.

Any paper you present on astrodynamics is going to be peppered with terms like "perturbations" and "Fourier," which are epicyclic theories. The underlying model may be a mass going around another mass, but the epicycle corrections layered upon that make it meaningless beneath.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 29, 2020, 02:11:06 AM
I did show you to be wrong wrong. I gave you an epicyclic Homer Simpson. The layered corrections made the underlying model of a circle with uniform motion meaningless.

Any paper you present on aerodynamics is going to be peppered with terms like "perturbations" and "Fourier," which are epicyclic theories. The underlying model may be a mass going around another mass, but the epicycle corrections layered upon that make it meaningless beneath.

How was the epicycle of the comet derived only having been discovered less than a year before impact and without a complete orbit?

And like I said, the page after page of calculations were not meaningless - They were required to help predict the orbit and time and location on Jupiter of the collision. That much is clear. And part of those calculations took into account the known size of Jupiter as previously shown. Without which the collision could not have been predicted.

So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 02:18:41 AM
Quote
How was the epicycle of the comet derived only having been discovered less than a year before impact and without a complete orbit?

The comet was just going in an ellipse, and it was only a portion of the ellipse that needed to be completed, which is a little easier to predict than a Homer Simpson.

Take a look at this simple circular uniform motion:

(https://mathworld.wolfram.com/images/gifs/UniformCircularMotion.gif)

Is it possible to predict where the body in orbit will be after x amount of time?

Quote
And like I said, the page after page of calculations were not meaningless - They were required to help predict the orbit and time and location on Jupiter of the collision. That much is clear.

How is it clear? As soon as you start adding on corrections to your model the underlying model becomes irrelevant. It's no longer your model.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 03:01:19 AM
So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.

Here you go. I used an epicycle with two terms to make an ellipse. With only these two terms it is possible to predict the path of the orbit and the shape of the ellipse for any given time in the future.

(https://i.ibb.co/gzhxSG3/ellipse-two-terms.gif)

We can see that with a uniform epicycle like this, that you would only need to build a small segment of the ellipse, in order to be able to make a model of the entire ellipse useful for prediction. You only need those two terms.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on April 29, 2020, 03:17:00 AM
Sounds pretty clear what the Newtonian Perturbation Theory is to me.

Everything you quoted was simply conjecture, guessing at the methods used, and guessing they were somehow wrong, even though you were shown papers where they described it, even though it worked perfectly.

You can claim it's perturbation this or epicycle that or pattern something, but none of that is evidence at all of anything, let alone evidence against the FACT that they correctly predicted it. You keep ignoring the fact that the math they used WORKS. You can not avoid addressing this and have any argument at all.

You claim that it's all fake math somehow that doesn't represent reality.

You can't do that without showing what this hidden reality looks like. Lets see some equations that predict better than what we have, then we can talk.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on April 29, 2020, 03:27:30 AM
How is a Columbia University Professor Emeritus of Celestial Mechanics an invalid source? I doubt that your credentials are as good to tell us how this works.

From the paper you posted (https://arxiv.org/pdf/0807.2708.pdf), in the summary and conclusion section:

Quote
In this paper, we derived the Copernican system of epicycles from Newton’s gravitational force law in vector form
via linear perturbation theory in Clifford (geometric) algebra Cl2,0 of the plane.

It says that they derived Copernicus's epicycles with the Newtonian perturbation theory, which we had learned were also epicycles with a gravitational disguise.

Ptolmy's epicycle theory is described as follows (https://books.google.com/books?id=aXU2AAAAQBAJ&lpg=PT38&ots=zNE0nJr1Qw&pg=PT37#v=onepage&q&f=false):

  “ The circle is the geometric figure possessing perfect symmetry, so Ptolemy and earlier Greek astronomers began with the intuition that celestial bodies orbit in circles at uniform speed. Observations then determined the deviations from the ideal, which Ptolemy modeled using mathematical contrivances unrelated to physical principles (deferents, epicycles, and equants).

...Ptolemy’s science was superficially anti-Platonic in that he emphasized the role of careful observation. However, at a deeper level, his science was a logical application of Platonism; in astronomy and in optics, he started with the “perfect” model and then merely described without explanation the inherently unintelligible deviations from it. ”

Charles Lane Poor says:

"The deviations from the “ideal” in the elements of a planet’s orbit are called “perturbations” or “variations”.... In calculating the perturbations, the mathematician is forced to adopt the old device of Hipparchus, the discredited and discarded epicycle."

Dr. Vijaya said earlier:

"In the process, a new form of theory became popular: Perturbation theory. In this approach, a small approximate deviation from Newton's law is assumed, based on empirical data, and then a rigorous calculation of differential equation is used to nail down the actual value of the deviation. It does not take much to recognize that this was simply the approach taken before Kepler by Copernicus and others for over a thousand years – adding epicycles to make the observations fit. It is the same concept, but now dressed up in gravitational disguise"

Sounds pretty clear what the Newtonian Perturbation Theory is to me.

It does sound clear, I agree. But you interpret the order incorrectly. The Newtonian theory DERIVES the epicycles.

The mathematics in my source has not been disputed.

Rather, you use non-scientific statements from sources to argue the philosophy. The hope is that since the sources used to be scientists, then their opinions will be convincing to an untrained reader. You can do this all day long, but the mathematical model remains unchallenged.

Until the mathematical model is directly challenged, all editorial comments from anyone is anecdotal.

Quoting an emeritus professor’s opinion of the history is an appeal to authority fallacy. His historical opinion is not automatically valid just because of his tenure in another field.

What you are doing is relying on the interpretation of the history by individuals who conclude your desired result.

What you SHOULD do is understand the mathematical model yourself so that you are in a position to debate it. Why don’t you try to do that, if you can.

Oh, by the way, attacking my credentials is an ad hominem fallacy. I would hope you would be better than that, Thomas.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 29, 2020, 04:59:50 AM
So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.

Here you go. I used an epicycle with two terms to make an ellipse. With only these two terms it is possible to predict the path of the orbit and the shape of the ellipse for any given time in the future.

(https://i.ibb.co/gzhxSG3/ellipse-two-terms.gif)

We can see that with a uniform epicycle like this, that you would only need to build a small segment of the ellipse, in order to be able to make a model of the entire ellipse useful for prediction. You only need those two terms.

'Uniform'?

From 'Lessons from Shoemaker-Levy 9 about Jupiter and Planetary Impacts

Jupiter most likely captured SL9 in 1929 ± 9, and tidally disrupted it during a perijove passage just 0.3 Jupiter radii above the cloudtops on July 7, 1992 (Chodas and Yeomans 1996, see also Chapter 12). Carolyn S. Shoemaker discovered SL9 on March 24, 1993, on a photographic plate that she, Eugene M. Shoemaker, and David H. Levy took with the Palomar 0.46-m Schmidt telescope (Shoemaker et al. 1993, Figure 8.2). On May 22, 1993, Nakano et al. (1993) predicted the impacts.
http://lasp.colorado.edu/home/mop/files/2015/08/jupiter_ch8-1.pdf

Here's what the comet's trajectory was modeled to look like up until impact:

(https://i.imgur.com/DH4KYOk.png)

Like I mentioned and cited before, the known size of Jupiter had to be taken into consideration for the calculations to know just when and where on Jupiter the collision would be made. In the Heliocentric world, Jupiter has a diameter of about 88,695 miles. What is the size of Jupiter in FET?



Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on April 29, 2020, 07:10:44 AM
So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.

Here you go. I used an epicycle with two terms to make an ellipse. With only these two terms it is possible to predict the path of the orbit and the shape of the ellipse for any given time in the future.

(https://i.ibb.co/gzhxSG3/ellipse-two-terms.gif)

We can see that with a uniform epicycle like this, that you would only need to build a small segment of the ellipse, in order to be able to make a model of the entire ellipse useful for prediction. You only need those two terms.

That's nice, but how does that help for predicting a collision? If the orbit is uniform, the comet never collides.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on April 29, 2020, 04:45:51 PM
So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.

Here you go. I used an epicycle with two terms to make an ellipse. With only these two terms it is possible to predict the path of the orbit and the shape of the ellipse for any given time in the future.

(https://i.ibb.co/gzhxSG3/ellipse-two-terms.gif)

We can see that with a uniform epicycle like this, that you would only need to build a small segment of the ellipse, in order to be able to make a model of the entire ellipse useful for prediction. You only need those two terms.

'Uniform'?

From 'Lessons from Shoemaker-Levy 9 about Jupiter and Planetary Impacts

Jupiter most likely captured SL9 in 1929 ± 9, and tidally disrupted it during a perijove passage just 0.3 Jupiter radii above the cloudtops on July 7, 1992 (Chodas and Yeomans 1996, see also Chapter 12). Carolyn S. Shoemaker discovered SL9 on March 24, 1993, on a photographic plate that she, Eugene M. Shoemaker, and David H. Levy took with the Palomar 0.46-m Schmidt telescope (Shoemaker et al. 1993, Figure 8.2). On May 22, 1993, Nakano et al. (1993) predicted the impacts.
http://lasp.colorado.edu/home/mop/files/2015/08/jupiter_ch8-1.pdf

Here's what the comet's trajectory was modeled to look like up until impact:

(https://i.imgur.com/DH4KYOk.png)

The 'final orbit', which is the only orbit that was predicted (a segment of the final orbit), looks pretty symmetrical. It looks something like the symmetrical ellipse I provided. The comet was discovered in its final orbit.

The prior orbits were unobserved, and are presumably based on someone's backwards-in-time orbit project.

Since they only predicted a (portion of a) single symmetrical orbit, it is much less impressive than if they had predicted multiple orbits from the beginning. In this case they did the equivalent of predicting the shape of one of Homer Simpson's epicyclic eyeballs before it was completed.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on April 29, 2020, 04:48:46 PM
Here is a short animation that depicts how Newtonian robots deliver epicycles as a geometric observational consequence.

https://www.reddit.com/r/Damnthatsinteresting/comments/ga5mn3/dance_of_mars_and_jupiter/
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on April 29, 2020, 06:25:13 PM
So again, if it's just an epicycle as you claim and "It can be done with anything, and any underlying model," as you claim, show us how FET could do it. Prove me wrong.

Here you go. I used an epicycle with two terms to make an ellipse. With only these two terms it is possible to predict the path of the orbit and the shape of the ellipse for any given time in the future.

(https://i.ibb.co/gzhxSG3/ellipse-two-terms.gif)

We can see that with a uniform epicycle like this, that you would only need to build a small segment of the ellipse, in order to be able to make a model of the entire ellipse useful for prediction. You only need those two terms.

'Uniform'?

From 'Lessons from Shoemaker-Levy 9 about Jupiter and Planetary Impacts

Jupiter most likely captured SL9 in 1929 ± 9, and tidally disrupted it during a perijove passage just 0.3 Jupiter radii above the cloudtops on July 7, 1992 (Chodas and Yeomans 1996, see also Chapter 12). Carolyn S. Shoemaker discovered SL9 on March 24, 1993, on a photographic plate that she, Eugene M. Shoemaker, and David H. Levy took with the Palomar 0.46-m Schmidt telescope (Shoemaker et al. 1993, Figure 8.2). On May 22, 1993, Nakano et al. (1993) predicted the impacts.
http://lasp.colorado.edu/home/mop/files/2015/08/jupiter_ch8-1.pdf

Here's what the comet's trajectory was modeled to look like up until impact:

(https://i.imgur.com/DH4KYOk.png)

The 'final orbit', which is the only orbit that was predicted (a segment of the final orbit), looks pretty symmetrical. It looks something like the symmetrical ellipse I provided. The comet was discovered in its final orbit.

The prior orbits were unobserved, and are presumably based on someone's backwards-in-time orbit project.

Absolutely, I agree.

Since they only predicted a (portion of a) single symmetrical orbit, it is much less impressive than if they had predicted multiple orbits from the beginning. In this case they did the equivalent of predicting the shape of one of Homer Simpson's epicyclic eyeballs before it was completed.

If you had read the papers I have cited you would see that the predicative efforts were far more complex than the Homer vid and the predictions were correct.

I noticed you didn't answer my question. Like I mentioned and cited before, the known size of Jupiter had to be taken into consideration for the calculations to know just when and where on Jupiter the collision would occur. In the Heliocentric world, Jupiter has a diameter of about 88,695 miles.

What is the size of Jupiter in FET?
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 03, 2020, 01:49:33 AM
Since they only predicted a (portion of a) single symmetrical orbit, it is much less impressive than if they had predicted multiple orbits from the beginning. In this case they did the equivalent of predicting the shape of one of Homer Simpson's epicyclic eyeballs before it was completed.

The following from the folks who greatly aided in deciphering and predicting all of the shards that would hit Jupiter, where and when on its surface:

The orbital motion and impact circumstances of Comet Shoemaker-Levy 9
ByPAU L W. CHODAS and DONALD K. YEOMANS Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA

To determine the basic characteristics of SL9's orbit and its impending impact, we quickly modified our software to provide jovicentric information, including position, velocity, and orbital elements as a function of time. It became clear tha t the comet was approaching the apojove of an extremely eccentric orbit about Jupiter, with eccentricity ~ 0.99 and apojove distance ~ 0.33 AU (see Fig. 1). By June 1, we had determined tha t the impact would occur in the mid-southern latitudes of Jupiter, and, unfortunately, on the side of the planet facing away from Earth. We defined impact to occur when the comet reached the one bar pressure level in Jupiter's atmosphere, which we modeled as an oblate spheroid with radius and flattening given by Davies et, al. (1992).


https://www.cambridge.org/core/services/aop-cambridge-core/content/view/7C7A50945B166FCC28D197F3A53EB2D5/S025292110011543Xa.pdf/orbital_motion_and_impact_circumstances_of_comet_shoemakerlevy_9.pdf

As you can see, data was required from a Jovian (Jupiter) perspective in order to predict the orbit and impact. Hence, size and position of Jupiter had to be factored not just through observation, but through calculation as well. And they nailed the prediction.

Which begs the questions: Where and what is the size of Jupiter in Flat Earth Theory?
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 03, 2020, 02:29:06 AM
Also from the linked paper:

Quote
"The need for accurate impact predictions required the modeling of the perturbative effects of the Galilean satellites and Jupiter's oblateness."

"Tidal disruption during an approach to within the Roche limit of a large perturbing body is a common mechanism for cometary splitting."

"In April, we upgraded the dynamical models used in our orbit determinations and impact predictions. Up until this time, we had used only point mass perturbations by the sun and planets, with planetary positions and masses taken from JPL planetary ephemeris DE200 (Standish 1990). But now, we switched to the more accurate planetary ephemeris DE245, and refined our models to include perturbations due to the Galilean satellites and the J2 and J4 zonal harmonic terms of Jupiter's gravity field."

"Our approach was to create a random ensemble of 1000 initial conditions whose statistics matched the actual orbital element uncertainties and correlations. Effectively, a six-dimensional uncertainty ellipsoid in orbital element space was populated with 1000 random points to obtain an ensemble of initial conditions consistent with the actual 6x 6 covariance matrix of the orbital solution. As before, our dynamic model included solar and planetary perturbations, as well as perturbations from the Galilean satellites and Jupiter's oblateness (J2 and J4 terms)."

