Why does astronomical software work?

In order to accept many versions of Flat Earth Theory, I understand that you're required to dispense with a lot of the Newtonian physical laws that govern the Round Earth conventional model of the cosmos. Most noticeably, the law of gravity. If gravity exists the way science understands it, planets naturally coalesce into some approximation of a sphere. This does not logically reconcile with having a flat earth.

I just downloaded Stellarium today and a thought occurred to me. If the Flat Earth Model is correct, why then am I able to accurately predict the positions of planets and stars using Stellarium, which itself is coded using Kepler's laws, which themselves necessarily rely on the concept of gravity and by extension spherical planets?

Before you go and say that the programmers are in on the conspiracy, there are plenty of open source alternatives. Anyone who understands code can look under the hood and see that these programs run on the Round Earth mathematical models and generate accurate, verifiable predictions of how celestial bodies behave.

Forget about NASA, forget about GPS, satellites, any alleged such fakery. Why does the software I can use right at home, even code myself if I wanted to, work? Why can I use it to predict where Venus will be for example, grab a telescope, and then verify later, every single time?

All flat earthers got from all you wrote was

In order to accept many versions of Flat Earth Theory, I understand that you're required to dispense with a lot of the Newtonian physical laws that govern the Round Earth conventional model of the cosmos. Most noticeably, the law of gravity. If gravity exists the way science understands it, bla bla bla bla bla bla............

Stellarium is open source.

As the most renowned RET poster here I can tell you no one has ever successfully refuted this argument against me.

I just downloaded Stellarium today and a thought occurred to me. If the Flat Earth Model is correct, why then am I able to accurately predict the positions of planets and stars using Stellarium, which itself is coded using Kepler's laws, which themselves necessarily rely on the concept of gravity and by extension spherical planets?

REer here, but in fairness Kepler's laws weren't developed in isolation. With this particular case it's more a matter of mathematically describing naturally predictable observations than it is anything intrinsic to Kepler. The hard part's why it happens, not what happens. RET says gravity, but there is nothing that would stop you, if you had the skills, of programming in a disc and programming in movements as observed. Once you've got that all you need to do is come up with rules, and you'd have a fully functioning FE equivalent.
Don't get me wrong, there are instances of RET making predictions from gravity, and coming up with a model of why the planets move the way they do if viewed from a FE is far from a trivial problem, but in and of itself providing a mathematical description of a predictable phenomenon is not all that persuasive.

but there is nothing that would stop you, if you had the skills, of programming in a disc and programming in movements as observed. Once you've got that all you need to do is come up with rules, and you'd have a fully functioning FE equivalent.

Yes there is, as the apparent don't match a disc.
If you wish to disagree, tell us how you have 2 points always 180 degrees apart on this disc of yours, while being able to completely circle the points.

in and of itself providing a mathematical description of a predictable phenomenon is not all that persuasive.

Good thing we have the explanation rather than just an ability to predict it.

Quote from: Evan on March 18, 2018, 09:57:20 PM

I just downloaded Stellarium today and a thought occurred to me. If the Flat Earth Model is correct, why then am I able to accurately predict the positions of planets and stars using Stellarium, which itself is coded using Kepler's laws, which themselves necessarily rely on the concept of gravity and by extension spherical planets?

REer here, but in fairness Kepler's laws weren't developed in isolation. With this particular case it's more a matter of mathematically describing naturally predictable observations than it is anything intrinsic to Kepler. The hard part's why it happens, not what happens. RET says gravity, but there is nothing that would stop you, if you had the skills, of programming in a disc and programming in movements as observed. Once you've got that all you need to do is come up with rules, and you'd have a fully functioning FE equivalent.
Don't get me wrong, there are instances of RET making predictions from gravity, and coming up with a model of why the planets move the way they do if viewed from a FE is far from a trivial problem, but in and of itself providing a mathematical description of a predictable phenomenon is not all that persuasive.

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

The predictability comes from observing it. You don't need any equations whatsoever to predict when/where the planets will be when you have years worth of observation and tracking. The length of a year (for any planet), the length of a day is all basically fixed, irrespective of what shape the world is.
Mercury was still predictable, that was why they knew the formula was off; they knew it wasn't going to magically match up the next time they looked at it because they had the figures. It was predictable, just not understood at that point in time. Why, rather than what.

