The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Investigations => Topic started by: Tom Bishop on June 27, 2018, 09:20:28 AM
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An interesting video about the stars slowing down as they approach the horizon. At the 1:15 mark the author states that "the stars get significantly closer together as they get closer to the horizon."
This contradicts the Round Earth Theory that says that the celestial bodies move at a constant speed across the sky as the earth rotates. The official Round Earth excuse is, of course, that there is a permanent mirage effect that slows down the stars, and which also reverses any observation that suggests a Flat Earth.
https://www.youtube.com/watch?time_continue=94&v=m-xXhrTG3Sk
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So does the angular distance between stars decrease at the horizon
(1) because refraction only kicks in when light passing close to the earth; or
(2) because perspective only kicks in when light passing close to the earth?
If (2), why does Rowbotham say that the law of perspective is 'visible everywhere'? Or something like that?
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What do the astronomical textbooks and journals have to say on the matter?
Surely that should be the first port of call?
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This may also help https://en.wikipedia.org/wiki/Atmospheric_refraction
Whenever possible, astronomers will schedule their observations around the times of culmination, when celestial objects are highest in the sky. Likewise, sailors will not shoot a star below 20° above the horizon. If observations of objects near the horizon cannot be avoided, it is possible to equip an optical telescope with control systems to compensate for the shift caused by the refraction.
[..]
Atmospheric refraction of the light from a star is zero in the zenith, less than 1′ (one arc-minute) at 45° apparent altitude, and still only 5.3′ at 10° altitude; it quickly increases as altitude decreases, reaching 9.9′ at 5° altitude, 18.4′ at 2° altitude, and 35.4′ at the horizon;[4] all values are for 10 °C and 1013.25 hPa in the visible part of the spectrum.
(https://upload.wikimedia.org/wikipedia/commons/0/06/BennettAtmRefractVsAlt.png)
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Why do they only get closer together vertically and not horizontally? Why would observers from other latitudes see the stars slowing in a different axis?
I'd like to remind you once again that you are wearing glasses in your profile photo and thus should agree that optics is a well understood field.
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This may also help https://en.wikipedia.org/wiki/Atmospheric_refraction
Whenever possible, astronomers will schedule their observations around the times of culmination, when celestial objects are highest in the sky. Likewise, sailors will not shoot a star below 20° above the horizon. If observations of objects near the horizon cannot be avoided, it is possible to equip an optical telescope with control systems to compensate for the shift caused by the refraction.
[..]
Atmospheric refraction of the light from a star is zero in the zenith, less than 1′ (one arc-minute) at 45° apparent altitude, and still only 5.3′ at 10° altitude; it quickly increases as altitude decreases, reaching 9.9′ at 5° altitude, 18.4′ at 2° altitude, and 35.4′ at the horizon;[4] all values are for 10 °C and 1013.25 hPa in the visible part of the spectrum.
(https://upload.wikimedia.org/wikipedia/commons/0/06/BennettAtmRefractVsAlt.png)
This looks suspiciously like an inverted Round Earth Drop Chart.
(https://i.imgur.com/2OIr4F9.png)
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Its a graph of an exponential relationship. Not surprising in the slightest.
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Its a graph of an exponential relationship. Not surprising in the slightest.
It is certainly interesting that you guys say that the earth drops by an exponential function, and that there is also a permanent reversed exponential refraction effect that you guys pull out whenever there is an observation of a Round Earth that looks flat.
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Its a graph of an exponential relationship. Not surprising in the slightest.
It is certainly interesting that you guys say that the earth drops by an exponential function, and that there is also a permanent reversed exponential refraction effect that you guys pull out whenever there is an observation of a Round Earth that looks flat.
And you claim there's a 'perspective effect' that precisely mimics a setting sun on a round Earth regardless of weather, as well as something that perfectly keeps the sun/moon the same size throughout the day/night no matter anything else. Do you have evidence to suggest the data that created the set involving the refraction effect was faked or similar? Or do you just like your fallacy?
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Its a graph of an exponential relationship. Not surprising in the slightest.
It is certainly interesting that you guys say that the earth drops by an exponential function, and that there is also a permanent reversed exponential refraction effect that you guys pull out whenever there is an observation of a Round Earth that looks flat.
That's not why we are saying there is refraction. There is refraction because of atmospheric density in this case. Nice try though. Empty try, but I have to admire your rearrangement of the deck chairs on the titanic.