"Our orbit computations used not only planetary and solar perturbations, but also perturbations due to the Galilean satellites and Jupiter's oblateness."

It sounds like this is based on perturbation theory to me.

As we read previously, perturbations are epicyclic corrections added to make an underlying model match observation.

Quote
And they nailed the prediction

Not really that impressive if they resorted to epicycles to make data fit.

Quote
Which begs the questions: Where and what is the size of Jupiter in Flat Earth Theory?

FE doesn't have a theory about Jupiter.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 03, 2020, 02:43:54 AM
Also from the linked paper:

Quote
"The need for accurate impact predictions required the modeling of the perturbative effects of the Galilean satellites and Jupiter's oblateness."

"Tidal disruption during an approach to within the Roche limit of a large perturbing body is a common mechanism for cometary splitting."

"In April, we upgraded the dynamical models used in our orbit determinations and impact predictions. Up until this time, we had used only point mass perturbations by the sun and planets, with planetary positions and masses taken from JPL planetary ephemeris DE200 (Standish 1990). But now, we switched to the more accurate planetary ephemeris DE245, and refined our models to include perturbations due to the Galilean satellites and the J2 and J4 zonal harmonic terms of Jupiter's gravity field."

"Our approach was to create a random ensemble of 1000 initial conditions whose statistics matched the actual orbital element uncertainties and correlations. Effectively, a six-dimensional uncertainty ellipsoid in orbital element space was populated with 1000 random points to obtain an ensemble of initial conditions consistent with the actual 6x 6 covariance matrix of the orbital solution. As before, our dynamic model included solar and planetary perturbations, as well as perturbations from the Galilean satellites and Jupiter's oblateness (J2 and J4 terms)."

"Our orbit computations used not only planetary and solar perturbations, but also perturbations due to the Galilean satellites and Jupiter's oblateness."

It sounds like this is based on perturbation theory to me.

As we read previously, perturbations are epicyclic corrections added to make an underlying model match observation.

How do "perturbations...make an underlying model match observation."

Are you saying that any underlying model can be fitted to perturbations? Like the FET model (whatever that may be) could be fitted into the perturbations and predicted almost exactly when and where the multitudes of comet debris would hit Jupiter?

 If so, how might FET have done so in this circumstance? How might the underlying model of FET be applied? Do tell.

Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 03, 2020, 10:19:56 PM
I see you edited your previous post to include this:

Quote
And they nailed the prediction

Not really that impressive if they resorted to epicycles to make data fit.

Quote
Which begs the questions: Where and what is the size of Jupiter in Flat Earth Theory?

FE doesn't have a theory about Jupiter.

I didn't ask if FE had a theory about Jupiter. I asked "If so, ("perturbations...make an underlying model match observation.") how might FET have done so in this circumstance? How might the underlying model of FET be applied? Do tell.

But, in essence, what you're saying is that FET has no idea where or how large Jupiter is. Therefore, FET could never have predicted the collision, let alone with the accuracy with which these aforementioned calculations did, the when and the where.

Decidedly, here is an example of where modern astronomical predictions based upon observations and calculations eclipses anything that FET could muster. In essence, FET fails to match heliocentricity.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 04, 2020, 02:53:55 AM
Quote from: stack
How do "perturbations...make an underlying model match observation."

As previously discussed, pertubations are calculated on basis of epicycles and are used to make a theory fit observations.

The dynamics of galaxies are also based on epicycles to make a theory fit data:

https://arxiv.org/ftp/arxiv/papers/0911/0911.1594.pdf

Lindblad’s epicycles – valid method or bad science?

Quote
In popular culture, epicycles have become almost synonymous with bad science; “adding epicycles” refers to a process of introducing fudges to make a theory fit data, when actually the theory needs to be replaced in its entirety. It is generally believed that epicycles were banished from science when Newton solved his equations of motion and showed that it follows from the inverse square law of gravity that planetary orbits are ellipses. So, it comes as something of a surprise to those unfamiliar with galactic dynamics that the galactic orbits of stars are treated in textbooks using a theory of epicycles revitalized by Bertil Lindblad in the 1920s, and used to introduce density wave theory, which, as reinforced by Lin & Shu (1964), by Lin, Yuan and Shu (1969) and by Kalnajs (1973), has been the leading model of spiral structure for nearly 40 years.

~

Conclusion

The implication to astrophysics is severe. The motions of stars are governed by known mathematical laws. Astrophysics is, or at least it should be, a mathematical science. One should therefore expect that theories in astrophysics are subjected to rigorous mathematical scrutiny. Regrettably, the degree of scrutiny applied to Lindblad’s epicycles and to density wave theory has been seriously lacking. Students should be made aware that these ideas can no longer be considered as science, and authors of textbooks should consider whether they merit anything more than a historical note.


Quote
If so, how might FET have done so in this circumstance? How might the underlying model of FET be applied? Do tell.

FE doesn't propose a planetary theory.

Quote
FET fails to match heliocentricity.

Interesting that you think that a model with epicycles is valid. However, epicycles do not make a system valid. It is the reason Ptolmy's model was rejected
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 04, 2020, 03:18:33 AM
Quote from: stack
How do "perturbations...make an underlying model match observation."

As previously discussed, pertubations are calculated on basis of epicycles and are used to make a theory fit observations.

The dynamics of galaxies are also based on epicycles to make a theory fit data:

https://arxiv.org/ftp/arxiv/papers/0911/0911.1594.pdf

Lindblad’s epicycles – valid method or bad science?

Quote
In popular culture, epicycles have become almost synonymous with bad science; “adding epicycles” refers to a process of introducing fudges to make a theory fit data, when actually the theory needs to be replaced in its entirety. It is generally believed that epicycles were banished from science when Newton solved his equations of motion and showed that it follows from the inverse square law of gravity that planetary orbits are ellipses. So, it comes as something of a surprise to those unfamiliar with galactic dynamics that the galactic orbits of stars are treated in textbooks using a theory of epicycles revitalized by Bertil Lindblad in the 1920s, and used to introduce density wave theory, which, as reinforced by Lin & Shu (1964), by Lin, Yuan and Shu (1969) and by Kalnajs (1973), has been the leading model of spiral structure for nearly 40 years.

~

Conclusion

The implication to astrophysics is severe. The motions of stars are governed by known mathematical laws. Astrophysics is, or at least it should be, a mathematical science. One should therefore expect that theories in astrophysics are subjected to rigorous mathematical scrutiny. Regrettably, the degree of scrutiny applied to Lindblad’s epicycles and to density wave theory has been seriously lacking. Students should be made aware that these ideas can no longer be considered as science, and authors of textbooks should consider whether they merit anything more than a historical note.


Quote
If so, how might FET have done so in this circumstance? How might the underlying model of FET be applied? Do tell.

FE doesn't propose a planetary theory.

Quote
FET fails to match heliocentricity.

Interesting that you think that a model with epicycles is valid. However, epicycles do not make a system valid. It is the reason Ptolmy's model was rejected

Interesting find, Tom. Strangely, I found another article by the same author who fits data to current elliptical orbits without appeal to epicycles.

https://arxiv.org/pdf/0901.3503.pdf

It appears reasonable, and empirical.

What do we conclude here, from finding two articles by the same author who seems to simultaneously confirm elliptical Newtonian orbits yet also questions spiral construction by density wave models?

It is interesting.
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 04, 2020, 05:53:43 AM
FE doesn't propose a planetary theory.

I think that's all I needed to know. FE doesn't even try to take into account phenomena that are described, understood and predicted in the heliocentric model.

Quote
FET fails to match heliocentricity.

Interesting that you think that a model with epicycles is valid. However, epicycles do not make a system valid. It is the reason Ptolmy's model was rejected

Interesting that you think that repeating the word "epicycle" enough times, especially out of context, will make people think that a model that does work does not actually work. Anyway so far, you've brought absolutely no evidence of epicycles being used to calculate the comet's orbit. It's just your interpretation from completely unrelated papers.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 04, 2020, 11:16:29 AM
Quote
Interesting find, Tom. Strangely, I found another article by the same author who fits data to current elliptical orbits without appeal to epicycles.

https://arxiv.org/pdf/0901.3503.pdf

It appears reasonable, and empirical.

The author is discussing his finding of a symmetrical Newtonian solution that does not require epicycle theory to exist.

Quote
We will describe an alternative mechanism, which does not depend on epicycles, and which also results in spiral structure. We will show that this structure is dynamically stable, and that the observed stream motions are precisely those which the structure predicts.

~

The results of our investigation have lead us to re-examine the hydrogen maps of the Milky Way, from which we identify the possibility of a symmetric two-armed spiral with half the conventionally accepted pitch angle.

~

Appendix C Spiral Galaxy Simulation
http://rqgravity.net/images/spiralmotions/gss.avi.

In this animation using 4 500 stars, each star follows a rosette. This is the form of orbits predicted under Newtonian gravity for mass distributed symmetrically in the galactic plane and in the halo. Rosettes are aligned by mutual gravity between stars. The gravity of the arm causes stars to follow the arm during the ingoing part of their orbit. The simulation uses orbits with random eccentricities between 0.10 and 0.18, corresponding to observations of local stars in the Milky Way. The pattern created is a grand-design two-armed spiral.

The accepted view of galactic dynamics is not this, and requires epicycles, which the author criticizes in the other paper. The author is correct that epicycles are used to make data fit observations and are invalid methods of describing celestial mechanics.

A perfectly symmetrical spiral galaxy might work with Newtonian gravity. As you will recall from the three and n body problems, only symmetrical solutions may exist:
https://wiki.tfes.org/Three_Body_Problem

Ask a Mathematician says: "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."

The sun-earth-moon system is not perfectly symmetric and does not work. Not does the solar system. Moons orbiting around planets which orbit a Sun do not work. Due to the n-body problems dynamical prediction is unavailable. The addition of epicycles are required to fit theory to observation.

Quote from: GreatATuin
Interesting that you think that repeating the word "epicycle" enough times, especially out of context, will make people think that a model that does work does not actually work. Anyway so far, you've brought absolutely no evidence of epicycles being used to calculate the comet's orbit. It's just your interpretation from completely unrelated papers.

https://archive.org/download/the-foundations-of-astrodynamics/The%20Foundations%20of%20Astrodynamics.pdf

Dr. Samuel Herrick (1911-1977) says the same as the previous authors, explaining that epicycles are still used in modern astrodynamics:

Quote from: Samuel Herrick
Physical celestial mechanics may be said to have begun with Galileo Galilei, Isaac Newton, and the laws of force and gravitation. Astrodynamics and mathematical celestial mechanics, on the other hand, date back at least to Heracleides of Pontus in the fourth century B.C. The Greek invention of epicycles and eccentrics was developed into a system by Apollonius of Perga in the third century and Hipparchus of Alexandria in the second century B.C. It was refined and published by Ptolemy of Alexandria in the second century A.D., and came to be known as the Ptolemaic system. It is generally assumed that the epicycle was discredited by Johannes Kepler some 1500 years later, but in point of fact epicycles have persisted in astrodynamics down to the present day, and have extended their domain into other areas of science under the guise of Fourier series! ”

~

  “ In modern perturbation theory we actually take account of the original epicyclic concept by combining several Fourier series that have arguments based upon different angular variables. ”

Again, another source explaining to us that Modern Perturbation Theory = Epicycles

They never stopped using them. They only called them something else once the term became discredited.

Quote
I think that's all I needed to know. FE doesn't even try to take into account phenomena that are described, understood and predicted in the heliocentric model.

Except for retrograde motion (https://wiki.tfes.org/Planets) FE has yet to explore or discuss the dynamics of the planets. Your presentation of a model based upon epicycles is hardly proof of it. Epicycles are a byword for bad science and a workaround for a lousy theory.
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 04, 2020, 12:42:57 PM
You can go on forever cherrypicking out of context citations in an attempt to associate the ancient concept of epicycles with current astronomy and call it a pseudoscience, but you'll never convince anyone.

Whether you like it or not, astronomical predictions work. The model they're based on works.

Quote
I think that's all I needed to know. FE doesn't even try to take into account phenomena that are described, understood and predicted in the heliocentric model.

Except for retrograde motion (https://wiki.tfes.org/Planets) FE has yet to explore or discuss the dynamics of the planets. Your presentation of a model based upon epicycles is hardly proof of it. Epicycles are a byword for bad science and a workaround for a non-working theory.

FE understandably has very little interest exploring things that don't fit any flat Earth model and are easily explained in the heliocentric model. And you can repeat the word "epicycles" as many times as you want, it won't make your point any more valid. The heliocentric model is not based on epicycles.

Anyway, as long as you refuse to acknowledge that Newton's equations can be used to build a working simulation with approximations through numerical methods, even if the n-body problem doesn't have a formal closed-form solution, I don't even know if there's any point in answering anything you say.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 04, 2020, 05:54:45 PM
Newton used epicycles for the Moon:

History of the Inductive Sciences (1846) (https://books.google.com/books?id=vdQyAQAAMAAJ&lpg=PA174&ots=aNPf5Bu6CP&dq=as%20we%20have%20already%20said%2C%20of%20the%20ancient%20epicycles%2C&pg=PA174#v=onepage&q&f=false)
By William Whewell, Historian of Science

Quote
3.— The Epicyclical Hypothesis was found capable of accommodating itself to such new discoveries. These new inequalities could be represented by new combinations of eccentrics and epicycles: all the realand imaginary discoveries by astronomers, up to Copernicus, were actually embodied in these hypotheses; Copernicus, as we have said, did not reject such hypotheses; the lunar inequalities which Tycho etected might have boen similarly exhibited; and even Newton36 represents the motion of the moon’s apogee by means of an epicycle. As a mode of expressing the law of the irregularity, and of calculating its results in particular cases, the epicyclical theory was capable of continuing to render great service to astronomy, however extensive the progress of the science might be. It was, in fact, as we have already said, the modern process of representing the motion by means of a series of circular functions.

Epicycles were all the rage in the 1800's, hundreds of years after Copernicus, Kepler, and Newton made their contributions to astronomy. Professor De Morgan is cited to explain the state of astronomy in University of Toronto Quarterly (1895) (http://[url=https://books.google.com/books?id=vzQ5AAAAMAAJ&pg=RA1-PA48#v=onepage&q&f=false):

Quote
Of the modern employment of the Ptolemaic epicycles, De Morgan, secretary of the Royal Astronomical Society of London, wrote in 1844: “ The common notion is that the theory of epicycles was a cumbrous and useless apparatus, thrown away by the moderns and originating in the Ptolemaic or rather Platonic notion that all celestial motions must either be circular and uniform motions or compounded of them. But, on the contrary, it was an elegant and most efficient mathematical instrument which enabled Hipparchus and Ptolemy to represent and predict much better than their predecessors had done; and it was probably at least as good a theory as their instruments and capabilities of observation required or deserved. And many readers will be surprised to hear that the modern astronomer to this day resolves the same motions into epicyelic ones. When the latter expresses a result by series of sines and cosines (especially when the angle is a mean motion or a multiple of it) he uses epicycles; and for one which Ptolemy scribbled on the, heavens, to use Milton’s phrase, he scribbles twenty. The difference is that the ancient believed in the necessity of these instruments, the modern only in their convenience; the former used those which do not sufficiently represent actual phenomena, the latter knows how to choose better; the former taking the instruments to be the actual contrivances of nature was obliged to make one set explain everything, the latter will adapt one set to latitude, another to longitude, another to distance. Difference enough no doubt, but not the sort of difference which the common notion supposes.”

