[jomples]

Recently I saw Tom talking about how Round Earthers haven't disproved a single wiki article yet. So, I thought I'd give it a try. The focus of this thread is https://wiki.tfes.org/Lunar_Eclipse_due_to_Electromagnetic_Acceleration. Please stay focused on this. Thanks.

[jomples]

Alright, let's get into this.

I chose this article specifically because it concerns one specific mechanism or theory, it's just a bit narrower in scope than some other things.

My first point of contention is with the curved shadow section. It contains two gifs, one showing a model of the moon with a flat object casting a shadow

 and the other showing an image of what the moon actually looks like.


There seems to be a notable difference here. Yes, the shadow on the model is curved, but it curves with the surface of the moon. From the point of an observer looking up at the moon while a straight shadow is cast upon it, the shadow is notably different from the one actually observed. This is what the gifs illustrate.  I just find it odd that evidence counter to the model being proposed is actually in the article. It says "Compare the warping of the shadow in the above example to the shadow on the real Moon during a Lunar Eclipse:", and there's a noticeable difference in the nature of the shadow.

The second main part of this also has some issues- it explains how the shadow on the moon seems to rotate during an eclipse, by about 120 degrees, and then shows this image:

without really saying why. It seems to be completely removed from any modelling, and could benefit from clarification. Again, the article explains a phenomenon without giving any explanation as to why it happens in the flat earth model. I could guess the author's intention- by creating a model which shows the moon moving out of the ecliptic, it shows a possible reason for why the shadow changes angles. I have another reason.

One of the sources shown is a timelapse of the total lunar eclipse which occured October 27, 2004:

I chose this one because it has a lot of data points and we know precisely where it was taken. I entered it into a round earth eclipse calculator https://in-the-sky.org/news.php?id=20041028_09_100.

In the image, the moon starts partially shaded, having come up from behind a hill. The shadow moves up from the lower left of the moon (in the timelapse, until it covers the entire body. The moon becomes red, and there is a light section which moves from the right of the moon, across the top, and over to the left. Finally, the shadow uncovers the moon, moving off to the left. Using the calculator, you can see that the path the shadow takes is also easily explained by the Round Earth Model.

This doesn't debunk the wiki article, though, so I'll now examine the same mechanism in a flat earth model. This is what sinks this explanation.

I took this image from the wiki

 and exported it into a free graphing program.
I then extrapolated the circles to their full size. I haven't figured out how to embed images I upload, but I've attached them here.

There's a problem here. Rather obviously, the edge of daylight curve dwarfs the moon's path. For the model to look like this, the arc of the moon would have to be significantly off center from the earth, or the daylight curve would. So this diagram can't work

I'll be responding to posts as usual. Let's focus on this one article, though.

[Tom Bishop]

There seems to be a notable difference here. Yes, the shadow on the model is curved, but it curves with the surface of the moon. From the point of an observer looking up at the moon while a straight shadow is cast upon it, the shadow is notably different from the one actually observed.

The shadows appears to warp on the sphere and on the Moon in a very similar manner to my eye.

The fact that the shadow warps on the Moon's surface appears to suggest that its curved shape is affected by a shadow being projected upon the Moon.



There appears to be different amounts of curvature here, as if the one on the left was a smaller "Earth" and the one on the right was a larger "Earth". Since the curvature of the Moon is causing warping, it casts some doubt that it is actually the Round Earth causing this.

I chose this one because it has a lot of data points and we know precisely where it was taken. I entered it into a round earth eclipse calculator https://in-the-sky.org/news.php?id=20041028_09_100.

I have not seen any evidence that there exists a clean "round earth" calculator or model that is based on physical properties rather than Ancient-Greek-like model based on epicycles, perturbations, etc., to fit  to observations. See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

I took this image from the wiki

 and exported it into a free graphing program.
I then extrapolated the circles to their full size. I haven't figured out how to embed images I upload, but I've attached them here.

