1. Henk001

    Henk001 Active Member

    South of the equator when you are looking south at the southern night sky you always see the same point in the sky: the south celestial pole. Therefore the lines of sight must be parallel.
    Three examples
    Sydney, Australia (notice the Sydney Opera House on the left)
    Image Source: http://www.rc.au.net/blog/2012/06/26/kirribilli-sydney-harbour-trails/
    From Reúnion
    From ESO, Chili
    So, instead of this
    We must assume this

    Last edited by a moderator: May 24, 2017
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  2. Mick West

    Mick West Administrator Staff Member

    Constellatons North vs South .

    In the norther hemisphere even the most casual observer is generally familiar with at least one constellation: Ursa Major, the Great Bear, aka "The Big Dipper" in the US or "The Plough" in the UK. People are also generally familiar with Polaris, the Pole Star or North star. You might even remember that the last two stars of Ursa Major point at Polaris, and Polaris is always within a degree of true north, so quite useful for navigation.

    Far fewer people in the northern hemisphere are familiar with the appearance of the skies in the Southern Hemisphere. This is a likely explanation as to why most successful flat earth promoters are in the Northern Hemisphere.

    In the Southern Hemisphere there's no easy equivalent of Polaris, as the southern celestial pole (the point at which all the stars seem to rotate about) is in a region of the sky with few bright stars. There is however an equivalent of Ursa Major, the constellation known as Crux, or more commonly The Southern Cross. Crux give us a similar useful locating tool for the southern celestial pole, as the longer arms of the cross point towards the pole.

    Another thing that people in the North don't often think about is that in the South the stars seem to rotate clockwise around the celestial south pole, whereas in the North they rotate counter-clockwise.

    This all creates an excellent demonstration of the shape of the Earth.

    Consider two places on the globe, Sydney in Australia and Santiago in Chile (any similar locations will do). Now in the southern winter the nights are long, just before sunrise in Sydney the sun has set in Santiago. If people in both places look South (i.e. away from the North Pole) at the same time, then what do they see in the sky?

    Here's the view from Santiago. Crux is at the bottom.

    Here's the view from Sydney, at the exact same time!


    Clearly, despite looking in nearly exactly opposite direction (on a flat earth), we are actually looking at the same piece of sky. This is only possible if we are on a globe.
    Flat_earth views crux metabunk.

    This is inarguable proof that the Earth is not flat, so if you ever get into an argument with someone who claims to believe in the Flat Earth (and a lot of them, of course, are just trolling), then ask them to explain this problem first to save time.
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  3. Mick West

    Mick West Administrator Staff Member

    Another way of visualizing the Southern Celestial Pole is to take Star Trail images looking South. Here's one from Chile:
    Image Source: https://commons.wikimedia.org/wiki/File:All_In_A_Spin_Star_trail.jpg

    And one from Australia (notice the Sydney Opera House on the left)
    Image Source: http://www.rc.au.net/blog/2012/06/26/kirribilli-sydney-harbour-trails/

    The centers of rotation in both images are due south. On the globe this is simply pointing towards the southern celestial pole. On a "Flat Earth" south is in totally opposite directions, yet somehow looking at the same thing.
    Last edited: May 13, 2017
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  4. Trailspotter

    Trailspotter Senior Member

    You do not need to go to the Southern hemisphere to confirm the existence of the Southern Celestial Pole. Instead, you can point a camera southwards and take a long exposure shot or night time-lapse video to visualise the star trails and see that there is the opposite centre of rotation to the Northern Celestial Pole below the horizon, so the celestial axis connecting the two poles comes through the Earth at an angle, corresponding the latitude of the observer. Such an observation that any Flat Earther can do for themselves, demonstrates that Earth is surrounded by the "Celestial Sphere" rather than covered by a Sky dome.
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  5. Mick West

    Mick West Administrator Staff Member

    Indeed, and you don't even need to be in the southern hemisphere to see the Southern Cross. You can see circling a point below the horizon from quite a ways north. Including Bangkok, home of Flat Earth promoter Eric Dubay.