Such was the state of affairs fifty years ago; today epicycles may be said to possess the heavens above and the earth beneath and the waters and the air between, nor has the all-pervading ether escaped them. In analytic guise they dominate the mathematics of hydrokinetics and sound, of heat, light and electricity; in fact, wherever there is either periodic or irregular motion, there the mathematician “ scribbles ” his epicycles, and not content like Ptolemy to wheel them on simple circles he rolls epicycle on epicycle to the third, the fourth or the fifth degree. Nor does their influence end here. Machines have been made to record for a sufficient length of time any motions for the character of which a working theory has to be found; other machines analyse the records into epicyclic movements, smoothing out or rejecting accidental irregularities, and still other machines recombine the epicycles to predict the motions as they will occur at a future time or under given changes of condition. Thus we have mechanical tide-predictors, harmonic analyzers of meteorological phenomena, epicyclic tracers of deviation curves for the compasses in iron ships, and a fast increasing array of other such machines.

Some perturbation terms are today still named after the ancient epicycles. Here a reference from modern day, on computing the planets:

How to compute planetary positions (https://www.themcintyres.dyndns.org/av/astro/HowTo%20-%20Computing%20planetary%20positions.pdf)
By Paul Schlyter, Stockholm, Sweden

Quote
All perturbation terms that are smaller than 0.01 degrees in longitude or latitude and smaller than 0.1 Earth radii in distance have been omitted here. A few of the largest perturbation terms even have their own names! The Evection (the largest perturbation) was discovered already by Ptolemy a few thousand years ago (the Evection was one of Ptolemy's epicycles). The Variation and the Yearly Equation were both discovered by Tycho Brahe in the 16'th century.

To calculate the celestial bodies we are told to use perturbation terms with the names of Ptolmy's ancient epicycles!
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 04, 2020, 06:19:31 PM
Quote
Interesting find, Tom. Strangely, I found another article by the same author who fits data to current elliptical orbits without appeal to epicycles.

https://arxiv.org/pdf/0901.3503.pdf

It appears reasonable, and empirical.

The author is discussing his finding of a symmetrical Newtonian solution that does not require epicycle theory to exist.

Quote
We will describe an alternative mechanism, which does not depend on epicycles, and which also results in spiral structure. We will show that this structure is dynamically stable, and that the observed stream motions are precisely those which the structure predicts.

~

The results of our investigation have lead us to re-examine the hydrogen maps of the Milky Way, from which we identify the possibility of a symmetric two-armed spiral with half the conventionally accepted pitch angle.

~

Appendix C Spiral Galaxy Simulation
http://rqgravity.net/images/spiralmotions/gss.avi.

In this animation using 4 500 stars, each star follows a rosette. This is the form of orbits predicted under Newtonian gravity for mass distributed symmetrically in the galactic plane and in the halo. Rosettes are aligned by mutual gravity between stars. The gravity of the arm causes stars to follow the arm during the ingoing part of their orbit. The simulation uses orbits with random eccentricities between 0.10 and 0.18, corresponding to observations of local stars in the Milky Way. The pattern created is a grand-design two-armed spiral.

The accepted view of galactic dynamics is not this, and requires epicycles, which the author criticizes in the other paper. The author is correct that epicycles are used to make data fit observations and are invalid methods of describing celestial mechanics.

A perfectly symmetrical spiral galaxy might work with Newtonian gravity. As you will recall from the three and n body problems, only symmetrical solutions may exist:
https://wiki.tfes.org/Three_Body_Problem

Ask a Mathematician says: "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."

The sun-earth-moon system is not perfectly symmetric and does not work. Not does the solar system. Moons orbiting around planets which orbit a Sun do not work. Due to the n-body problems dynamical prediction is unavailable. The addition of epicycles are required to fit theory to observation.

Quote from: GreatATuin
Interesting that you think that repeating the word "epicycle" enough times, especially out of context, will make people think that a model that does work does not actually work. Anyway so far, you've brought absolutely no evidence of epicycles being used to calculate the comet's orbit. It's just your interpretation from completely unrelated papers.

https://archive.org/download/the-foundations-of-astrodynamics/The%20Foundations%20of%20Astrodynamics.pdf

Dr. Samuel Herrick (1911-1977) says the same as the previous authors, explaining that epicycles are still used in modern astrodynamics:

Quote from: Samuel Herrick
Physical celestial mechanics may be said to have begun with Galileo Galilei, Isaac Newton, and the laws of force and gravitation. Astrodynamics and mathematical celestial mechanics, on the other hand, date back at least to Heracleides of Pontus in the fourth century B.C. The Greek invention of epicycles and eccentrics was developed into a system by Apollonius of Perga in the third century and Hipparchus of Alexandria in the second century B.C. It was refined and published by Ptolemy of Alexandria in the second century A.D., and came to be known as the Ptolemaic system. It is generally assumed that the epicycle was discredited by Johannes Kepler some 1500 years later, but in point of fact epicycles have persisted in astrodynamics down to the present day, and have extended their domain into other areas of science under the guise of Fourier series! ”

~

  “ In modern perturbation theory we actually take account of the original epicyclic concept by combining several Fourier series that have arguments based upon different angular variables. ”

Again, another source explaining to us that Modern Perturbation Theory = Epicycles

They never stopped using them. They only called them something else once the term became discredited.

Quote
I think that's all I needed to know. FE doesn't even try to take into account phenomena that are described, understood and predicted in the heliocentric model.

Except for retrograde motion (https://wiki.tfes.org/Planets) FE has yet to explore or discuss the dynamics of the planets. Your presentation of a model based upon epicycles is hardly proof of it. Epicycles are a byword for bad science and a workaround for a lousy theory.

I agree with some of that. But a symmetric solution permits symmetric solutions using perturbation analysis. So if a symmetric solution is found, and the perturbative expansions are identified, the the asymmetric extensions are defined.
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 04, 2020, 07:24:11 PM
Epicycles were all the rage, hundreds of years after Copernicus, Kepler, and Newton made their contributions to astronomy. From University of Toronto Quarterly (1895): (http://[url=https://books.google.com/books?id=vzQ5AAAAMAAJ&pg=RA1-PA48#v=onepage&q&f=false)

Quote
Of the modern employment of the Ptolemaic epicycles, De Morgan, secretary of the Royal Astronomical Society of London, wrote in 1844: “ The common notion is that the theory of epicycles was a cumbrous and useless apparatus, thrown away by the moderns and originating in the Ptolemaic or rather Platonic notion that all celestial motions must either be circular and uniform motions or compounded of them. But, on the contrary, it was an elegant and most efficient mathematical instrument which enabled Hipparchus and Ptolemy to represent and predict much better than their predecessors had done; and it was probably at least as good a theory as their instruments and capabilities of observation required or deserved. And many readers will be surprised to hear that the modern astronomer to this day resolves the same motions into epicyelic ones. When the latter expresses a result by series of sines and cosines (especially when the angle is a mean motion or a multiple of it) he uses epicycles; and for one which Ptolemy scribbled on the, heavens, to use Milton’s phrase, he scribbles twenty. The difference is that the ancient believed in the necessity of these instruments, the modern only in their convenience; the former used those which do not sufficiently represent actual phenomena, the latter knows how to choose better; the former taking the instruments to be the actual contrivances of nature was obliged to make one set explain everything, the latter will adapt one set to latitude, another to longitude, another to distance. Difference enough no doubt, but not the sort of difference which the common notion supposes.

Such was the state of affairs fifty years ago; today epicycles may be said to possess the heavens above and the earth beneath and the waters and the air between, nor has the all-pervading ether escaped them. In analytic guise they dominate the mathematics of hydrokinetics and sound, of heat, light and electricity; in fact, wherever there is either periodic or irregular motion, there the mathematician “ scribbles ” his epicycles, and not content like Ptolemy to wheel them on simple circles he rolls epicycle on epicycle to the third, the fourth or the fifth degree. Nor does their influence end here. Machines have been made to record for a sufficient length of time any motions for the character of which a working theory has to be found; other machines analyse the records into epicyclic movements, smoothing out or rejecting accidental irregularities, and still other machines recombine the epicycles to predict the motions as they will occur at a future time or under given changes of condition. Thus we have mechanical tide-predictors, harmonic analyzers of meteorological phenomena, epicyclic tracers of deviation curves for the compasses in iron ships, and a fast increasing array of other such machines.


It looks like you've missed an important part, I tried to help you figure it out.

For Ptolemy and Hipparchus, epicycles were the theory.

After Kepler and Newton, epicycles were, at best, mathematical tools used to find solutions that fit the new theory, especially before the computer was invented and better tools were available. It strikes me that some of your references are not from the last century, but from the previous one.


Some perturbation terms are today still named after the ancient epicycles. Here a reference from modern day, on computing the planets:

Quote
All perturbation terms that are smaller than 0.01 degrees in longitude or latitude and smaller than 0.1 Earth radii in distance have been omitted here. A few of the largest perturbation terms even have their own names! The Evection (the largest perturbation) was discovered already by Ptolemy a few thousand years ago (the Evection was one of Ptolemy's epicycles). The Variation and the Yearly Equation were both discovered by Tycho Brahe in the 16'th century.

To calculate the celestial bodies we are told to use perturbation terms with the names of Ptolmy's ancient epicycles!

The Lunar orbit has variations, or perturbations. Some of them were known to Ptolemy, who accounted for them with the only tool he had, epicycles, but any model will have to do it one way or another to be accurate. Giving the perturbation a new name, or an old one, or no name at all doesn't change anything. By the way, according to https://en.wikipedia.org/wiki/Evection, the name was coined by Bullialdus in the 17th century, which makes an already weak point totally moot.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 04, 2020, 07:28:09 PM
Quote from: stack
How do "perturbations...make an underlying model match observation."

As previously discussed, pertubations are calculated on basis of epicycles and are used to make a theory fit observations.

The dynamics of galaxies are also based on epicycles to make a theory fit data:

https://arxiv.org/ftp/arxiv/papers/0911/0911.1594.pdf

Lindblad’s epicycles – valid method or bad science?

Quote
In popular culture, epicycles have become almost synonymous with bad science; “adding epicycles” refers to a process of introducing fudges to make a theory fit data, when actually the theory needs to be replaced in its entirety. It is generally believed that epicycles were banished from science when Newton solved his equations of motion and showed that it follows from the inverse square law of gravity that planetary orbits are ellipses. So, it comes as something of a surprise to those unfamiliar with galactic dynamics that the galactic orbits of stars are treated in textbooks using a theory of epicycles revitalized by Bertil Lindblad in the 1920s, and used to introduce density wave theory, which, as reinforced by Lin & Shu (1964), by Lin, Yuan and Shu (1969) and by Kalnajs (1973), has been the leading model of spiral structure for nearly 40 years.

~

Conclusion

The implication to astrophysics is severe. The motions of stars are governed by known mathematical laws. Astrophysics is, or at least it should be, a mathematical science. One should therefore expect that theories in astrophysics are subjected to rigorous mathematical scrutiny. Regrettably, the degree of scrutiny applied to Lindblad’s epicycles and to density wave theory has been seriously lacking. Students should be made aware that these ideas can no longer be considered as science, and authors of textbooks should consider whether they merit anything more than a historical note.


Quote
If so, how might FET have done so in this circumstance? How might the underlying model of FET be applied? Do tell.

FE doesn't propose a planetary theory.

Quote
FET fails to match heliocentricity.

Interesting that you think that a model with epicycles is valid. However, epicycles do not make a system valid. It is the reason Ptolmy's model was rejected

Ya know, it just occurred to me that Francis fails to incorporate the spiral arm magnetic fields in his discussions. This seems severely problematic, as it has long been known that B fields are integral to studying these dynamical systems. For example:

https://www.aanda.org/articles/aa/full_html/2018/01/aa29988-16/aa29988-16.html

But there are many, many more examples, which I can provide upon request, but omit until then so as not to spam readables.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 04, 2020, 09:11:52 PM
Quote from: GreatATuin
Quote
The difference is that the ancient believed in the necessity of these instruments, the modern only in their convenience; the former used those which do not sufficiently represent actual phenomena, the latter knows how to choose better; the former taking the instruments to be the actual contrivances of nature was obliged to make one set explain everything, the latter will adapt one set to latitude, another to longitude, another to distance. Difference enough no doubt, but not the sort of difference which the common notion supposes.

It looks like you've missed an important part, I tried to help you figure it out.

So you think that astronomers are using epicycles, but that's not a problem, because they are only using them "it's convenient"?

That's just an excuse. "We only do it because it's convenient" and "We already know that Newton's system is true (despite that he used epicycles in practice)" are  fairytales. It is admitted that there is no dynamical model of the solar system.

Perturbation Theory for Restricted Three-Body Orbits (https://apps.dtic.mil/dtic/tr/fulltext/u2/a243899.pdf)
1991 Thesis by David A. Ross

Quote
I. Introduction

Before the astrodynamics of man-made objects in space can be fully understood, one must first comprehend basic planetary motion. Thanks to Sir Isaac Newton and his three laws of motion, and to Johann Kepler for his three laws of orbital motion, it can be shown that nearly all astrodynamical systems are dominated by a single conservative force known as gravity. In fact, the most general description of the motion of a collection of objects in space is defined by the n-body problem.

In an n-body system, the nth body is acted upon by the other n-1 gravitational masses present. In this way, the motion of any mass in a system affects and is affected by every other mass in the system. The overwhelming task of representing each body is well illustrated by Wiesel.

    "Our own solar system consists of one star, nine planets, over fifty moons, tens of thousands of asteroids, and millions of comets. The description of the motion of this system is clearly important, but an exact solution to this problem has not been found in over three hundred years of study." (8:33)

Therefore, the use of the exact n-body description of a dynamical system is not simply a nuisance, it is virtually impossible to implement.

The paper goes on to talk about perturbation theory and fourier methods.

There you have it. Ross quotes Dr. William Weisel (https://www.afit.edu/BIOS/bio.cfm?facID=239) who admits that there is no dynamical gravity model. The dynamical way is not simply a nuisance—it is impossible and not even attempted. They are using a workaround.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 04, 2020, 10:06:42 PM
Quote from: GreatATuin
Quote
The difference is that the ancient believed in the necessity of these instruments, the modern only in their convenience; the former used those which do not sufficiently represent actual phenomena, the latter knows how to choose better; the former taking the instruments to be the actual contrivances of nature was obliged to make one set explain everything, the latter will adapt one set to latitude, another to longitude, another to distance. Difference enough no doubt, but not the sort of difference which the common notion supposes.

It looks like you've missed an important part, I tried to help you figure it out.

So you think that astronomers are using epicycles, but that's not a problem, because they are only using them "it's convenient"?

That's just an excuse. "We only do it because it's convenient" and "We already know that Newton's system is true (despite that he used epicycles in practice)" are  fairytales. It is admitted that there is no dynamical model of the solar system.