Quote from: Lonegranger on March 19, 2018, 02:09:49 PM

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

The predictability comes from observing it. You don't need any equations whatsoever to predict when/where the planets will be when you have years worth of observation and tracking. The length of a year (for any planet), the length of a day is all basically fixed, irrespective of what shape the world is.
Mercury was still predictable, that was why they knew the formula was off; they knew it wasn't going to magically match up the next time they looked at it because they had the figures. It was predictable, just not understood at that point in time. Why, rather than what.

You cannot use predictability and patterns to match our observations with a flat earth model.  The number of inconsistencies with reality that would occur would be astronomical.  Simply put, if they create a simulation that predicts what will be seen from a specific view point, almost all of the objects they are predicting would appear in the wrong place somewhere else.

Quote from: Lonegranger on March 19, 2018, 02:09:49 PM

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

The predictability comes from observing it. You don't need any equations whatsoever to predict when/where the planets will be when you have years worth of observation and tracking. The length of a year (for any planet), the length of a day is all basically fixed, irrespective of what shape the world is.
Mercury was still predictable, that was why they knew the formula was off; they knew it wasn't going to magically match up the next time they looked at it because they had the figures. It was predictable, just not understood at that point in time. Why, rather than what.

Astronomical models run on calculations not observations.

You cannot use predictability and patterns to match our observations with a flat earth model.  The number of inconsistencies with reality that would occur would be astronomical.  Simply put, if they create a simulation that predicts what will be seen from a specific view point, almost all of the objects they are predicting would appear in the wrong place somewhere else.

You can, easy. You just put the objects where they need to be. That might well mean there are multiple identical star systems or things teleporting across the sky or bizarre things happening with light or non-Euclidean goodness, but you can do it. The problem then is explaining why on earth any of it happens.
They could predict the movements of planets when they still believed in a geocentric universe, they just had to resort to weird things when it came to retrograde motion.

Astronomical models run on calculations not observations.

Bit of both. Calculations to describe the physical world do rely on input from said physical world.

Quote from: Lonegranger on March 19, 2018, 02:09:49 PM

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

The predictability comes from observing it. You don't need any equations whatsoever to predict when/where the planets will be when you have years worth of observation and tracking. The length of a year (for any planet), the length of a day is all basically fixed, irrespective of what shape the world is.
Mercury was still predictable, that was why they knew the formula was off; they knew it wasn't going to magically match up the next time they looked at it because they had the figures. It was predictable, just not understood at that point in time. Why, rather than what.

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

Quote from: smokified on March 19, 2018, 02:55:43 PM

You cannot use predictability and patterns to match our observations with a flat earth model.  The number of inconsistencies with reality that would occur would be astronomical.  Simply put, if they create a simulation that predicts what will be seen from a specific view point, almost all of the objects they are predicting would appear in the wrong place somewhere else.

You can, easy. You just put the objects where they need to be. That might well mean there are multiple identical star systems or things teleporting across the sky or bizarre things happening with light or non-Euclidean goodness, but you can do it. The problem then is explaining why on earth any of it happens.
They could predict the movements of planets when they still believed in a geocentric universe, they just had to resort to weird things when it came to retrograde motion.

Quote from: EvolvedMantisShrimp on March 19, 2018, 03:02:18 PM

Astronomical models run on calculations not observations.

Bit of both. Calculations to describe the physical world do rely on input from said physical world.

Will this be another discussion when you fail to accept facts that you don't like or fit with your worldview?

Actually, the original question may also want to consider the code that was written for the GPS system that has to account for the varying relativistic effects on the satellites given their pretty weird elliptical orbits. Again it only works if GR is factored into the calculations.

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

Will this be another discussion when you fail to accept facts that you don't like or fit with your worldview?

Is this going to be another discussion where you completely ignore what everyone else says because it better serves your ego?

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

But without the mathematical calculations that the physics of astronomy brings to us, how would you predict the next transit of Mercury across the Sun? Or the one after that? Accurate models need understanding.

But without the mathematical calculations that the physics of astronomy brings to us, how would you predict the next transit of Mercury across the Sun? Or the one after that? Accurate models need understanding.

Just watch it, take note of how long it takes for it to complete a revolution of the Sun, do the same for the Earth (or whatever the equivalent to a revolution is), then starting from one transit you've got a simple enough way to find all successive transits.

Quote from: EvolvedMantisShrimp on March 19, 2018, 04:18:15 PM

But without the mathematical calculations that the physics of astronomy brings to us, how would you predict the next transit of Mercury across the Sun? Or the one after that? Accurate models need understanding.