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I sound like a broken record here, but you've stumbled onto a bit of scientific trivia that is not often taught but is, in fact, well-known. I would encourage you to simply restructure your approach when you encounter something like this. Instead of saying, "This contradicts the Round Earth Theory," try a slightly different approach like, "Can anyone explain this to me?" As you saw, there are plenty of people that can help you answer these questions. I don't see the need for the antagonism.
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An interesting video about the stars slowing down as they approach the horizon. At the 1:15 mark the author states that "the stars get significantly closer together as they get closer to the horizon."
This contradicts the Round Earth Theory that says that the celestial bodies move at a constant speed across the sky as the earth rotates.
It also contradicts your FE claim that they do too...
https://wiki.tfes.org/Constant_Speed_of_the_Sun
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An interesting video about the stars slowing down as they approach the horizon. At the 1:15 mark the author states that "the stars get significantly closer together as they get closer to the horizon."
This contradicts the Round Earth Theory that says that the celestial bodies move at a constant speed across the sky as the earth rotates.
It also contradicts your FE claim that they do too...
https://wiki.tfes.org/Constant_Speed_of_the_Sun
Actually the article does leave room for slowing a bit in the Flat Earth model:
"In FET the stars and celestial bodies are at such a great height that they have maximized the perspective lines. They are descending into the horizon at a consistent or near consistent velocity. As consequence they do not slow down in the distance by any significant degree, and hence the stars do not appear to change configuration and build up in the distance, nor does the sun or moon appear to slow as they approach the horizon. "
According to the Ancient Greek model of perspective they should slow by a much greater amount than demonstrated in the video.
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According to the Ancient Greek model of perspective they should slow by a much greater amount than demonstrated in the video.
Only if the stars are moving round above a flat plane.
If they are distant and the earth is rotating then that would perfectly explain the observations.
The slowing near the horizon is due to refraction.
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According to the Ancient Greek model of perspective they should slow by a much greater amount than demonstrated in the video.
Only if the stars are moving round above a flat plane.
If they are distant and the earth is rotating then that would perfectly explain the observations.
The slowing near the horizon is due to refraction.
I'm obviously talking about the Flat Earth model.
You quoted me a page of our Wiki which clearly leaves room for the stars to slow down. I would suggest reading carefully next time.
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An interesting video about the stars slowing down as they approach the horizon. At the 1:15 mark the author states that "the stars get significantly closer together as they get closer to the horizon."
This contradicts the Round Earth Theory that says that the celestial bodies move at a constant speed across the sky as the earth rotates.
Please show where "Round Earth Theory that says that the celestial bodies move at a" precisely "constant speed across the sky as the earth rotates."
Now read and study all of Lecture 1: Introduction to Astronomy 250 (http://ircamera.as.arizona.edu/astr_250/Lectures/LECTURE_01.HTM). Especially the section that starts with: When making precise measurements of stellar positions, various effects must be taken into account:
- Aberration -- an object's position will be shifted slightly because of the finite speed of light and the observer's motion
(http://ircamera.as.arizona.edu/astr_250/images/aberra.gif)
- Refraction -- light gets bent (refracted) by the Earth's atmosphere, a star's altitude is increased by refraction. When the Sun is setting, it is actually beneath the horizon when its lower limb just appears to touch the horizon -- in other words, the refraction amounts to ~35', the apparent diameter of the Sun. Refraction depends on your altitude, the atmospheric conditions, and the wavelength of the observation.
(http://ircamera.as.arizona.edu/astr_250/images/refract.gif)
The official Round Earth excuse is, of course, that there is a permanent mirage effect that slows down the stars, and which also reverses any observation that suggests a Flat Earth.
Sure, you call it an excuse but the deflection of objection near horizon has been observed for around 2 millennia.Abstract
Astronomical refraction has had a long and fascinating history. Cleomedes (100 A.D.) and Ptolemy (200 A.D.) were aware of its existence and understood in a qualitative way some of its properties. Alhazen (1100 A.D.) quite correctly suggested that the flattening of the sun’s disk near the horizon was due to astronomical refraction. Tycho Brahe in 1587, however, was the first to make direct measurements of the magnitude of the refraction.
Astronomical Refraction–Some History and Theories, A. I. Mahan (https://www.osapublishing.org/ao/abstract.cfm?uri=ao-1-4-497)
So I would say that your claim that this slight variation due to long known refraction "contradicts the Round Earth Theory" is totally without foundation.
