[Tom Bishop]

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/

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).

[JSS]

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/

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.

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.

[Tom Bishop]

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)."

[JSS]

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.

[Tom Bishop]

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)."

[BRrollin]

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.

[stack]

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.

[JSS]

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.

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.

[Tom Bishop]

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

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

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.

[JSS]

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.

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”).

[Tom Bishop]

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:

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?

[JSS]

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.

[stack]

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:

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.

[BRrollin]

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

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

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.

[Tom Bishop]

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.

[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:



Note: R3 is Jupiter’s equatorial radius

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



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

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.

[BRrollin]

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.

[somerled]

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?

[totallackey]

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....

[JSS]

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