Just watch it, take note of how long it takes for it to complete a revolution of the Sun, do the same for the Earth (or whatever the equivalent to a revolution is), then starting from one transit you've got a simple enough way to find all successive transits.

Wouldn't in open source software the difference in algorithm be obvious?

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

Quote from: Lonegranger on March 19, 2018, 03:14:03 PM

Will this be another discussion when you fail to accept facts that you don't like or fit with your worldview?

Is this going to be another discussion where you completely ignore what everyone else says because it better serves your ego?

I never mentioned the sun, I was reffering about the unpredictability of one particular planet, Mercury. Why can’t you stick to the point rather than once more distorting the topic to suit yourself. Are you saying the orbit of Mercury can be predicted by observation alone?

Quote from: Jane on March 19, 2018, 04:14:35 PM

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

Quote from: Lonegranger on March 19, 2018, 03:14:03 PM

Will this be another discussion when you fail to accept facts that you don't like or fit with your worldview?

Is this going to be another discussion where you completely ignore what everyone else says because it better serves your ego?

I never mentioned the sun, I was reffering about the unpredictability of one particular planet, Mercury. Why can’t you stick to the point rather than once more distorting the topic to suit yourself. Are you saying the orbit of Mercury can be predicted by observation alone?

Looks like it would have to be derived from many years of observation.
Jupiter's years.
Jupiter's orbital time is 11.862 times longer than Earth's.

The planet Mercury is especially susceptible to Jupiter's influence because
of a small celestial coincidence: Mercury's perihelion, the point where it gets closest
to the Sun, precesses at a rate of about 1.5 degrees every 1000 years, and Jupiter's
perihelion precesses only a little slower. At one point, the two may fall into sync, ...

(from: https://en.wikipedia.org/wiki/Stability_of_the_Solar_System)

If the earth were flat and not the Globe that both Tycho Brahe assumed in his observantions and Johannes Kepler used in his calculations.
Please suggest how Kepler was able to predict (based largely on observations from Tycho Brahe) when transits of both Mercury and Venus would occur when neither had ever been observed before.

This is how it transpired:

Transits of Venus in History: 1631-1716
The First Transit Predictions and Sightings

The story begins with the great German astronomer Johannes Kepler (1571-1630), who was the first human to successfully predict transits of both Mercury and Venus. Remarkably, his calculations of planetary motions (based largely on observations from Tycho Brahe) enabled him to accurately predict a transit of Mercury on November 7, 1631, and a transit of Venus just a month later, on December 6th. Sadly, Kepler died a year before these events, so he was unable to personally confirm his predictions. (Note: all dates in this article use the current Gregorian calendar.)

Fortunately, three astronomers in Europe, most notably French scientist and priest Pierre Gassendi (1592-1665), witnessed the transit of Mercury. In doing so, they became the first humans to view a planetary transit with a clear understanding of exactly what they were seeing. Gassendi also looked for the predicted transit of Venus, but the transit had already ended before the Sun rose from his Paris location.

Sadly, no documentation exists of anyone in the world seeing the 1631 transit of Venus — a missed opportunity. Given the fact that Venus's silhouette is big enough for people to see with their naked eyes, it's likely that a few people around the world saw Venus as they glanced at the Sun (particularly around sunrise or sunset). But without access to the published materials possessed by a small number of educated Europeans, they would not have recognized what they were seeing.

Rest of Part 1 in Transits of Venus in History: 1631-1716.

Part 2 in Transits of Venus in History: 1761
Part 3 in Transits of Venus in History: 1769-today

You can, easy.

No you can't.
This has repeatedly been raised and shown as a problem with a FE. It cannot explain the apparent position of objects.

You just put the objects where they need to be.

Which only works for one location.
Move to another location and its wrong.

That might well mean there are multiple identical star systems

Which would allow it to be seen from multiple locations.

or non-Euclidean goodness

i.e. making it non-Flat.

but you can do it.

Prove it or stop repeating this lie.

They could predict the movements of planets when they still believed in a geocentric universe, they just had to resort to weird things when it came to retrograde motion.

Yes, a geocentric one, not a flat one.
The only time they could do it for a flat one is with a tiny Earth.

Quote from: Jane on March 19, 2018, 04:14:35 PM

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

I never mentioned the sun, I was reffering about the unpredictability of one particular planet, Mercury. Why can’t you stick to the point rather than once more distorting the topic to suit yourself. Are you saying the orbit of Mercury can be predicted by observation alone?