Perturbation Theory for Restricted Three-Body Orbits (https://apps.dtic.mil/dtic/tr/fulltext/u2/a243899.pdf)
1991 Thesis by David A. Ross

Quote
I. Introduction

Before the astrodynamics of man-made objects in space can be fully understood, one must first comprehend basic planetary motion. Thanks to Sir Isaac Newton and his three laws of motion, and to Johann Kepler for his three laws of orbital motion, it can be shown that nearly all astrodynamical systems are dominated by a single conservative force known as gravity. In fact, the most general description of the motion of a collection of objects in space is defined by the n-body problem.

In an n-body system, the nth body is acted upon by the other n-1 gravitational masses present. In this way, the motion of any mass in a system affects and is affected by every other mass in the system. The overwhelming task of representing each body is well illustrated by Wiesel.

    "Our own solar system consists of one star, nine planets, over fifty moons, tens of thousands of asteroids, and millions of comets. The description of the motion of this system is clearly important, but an exact solution to this problem has not been found in over three hundred years of study." (8:33)

Therefore, the use of the exact n-body description of a dynamical system is not simply a nuisance, it is virtually impossible to implement.

The paper goes on to talk about perturbation theory and fourier methods.

There you have it. Ross quotes Dr. William Weisel (https://www.afit.edu/BIOS/bio.cfm?facID=239) who admits that there is no dynamical gravity model. The dynamical way is not simply a nuisance—it is impossible and not even attempted. They are using a workaround.

My concern, Tom, is that you tend to link such esoteric works that lack follow-up by the scientific community. If published, they are never referenced much nor duplicated. It’s...odd.

Here’s a recent paper that removes any doubt that celestial mechanics must appeal to epicycles.

https://www.sciencedirect.com/science/article/abs/pii/S1384107618303336?via%3Dihub.

Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 04, 2020, 10:19:47 PM
You posted a paper with the title "Central-body square configuration of restricted six-body problem".

Have you seen what this problem actually looks like? The available solutions to the n-body problems are inherently symmetrical, unlike real astronomical systems like the supposed Sun-Earth-Moon system.

N Bodies (https://web.archive.org/web/20180816124720/http://www.preposterousuniverse.com/blog/2006/07/23/n-bodies/)
Caltech Physicist Sean Carroll

Quote from: Sean Carroll
This will be familiar to anyone who reads John Baez’s This Week’s Finds in Mathematical Physics, but I can’t help but show these lovely exact solutions to the gravitational N-body problem. This one is beautiful in its simplicity: twenty-one point masses moving around in a figure-8.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/figure821.loop.gif)

The N-body problem is one of the most famous, and easily stated, problems in mathematical physics: find exact solutions to point masses moving under their mutual Newtonian gravitational forces (i.e. the inverse-square law). For N=2 the complete set of solutions is straightforward and has been known for a long time — each body moves in a conic section (circle, ellipse, parabola or hyperbola) around the center of mass. In fact, Kepler found the solution even before Newton came up with the problem!

But let N=3 and chaos breaks loose, quite literally. For a long time people recognized that the motion of three gravitating bodies would be a difficult problem, but there were hopes to at least characterize the kinds of solutions that might exist (even if we couldn’t write down the solutions explicitly). It became a celebrated goal for mathematical physicists, and the very amusing story behind how it was resolved is related in Peter Galison’s book Einstein’s Clocks and Poincare’s Maps. In 1885, a mathematical competition was announced in honor of the 60th birthday of King Oscar II of Sweden, and the three-body problem was one of the questions. (Feel free to muse about the likelihood of the birthday of any contemporary world leader being celebrated by mathematical competitions.) Henri Poincare was a favorite to win the prize, and he submitted an essay that demonstrated the stability of planetary motions in the three-body problem (actually the “restricted” problem, in which one test body moves in the gravitational field generated by two others). In other words, without knowing the exact solutions, we could at least be confident that the orbits wouldn’t go crazy; more technically, solutions starting with very similar initial conditions would give very similar orbits. Poincare’s work was hailed as brilliant, and he was awarded the prize.

But as his essay was being prepared for publication in Acta Mathematica, a couple of tiny problems were pointed out by Edvard Phragmen, a Swedish mathematician who was an assistant editor at the journal. Gosta Mittag-Leffler, chief editor, forwarded Phragmen’s questions to Poincare, asking him to fix up these nagging issues before the prize essay appeared in print. Poincare went to work, but discovered to his consternation that one of the tiny problems was in fact a profoundly devastating possibility that he hadn’t really taken seriously. What he ended up proving was the opposite of his original claim — three-body orbits were not stable at all. Not only were orbits not periodic, they didn’t even approach some sort of asymptotic fixed points. Now that we have computers to run simulations, this kind of behavior is less surprising (example here from Steve McMillan — note how the final “binary” is not made of the same “stars” as the original one), but at the time it came as an utter shock. In his attempt to prove the stability of planetary orbits, Poincare ended up inventing chaos theory.

But the story doesn’t quite end there. Mittag-Leffler, convinced that Poincare would be able to tie up the loose threads in his prize essay, went ahead and printed it. By the time he heard from Poincare that no such tying-up would be forthcoming, the journal had already been mailed to mathematicians throughout Europe. Mittag-Leffler swung into action, telegraphing Berlin and Paris in an attempt to have all copies of the journal destroyed. He basically succeeded, but not without creating a minor scandal in elite mathematical circles across the Continent. (The Wikipedia entry on Poincare tells a much less interesting, and less accurate, version of the story.)

However, just because the general solution to the three-body (and more-body) problem is chaotic, doesn’t mean we can’t find special exact solutions in highly-symmetric conditions, and that’s just what Cris Moore and Michael Nauenberg have recently been doing. The image at the top really is an exact solution to twenty-one equal-mass objects moving in a figure-eight under their mutual gravitational attraction. They’re moving in a plane, of course, but that’s not strictly necessary; here’s a close relative of the figure-8, perturbed outside the plane.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/rot8x.loop.gif)

From there you can just go nuts; here’s an example with twelve objects orbiting with cubic symmetry — four distinct periodic paths with three particles each.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/orbit12.loop.gif)

Knowledge of this exact solution, plus $3.50, will get you a grande latte at Starbucks. Mathematicians have all the fun.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 04, 2020, 11:21:08 PM
You posted a paper with the title "Central-body square configuration of restricted six-body problem".

Have you seen what this problem actually looks like? The available solutions to the n-body problems are inherently symmetrical, unlike real astronomical systems like the supposed Sun-Earth-Moon system.

N Bodies (https://web.archive.org/web/20180816124720/http://www.preposterousuniverse.com/blog/2006/07/23/n-bodies/)
Caltech Physicist Sean Carroll

Quote from: Sean Carroll
This will be familiar to anyone who reads John Baez’s This Week’s Finds in Mathematical Physics, but I can’t help but show these lovely exact solutions to the gravitational N-body problem. This one is beautiful in its simplicity: twenty-one point masses moving around in a figure-8.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/figure821.loop.gif)

The N-body problem is one of the most famous, and easily stated, problems in mathematical physics: find exact solutions to point masses moving under their mutual Newtonian gravitational forces (i.e. the inverse-square law). For N=2 the complete set of solutions is straightforward and has been known for a long time — each body moves in a conic section (circle, ellipse, parabola or hyperbola) around the center of mass. In fact, Kepler found the solution even before Newton came up with the problem!

But let N=3 and chaos breaks loose, quite literally. For a long time people recognized that the motion of three gravitating bodies would be a difficult problem, but there were hopes to at least characterize the kinds of solutions that might exist (even if we couldn’t write down the solutions explicitly). It became a celebrated goal for mathematical physicists, and the very amusing story behind how it was resolved is related in Peter Galison’s book Einstein’s Clocks and Poincare’s Maps. In 1885, a mathematical competition was announced in honor of the 60th birthday of King Oscar II of Sweden, and the three-body problem was one of the questions. (Feel free to muse about the likelihood of the birthday of any contemporary world leader being celebrated by mathematical competitions.) Henri Poincare was a favorite to win the prize, and he submitted an essay that demonstrated the stability of planetary motions in the three-body problem (actually the “restricted” problem, in which one test body moves in the gravitational field generated by two others). In other words, without knowing the exact solutions, we could at least be confident that the orbits wouldn’t go crazy; more technically, solutions starting with very similar initial conditions would give very similar orbits. Poincare’s work was hailed as brilliant, and he was awarded the prize.

But as his essay was being prepared for publication in Acta Mathematica, a couple of tiny problems were pointed out by Edvard Phragmen, a Swedish mathematician who was an assistant editor at the journal. Gosta Mittag-Leffler, chief editor, forwarded Phragmen’s questions to Poincare, asking him to fix up these nagging issues before the prize essay appeared in print. Poincare went to work, but discovered to his consternation that one of the tiny problems was in fact a profoundly devastating possibility that he hadn’t really taken seriously. What he ended up proving was the opposite of his original claim — three-body orbits were not stable at all. Not only were orbits not periodic, they didn’t even approach some sort of asymptotic fixed points. Now that we have computers to run simulations, this kind of behavior is less surprising (example here from Steve McMillan — note how the final “binary” is not made of the same “stars” as the original one), but at the time it came as an utter shock. In his attempt to prove the stability of planetary orbits, Poincare ended up inventing chaos theory.

But the story doesn’t quite end there. Mittag-Leffler, convinced that Poincare would be able to tie up the loose threads in his prize essay, went ahead and printed it. By the time he heard from Poincare that no such tying-up would be forthcoming, the journal had already been mailed to mathematicians throughout Europe. Mittag-Leffler swung into action, telegraphing Berlin and Paris in an attempt to have all copies of the journal destroyed. He basically succeeded, but not without creating a minor scandal in elite mathematical circles across the Continent. (The Wikipedia entry on Poincare tells a much less interesting, and less accurate, version of the story.)

However, just because the general solution to the three-body (and more-body) problem is chaotic, doesn’t mean we can’t find special exact solutions in highly-symmetric conditions, and that’s just what Cris Moore and Michael Nauenberg have recently been doing. The image at the top really is an exact solution to twenty-one equal-mass objects moving in a figure-eight under their mutual gravitational attraction. They’re moving in a plane, of course, but that’s not strictly necessary; here’s a close relative of the figure-8, perturbed outside the plane.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/rot8x.loop.gif)

From there you can just go nuts; here’s an example with twelve objects orbiting with cubic symmetry — four distinct periodic paths with three particles each.

(https://web.archive.org/web/20180816124720im_/http://blogs.discovermagazine.com/cosmicvariance/files/uploads/orbit12.loop.gif)

Knowledge of this exact solution, plus $3.50, will get you a grande latte at Starbucks. Mathematicians have all the fun.

Oh sure, I’ve seen the problem. Hell - I’ve done it!

There are plenty of symmetric solutions, crazy unstable solutions, beautiful orbits that trace out flower patterns. So many solutions have been computed.

Give the article a try :)

I think it would be well worth it for you. At the very least, it will update you on some of the current developments, computations.

In this paper, 6 bodies have their stable liberation points computed - not a epicycle in sight!
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 05, 2020, 01:25:17 AM
Yep. Those are the orbits Newton's gravity produces. And here are over a thousand more solutions, as described by New Scientist. Read carefully:

Infamous three-body problem has over a thousand new solutions - New Scientist (https://www.newscientist.com/article/2148074-infamous-three-body-problem-has-over-a-thousand-new-solutions/)

Quote
For more than 300 years, mathematicians have puzzled over the three-body problem – the question of how three objects orbit one another according to Newton’s laws. Now, there are 1223 new solutions to the conundrum, more than doubling the current number of possibilities.

No single equation can predict how three bodies will move in relation to one another and whether their orbits will repeat or devolve into chaos. Mathematicians must test each specific scenario to see if the objects will stay bound in orbit or be flung away.

The new solutions were found when researchers at Shanghai Jiaotong University in China tested 16 million different orbits using a supercomputer.

All the fresh orbits found are periodic. This means that each object, whether it’s a planet or a proton, ends up where it first began its orbit, with their paths forming three intertwined, closed loops.

“It is impressive that they’ve made the list a lot longer,” says Robert Vanderbei at Princeton University in New Jersey – though he adds that there is “basically an unlimited number of orbits”, so it may be overkill if anyone sought to find them all.

Perhaps the most important application of the three-body problem is in astronomy, for helping researchers figure out how three stars, a star with a planet that has a moon, or any other set of three celestial objects can maintain a stable orbit.

But these new orbits rely on conditions that are somewhere between unlikely and impossible for a real system to satisfy. In all of them, for example, two of the three bodies have exactly the same mass and they all remain in the same plane.


Knot-like paths

In addition, the researchers did not test the orbits’ stability. It’s possible that the tiniest disturbance in space or rounding error in the equations could rip the objects away from one another.

“These orbits have nothing to do with astronomy, but you’re solving these equations and you’re getting something beautiful,” says Vanderbei.

Aside from giving us a thousand pretty pictures of knot-like orbital paths, the new three-body solutions also mark a starting point for finding even more possible orbits, and eventually figuring out the whole range of winding paths that three objects can follow around one another.

This is kind of the zeroth step. Then the question becomes, how is the space of all possible positions and velocities filled up by solutions?” says Richard Montgomery at the University of California, Santa Cruz. “These simple orbits are kind of like a skeleton to build the whole system up from.”

As suggested by the above article, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

From the linked source paper (https://arxiv.org/pdf/1709.04775.pdf) at the bottom of the article:

(https://i.imgur.com/bs38Fcx.png)

All highly symmetric orbits, as Dr. Carroll described.

Symmetrical orbits with two of three masses being identical which "have nothing to do with astronomy" and which "are somewhere between unlikely and impossible for a real system to satisfy."

The phys.org article Scientists discover more than 600 new periodic orbits of the famous three-body problem (https://phys.org/news/2017-10-scientists-periodic-orbits-famous-three-body.html) describes the discovery of other orbits:

Quote
(https://wiki.tfes.org/images/thumb/1/18/47-scientistsdi.jpg/600px-47-scientistsdi.jpg)

"These 695 periodic orbits include the well-known figure-eight family found by Moore in 1993, the 11 families found by Suvakov and Dmitrasinovic in 2013, and more than 600 new families reported for the first time."

Again, highly symmetrical orbits.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 05, 2020, 02:48:39 AM
Yep. Those are the orbits Newton's gravity produces. And here are over a thousand more solutions, as described by New Scientist. Read carefully:

Infamous three-body problem has over a thousand new solutions - New Scientist (https://www.newscientist.com/article/2148074-infamous-three-body-problem-has-over-a-thousand-new-solutions/)

Quote
For more than 300 years, mathematicians have puzzled over the three-body problem – the question of how three objects orbit one another according to Newton’s laws. Now, there are 1223 new solutions to the conundrum, more than doubling the current number of possibilities.

No single equation can predict how three bodies will move in relation to one another and whether their orbits will repeat or devolve into chaos. Mathematicians must test each specific scenario to see if the objects will stay bound in orbit or be flung away.

The new solutions were found when researchers at Shanghai Jiaotong University in China tested 16 million different orbits using a supercomputer.

All the fresh orbits found are periodic. This means that each object, whether it’s a planet or a proton, ends up where it first began its orbit, with their paths forming three intertwined, closed loops.