For the last point, the desire for accuracy is noted, but it doesn't really matter how the larger edge of daylight curve is exactly illustrated. Even a flat line will cause the same 120 degree angle rotation between where the points intersect:

[SteelyBob]

I have not seen any evidence that there exists a clean "round earth" calculator or model that is based on physical properties rather than Ancient-Greek-like model based on epicycles, perturbations, etc., to fit  to observations. See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

Maybe you aren’t looking hard enough? Or maybe you just reject anything that doesn’t conform to your preconceived idea? This has been discussed on numerous occasions. Here’s one, with lots of links to ephemeris models and what goes into them.

https://forum.tfes.org/index.php?topic=18054.msg237363#msg237363

[Tumeni]

Addressing the rotation of the shadow in the 28 Sept 2015 example, for instance, timeanddate.com says;

"The curvature of the shadow's path and the apparent rotation of the Moon's disk is due to the Earth's rotation."

https://www.timeanddate.com/eclipse/lunar/2015-september-28

There are multiple graphics showing how it works, the first of these on each page showing rotation of the Moon according to observer viewpoint, and how umbral and penumbral shadows move across its face. 

Same applies to March 2007.

I have not seen any evidence that there exists a clean "round earth" calculator or model that is based on physical properties

timeanddate certainly appears to be taking these into account, and have animations already uploaded for the next 10 years' worth of lunar eclipses. How would they do this without calculating or modelling? 

The Wiki shows only three examples, but timeanddate appears to have a page dedicated to each and every one.

There's one coming up in May this year. I suggest an informative line of study would be to read up on it in advance, view all the animations in timeanddate's page for this eclipse, then see if observer experience matches it on the day.

[Tom Bishop]

I have not seen any evidence that there exists a clean "round earth" calculator or model that is based on physical properties rather than Ancient-Greek-like model based on epicycles, perturbations, etc., to fit  to observations. See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

Maybe you aren’t looking hard enough? Or maybe you just reject anything that doesn’t conform to your preconceived idea? This has been discussed on numerous occasions. Here’s one, with lots of links to ephemeris models and what goes into them.

https://forum.tfes.org/index.php?topic=18054.msg237363#msg237363

Actually the models discussed in that link is the JPL DE, which is discussed in the Wiki. It is pointed out that it is based on perturbations - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns#Jet_Propulsion_Laboratory_Development_Ephemeris

timeanddate certainly appears to be taking these into account, and have animations already uploaded for the next 10 years' worth of lunar eclipses. How would they do this without calculating or modelling?

I would suggest looking into how Eclipses have been predicted throughout history - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns#The_Eclipses

[stack]

I have not seen any evidence that there exists a clean "round earth" calculator or model that is based on physical properties rather than Ancient-Greek-like model based on epicycles, perturbations, etc., to fit  to observations. See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

Maybe you aren’t looking hard enough? Or maybe you just reject anything that doesn’t conform to your preconceived idea? This has been discussed on numerous occasions. Here’s one, with lots of links to ephemeris models and what goes into them.

https://forum.tfes.org/index.php?topic=18054.msg237363#msg237363

Actually the models discussed in that link is the JPL DE, which is discussed in the Wiki. It is pointed out that it is based on perturbations - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns#Jet_Propulsion_Laboratory_Development_Ephemeris

In the wiki it says:

Jet Propulsion Laboratory Development Ephemeris
The Jet Propulsion Laboratory Development Ephemeris (JPL DE or DE) is a 'mathematical model of the Solar System' produced by the Jet Propulsion laboratory in Pasadena, California. It has been claimed that JPL DE is a simulation of the Solar System which is based on gravity. However, it is seen that it uses perturbation-based methods.

https://en.wikipedia.org/wiki/Jet_Propulsion_Laboratory_Development_Ephemeris

  “Each ephemeris was produced by numerical integration of the equations of motion, starting from a set of initial conditions. Due to the precision of modern observational data, the analytical method of general perturbations could no longer be applied to a high enough accuracy to adequately reproduce the observations. The method of special perturbations was applied, using numerical integration ”

Regarding "Special perturbations", from Wikipedia:

Special perturbations
In methods of special perturbations, numerical datasets, representing values for the positions, velocities and accelerative forces on the bodies of interest, are made the basis of numerical integration of the differential equations of motion.[6] In effect, the positions and velocities are perturbed directly, and no attempt is made to calculate the curves of the orbits or the orbital elements.[2]

Special perturbations can be applied to any problem in celestial mechanics, as it is not limited to cases where the perturbing forces are small.[4] Once applied only to comets and minor planets, special perturbation methods are now the basis of the most accurate machine-generated planetary ephemerides of the great astronomical almanacs.[2][7] Special perturbations are also used for modeling an orbit with computers.