Not only that, but you claim "The official Round Earth excuse is, of course, that there is a permanent mirage effect << emotive term for 'slight refraction' >>" yet your own "Flat Earth Society Wiki" uses refraction to explain "Horizon Limits". Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
So this seems just another "strawman augment" from someone who has an imperfect and incomplete knowledge of so-called "Round Earth Theory".
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According to the Ancient Greek model of perspective they should slow by a much greater amount than demonstrated in the video.
Only if the stars are moving round above a flat plane.
If they are distant and the earth is rotating then that would perfectly explain the observations.
The slowing near the horizon is due to refraction.
I'm obviously talking about the Flat Earth model.
In which case I agree. Using that model the stars' angular velocity should change as they recede into the distance.
They don't, ergo your model is wrong.
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In which case I agree. Using that model the stars' angular velocity should change as they recede into the distance.
They don't, ergo your model is wrong.
According to what evidence?
Discussions on how perspective scales according to the Ancient Greek perspective theory never ends well for you. There is no demonstration for the infinitely receding perspective lines, for which your "proofs" of things like "the sun can never set" and discussions like these depend upon. The perspective of the Ancient Greeks was a hypothesis.
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In which case I agree. Using that model the stars' angular velocity should change as they recede into the distance.
They don't, ergo your model is wrong.
According to what evidence?
According to every observation of a receding body conforming to the predictions of the perspective model used by basically everyone.
You are the one claiming that a high plane's angular velocity doesn't change. You are an empiricist, I assume that claim is based on your own observations.
Can we see the results of those observations? How have you measured the angular velocity of a high plane over time and shown it to be consistent?
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Discussions on how perspective scales according to the Ancient Greek perspective theory never ends well for you.
There was never any 'Ancient Greek perspective theory '. Euclid wrote about geometry and optics. If FE is now a debating club, we need rules for debate. I propose a rule that every substantive claim should be backed by a citation. So, please cite a work by Euclid or any other ancient Greek that discusses perspective. Claims without evidence will be dismissed without evidence.
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I see. Your avoidance tactics show that there is no evidence for the infinite perspective theory of the Ancient Greeks. Thank you for clearing that up.
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I see. Your avoidance tactics show that there is no evidence for the infinite perspective theory of the Ancient Greeks. Thank you for clearing that up.
What "infinite perspective theory of the Ancient Greeks"?? You keep saying that the ancient Greeks had an "infinite perspective theory" What theory?
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It is certainly interesting that you guys say that the earth drops by an exponential function ...
Do you mean that "8 inches per mile squared" that every Flat Earther pulls out every so often, but which never appears in a single textbook, science journal or paper ...?
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I see. Your avoidance tactics show that there is no evidence for the infinite perspective theory of the Ancient Greeks. Thank you for clearing that up.
What "infinite perspective theory of the Ancient Greeks"?? You keep saying that the ancient Greeks had an "infinite perspective theory" What theory?
You should pay attention in school. It was taught to you there.
It is certainly interesting that you guys say that the earth drops by an exponential function ...
Do you mean that "8 inches per mile squared" that every Flat Earther pulls out every so often, but which never appears in a single textbook, science journal or paper ...?
False. Read Earth Not a Globe.
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You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
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False. Read Earth Not a Globe.
What, the whole of it? Just to find the one reference that you mean?
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I see. Your avoidance tactics show that there is no evidence for the infinite perspective theory of the Ancient Greeks. Thank you for clearing that up.
What "infinite perspective theory of the Ancient Greeks"?? You keep saying that the ancient Greeks had an "infinite perspective theory" What theory?
You should pay attention in school. It was taught to you there.
Please give an exact citation for the work you are referring to. I have read Euclid's Elements. There is no 'theory of perspective' in that work. Or if you think so, please provide a citation. Claims without evidence will be dismissed etc.
You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
What is 'it'?? The Elements contains no 'theory of perspective'.
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You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
Why? Your school doesn't teach geometry? ???
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You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
Why? Your school doesn't teach geometry? ???
Schools teach geometry. What are you talking about???
And still waiting for that citation, Tom.
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You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
Why? Your school doesn't teach geometry? ???
Schools teach geometry. What are you talking about???
And still waiting for that citation, Tom.
If you have taken geometry then you should know about its infinite nature. If you were paying close attention, you would know that geometry comes from the ancients.
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Why? Your school doesn't teach geometry? ???