“It is impressive that they’ve made the list a lot longer,” says Robert Vanderbei at Princeton University in New Jersey – though he adds that there is “basically an unlimited number of orbits”, so it may be overkill if anyone sought to find them all.

Perhaps the most important application of the three-body problem is in astronomy, for helping researchers figure out how three stars, a star with a planet that has a moon, or any other set of three celestial objects can maintain a stable orbit.

But these new orbits rely on conditions that are somewhere between unlikely and impossible for a real system to satisfy. In all of them, for example, two of the three bodies have exactly the same mass and they all remain in the same plane.


Knot-like paths

In addition, the researchers did not test the orbits’ stability. It’s possible that the tiniest disturbance in space or rounding error in the equations could rip the objects away from one another.

“These orbits have nothing to do with astronomy, but you’re solving these equations and you’re getting something beautiful,” says Vanderbei.

Aside from giving us a thousand pretty pictures of knot-like orbital paths, the new three-body solutions also mark a starting point for finding even more possible orbits, and eventually figuring out the whole range of winding paths that three objects can follow around one another.

This is kind of the zeroth step. Then the question becomes, how is the space of all possible positions and velocities filled up by solutions?” says Richard Montgomery at the University of California, Santa Cruz. “These simple orbits are kind of like a skeleton to build the whole system up from.”

As suggested by the above article, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

From the linked source paper (https://arxiv.org/pdf/1709.04775.pdf) at the bottom of the article:

(https://i.imgur.com/bs38Fcx.png)

All highly symmetric orbits, as Dr. Carroll described.

Symmetrical orbits with two of three masses being identical which "have nothing to do with astronomy" and which "are somewhere between unlikely and impossible for a real system to satisfy."

The phys.org article Scientists discover more than 600 new periodic orbits of the famous three-body problem (https://phys.org/news/2017-10-scientists-periodic-orbits-famous-three-body.html) describes the discovery of other orbits:

Quote
(https://wiki.tfes.org/images/thumb/1/18/47-scientistsdi.jpg/600px-47-scientistsdi.jpg)

"These 695 periodic orbits include the well-known figure-eight family found by Moore in 1993, the 11 families found by Suvakov and Dmitrasinovic in 2013, and more than 600 new families reported for the first time."

Again, highly symmetrical orbits.

Oh! No no no, I see what’s happened. It’s not that it’s in “the Stone Age,” it’s just that the solutions are sensitive to initial conditions. This is why you get so many solutions. The equations can tell you how ANY three bodies will behave, and there isn’t (/edit meant to write: IS) literally millions of ways that can happen, depending on how the system started out.

This is indeed fascinating. I suppose they hoped that nature would be nice and only permit a few. But that is not what happened.

Hence, they are able to model any 3 body system across all times with the initial conditions known.

Knowing the initial conditions of the solar system isn’t too easy :)

But this is not the fault of the THEORY. It’s just our own ignorance of things a long time ago, and the misfortune of having systems that can behave quite different if you get the initial conditions even a bit wrong.

Have you studied chaotic systems? It is a fascinating mathematical field. It doesn’t mean that the system is poorly defined, or unknown. It just means a high sensitivity to initial conditions.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 11, 2020, 06:58:34 PM
As suggested by the above article, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

'Stone Age' astrophysics predicted the when and where of the collision for each of the fragments. The operative word is 'where'. You said that FET has no theories about Jupiter. That's fine. But that means FET could never have predicted the 'where' the collisions occurred on Jupiter. FET would need to know the size of Jupiter, not to mention calculating it's gravitational pull among other things.

You can go on and on about the N-Body problem as you always seem to default to, but you can't predict the 'where'. Heliocentric astrophysics can and did. That puts a solid point in the Helio win column.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 11, 2020, 10:01:35 PM
Yep. Those are the orbits Newton's gravity produces. And here are over a thousand more solutions, as described by New Scientist. Read carefully:

Infamous three-body problem has over a thousand new solutions - New Scientist (https://www.newscientist.com/article/2148074-infamous-three-body-problem-has-over-a-thousand-new-solutions/)

Quote
For more than 300 years, mathematicians have puzzled over the three-body problem – the question of how three objects orbit one another according to Newton’s laws. Now, there are 1223 new solutions to the conundrum, more than doubling the current number of possibilities.

No single equation can predict how three bodies will move in relation to one another and whether their orbits will repeat or devolve into chaos. Mathematicians must test each specific scenario to see if the objects will stay bound in orbit or be flung away.

The new solutions were found when researchers at Shanghai Jiaotong University in China tested 16 million different orbits using a supercomputer.

All the fresh orbits found are periodic. This means that each object, whether it’s a planet or a proton, ends up where it first began its orbit, with their paths forming three intertwined, closed loops.

“It is impressive that they’ve made the list a lot longer,” says Robert Vanderbei at Princeton University in New Jersey – though he adds that there is “basically an unlimited number of orbits”, so it may be overkill if anyone sought to find them all.

Perhaps the most important application of the three-body problem is in astronomy, for helping researchers figure out how three stars, a star with a planet that has a moon, or any other set of three celestial objects can maintain a stable orbit.

But these new orbits rely on conditions that are somewhere between unlikely and impossible for a real system to satisfy. In all of them, for example, two of the three bodies have exactly the same mass and they all remain in the same plane.


Knot-like paths

In addition, the researchers did not test the orbits’ stability. It’s possible that the tiniest disturbance in space or rounding error in the equations could rip the objects away from one another.

“These orbits have nothing to do with astronomy, but you’re solving these equations and you’re getting something beautiful,” says Vanderbei.

Aside from giving us a thousand pretty pictures of knot-like orbital paths, the new three-body solutions also mark a starting point for finding even more possible orbits, and eventually figuring out the whole range of winding paths that three objects can follow around one another.

This is kind of the zeroth step. Then the question becomes, how is the space of all possible positions and velocities filled up by solutions?” says Richard Montgomery at the University of California, Santa Cruz. “These simple orbits are kind of like a skeleton to build the whole system up from.”

As suggested by the above article, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

From the linked source paper (https://arxiv.org/pdf/1709.04775.pdf) at the bottom of the article:

(https://i.imgur.com/bs38Fcx.png)

All highly symmetric orbits, as Dr. Carroll described.

Symmetrical orbits with two of three masses being identical which "have nothing to do with astronomy" and which "are somewhere between unlikely and impossible for a real system to satisfy."

The phys.org article Scientists discover more than 600 new periodic orbits of the famous three-body problem (https://phys.org/news/2017-10-scientists-periodic-orbits-famous-three-body.html) describes the discovery of other orbits:

Quote
(https://wiki.tfes.org/images/thumb/1/18/47-scientistsdi.jpg/600px-47-scientistsdi.jpg)

"These 695 periodic orbits include the well-known figure-eight family found by Moore in 1993, the 11 families found by Suvakov and Dmitrasinovic in 2013, and more than 600 new families reported for the first time."

Again, highly symmetrical orbits.

I’d like to draw attention to a few things. First the article:

“This is kind of the zeroth step. Then the question becomes, how is the space of all possible positions and velocities filled up by solutions?” says Richard Montgomery at the University of California, Santa Cruz. “These simple orbits are kind of like a skeleton to build the whole system up from.”

The second is your comment on the above:

“As suggested by the above article, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

The zeroth step is in reference to finding ALL analytical solutions, not the entire field of celestial mechanics, as you inferred.

This zeroth step apparently is being used to build up an understanding of all analytical solutions, not the relatively simple orbits of our solar system.

As I mentioned before, and provided evidence in support, those simple orbits have already been modeled both computationally and analytically - see my two posts on 3 body evidence.

In my opinion, there can be a danger in conflating the two efforts of computational and analytical methods, or generalizing the 3 body problem to celestial mechanics as a whole.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 11, 2020, 10:04:40 PM
The zeroth step is in reference to finding ALL analytical solutions, not the entire field of celestial mechanics, as you inferred.

That is incorrect. Those are all numerical solutions they are finding.

https://wiki.tfes.org/Three_Body_Problem#Analytical_Vs._Numerical

Quote
Analytical Vs. Numerical

Q. I think those quotes are talking about analytical solutions. There are working numerical solutions...

A. This is a misconception which stems from some sources which state that there are no analytical solutions, only numerical solutions. This might cause a casual reader to assume that there must be solutions in which the conventional systems of astronomy work. While it is true that the analytical approach of creating an equation to predict future positions based on initial conditions is much more difficult, the working 'numerical solutions' are the special cases described above -- the figure eight and other highly symmetric configurations.

The "numerical solutions" are symmetrical and require at least two of the three bodies to be of the same mass.

Over a Thousand New Solutions - New Scientist

From the New Scientist article Infamous three-body problem has over a thousand new solutions (https://web.archive.org/web/20191010222522/https://www.newscientist.com/article/2148074-infamous-three-body-problem-has-over-a-thousand-new-solutions/) we read:

  “ Perhaps the most important application of the three-body problem is in astronomy, for helping researchers figure out how three stars, a star with a planet that has a moon, or any other set of three celestial objects can maintain a stable orbit.
But these new orbits rely on conditions that are somewhere between unlikely and impossible for a real system to satisfy. In all of them, for example, two of the three bodies have exactly the same mass and they all remain in the same plane. ”

Clicking on the arxiv.org source at the bottom of the that article takes us to the paper The 1223 new periodic orbits of planar three-body problem with unequal mass and zero angular momentum (https://web.archive.org/web/20191010222453/https://arxiv.org/pdf/1709.04775.pdf), where we see at the bottom of p.1:

  “ Therefore, without loss of generality, we consider m1 = m2 = 1 and m3 is varied. ”

Elsewhere in the paper it describes:

  “ Thus, we further integrate the motion equations by means of “Clean Numerical Simulation” (CNS) [17–20] with negligible numerical noises in a long enough interval of time ”

Over 600 New Orbits

Similarly, the phys.org article Scientists discover more than 600 new periodic orbits of the famous three-body problem (https://phys.org/news/2017-10-scientists-periodic-orbits-famous-three-body.html) describes the discovery of other symmetrical orbits:

(https://wiki.tfes.org/images/thumb/1/18/47-scientistsdi.jpg/600px-47-scientistsdi.jpg)

  “ These 695 periodic orbits include the well-known figure-eight family found by Moore in 1993, the 11 families found by Suvakov and Dmitrasinovic in 2013, and more than 600 new families reported for the first time. The two scientists used the so-called clean numerical simulation (CNS), a new numerical strategy for reliable simulations of chaotic dynamic systems proposed by the second author in 2009, which is based on a high order of Taylor series and multiple precision data, plus a convergence/reliability check. ”

Figure Eight

The famous symmetrical Figure Eight problem was discovered numerically:

http://numericaltank.sjtu.edu.cn/three-body/three-body.htm

  “ The famous figure-eight family was numerically discovered by Moore [10] in 1993 and rediscovered by Chenciner and Montgomery [11] in 2000. ”

1349 New Families

Over a thousand new periodic orbits of a planar three-body system with unequal masses (https://web.archive.org/save/https://academic.oup.com/pasj/article/70/4/64/4999993)

  “ Here, we report 1349 new families of planar periodic orbits of the triple system where two bodies have the same mass and the other has a different mass. ”

Further down in the same paper, in the section "Numerical searching for periodic orbits" we verify that these are numerical simulations:

  “ As mentioned by Li and Liao (2017), many periodic orbits might be lost by means of traditional algorithms in double precision. Thus, we further integrate the equations of motion by means of a "clean numerical simulation"

We see that these special solutions are the numerical solutions. Just where are the solutions with different masses and non-symmetrical configurations? Opponents are unable to show that there are  non-symmetrical configurations, or that the Sun-Earth-Moon system can be simulated by the Three Body Problem.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 11, 2020, 10:19:24 PM
The zeroth step is in reference to finding ALL analytical solutions, not the entire field of celestial mechanics, as you inferred.

That is incorrect. Those are all numerical solutions.

https://wiki.tfes.org/Three_Body_Problem#Analytical_Vs._Numerical

Quote
Analytical Vs. Numerical

Q. I think those quotes are talking about analytical solutions. There are working numerical solutions...

A. This is a misconception which stems from some sources which state that there are no analytical solutions, only numerical solutions. This might cause a casual reader to assume that there must be solutions in which the conventional systems of astronomy work. While it is true that the analytical approach of creating an equation to predict future positions based on initial conditions is much more difficult, the working 'numerical solutions' are the special cases described above -- the figure eight and other highly symmetric configurations.

The "numerical solutions" are symmetrical and require at least two of the three bodies to be of the same mass.

Over a Thousand New Solutions - New Scientist

From the New Scientist article Infamous three-body problem has over a thousand new solutions (https://web.archive.org/web/20191010222522/https://www.newscientist.com/article/2148074-infamous-three-body-problem-has-over-a-thousand-new-solutions/) we read:

  “ Perhaps the most important application of the three-body problem is in astronomy, for helping researchers figure out how three stars, a star with a planet that has a moon, or any other set of three celestial objects can maintain a stable orbit.
But these new orbits rely on conditions that are somewhere between unlikely and impossible for a real system to satisfy. In all of them, for example, two of the three bodies have exactly the same mass and they all remain in the same plane. ”

Clicking on the arxiv.org source at the bottom of the that article takes us to the paper The 1223 new periodic orbits of planar three-body problem with unequal mass and zero angular momentum (https://web.archive.org/web/20191010222453/https://arxiv.org/pdf/1709.04775.pdf), where we see at the bottom of p.1:

  “ Therefore, without loss of generality, we consider m1 = m2 = 1 and m3 is varied. ”

Elsewhere in the paper it describes:

  “ Thus, we further integrate the motion equations by means of “Clean Numerical Simulation” (CNS) [17–20] with negligible numerical noises in a long enough interval of time ”

Over 600 New Orbits

Similarly, the phys.org article Scientists discover more than 600 new periodic orbits of the famous three-body problem (https://phys.org/news/2017-10-scientists-periodic-orbits-famous-three-body.html) describes the discovery of other symmetrical orbits:

(https://wiki.tfes.org/images/thumb/1/18/47-scientistsdi.jpg/600px-47-scientistsdi.jpg)

  “ These 695 periodic orbits include the well-known figure-eight family found by Moore in 1993, the 11 families found by Suvakov and Dmitrasinovic in 2013, and more than 600 new families reported for the first time. The two scientists used the so-called clean numerical simulation (CNS), a new numerical strategy for reliable simulations of chaotic dynamic systems proposed by the second author in 2009, which is based on a high order of Taylor series and multiple precision data, plus a convergence/reliability check. ”

Figure Eight

The famous symmetrical Figure Eight problem was discovered numerically:

http://numericaltank.sjtu.edu.cn/three-body/three-body.htm

  “ The famous figure-eight family was numerically discovered by Moore [10] in 1993 and rediscovered by Chenciner and Montgomery [11] in 2000. ”

1349 New Families

Over a thousand new periodic orbits of a planar three-body system with unequal masses (https://web.archive.org/save/https://academic.oup.com/pasj/article/70/4/64/4999993)

  “ Here, we report 1349 new families of planar periodic orbits of the triple system where two bodies have the same mass and the other has a different mass. ”

Further down in the same paper, in the section "Numerical searching for periodic orbits" we verify that these are numerical simulations:

  “ As mentioned by Li and Liao (2017), many periodic orbits might be lost by means of traditional algorithms in double precision. Thus, we further integrate the equations of motion by means of a "clean numerical simulation"

We see that these special solutions are the numerical solutions. Just where are the solutions with different masses? Opponents are unable to show that there are solutions with different masses, that there are non-symmetrical configurations, or that the Sun-Earth-Moon system can be simulated by the Three Body Problem.