Cowell's formulation

Cowell's method. Forces from all perturbing bodies (black and gray) are summed to form the total force on body i (red), and this is numerically integrated starting from the initial position (the epoch of osculation).
Cowell's formulation (so named for Philip H. Cowell, who, with A.C.D. Cromellin, used a similar method to predict the return of Halley's comet) is perhaps the simplest of the special perturbation methods.[8] In a system of n mutually interacting bodies, this method mathematically solves for the Newtonian forces on body by summing the individual interactions from the other bodies:




Cowell's method. Forces from all perturbing bodies (black and gray) are summed to form the total force on body i (red), and this is numerically integrated starting from the initial position (the epoch of osculation).

Special perturbations doesn't appear to be ancient, Babylonian. Looks like it's steeped in "gravity". So I'm not sure why you're saying it isn't. The proof is right there in the equation - That big olde G.

[SteelyBob]

Actually the models discussed in that link is the JPL DE, which is discussed in the Wiki. It is pointed out that it is based on perturbations - https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns#Jet_Propulsion_Laboratory_Development_Ephemeris

All you're doing here is presenting yet more evidence of cherry picking, dishonesty and lack of comprehension, including in the wiki. The wiki talks about perturbations and then jumps into Fourier analysis - all true. But that's not the whole story, as you would know if you actually read the detailed description of, for example, DE405 - https://web.archive.org/web/20120220062549/http://iau-comm4.jpl.nasa.gov/de405iom/de405iom.pdf

The point you are either deliberately or incompetently missing out is that there are other ways of using perturbation theory, and that's very much involved in the ephemeris paper I linked to. For example, take the section on modelling the influence of asteroids on the earth, moon and sun:



The numerous components (and there are many - amusingly most with starting positions and velocities obtained by space-based activity, and other things like lunar ranging that you don't think are possible) aren't modelled using Fourier series - they have their influence on the earth, moon etc, and in the case of the larger ones, themselves modelled via a step-wise numerical integration process. You've said before that you think numerical integration is indicative of some kind of fraud, but that's an absurd argument, given its widespread usage in all sorts of numerical challenges, such as fluid dynamics.

And that paper is old news - here's a much more up to date one: https://iopscience.iop.org/article/10.3847/1538-3881/abd414/pdf. Not a Fourier series in sight...

You can read all about it...if you want to. It is abundantly obvious to anybody reading this stuff that there is far, far more going on than a simple cyclical, periodic estimation process as you assert. It's fascinating stuff - they even model the geology of each planet and the moon. The use of the various spacecraft improve starting point data is also really interesting.

[Tom Bishop]

Special perturbations doesn't appear to be ancient, Babylonian. Looks like it's steeped in "gravity". So I'm not sure why you're saying it isn't. The proof is right there in the equation - That big olde G.

It's like you forgot that we have had this discussion numerous times in the past and are choosing to conveniently forget or completely ignore the arguments presented to you. The Wiki contains this, and I've posted this before to you in previous discussions. It is explained that the modern version of epicycles/perturbations does use gravitational theory.

In a 2017 paper Dr. Gopi Krishna Vijaya says that Newtonian astronomers use perturbations/epicycles with a gravitational disguise:

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:

         

         

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. ”

...

“ The Dead End

In the late 19th century, one of the French mathematicians – Henri Poincaré – had already discovered that many of the terms being used in the “perturbation” series by mathematicians like Laplace and Lagrange were becoming infinite for long periods of time, making the system unstable. In simple words, the solutions ‘blow up’ fairly quickly. He also showed that the general problem of 3 mutually gravitating bodies was insoluble through any mathematical analysis! Many physicists and mathematicians built up modern “Chaos theory” based on these ideas, to show simply that one cannot calculate the movements of the planets accurately. Thus began the field of non-linear
dynamics.