Learn what an illustration or analogy is sometime, this is tedious.
Yes, I'm saying that, and I'm pretty sure you're the only person confused by that. It takes 89.7 days for Mercury to rotate around the Sun once. The mathematics as to why that happens is complicated, but the reason they knew there was more to the maths is because they were perfectly capable of observing what was going on.

If the earth were flat and not the Globe that both Tycho Brahe assumed in his observantions and Johannes Kepler used in his calculations.
Please suggest how Kepler was able to predict (based largely on observations from Tycho Brahe) when transits of both Mercury and Venus would occur when neither had ever been observed before.

i don't think that's entirely true. Certainly Kepler's the best known, but I've found at least one reference to a twelfth century mathematician and astronomer (Averrhoes) who said they saw a transit, during a time one was predicted to occur. Given how many people watched the stars and Sun, it's just force of numbers to say they observed it, the quetsion is just whether they knew what they saw.

Wouldn't in open source software the difference in algorithm be obvious?

Not really, it'd still follow Kepler's laws, I'm just saying that a fair bit of Kepler's laws were based on observation as much as pure theory. Both true for undeniable reality, though perhaps to a greater extent under an FE model.

Quote from: Lonegranger on March 20, 2018, 12:45:47 AM

Quote from: Jane on March 19, 2018, 04:14:35 PM

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

I never mentioned the sun, I was reffering about the unpredictability of one particular planet, Mercury. Why can’t you stick to the point rather than once more distorting the topic to suit yourself. Are you saying the orbit of Mercury can be predicted by observation alone?

Learn what an illustration or analogy is sometime, this is tedious.
Yes, I'm saying that, and I'm pretty sure you're the only person confused by that. It takes 89.7 days for Mercury to rotate around the Sun once. The mathematics as to why that happens is complicated, but the reason they knew there was more to the maths is because they were perfectly capable of observing what was going on.

Quote from: rabinoz on March 20, 2018, 01:42:00 AM

If the earth were flat and not the Globe that both Tycho Brahe assumed in his observantions and Johannes Kepler used in his calculations.
Please suggest how Kepler was able to predict (based largely on observations from Tycho Brahe) when transits of both Mercury and Venus would occur when neither had ever been observed before.

i don't think that's entirely true. Certainly Kepler's the best known, but I've found at least one reference to a twelfth century mathematician and astronomer (Averrhoes) who said they saw a transit, during a time one was predicted to occur. Given how many people watched the stars and Sun, it's just force of numbers to say they observed it, the quetsion is just whether they knew what they saw.

Quote from: Macarios on March 19, 2018, 10:00:52 PM

Wouldn't in open source software the difference in algorithm be obvious?

Not really, it'd still follow Kepler's laws, I'm just saying that a fair bit of Kepler's laws were based on observation as much as pure theory. Both true for undeniable reality, though perhaps to a greater extent under an FE model.

Lonegranger is right on this one Jane.  While you can simplify the motion of Mercury to simple orbits, the retrograde motion, when those retrograde periods occur, and the length of time Mercury is retrograde is not as simple.  The procession of those events cannot be determined by observation alone.  For example here is a list of dates where Mercury was retrograde:

Mercury Retrograde 2009
January 11-31
May 6-20
September 6-29
December 26-January 15, 2010

Mercury Retrograde 2010
April 17-May 11
August 20 – September 12
December 10-December 29

Mercury Retrograde 2011
March 30-April 23
August 2 – August 26
November 23 – December 13

Mercury Retrograde 2012
March 11-April 4
July 14 – August 7
November 6 – November 26

There is no pattern evident in this four year period, at least none that is immediately evident.  However, programs like Stellarium can predict these events with accuracy well into the future, based on calculations derived from what others have indicated in this thread.

Quote from: Lonegranger on March 20, 2018, 12:45:47 AM

Quote from: Jane on March 19, 2018, 04:14:35 PM

Quote from: Lonegranger on March 19, 2018, 03:12:21 PM

You are not correct. The orbit of Mercury can only be properly understood once overlaid by general relativity no matter how you may wish to spin this. Go ask an astronomer.
In reality and as recorded by history the orbit of Mercury was a mystery as it did not abide to any known laws of motion, and that as they say is historical fact, take it or leave it.

I'm not talking about understanding it, I'm talking about predicting it. You don't need to know the slightest thing about the solar system to know the Sun's going to rise tomorrow. Predicting regular, repeating occurences is not hard.