  6. Amber Robot

    Amber Robot Member

    Basically, the flat earth proponents take a single observable, like "I can't see curvature", and based on that create a model that blatantly disagrees with a hundred other observables. They never seem to attempt to look at even the simplest calculations of the predictions of their model. Sigh...
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  7. Astro

    Astro Active Member

    Here's a timelapse I took of the south celestial pole during a trip to South Africa last year:

    The stars are definitely moving clockwise around the south celestial pole, in direct contradiction to what a flat earth would predict.
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  8. dove779

    dove779 New Member

    Hello and thank you for this great forum. Personally, I find the view of the stars from the southern hemisphere to be the best globe earth proof. But is there a way I can find a proof, in the form of a clear, non edited picture or a video, of the southern cross and the rest of the southern celestial pole, that has been taken from Australia, South America, and South Africa? Even better - a proof that you can watch the southern cross from South America and South Africa at the same point in time? For some reason I could not find such proofs on a simple google search.
  9. Mick West

    Mick West Administrator Staff Member

    There's an indirect proof in that Stellarium has always been shown to match photos exactly for any given time and location. So you can just view from that location (and time) in Stellarium.

    The way to falsify this would be to demonstrate Stellarium does not match reality.

    A more zetetic proof is always going to rely on you trusting someone. I would suggest some kind of live stream between two flat earth believers who can stream what they see on their cameras at the same time.

    Unfortunately, there's not a lot of flat earth believers in the Southern hemisphere, for obvious reason.
  10. Movie Vertigo

    Movie Vertigo New Member

    I did just that in my latest video. Even though I'm 52 degrees north, you can still see the stars are rotating about the south celestial pole.

    There's also enough vertical field of view that you can see the celestial equator towards the top of the video, and above that a small section stars rotating about the north celestial pole.
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  11. Mad Lord Snapcase

    Mad Lord Snapcase New Member

    I took an all night time lapse looking south east from the west coast of New Zealand. It's not edited beyond placing all the individual photos in Windows Movie Maker and saving them as a video. It was my first attempt at doing this, so the quality is not great, but it's still clear enough to see the stars rotating clockwise followed by the sun rising in the east. I manually changed the exposure time on the camera as dawn approached, not in post processing.

    Source: https://youtu.be/cMTg3FZNZP0
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  12. Enricks

    Enricks Member

    From ESO, Chili

    Just a side question: why are some trails in this pic in front of the building top?
  13. Hevach

    Hevach Senior Member

    You can see some other ghosting around the observatory, particularly on the left side, and weird repeated shadows. Likely the observatory changed positions during the exposure.
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  14. Mick West

    Mick West Administrator Staff Member

  15. DavidB66

    DavidB66 Member

    Just a word of warning on star trail time lapse photographs: some popular images on the internet, including several showing the south celestial pole with Sydney Opera House in the background, are composites. Searching Google Images for 'Sydney star trails', I would say at least half of the top twenty results are physically impossible, because the celestial pole is in the wrong place. Either it is too low in the sky, or it is not to the south of the viewpoint, or both. This one is a conspicuous example: http://www.flickriver.com/photos/wild_images/15283220928/
    Metabunk 2018-04-15 09-49-58.
    To be fair, the photographer describes it as 'Southern Hemisphere star trails stacked over a night image of the Sydney Opera House', so the use of the word 'stacked' might give a warning that it is a composite. I guess that any photographer wanting to take a striking image of Sydney will try to get its most familiar landmarks, the Harbour Bridge and the Opera House, in the picture somehow, even if it means throwing geography to the winds! Fortunately the picture showing star trails over the Opera House earlier in this thread does appear to be physically possible, though the photographer's blog describing his methods does imply there was a great deal of processing involved.
    Last edited by a moderator: Apr 15, 2018
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  16. Z.W. Wolf

    Z.W. Wolf Senior Member

    Even odder... it looks like there are interference patterns. I can't think of any reason for that.
  17. Mick West