In the middle of the 20th century, with computers entering the field, the mathematicians pretty much gave up on calculating the orbits by themselves and programmed the computer to do it, even though it was mathematically shown that these orbits were incalculable. They had to be satisfied with approximations or numerical methods (or “brute force” methods.) The result of it all was that after 300 years, Newtonian/Einsteinian thought lands in the same spot that Kepler ended: the orbits point to a living or chaotic system. Only now, there is the additional baggage of all the wrong concepts introduced with regard to “inverse-square law”, “gravitational attraction”, “gravitational mass” and “curved space-time” along with uncountable number of minor assumptions. In this process, an enormous amount of human effort was put to derive thousands of terms in equations over centuries. The entire enterprise has been a wild goose chase ”

Professor Charles Lane Poor related the same in a 1922 book called Gravitation Vs. Relativity under his  Motions of the Planets chapter:

“ 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. ”

[Tom Bishop]

The numerous components (and there are many - amusingly most with starting positions and velocities obtained by space-based activity, and other things like lunar ranging that you don't think are possible) aren't modelled using Fourier series - they have their influence on the earth, moon etc, and in the case of the larger ones, themselves modelled via a step-wise numerical integration process. You've said before that you think numerical integration is indicative of some kind of fraud, but that's an absurd argument, given its widespread usage in all sorts of numerical challenges, such as fluid dynamics.

It looks like your argument amounts to "that's an absurd argument", which is a pathetic way to argue, to say the least.

"Computing the perturbations" or "Modeling the Asteroid Perturbations" can mean fitting a model to observations with epicycles, as described in the sources above.

You childishly appeal to perturbations used in Fluid Mechanics without any attempt at demonstration of valid processes, as if we should blindly assume things to be true. You provide no argument other than incredulity and wispy undemonstrated appeals of faith.

[SteelyBob]

The numerous components (and there are many - amusingly most with starting positions and velocities obtained by space-based activity, and other things like lunar ranging that you don't think are possible) aren't modelled using Fourier series - they have their influence on the earth, moon etc, and in the case of the larger ones, themselves modelled via a step-wise numerical integration process. You've said before that you think numerical integration is indicative of some kind of fraud, but that's an absurd argument, given its widespread usage in all sorts of numerical challenges, such as fluid dynamics.

It looks like your argument amount to "that's an absurd argument", which is a pathetic way to argue, to say the least.

If it looks that way to you, it's because you don't understand the subject being discussed. That's fine, it's ok not to understand stuff.

"Computing the perturbations" or "Modeling the Asteroid Perturbations" can mean fitting a model to observations with epicycles, as described in the sources above.

But that's not what's happening in the papers I linked to. The methods used involve calculations based on the effect of orbiting bodies' gravitational influence on each other. The perturbation theory involved helps to simplify the calculations - but it is not basing the calculations on the observed periodicity of the orbits, which is what you seem to be suggesting.

You childishly appeal to perturbations used in Fluid Mechanics without any attempt at demonstration of valid processes, as if we should just assume things to be true. You provide no argument other than your incredulity and wispy undemonstrated appeals of faith.

I didn't say perturbations in that context; again, you obviously don't understand what is being discussed here. I said numerical integration - that's not quite the same thing, although they are often found together.

To be clear, I'm not really trying to change your mind here - it clearly isn't for changing. I'm just making sure that others reading this understand what's going on if they aren't sure. To be honest, you're doing an excellent job of proving the OP's point, so it's all good.

[Tom Bishop]

But that's not what's happening in the papers I linked to. The methods used involve calculations based on the effect of orbiting bodies' gravitational influence on each other. The perturbation theory involved helps to simplify the calculations - but it is not basing the calculations on the observed periodicity of the orbits, which is what you seem to be suggesting.

The sources I gave are telling us differently from you are, as well as others references the Wiki. They have relevant credentials while you are an anonymous user on an internet forum who refuses to give us his identity or credentials. Please do not bother with your personal view on "what's happening" and refrain from presenting your non-validated internet comments and interpretations as your source. You are not qualified. Those types of opinions are entirely worthless when we have a source on the matter telling us how it works.

[stack]

Special perturbations doesn't appear to be ancient, Babylonian. Looks like it's steeped in "gravity". So I'm not sure why you're saying it isn't. The proof is right there in the equation - That big olde G.

It's like you forgot that we have had this discussion numerous times in the past and are choosing to conveniently forget or completely ignore the arguments presented to you.

I guess, according to you, JPL should stop using this:

[Tom Bishop]

Special perturbations doesn't appear to be ancient, Babylonian. Looks like it's steeped in "gravity". So I'm not sure why you're saying it isn't. The proof is right there in the equation - That big olde G.

It's like you forgot that we have had this discussion numerous times in the past and are choosing to conveniently forget or completely ignore the arguments presented to you.

I guess, according to you, JPL should stop using this:

Perturbations use Newton's laws, see the source in my previous comment.