I never mentioned the sun, I was reffering about the unpredictability of one particular planet, Mercury. Why can’t you stick to the point rather than once more distorting the topic to suit yourself. Are you saying the orbit of Mercury can be predicted by observation alone?

Learn what an illustration or analogy is sometime, this is tedious.
Yes, I'm saying that, and I'm pretty sure you're the only person confused by that. It takes 89.7 days for Mercury to rotate around the Sun once.

And how does that let anyone predict transits of Mercury?

 The mathematics as to why that happens is complicated, but the reason they knew there was more to the maths is because they were perfectly capable of observing what was going on.

Quote from: rabinoz on March 20, 2018, 01:42:00 AM

If the earth were flat and not the Globe that both Tycho Brahe assumed in his observantions and Johannes Kepler used in his calculations.
Please suggest how Kepler was able to predict (based largely on observations from Tycho Brahe) when transits of both Mercury and Venus would occur when neither had ever been observed before.

i don't think that's entirely true. Certainly Kepler's the best known, but I've found at least one reference to a twelfth century mathematician and astronomer (Averrhoes) who said they saw a transit, during a time one was predicted to occur. Given how many people watched the stars and Sun, it's just force of numbers to say they observed it, the quetsion is just whether they knew what they saw.

But my point is how can the transits possibly occur on the flat earth model?
In that model the planets are supposedly at about the same height above the earth as the sun and I fail to see how that geometry could explain these transits.

Then take the astronomical measurements during a transit if Venus - there not the ghost of a chance of fitting them into that flat earth model.
Proving that was why I'd hoped for a mathematician competent on astronomical calculations.
I'm no mathematician and you certainly don't seem to be able to visualise the problem, let alone solve it!

You "don't think that's entirely true." Really?

A naked-eye observation of a sunspot by Ibn Rushd
The Spanish philosopher Ibn Rushd (1126–98), also called Averroes, has been the subject of a number of studies. The main experts on this topic have passed over the astronomical aspect of his work far too hastily
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nevertheless, Copernicus wrote in chapter X of his famous Revolutionibus
“Although Averroes remembers in his paraphrase to Ptolemy that he had seen something dark when observed the conjunction of the Sun and Mercury that he had computed.”
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
It is clear that Averroes observed a sunspot because the only other candidate for such a dark object, a transit of Mercury, is not visible to the unaided eye.

See: A naked-eye observation of a sunspot by Ibn Rushd

Yes, your transit seems to be a sunspot!
But, I will agree on one point. The work of the Islamic mathematicians, astronomers and surveyors of the period say from 600 AD to 1200 AD is largely neglected.

Quote from: Macarios on March 19, 2018, 10:00:52 PM

Wouldn't in open source software the difference in algorithm be obvious?

Not really, it'd still follow Kepler's laws, I'm just saying that a fair bit of Kepler's laws were based on observation as much as pure theory. Both true for undeniable reality, though perhaps to a greater extent under an FE model.

In Heliocentric system Kepler's laws are applied on Earth as well.
On what is that part applied in Flat model where Earth is unmovable?

Ah Kepler.

I once did a paper on him but placed all my focus on his work combining the model of a solar system with things such as inscribed polygons and octaves.

My lecturer said I had completely missed the point of his theories so I don't really feel I can contribute too much to this thread lol.

Quote from: Jane on March 19, 2018, 02:50:14 PM

Quote from: Lonegranger on March 19, 2018, 02:09:49 PM

Sorry but that is totally incorrect as in the case of Mercury which is not predictable and was not fully understood until general relativity offered a precise explanation of its orbit. An orbit that could only happen if the sun was 93 million miles from earth and had a mass of 2x10^30 Kg. give or take. This is the problem of various flat earth ideas, they constantly forget the knock on implications.

The predictability comes from observing it. You don't need any equations whatsoever to predict when/where the planets will be when you have years worth of observation and tracking. The length of a year (for any planet), the length of a day is all basically fixed, irrespective of what shape the world is.
Mercury was still predictable, that was why they knew the formula was off; they knew it wasn't going to magically match up the next time they looked at it because they had the figures. It was predictable, just not understood at that point in time. Why, rather than what.

Astronomical models run on calculations not observations.

Models are made from observations.  The calculations are there to explain why the model works.

Jane's not 100% wrong.  Planetary motion was accurately observed and modeled long before we had any mathematical understanding of what was happening.  Ptolemy's geocentric model is functional to describe what is observed in the sky, if you allow a margin of error and don't mind planetary epicycles that exist for no explainable reason other than that's the apparent motion that was observed. 