I did not say they weren’t numerical solutions. I said they are being used as a zeroth order step in finding all analytical solutions. My other statements this hold unchanged.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 11, 2020, 10:25:26 PM
Quote
I did not say they weren’t numerical solutions. I said they are being used as a zeroth order step in finding all analytical solutions. My other statements this hold unchanged.

It says nothing about that.

The found orbits that are symmetrical and of identical masses are numerical solutions, not analytical solutions. Analytical solutions have nothing to do with this, and are not even attempted.

The problem with Newtonian gravity is that it can only produce these weird orbits. Hence, the 'zeroth step' on figuring it all out.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 11, 2020, 10:30:02 PM
The problem with Newtonian gravity is that it can only produce these weird orbits. Hence, the 'zeroth step' on figuring it all out.

Where do you get that Newtonian gravity can only produce 'weird' orbits?  I have yet to see any published paper say that numerical methods are invalid. Numerical integration is used all over science and engineering and is just another valid tool. All kinds of problems that don't have exact solutions use numerical methods to solve them. Citation is needed.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 11, 2020, 10:32:10 PM
The problem with Newtonian gravity is that it can only produce these weird orbits. Hence, the 'zeroth step' on figuring it all out.

Where do you get that Newtonian gravity can only produce 'weird' orbits?  I have yet to see any published paper say that numerical methods are invalid. Numerical integration is used all over science and engineering and is just another valid tool. All kinds of problems that don't have exact solutions use numerical methods to solve them. Citation is needed.

There are plenty of resources on that subject. Ask a Mathematician:

https://www.askamathematician.com/2011/10/q-what-is-the-three-body-problem/

Quote
Q: What is the three body problem?

Physicist: The three body problem is to exactly solve for the motions of three (or more) bodies interacting through an inverse square force (which includes gravitational and electrical attraction).

The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits).
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 11, 2020, 10:53:12 PM
The problem with Newtonian gravity is that it can only produce these weird orbits. Hence, the 'zeroth step' on figuring it all out.

Where do you get that Newtonian gravity can only produce 'weird' orbits?  I have yet to see any published paper say that numerical methods are invalid. Numerical integration is used all over science and engineering and is just another valid tool. All kinds of problems that don't have exact solutions use numerical methods to solve them. Citation is needed.

There are plenty of resources on that subject. Ask a Mathematician:

https://www.askamathematician.com/2011/10/q-what-is-the-three-body-problem/

Quote
Q: What is the three body problem?

Physicist: The three body problem is to exactly solve for the motions of three (or more) bodies interacting through an inverse square force (which includes gravitational and electrical attraction).

The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits).

I should have asked for a published paper, but I'll answer the blog quote anyway. Do you have a published paper that states we can't use numerical solutions to solve n-body problems?

The blog you mentioned isn't claiming what you say it does.  It states pretty clearly that we can use numerical solutions to solve it just fine for real world use.

Quote
Point is, this effect only shows up in systems with three or more bodies, it’s chaotic (in the chaos theory sense), and there is no way to predict it exactly.  That being said, we can still get computers to come pretty close (up to a point, because chaos is a punk), and there are even some mathematical tricks to get reasonable solutions that, while not perfect, are still pretty good (and can even get us well into that last “1% of weirdness”).

Sounds like he is saying you can use numeric solutions to get reasonable solutions. Like predicting comet fragments hitting Jupiter.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 11, 2020, 10:57:31 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 11, 2020, 11:07:27 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."

That's not at all what he's talking about. he says the word 'chaos' not that they use chaos theory equations to model anything.

He's saying you can use numerical methods to solve the 3 body problem. Which is the opposite of what you are claiming.

You are also the one claiming we need stable solutions, but we don't. The solar system is only 'stable' in the short term, it's unstable in the long run.

Again, numerical solutions can solve any amount of n-body problems to the amount of precision you need.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 11, 2020, 11:10:01 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."

That's not at all what he's talking about. he says the word 'chaos' not that they use chaos theory equations to model anything.

He's saying you can use numerical methods to solve the 3 body problem. Which is the opposite of what you are claiming.

You are also the one claiming we need stable solutions, but we don't. The solar system is only 'stable' in the short term, it's unstable in the long run.

Again, numerical solutions can solve any amount of n-body problems to the amount of precision you need.

That's your own unsourced speculation. He clearly says "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 11, 2020, 11:21:19 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."

That's not at all what he's talking about. he says the word 'chaos' not that they use chaos theory equations to model anything.

He's saying you can use numerical methods to solve the 3 body problem. Which is the opposite of what you are claiming.

You are also the one claiming we need stable solutions, but we don't. The solar system is only 'stable' in the short term, it's unstable in the long run.

Again, numerical solutions can solve any amount of n-body problems to the amount of precision you need.

That's your own speculation. He clearly says "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."

I think you may be conflating “stable” with “analytic.”

There are actual stable 3 body orbits that are known. One is Jupiter-Sun-some asteroid that I forget the name of. But you can look it up. This 3 body system is stable and described by the equations. That’s how it was found to be stable.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 11, 2020, 11:29:32 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."

That's not at all what he's talking about. he says the word 'chaos' not that they use chaos theory equations to model anything.

He's saying you can use numerical methods to solve the 3 body problem. Which is the opposite of what you are claiming.

You are also the one claiming we need stable solutions, but we don't. The solar system is only 'stable' in the short term, it's unstable in the long run.

Again, numerical solutions can solve any amount of n-body problems to the amount of precision you need.

That's your own unsourced speculation. He clearly says "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."

I think there's a 3 body thread going already if you want to take all this there because it's neither here nor there in this thread.

This thread is about how Helio astrophysicists predicted the when and where shards from a shattered comet would hit Jupiter. They succeeded in doing so with great precision and it was observed.

FET could never have predicted the 'where' the collisions occurred on Jupiter. FET would need to know the size of Jupiter, not to mention calculating it's gravitational pull among other things. FET has no knowledge of any of that. FET is unclear as to where Jupiter is, let alone its size.

Heliocentric astrophysics can and did predict the when and where. This falls into the category of "Things FET can't do that RET can" bucket.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 11, 2020, 11:32:10 PM
He's talking about predicting what will happen to unequal bodies with chaos theory, not that they are stable. The only stable solutions are the ones with the "small set of frankly goofy scenarios (like identical planets following identical orbits)."

That's not at all what he's talking about. he says the word 'chaos' not that they use chaos theory equations to model anything.

He's saying you can use numerical methods to solve the 3 body problem. Which is the opposite of what you are claiming.

You are also the one claiming we need stable solutions, but we don't. The solar system is only 'stable' in the short term, it's unstable in the long run.

Again, numerical solutions can solve any amount of n-body problems to the amount of precision you need.

That's your own speculation. He clearly says "The problem with the 3-body problem is that it can’t be done, except in a very small set of frankly goofy scenarios (like identical planets following identical orbits)."

It's not my own speculation, it's written in that very blog.

Quote
Despite that, we do alright, and happily, reality doesn’t concern itself with doing math, it just kinda “does”.  For example, quantum field theory, despite being the most accurate theory that ever there was, never involves exactly solving anything.  Once a physicist gets a hold of all the appropriate equations and a big computer, they can start approximating things.  With enough computing power and time, these approximations can be made amazingly good.  Computer simulation and approximation is a whole science unto itself.

You keep getting confused between being able to exactly solve math problems, and being able to use numeric methods to solve them instead. You are seriously cherry-picking this blog and should read the entire thing.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 12, 2020, 12:12:19 AM
Comparing the 'approximate equations' in the gravity simulations that they are forced to use to simulate the Sun-Earth-Moon system to Quantum Mechanics is hardly an endorsement, considering that QM and theories like String Theory are much like the discredited epicycles which have been used for thousands of years to explain the motions of planets.

A giant of physics takes string theory, quantum mechanics and inflation to task (https://cosmosmagazine.com/physics/a-giant-of-physics-takes-string-theory-quantum-mechanics-and-inflation-to-task)

Quote
Fashion, according to Penrose, has long played a role in science. To remind us of how easy it can be for spurious ideas to achieve a status of dogma, he describes several fashionable junk theories of history. For example, Ptolemy’s theory of epicycles (the idea that the orbits of the planets could be described by circles upon circles) was kept alive through 14 centuries of mental gymnastics on the part of proponents whose worldview placed Earth at the centre of the universe and everything else in orbit around it.

Today’s modern equivalent, perhaps, is string theory, the idea that all of physics is based on fundamental vibrating strings, far tinier than any quark or electron. The idea, so tantalising in its simplicity and scope, has dominated theoretical physics for two decades despite making no testable predictions. Joseph Polchinski, a leading string theorist has said “there are no alternatives … all good ideas are part of string theory”.

For Penrose, on the other hand, string theory’s "stranglehold on developments in fundamental physics has been stultifying”. He exposes a series of technical holes in the theory, questioning, in the tone of a bemused schoolmaster, why they have not been seriously addressed. The implication is that string theorists are too caught up in following their field’s latest fashions to be worried about the foundational problems of the theory.

https://bayes.wustl.edu/etj/articles/scattering.by.free.pdf

Quote
IS QUANTUM THEORY A SYSTEM OF EPICYCLES?

Today, Quantum Mechanics (QM) and Quantum Electrodynamics (QED) have great pragmatic
success - small wonder, since they were created, like epicycles, by empirical trial-and-error guided
by just that requirement.

...Because of their empirical origins, QM and QED are not physical theories at all.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 12, 2020, 12:14:34 AM
Comparing the 'approximate equations' in gravity studies to quantum mechanics is hardly an endorsement, considering that theories like String Theory are much like the discredited epicycles which have been used for thousands of years to present to explain the motions of planets.

You will note if you read BOTH quotes from that article, he is saying computers can numerically solve for the 3 body problem. I'll quote it again.

And yes, as others pointed out, the proof that they work is the predictions of the comet, landing probes on other planets, visiting Pluto. You can keep claiming the 3 body problem is impossible, but the reality is we can use it, and do, and the proof is in the predictions.

Quote
Point is, this effect only shows up in systems with three or more bodies, it’s chaotic (in the chaos theory sense), and there is no way to predict it exactly.  That being said, we can still get computers to come pretty close (up to a point, because chaos is a punk), and there are even some mathematical tricks to get reasonable solutions that, while not perfect, are still pretty good (and can even get us well into that last “1% of weirdness”).
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 12, 2020, 12:22:04 AM
In your previous you posted a quote from him saying that 'approximations' are needed. This means that they can't really do it.

From the page:

Quote
Despite that, we do alright, and happily, reality doesn’t concern itself with doing math, it just kinda “does”.  For example, quantum field theory, despite being the most accurate theory that ever there was, never involves exactly solving anything.  Once a physicist gets a hold of all the appropriate equations and a big computer, they can start approximating things.  With enough computing power and time, these approximations can be made amazingly good.  Computer simulation and approximation is a whole science unto itself.

But even with just mechanical pencil and paper there are cheats.  For example, although there are more than three bodies in the solar system (the Sun, eight planets, dozens of moons, and millions of asteroids and comets), almost everything behaves, roughly, as though it were in a two body system.  Basically, this is due to the pronounced size differences between things.  As far as each planet is concerned, the only important body in the rest of the universe is the Sun.  To get some idea of why; the Sun pulls on the Earth about 200 times harder than the Moon, and about 20,000 times harder than Jupiter.  Nothing else even deserves a mention.  So, if you want to calculate the orbits of all the planets, a “2-body approximation” will get you more than 99% of the way to the right answer.

They talk about "approximations" and "cheating" with two body problems.

Why would they need to cheat if there were solutions?
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 12, 2020, 01:13:33 AM
In your previous you posted a quote from him saying that 'approximations' are needed. This means that they can't really do it.

They talk about "approximations" and "cheating" with two body problems.

Why would they need to cheat if there were solutions?

You use the words, but don't seem to understand their meanings. Or are intentionally misunderstanding them.

Either way, I'm not going to argue semantics. Someone else can go down that particular rabbit hole with you.

The point still stands, Newton mechanics work. We can predict things. We can navigate spacecraft with them. You can ignore those points over and over, but it doesn't make them go away.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 12, 2020, 01:46:23 AM
In your previous you posted a quote from him saying that 'approximations' are needed. This means that they can't really do it.

From the page:

Quote
Despite that, we do alright, and happily, reality doesn’t concern itself with doing math, it just kinda “does”.  For example, quantum field theory, despite being the most accurate theory that ever there was, never involves exactly solving anything.  Once a physicist gets a hold of all the appropriate equations and a big computer, they can start approximating things.  With enough computing power and time, these approximations can be made amazingly good.  Computer simulation and approximation is a whole science unto itself.

But even with just mechanical pencil and paper there are cheats.  For example, although there are more than three bodies in the solar system (the Sun, eight planets, dozens of moons, and millions of asteroids and comets), almost everything behaves, roughly, as though it were in a two body system.  Basically, this is due to the pronounced size differences between things.  As far as each planet is concerned, the only important body in the rest of the universe is the Sun.  To get some idea of why; the Sun pulls on the Earth about 200 times harder than the Moon, and about 20,000 times harder than Jupiter.  Nothing else even deserves a mention.  So, if you want to calculate the orbits of all the planets, a “2-body approximation” will get you more than 99% of the way to the right answer.

They talk about "approximations" and "cheating" with two body problems.

Why would they need to cheat if there were solutions?

I still don't think you get it. FET could never have predicted the 'where' the collisions occurred on Jupiter. FET would need to know the size of Jupiter, not to mention calculating it's gravitational pull among other things. FET has no knowledge of any of that. FET is unclear as to where Jupiter is, let alone its size.

You harp on modern helio-astrophysics for not 'solving' the N-Body Problem to your satisfaction but fail to see that FET has less than zero of a solution. Or even an attempt. FET has no knowledge of the heavens at all. Helio has quite the leg up in that regard.

Now, can FET do what Helio did and calculate the when and where each of the comet shards impacted Jupiter? That is the question.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 12, 2020, 03:05:43 AM
Comparing the 'approximate equations' in the gravity simulations that they are forced to use to simulate the Sun-Earth-Moon system to Quantum Mechanics is hardly an endorsement, considering that QM and theories like String Theory are much like the discredited epicycles which have been used for thousands of years to explain the motions of planets.

A giant of physics takes string theory, quantum mechanics and inflation to task (https://cosmosmagazine.com/physics/a-giant-of-physics-takes-string-theory-quantum-mechanics-and-inflation-to-task)

Quote
Fashion, according to Penrose, has long played a role in science. To remind us of how easy it can be for spurious ideas to achieve a status of dogma, he describes several fashionable junk theories of history. For example, Ptolemy’s theory of epicycles (the idea that the orbits of the planets could be described by circles upon circles) was kept alive through 14 centuries of mental gymnastics on the part of proponents whose worldview placed Earth at the centre of the universe and everything else in orbit around it.