[stack]

Special perturbations doesn't appear to be ancient, Babylonian. Looks like it's steeped in "gravity". So I'm not sure why you're saying it isn't. The proof is right there in the equation - That big olde G.

It's like you forgot that we have had this discussion numerous times in the past and are choosing to conveniently forget or completely ignore the arguments presented to you.

I guess, according to you, JPL should stop using this:

Perturbations use Newton's laws, see the source in my previous comment.

Your contention. however, at the top of the wiki page is:

This page will demonstrate that prediction in astronomy is based solely on patterns in the sky. Celestial events come in patterns and trends. By analyzing the patterns of past behaviors from historic tables it is possible to create an equation that will predict a future event. This is how prediction in astronomy has been performed for thousands of years, and how it is still performed today.

Apparently, that's not entirely true. JPL's equation for special pertubations uses Gravity. Using Gravity has not been done for "thousands of years."

[Tom Bishop]

Your contention. however, at the top of the wiki page is:

This page will demonstrate that prediction in astronomy is based solely on patterns in the sky. Celestial events come in patterns and trends. By analyzing the patterns of past behaviors from historic tables it is possible to create an equation that will predict a future event. This is how prediction in astronomy has been performed for thousands of years, and how it is still performed today.

Apparently, that's not entirely true. JPL's equation for special pertubations uses Gravity. Using Gravity has not been done for "thousands of years."

Your reading comprehension needs work.

It clearly says that creating equations that make patterns has been done for thousands of years. It does not say that the same equations have been used for thousands of years.

[stack]

Your contention. however, at the top of the wiki page is:

This page will demonstrate that prediction in astronomy is based solely on patterns in the sky. Celestial events come in patterns and trends. By analyzing the patterns of past behaviors from historic tables it is possible to create an equation that will predict a future event. This is how prediction in astronomy has been performed for thousands of years, and how it is still performed today.

Apparently, that's not entirely true. JPL's equation for special pertubations uses Gravity. Using Gravity has not been done for "thousands of years."

Your reading comprehension needs work.

It clearly says that creating equations that make patterns has been done for thousands of years. It does not say that the same equations have been used for thousands of years.

Got it. So you agree that JPL uses Gravity as a part of their ephemeride calculations and that it's not just Babylonian observations. Cool. That's not entirely clear from the wiki.

[SteelyBob]

The sources I gave are telling us differently from you are, as well as others references the Wiki. They have relevant credentials while you are an anonymous user on an internet forum who refuses to give us his identity or credentials. Please do not bother with your personal view on "what's happening" and refrain from presenting your non-validated internet comments and interpretations as your source. You are not qualified. Those types of opinions are entirely worthless when we have a source on the matter telling us how it works.

Are you suggesting that the DE440/441 paper is wrong? Or perhaps dishonest? Is it part of the space travel conspiracy?

I must admit I'm now unclear as to what your point is. You, and your sources, seem to be saying that the ephemerides are just ' fitting curves to the data or minor linear extrapolations ', but that is quite obviously not what is being described in the ephemerides paper. The models take accurate position and velocity data, estimations of mass and moments of inertia etc for each body, and then calculate future position data using numerical integration, capturing the gravitational interaction between hundreds of bodies.

This is where you've lost me...as Stack says, you now seem to be acknowledging that the modern ephemerides do use a gravity-derived model. They are modelling, years ahead of now, the future position of hundreds of bodies in our solar system, and the influence between them on each other...you seem to be agreeing with that now?

[Tumeni]

.... as well as others references the Wiki. They have relevant credentials while you are an anonymous user on an internet forum who refuses to give us his identity or credentials.

Well, the photographic examples in the Wiki appear to all be uncredited, and are apparently taken from anonymous places on the internet...

[robinofloxley]

Alright, let's get into this.

I chose this article specifically because it concerns one specific mechanism or theory, it's just a bit narrower in scope than some other things.

My first point of contention is with the curved shadow section. It contains two gifs, one showing a model of the moon with a flat object casting a shadow

Interesting that you picked this one to start with. I took a close look at it myself a while back and to better understand it, modelled it. Here's my attempt to reproduce it. I think I got pretty close...



However in doing so, I discovered that to get this result, I had to position the virtual observer approximately 90,000 miles off to the side of the earth. Basically this image is not to be trusted at all. If you put the observer on the earth where they should be, it looks like this...