It's a long time since I was at school, but "infinite perspective theory of the Ancient Greeks" was not in my syllabus.
Are you saying "Geometry" and "infinite perspective theory of the Ancient Greeks" are the same thing?
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You should pay attention in school. It was taught to you there.
Won't that depend on regional syllabuses? What is/was taught in your region may not be taught in another
Why? Your school doesn't teach geometry? ???
Schools teach geometry. What are you talking about???
And still waiting for that citation, Tom.
If you have taken geometry then you should know about its infinite nature. If you were paying close attention, you would know that geometry comes from the ancients.
More avoidance. Geometry comes from Euclid, among others. Where is his theory of perspective?? You used the word 'perspective'.
And no, the ancients did not acknowledge the actual infinite, as you must surely know from Aristotle.
Still waiting for the citation.
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Why? Your school doesn't teach geometry? ???
It's a long time since I was at school, but "infinite perspective theory of the Ancient Greeks" was not in my syllabus.
Are you saying "Geometry" and "infinite perspective theory of the Ancient Greeks" are the same thing?
Yes, that's why the Wikipedia page on perspective (https://en.wikipedia.org/wiki/Perspective_(geometry)) is titled "Perspective (geometry)".
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Why? Your school doesn't teach geometry? ???
It's a long time since I was at school, but "infinite perspective theory of the Ancient Greeks" was not in my syllabus.
Are you saying "Geometry" and "infinite perspective theory of the Ancient Greeks" are the same thing?
Yes, that's why the Wikipedia page on perspective (https://en.wikipedia.org/wiki/Perspective_(geometry)) is titled "Perspective (geometry)".
Please cite the work of Euclid, or any other ancient Greek writer, that deals with Perspective in geometry. Fourth time asking (?).
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Of course Euclid's Theorem https://en.wikipedia.org/wiki/Euclid%27s_theorem states that there are infinitely many primes. But that means there is no largest prime number.
Are you saying there is a largest prime number? Which one?
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Why? Your school doesn't teach geometry? ???
It's a long time since I was at school, but "infinite perspective theory of the Ancient Greeks" was not in my syllabus.
Are you saying "Geometry" and "infinite perspective theory of the Ancient Greeks" are the same thing?
Yes, that's why the Wikipedia page on perspective (https://en.wikipedia.org/wiki/Perspective_(geometry)) is titled "Perspective (geometry)".
You DO understand the geometry of perspective and 'geometry' are two different things for this right? In case you didn't notice, the references cited for the wiki page you linked do not include anything older than 1930. I see nothing that would imply it is based upon an 'ancient Greek theory of perspective' on that page. In fact, if we look for 'Perspective' (https://en.wikipedia.org/wiki/Perspective) we'll find you didn't even link to the actual page on perspective, but rather a sub-page of it! So either you can't manage to find a simple page on the web, or perhaps you were purposefully attempting to present an argument that looks on it's surface like you were in the right, knowing you were deceiving the reader. Following in Rowbotham's shoes, you are. As a note, the proper wikipedia page on perspective/perspectivity references a work in 1453 as the first author to describe it. Which would support Edby's statement that the Greeks' HAD no perspective theory for you to keep demanding we provide evidence for. No wonder you've never gotten evidence for something that doesn't exist!
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I see. Your avoidance tactics show that there is no evidence for the infinite perspective theory of the Ancient Greeks. Thank you for clearing that up.
I quite liked this, and very clever. It is ambiguous between 'there is no evidence that the Greeks had an infinite perspective theory', which was what [you knew?] I meant, and 'the Greeks did have an infinite perspective theory, but there is NO evidence it is true'.
To clear that up, I meant the former. And as Squirrel says above, there was no perspective theory as we understand it until about the 15th century.
Adding 'Thank you for clearing that up' also a nice touch.
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The stars movement:
The earth rotates at a constant speed.
The stars will therefore move in the sky at a constant speed due to perspective.
Near the horizon, the stars will seem to slow down / compress due to refraction being way higher when looking through atmosphere near the surface of earth.
Perspective:
Perspective is extremely well understood and extremely simple, and I do not get why you constantly bring up ancient greeks...
We know that parallel lines will never touch (simple geometry), and we know that perspective will only let them seem to converge at a point at infinity (but they never will)
We also know that with our eyes and cameras limited resolution, parallel lines will seem to converge much earlier depending on their closeness and the closeness of the observer.