Today’s modern equivalent, perhaps, is string theory, the idea that all of physics is based on fundamental vibrating strings, far tinier than any quark or electron. The idea, so tantalising in its simplicity and scope, has dominated theoretical physics for two decades despite making no testable predictions. Joseph Polchinski, a leading string theorist has said “there are no alternatives … all good ideas are part of string theory”.

For Penrose, on the other hand, string theory’s "stranglehold on developments in fundamental physics has been stultifying”. He exposes a series of technical holes in the theory, questioning, in the tone of a bemused schoolmaster, why they have not been seriously addressed. The implication is that string theorists are too caught up in following their field’s latest fashions to be worried about the foundational problems of the theory.

https://bayes.wustl.edu/etj/articles/scattering.by.free.pdf

Quote
IS QUANTUM THEORY A SYSTEM OF EPICYCLES?

Today, Quantum Mechanics (QM) and Quantum Electrodynamics (QED) have great pragmatic
success - small wonder, since they were created, like epicycles, by empirical trial-and-error guided
by just that requirement.

...Because of their empirical origins, QM and QED are not physical theories at all.

Please see my post for the analytic solutions to the 3 body problem. It stands as evidence that the statement: “being forced to use approximations,” is in error.

It would benefit the conversation if, when evidence is requested and then provided, the requester then purviews the evidence.

I take the time to read through all of your wiki references carefully, because I respect the arguments you wish to bring to the conversation.

If honest discourse is desirable - on par with traditional scientific discourse, then consideration of presented evidence comes with the territory.

I wouldn’t be very professional or polite if I diverted the conversation when contrary evidence was presented to me. It would indicate to the scientific community that I was not to be taken seriously.
Title: Re: Comet Shoemaker–Levy 9
Post by: Tom Bishop on May 14, 2020, 11:20:28 PM
Quote from: Stack
Now, can FET do what Helio did and calculate the when and where each of the comet shards impacted Jupiter? That is the question.

I don't see that Helio did anything except use the discredited epicycles to make data fit a theory.

Please see my post for the analytic solutions to the 3 body problem. It stands as evidence that the statement: “being forced to use approximations,” is in error.

Please provide a source for your arguments other than your own self.
Title: Re: Comet Shoemaker–Levy 9
Post by: stack on May 14, 2020, 11:34:41 PM
Quote from: Stack
Now, can FET do what Helio did and calculate the when and where each of the comet shards impacted Jupiter? That is the question.

I don't see that Helio did anything except use the discredited epicycles to make data fit a theory.

Just because you don't see it doesn't mean it's not there. I already pointed this all out in post #23 as well as others:

Wait, so now FET is in agreement with the fact that Jupiter has a diameter of about 88,695 miles which is more than 11 times the diameter of Earth? FET would need to because part of the astronomers' calculations had to take into account the diameter of Jupiter to determine when and where on the planet the debris would hit.

No, they did not take it into account for any meaningful purpose. Once you start adding epicycles, the underlying model is meaningless.

You are wrong. They most certainly took the known size of Jupiter into account. From the paper I cited before, titled 'Tidal Disruption and the Appearance of Periodic Comet Shoemaker-Levy 9', one of just page after page of calculations used to model/predict the collision:

(https://i.imgur.com/SNIRZ3U.png)

Note: R3 is Jupiter’s equatorial radius

And that's just scratching the surface, as it where:

(https://i.imgur.com/xow11EM.png)

https://trs.jpl.nasa.gov/handle/2014/36567

Quote
Could FET make the prediction just using an epicycle?

It can be done with anything, and any underlying model. FE does not propose an underlying 'ideal' celestial dogma model or force that must be justified and adhered to with epicycles.

Wrong again. Read the paper I referenced that describes how it was calculated. A massive undertaking.

Bottom line, FET could not have predicted the collision and modern heliocentric calculation could and did.

So again, if "It can be done with anything, and any underlying model," show us how FET could do it. Prove me wrong.

How is, at a minimum, having to calculate the Jupiter radius an epicycle? Again, it comes down to the 'where' that FET fails. FET would have needed to know the size of Jupiter to predict where the collisions would occur. FET can't do that as it has no knowledge about Jupiter. Helio does and did predict the where and it was observed. Helio = 1 / FET = 0.
Title: Re: Comet Shoemaker–Levy 9
Post by: BRrollin on May 14, 2020, 11:44:30 PM
Quote from: Stack
Now, can FET do what Helio did and calculate the when and where each of the comet shards impacted Jupiter? That is the question.

I don't see that Helio did anything except use the discredited epicycles to make data fit a theory.

Please see my post for the analytic solutions to the 3 body problem. It stands as evidence that the statement: “being forced to use approximations,” is in error.

Please provide a source for your arguments other than your own self.

I find this to be an obvious empty reply, which goes against forum rules, and quite dishonest. The post provides a link to a source.

If you choose not to discuss the source, that is your prerogative. Yet to claim it is not there is incredibly poor form.
Title: Re: Comet Shoemaker–Levy 9
Post by: somerled on May 19, 2020, 01:21:38 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 01:32:42 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?
We don't.

Some guys in lab coats, with  slightly loosened neck ties, ink pen pocket protectors, wire frame glasses, and some pretty paintings of the event, tell us we do though...better believe 'em too or else....
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 01:38:03 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?
We don't.

Some guys in lab coats, with  slightly loosened neck ties, ink pen pocket protectors, wire frame glasses, and some pretty paintings of the event, tell us we do though...better believe 'em too or else....

Actually we were able to witness it. The Galileo spacecraft was on it's way to Jupiter and was in position to see the impacts and their exact timing. The lab coat guys made sure it was watching so we could catch the event.

Although the impacts took place on the side of Jupiter hidden from Earth, Galileo, then at a distance of 1.6 AU (240 million km; 150 million mi) from the planet, was able to see the impacts as they occurred. Jupiter's rapid rotation brought the impact sites into view for terrestrial observers a few minutes after the collisions - https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9#Impacts

Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 01:56:48 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?
We don't.

Some guys in lab coats, with  slightly loosened neck ties, ink pen pocket protectors, wire frame glasses, and some pretty paintings of the event, tell us we do though...better believe 'em too or else....

Actually we were able to witness it. The Galileo spacecraft was on it's way to Jupiter and was in position to see the impacts and their exact timing. The lab coat guys made sure it was watching so we could catch the event.

Although the impacts took place on the side of Jupiter hidden from Earth, Galileo, then at a distance of 1.6 AU (240 million km; 150 million mi) from the planet, was able to see the impacts as they occurred. Jupiter's rapid rotation brought the impact sites into view for terrestrial observers a few minutes after the collisions - https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9#Impacts
Actually, you witnessed what you were told you witnessed.

There is no such thing as an "outer space," that you know.

There is such a thing as an "outer space," which you believe in.
Title: Re: Comet Shoemaker–Levy 9
Post by: somerled on May 19, 2020, 02:04:08 PM
Who are "we"? Did galimeleo have a nice scope on board ?
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 02:18:55 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?
We don't.

Some guys in lab coats, with  slightly loosened neck ties, ink pen pocket protectors, wire frame glasses, and some pretty paintings of the event, tell us we do though...better believe 'em too or else....

Actually we were able to witness it. The Galileo spacecraft was on it's way to Jupiter and was in position to see the impacts and their exact timing. The lab coat guys made sure it was watching so we could catch the event.

Although the impacts took place on the side of Jupiter hidden from Earth, Galileo, then at a distance of 1.6 AU (240 million km; 150 million mi) from the planet, was able to see the impacts as they occurred. Jupiter's rapid rotation brought the impact sites into view for terrestrial observers a few minutes after the collisions - https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9#Impacts
Actually, you witnessed what you were told you witnessed.

There is no such thing as an "outer space," that you know.

There is such a thing as an "outer space," which you believe in.

Well if you are going to claim any evidence presented is all lies, then I suppose there is not much point debating. Nothing anyone can say will change your mind if it's already made up.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 02:22:33 PM
Who are "we"? Did galimeleo have a nice scope on board ?

We as in, everyone who can see the pictures.

To be more exact, NASA launched the probe and radioed it to watch the impacts as it neared Jupiter.

It did have a nice scope on board. It was equipped with a cassegrain telescope (https://en.wikipedia.org/wiki/Cassegrain_reflector), among other instruments.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 02:24:03 PM
Well if you are going to claim any evidence presented is all lies, then I suppose there is not much point debating. Nothing anyone can say will change your mind if it's already made up.
The only thing lacking from your description of the evidence is the word, "supposed."

That is really the extent of the evidence when it comes to RE.

It is all a supposition with no validity.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 02:32:59 PM
Well if you are going to claim any evidence presented is all lies, then I suppose there is not much point debating. Nothing anyone can say will change your mind if it's already made up.
The only thing lacking from your description of the evidence is the word, "supposed."

That is really the extent of the evidence when it comes to RE.

It is all a supposition with no validity.

What evidence of the Galileo spacecraft being real would it take to convince you?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 02:47:55 PM
Well if you are going to claim any evidence presented is all lies, then I suppose there is not much point debating. Nothing anyone can say will change your mind if it's already made up.
The only thing lacking from your description of the evidence is the word, "supposed."

That is really the extent of the evidence when it comes to RE.

It is all a supposition with no validity.

What evidence of the Galileo spacecraft being real would it take to convince you?
You cannot come to grips with the definition of "objective," when it comes to the word, "evidence."

Once you get over that hurdle, perhaps we could have meaningful dialogue.

When I see two apples to my left and two apples to my right and I gather the apples and place them directly in front of me I can then see four apples in total.

That is objective evidence.

"But what about this?!" you might say...or ..."whatabout that!?" you might ask...

Indeed...what about it?
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 02:57:42 PM
Well if you are going to claim any evidence presented is all lies, then I suppose there is not much point debating. Nothing anyone can say will change your mind if it's already made up.
The only thing lacking from your description of the evidence is the word, "supposed."

That is really the extent of the evidence when it comes to RE.

It is all a supposition with no validity.

What evidence of the Galileo spacecraft being real would it take to convince you?
You cannot come to grips with the definition of "objective," when it comes to the word, "evidence."

Once you get over that hurdle, perhaps we could have meaningful dialogue.

When I see two apples to my left and two apples to my right and I gather the apples and place them directly in front of me I can then see four apples in total.

That is objective evidence.

"But what about this?!" you might say...or ..."whatabout that!?" you might ask...

Indeed...what about it?

I'm not sure what hurdle you are talking about. The word "objective" hasn't even been mentioned until you brought it up.

So you are saying there is no evidence you could possibly be shown that would convince you the Galileo spacecraft is real? Nothing at all?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 03:08:48 PM
I'm not sure what hurdle you are talking about. The word "objective" hasn't even been mentioned until you brought it up.

So you are saying there is no evidence you could possibly be shown that would convince you the Galileo spacecraft is real? Nothing at all?
Do you have objective evidence in this case?
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 03:34:34 PM
I'm not sure what hurdle you are talking about. The word "objective" hasn't even been mentioned until you brought it up.

So you are saying there is no evidence you could possibly be shown that would convince you the Galileo spacecraft is real? Nothing at all?
Do you have objective evidence in this case?

I'm asking you, what objective evidence would you accept?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 19, 2020, 03:35:33 PM
I'm not sure what hurdle you are talking about. The word "objective" hasn't even been mentioned until you brought it up.

So you are saying there is no evidence you could possibly be shown that would convince you the Galileo spacecraft is real? Nothing at all?
Do you have objective evidence in this case?

I'm asking you, what objective evidence would you accept?
I will accept any objective evidence you have.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 19, 2020, 03:45:23 PM
I'm not sure what hurdle you are talking about. The word "objective" hasn't even been mentioned until you brought it up.

So you are saying there is no evidence you could possibly be shown that would convince you the Galileo spacecraft is real? Nothing at all?
Do you have objective evidence in this case?

I'm asking you, what objective evidence would you accept?
I will accept any objective evidence you have.

You can take your pick as evidence from anything listed here.

https://en.wikipedia.org/wiki/Galileo_(spacecraft)

If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 19, 2020, 09:46:02 PM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?

Anyone with a telescope pointed at Jupiter. It was at least as visible as the famous Great Red Spot (https://link.springer.com/article/10.1007/BF00612878). And even if the collision happened on the far side, Jupiter completes a rotation in just under 10 hours, so you just had to wait a little.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 10:19:00 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 10:19:46 AM
Who witnessed the supposed collision between this comet and Jupiter ? It impacted on the night side of the planet apparently . How does we know the exact moment it hit the planet?

Anyone with a telescope pointed at Jupiter. It was at least as visible as the famous Great Red Spot (https://link.springer.com/article/10.1007/BF00612878). And even if the collision happened on the far side, Jupiter completes a rotation in just under 10 hours, so you just had to wait a little.
So they didn't witness the event.

Thank you.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 11:03:38 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 11:38:15 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 11:45:47 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?

You quoted my response, then deleted the part where I provided you with evidence and asked questions.  Can we stay on subject please?

As asked above, what do you consider objective evidence, and what evidence would you accept of the Galileo spacecraft being real?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 11:48:48 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?

You quoted my response, then deleted the part where I provided you with evidence and asked questions.  Can we stay on subject please?

As asked above, what do you consider objective evidence, and what evidence would you accept of the Galileo spacecraft being real?
Your link is still there.

You accused me of deleting it.

Accusing me of deleting something when I didn't is not staying on subject.

Aside from that, I am not going to repost a non-working link.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 11:57:35 AM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?

You quoted my response, then deleted the part where I provided you with evidence and asked questions.  Can we stay on subject please?

As asked above, what do you consider objective evidence, and what evidence would you accept of the Galileo spacecraft being real?
Your link is still there.

You accused me of deleting it.

Accusing me of deleting something when I didn't is not staying on subject.

Aside from that, I am not going to repost a non-working link.

The board doesn't parse Wiki links well it seems.  Here is a fixed link.

https://en.wikipedia.org/wiki/Galileo_(spacecraft) (https://en.wikipedia.org/wiki/Galileo_(spacecraft))

Now, will you please answer my questions? Thanks.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 12:07:21 PM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?

You quoted my response, then deleted the part where I provided you with evidence and asked questions.  Can we stay on subject please?

As asked above, what do you consider objective evidence, and what evidence would you accept of the Galileo spacecraft being real?
Your link is still there.

You accused me of deleting it.

Accusing me of deleting something when I didn't is not staying on subject.

Aside from that, I am not going to repost a non-working link.

The board doesn't parse Wiki links well it seems.  Here is a fixed link.

https://en.wikipedia.org/wiki/Galileo_(spacecraft) (https://en.wikipedia.org/wiki/Galileo_(spacecraft))

Now, will you please answer my questions? Thanks.
There is no doubt the Galileo spacecraft exists.

People have seen it and touched it.

I only have doubt regarding its stated mission.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 12:13:13 PM
If you only accept strictly objective evidence, well that's going to prevent you from believing in almost everything, as you can only directly measure a very tiny part of the world around you. Anything that happened in the past will be a total mystery, and impossible to ever prove.
Here is your strawman.

Totally ridiculous conditions on what qualifies as objective and the issue of belief.

More a topic for the Philosophy thread I suppose...