The Copernican model is also based on observation, but it has much more consistent planetary movement and the engine of gravity to explain how it all works.  The better our mathematical descriptions of gravity have become the more accurate the Copernican model has become. 

Jane's mistake here is trying to allege that the same observations will be consistent if the Earth were flat.  That's absolutely false, but Jack explained it above more succinctly than I would, so I won't bother going through it again.

And how does that let anyone predict transits of Mercury?

Literally all it is, is looking for times the orbit proportions line up; say Mercury being 22.425 days into its orbit and the Earth being 91.3125 days into its, using the occurence of a transit as a zero. Sure, it's a little tricky, but you don't need any Kepler's laws based model, just a few observations of relative position. You'd know how the Sun looks from Earth relative to the stars, you'd know the same for Mercury, using those as landmarks...
The FE analogue would technically be the Sun's path over the Earth rather than the Earth's around the Sun, but the basic principle is still the same.

But my point is how can the transits possibly occur on the flat earth model?
In that model the planets are supposedly at about the same height above the earth as the sun and I fail to see how that geometry could explain these transits.

About the same height does not equal exactly the same height. Only even potential oddity is trying to explain why some sometimes go above and sometimes go beneath, and the rest never transit, but that's a query rather than a contradiction.

Yes, your transit seems to be a sunspot!
But, I will agree on one point. The work of the Islamic mathematicians, astronomers and surveyors of the period say from 600 AD to 1200 AD is largely neglected.

Possibly, but it is still a fair indication that the idea of Kepler being the first is not inherently true. People were watching for similar phenomenon long before, it's not suprising the ones Kepler noted got more notice simply for being predicted, but even so.
Equally, like you say, the work of Islamic scientists of the period is widely neglected. We know they had a fair understanding of lenses and their reaction to light (Ibn al-Haytham, Ibn Sahl for the easy examples; the latter of which discovering Snell's law centuries before, well, Snellius and his contemporaries, and the former doing plenty with the magnifying properties of lenses), it's wholly possibly Averroes didn't use his naked eye given they were a century before his time. A lot of the records are missing.

In Heliocentric system Kepler's laws are applied on Earth as well.
On what is that part applied in Flat model where Earth is unmovable?

They're not. Why is that relevant? No one's claiming the models are identical, just that regular, repeating phenomenon are predictable.

Jane's not 100% wrong.  Planetary motion was accurately observed and modeled long before we had any mathematical understanding of what was happening.  Ptolemy's geocentric model is functional to describe what is observed in the sky, if you allow a margin of error and don't mind planetary epicycles that exist for no explainable reason other than that's the apparent motion that was observed. 

The Copernican model is also based on observation, but it has much more consistent planetary movement and the engine of gravity to explain how it all works.  The better our mathematical descriptions of gravity have become the more accurate the Copernican model has become. 

Jane's mistake here is trying to allege that the same observations will be consistent if the Earth were flat.  That's absolutely false, but Jack explained it above more succinctly than I would, so I won't bother going through it again.

The observations are consistent. Observations aren't going to change. What the hell they mean, meanwhile, is entirely different. Even if you want to take the most extreme potential distortion, you're going to get stars teleporting across the sky or two identical things existing simultaneously etc etc, which is all a hell of a job to explain, but (barring entirely separate arguments against FET which can and so should be made independently of astronomical software) it's all still perfectly predictable.
I've gto Jack blocked, though I did skim his post when you mentioned it, and 'succinct' is not the same as 'rapidfire.' It's the reason I've got him blocked; he is never trying to make informed arguments, just cheap quips. When you cut parts of my post out of context, sure, you can quip a one-sentence response that seems to refute it, but you need to actually ignore everything that's being said and refuse any attempt to actually understand in order to really do so.
Why things happen, and what happens, are not the same thing. Trying to explain why the things we see in the sky happen under FET is a long, complicated task, but knowing that it's going to happen isn't the same.

Quote from: rabinoz on March 20, 2018, 05:36:20 AM

And how does that let anyone predict transits of Mercury?

Literally all it is, is looking for times the orbit proportions line up; say Mercury being 22.425 days into its orbit and the Earth being 91.3125 days into its, using the occurence of a transit as a zero. Sure, it's a little tricky, but you don't need any Kepler's laws based model, just a few observations of relative position.

The biggest problem with relying on observations of transits of Mercury is that they are very easy to miss if you don't know where and when they will be visible.  A good model can tell you things like that.