You have asked me for evidence, I have given you examples several times now.  Just now you deleted the evidence I provided and ignored it.

If my description of objective evidence is incorrect, please explain what you think qualifies as objective evidence .

What evidence would you accept that the Galileo spacecraft is real?
I didn't delete anything.

Why would you accuse me of deleting anything?

You quoted my response, then deleted the part where I provided you with evidence and asked questions.  Can we stay on subject please?

As asked above, what do you consider objective evidence, and what evidence would you accept of the Galileo spacecraft being real?
Your link is still there.

You accused me of deleting it.

Accusing me of deleting something when I didn't is not staying on subject.

Aside from that, I am not going to repost a non-working link.

The board doesn't parse Wiki links well it seems.  Here is a fixed link.

https://en.wikipedia.org/wiki/Galileo_(spacecraft) (https://en.wikipedia.org/wiki/Galileo_(spacecraft))

Now, will you please answer my questions? Thanks.
There is no doubt the Galileo spacecraft exists.

People have seen it and touched it.

I only have doubt regarding its stated mission.

Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 12:14:34 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 12:23:20 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.

None that I can provide, or none that can exist? You are stating that no matter what, you will never believe it?
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 12:30:13 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.

None that I can provide, or none that can exist? You are stating that no matter what, you will never believe it?
Again, what constitutes objective in this case is more a discussion related to Philosophy.

We more than likely disagree on what that is which is okay.
Title: Re: Comet Shoemaker–Levy 9
Post by: somerled on May 20, 2020, 12:47:13 PM
JSS you are mistaken in the belief that lighter than aircraft Galileo carried a telescope. Not listed in onboard optical instruments.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 12:50:52 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.

None that I can provide, or none that can exist? You are stating that no matter what, you will never believe it?
Again, what constitutes objective in this case is more a discussion related to Philosophy.

We more than likely disagree on what that is which is okay.

We can disagree about your personal beliefs, sure. We can discuss that elsewhere.

Back to the topic on hand, Galileo sent back pictures of the impacts. Here are several of those images. They show the exact time and placement of the impacts. This is how we know when they took place.

(https://nssdc.gsfc.nasa.gov/imgcat/hires/gal_p44542.gif)
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 12:53:14 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.

None that I can provide, or none that can exist? You are stating that no matter what, you will never believe it?
Again, what constitutes objective in this case is more a discussion related to Philosophy.

We more than likely disagree on what that is which is okay.

We can disagree about your personal beliefs, sure. We can discuss that elsewhere.

Back to the topic on hand, Galileo sent back pictures of the impacts. Here are several of those images. They show the exact time and placement of the impacts. This is how we know when they took place.

(https://nssdc.gsfc.nasa.gov/imgcat/hires/gal_p44542.gif)
Yes, that is how you believe they took place.

There is certainly a difference in knowing and believing.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 12:55:26 PM
JSS you are mistaken in the belief that lighter than aircraft Galileo carried a telescope. Not listed in onboard optical instruments.

I'm not sure what 'lighter than aircraft' means so I can't respond to that.

It absolutely did contain a telescope.

https://en.wikipedia.org/wiki/Galileo_(spacecraft)#Solid_State_Imager_(SSI) (https://en.wikipedia.org/wiki/Galileo_(spacecraft)#Solid_State_Imager_(SSI))

Here is another description.

The optical system used was a modified flight spare of the narrow-angle telescope flown on Voyager and was similar in its basic design to the telescopes flown on Mariner 10. The telescope was a 1500 nm focal length (f/8.5), all-spherical, catadioptric telescope, 90 cm in length and 25 cm in diameter. The field of view of the telescope was 0.46 degrees with an angular resolution of 10.16 microradians/pixel.

 - https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1989-084B-10
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 12:59:22 PM
Ok, we can agree that it was built. That's good.

What evidence would you need to believe it was at Jupiter and saw the comet impacts?
Here is where I can state there is none you can provide.

None that I can provide, or none that can exist? You are stating that no matter what, you will never believe it?
Again, what constitutes objective in this case is more a discussion related to Philosophy.

We more than likely disagree on what that is which is okay.

We can disagree about your personal beliefs, sure. We can discuss that elsewhere.

Back to the topic on hand, Galileo sent back pictures of the impacts. Here are several of those images. They show the exact time and placement of the impacts. This is how we know when they took place.

(https://nssdc.gsfc.nasa.gov/imgcat/hires/gal_p44542.gif)
Yes, that is how you believe they took place.

There is certainly a difference in knowing and believing.

If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 01:29:35 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I can see them.

That means the images exist.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 01:43:32 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

A kangaroo shooting a gun is not evidence of the Galileo images being faked. Simply claiming a picture is fake is not evidence.

Here is evidence.

The Galileo images were seen and reported on before Earth based telescopes saw the impacts. Pretty impressive fakes, done before the event could even be seen from Earth.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 01:56:54 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

A kangaroo shooting a gun is not evidence of the Galileo images being faked. Simply claiming a picture is fake is not evidence.

Here is evidence.

The Galileo images were seen and reported on before Earth based telescopes saw the impacts. Pretty impressive fakes, done before the event could even be seen from Earth.
Earth based telescopes did not take pictures and see the impacts.

Again, you are demonstrating you are not reading AND comprehending my posts.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 02:13:51 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

A kangaroo shooting a gun is not evidence of the Galileo images being faked. Simply claiming a picture is fake is not evidence.

Here is evidence.

The Galileo images were seen and reported on before Earth based telescopes saw the impacts. Pretty impressive fakes, done before the event could even be seen from Earth.
Earth based telescopes did not take pictures and see the impacts.

Again, you are demonstrating you are not reading AND comprehending my posts.

I'm comprehending your posts just fine.

Earth based telescopes took pictures of the impact sites 10 minutes after the space based telescope Galileo saw the actual impacts happen.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 02:23:08 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

A kangaroo shooting a gun is not evidence of the Galileo images being faked. Simply claiming a picture is fake is not evidence.

Here is evidence.

The Galileo images were seen and reported on before Earth based telescopes saw the impacts. Pretty impressive fakes, done before the event could even be seen from Earth.
Earth based telescopes did not take pictures and see the impacts.

Again, you are demonstrating you are not reading AND comprehending my posts.

I'm comprehending your posts just fine.

Earth based telescopes took pictures of the impact sites 10 minutes after the space based telescope Galileo saw the actual impacts happen.
No, you are not.

It is quite evident you are not cognizant and aware of what you are writing, let alone what I write.

I did not make the claim the images are fake.

You wrote that Earth bound telescopes were able to see the impacts.

The fact of the matter is this.

They did not.

If you are going to continue to post blatantly false information, we might as well stop.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 02:30:20 PM
If you have evidence that those images are fake, please state it. If you want to debate philosophy we can do that elsewhere.
I do not dispute the fact you have posted real images.

I dispute the images present an accurate depiction of reality.

My evidence the images depict something other than reality is this:
(https://ethicsalarms.files.wordpress.com/2017/11/kangaroo-with-gun.jpg?w=640)

A kangaroo shooting a gun is not evidence of the Galileo images being faked. Simply claiming a picture is fake is not evidence.

Here is evidence.

The Galileo images were seen and reported on before Earth based telescopes saw the impacts. Pretty impressive fakes, done before the event could even be seen from Earth.
Earth based telescopes did not take pictures and see the impacts.

Again, you are demonstrating you are not reading AND comprehending my posts.

I'm comprehending your posts just fine.

Earth based telescopes took pictures of the impact sites 10 minutes after the space based telescope Galileo saw the actual impacts happen.
No, you are not.

It is quite evident you are not cognizant and aware of what you are writing, let alone what I write.

I did not make the claim the images are fake.

You wrote that Earth bound telescopes were able to see the impacts.

The fact of the matter is this.

They did not.

If you are going to continue to post blatantly false information, we might as well stop.

What exactly did you mean by "I dispute the images present an accurate depiction of reality" then? That sounds like a long-winded way of saying they are fake.

Earth telescopes could see the impact sites 10 minutes after they occurred. A space based telescope saw them as they happened.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 02:41:07 PM
What exactly did you mean by "I dispute the images present an accurate depiction of reality" then? That sounds like a long-winded way of saying they are fake.
It is not a long winded way of saying anything else other than exactly what I wrote.

Which evidently you do not understand.

You do realize I posted an image of a kangaroo with a long rifle, correct?

Did I post a real image?

Can you see it?

Earth telescopes could see the impact sites 10 minutes after they occurred. A space based telescope saw them as they happened.
So, you admit the Earth based telescopes did not see the impacts.

Thank you for finally writing some factual information.
Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 20, 2020, 02:51:53 PM
OK, so telescopes on Earth didn't see the collision itself, just the result of the collision shortly after it happened.

Indeed. But, what does that change exactly? It still shows the prediction was correct.
Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 02:54:10 PM
OK, so telescopes on Earth didn't see the collision itself, just the result of the collision shortly after it happened.

Indeed. But, what does that change exactly? It still shows the prediction was correct.
It shows images can possibly be generated to support a larger narrative.
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 02:58:54 PM
What exactly did you mean by "I dispute the images present an accurate depiction of reality" then? That sounds like a long-winded way of saying they are fake.
It is not a long winded way of saying anything else other than exactly what I wrote.

Which evidently you do not understand.

You do realize I posted an image of a kangaroo with a long riffle, correct?

Did I post a real image?

Can you see it?

Earth telescopes could see the impact sites 10 minutes after they occurred. A space based telescope saw them as they happened.
So, you admit the Earth based telescopes did not see the impacts.

Thank you for finally writing some factual information.

I understand you are saying the images do not "depict reality" and since NASA says they do, what are you implying? Why can't you come out and just say they are lying?

You are using "real image" in a very strange way. Every single image is a "real image" by your definition, so saying an image is a "real image" is redundant, pointless and doesn't add to the discussion. Nobody else would use "real image" in the way you do.

You also seem to be hung up on the word "impact" so let me try and explain without using that word.

1. The Galileo spacecraft took pictures of multiple comets as they each hit Jupiter, each causing a massive explosion. This told us exactly when they first hit.

2. Ten minutes later after the comets hit, as Jupiter rotated, Earth based telescopes saw the these explosions.

Just like you can see a mushroom cloud after a large explosion, Earth based telescopes could see the expanding explosions ten minutes after they started, and for much longer. They were massive events and were observed for days.

No, Earth based telescopes did not see the comets when they first hit, but saw the results 10 minutes later. Galileo saw the comets first hit the planet.

Title: Re: Comet Shoemaker–Levy 9
Post by: totallackey on May 20, 2020, 03:14:36 PM
What exactly did you mean by "I dispute the images present an accurate depiction of reality" then? That sounds like a long-winded way of saying they are fake.
It is not a long winded way of saying anything else other than exactly what I wrote.

Which evidently you do not understand.

You do realize I posted an image of a kangaroo with a long riffle, correct?

Did I post a real image?

Can you see it?

Earth telescopes could see the impact sites 10 minutes after they occurred. A space based telescope saw them as they happened.
So, you admit the Earth based telescopes did not see the impacts.

Thank you for finally writing some factual information.

I understand you are saying the images do not "depict reality" and since NASA says they do, what are you implying? Why can't you come out and just say they are lying?
Well, you didn't write that earlier.

You kept writing that I claimed the images were fake.

I believe that is highly disingenuous on your part.

I believe it is deliberate.

And I am more concerned about that issue rather than what you believe my opinion on NASA is.

I am not even going to get into the motives of NASA with you engaging in this obvious misrepresentation of my points.
You are using "real image" in a very strange way. Every single image is a "real image" by your definition, so saying an image is a "real image" is redundant, pointless and doesn't add to the discussion. Nobody else would use "real image" in the way you do.
Like this^

This type of classification from you.

A personal attack.

Something someone does when they have no response.

You write that my application of the words,"real image," is deficient, yet you know the image is visible and available for viewing.

I got a clue for you.

That makes the image, "real," in every sense of the word.

In fact, the only sense of the word.
You also seem to be hung up on the word "impact" so let me try and explain without using that word.

1. The Galileo spacecraft took pictures of multiple comets as they each hit Jupiter, each causing a massive explosion. This told us exactly when they first hit.

2. Ten minutes later after the comets hit, as Jupiter rotated, Earth based telescopes saw the these explosions.

Just like you can see a mushroom cloud after a large explosion, Earth based telescopes could see the expanding explosions ten minutes after they started, and for much longer. They were massive events and were observed for days.

No, Earth based telescopes did not see the comets when they first hit, but saw the results 10 minutes later. Galileo saw the comets first hit the planet.
No, I am not hung up on the word "impacts."

Seeing impacts and seeing sites are two different things.

If you cannot come to grips with using language correctly and honestly, then we do need to stop.

Nothing you have posted here is honest and I am not going to engage it any longer.

Buh bye...
Title: Re: Comet Shoemaker–Levy 9
Post by: JSS on May 20, 2020, 03:52:37 PM
Nothing you have posted here is honest and I am not going to engage it any longer.

Buh bye...

If you want to have the last word and abandon the discussion, feel free. But I have to respond to this...

You are using "real image" in a very strange way. Every single image is a "real image" by your definition, so saying an image is a "real image" is redundant, pointless and doesn't add to the discussion. Nobody else would use "real image" in the way you do.
Like this^

This type of classification from you.

A personal attack.

Something someone does when they have no response.

You write that my application of the words,"real image," is deficient, yet you know the image is visible and available for viewing.

I got a clue for you.

That makes the image, "real," in every sense of the word.

In fact, the only sense of the word.

Pointing out you are using words and phrases in confusing ways is not a personal attack, it's trying to understand what you are saying, and perhaps explain to you why what you are saying is hard for others to understand.

Let me try and explain why I think your use of "real image," is deficient.

If you hold up a picture and ask someone "Is this a real picture?' nobody is going to seriously say, "Yes, you are holding a physical picture it is a real object that exists". How would you even ever say no to that question, "You are holding a picture that is not a picture?"

You are using that phrase in a very literal manner that simply isn't used in actual debate or even serious conversation. I am trying to help you understand this.

This is what caused so much back and forth. When you say "It's a real image" you mean something very different than how that is used by everyone else.

The quote below is an example. It's taking things extremely literally, and when this usage is used in the middle of a conversation it can get very confusing just what is being argued about.

I do not dispute the fact you have posted real images.

I can see them.

That means the images exist.

I dispute the images present an accurate depiction of reality.


Title: Re: Comet Shoemaker–Levy 9
Post by: GreatATuin on May 20, 2020, 09:57:03 PM
OK, so telescopes on Earth didn't see the collision itself, just the result of the collision shortly after it happened.

Indeed. But, what does that change exactly? It still shows the prediction was correct.
It shows images can possibly be generated to support a larger narrative.

What larger narrative? Astronomers predicted that a comet would crash into Jupiter and that the effects might be visible from Earth. They predicted months in advance that something potentially spectacular would happen on Jupiter and it turned out it was even more spectacular than expected (https://www.nature.com/articles/375358a0.pdf?origin=ppub). Professional and amateur astronomers all over the world were able to see it for themselves in their telescopes.

If the event they predicted was not a comet impact, then what was it? And how did they know? If Jupiter is not a gas giant orbiting the Sun at a distance of approximately 780 million km, what is it and how do we know what happens on its surface?