    Mick West Administrator Staff Member

    Moire patterns, that's where they are strongest for Moire on concentric circles (made of square pixels). Take a pattern like this:
    Metabunk 2018-04-15 21-06-10.
    You can probably see the patterns just on the screen, especially as you scroll the image, but if you resample it, it's more apparent as a still image:
    Metabunk 2018-04-15 21-07-19.
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  18. edby

    edby Member

    From p.23 of Zetetic Astronomy by 'Lady Blount' and Albert Smith. This explains how the southern stars appear to rotate clockwise around a southern axis, while the northern stars appear to rotate anticlockwise around a northern axis, rather like two gear wheels rotating in opposition.

    Note that unlike pre-Copernican astronomy, where the celestial sphere is a sphere, in Zetetic Astronomy they move in a plane. The sun spirals round from a northern orbit (in London summer) to a southern one (in Sydney summer).

    Only one problem I think. A star in the southern hemisphere which is close to a star in the northern hemisphere where the gears come into contact will appear to move away as the gears rotate. But we don't in fact see this when we stand on the equator. All the stars appear to have fixed position with respect to each other. Nor do we see any blank space in the parts, e.g. ACF where they are diverging.

    Interesting theory though.

    Celestial gears.
    Last edited: Jun 4, 2018
  19. Mick West

    Mick West Administrator Staff Member

    That's the key. It's very hard to convey though. The notion of something that looks like an infinitely distant celestial sphere is just something that the mind rejects. The problem is you can't draw a diagram because of the scale.

    This video shows a typical representation, utterly unlike reality, which confuses people.

    Source: https://www.youtube.com/watch?v=1Toya19H12w
  20. edby

    edby Member

    Does it confuse people? I find it perfectly natural to think of it as a sphere, rotating around the earth.

    It's imagining it as a flat plane that I find difficult, indeed impossible.

    My natural model, conforming to senses is: flat earth, spherical heavens.

    However the Zetetic movement was born at a time when people knew about different 24 hr time zones. That is inconsistent in a model where everyone lives on the top of the flat earth, and the sun would be invisible to everyone at the same time.
  21. Mick West

    Mick West Administrator Staff Member

    I confuses people because the stars are actually trillions of miles away scattered through the universe like specks of dust — then they see a diagram where the stars are about 20,000 miles away fixed on a semi-transparent sphere.

    It's a very useful way to thinking about the night sky, but A) it's not like that, and B) the constellations would change size if it was that close (smaller at the horizon) — so you've got to also note it's trillions of miles away, despite the diagram.

    Once you get it, then it's natural. But if you're starting out thinking the Earth it flat, then you will have problems. It's an abstraction with problems, so accepting that then lets them accept other abstractions, like intermeshed cogs and atmospheric lensing.
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  22. edby

    edby Member

    Ah right. Indeed, but the Ptolemaic system doesn't make any such assumptions about the vast distance of stars.

    Stellar parallax wasn't observable until 1838, I think. https://en.wikipedia.org/wiki/Stellar_parallax, from which the true distance of stars can be worked out.
  23. edby

    edby Member

    [edit] Here we are

  24. Mick West

    Mick West Administrator Staff Member

    Well, it would have to have a fairly large distance, otherwise the constellations would be measurably smaller near the horizon.

    And talking about Ptolemaic, it might confuse everyone if you are explaining why the Earth is not flat by showing how things work better in a geocentric spherical model, when really they know you at least think it's heliocentric.
  25. edby

    edby Member

    Right, but the guiding principle of Zetetic theory is to prefer an explanation where things are actually the way they appear to be. If you look at YouTube, the most common comment is 'I know what it looks like, and it looks like it's flat', 'water can't be curved' etc.

    However there is a problem when we extend this to the heavens. Pre-theoretically, it looks like a large sphere with the stars and moon at some large, but not incredibly large, distance from us. And that works fine until we find out about time zones, which we didn't know about in ancient days. So there is a conflict between 3 perfectly natural ideas (1) earth appears flat (2) heavens look like a rotating sphere (3) you can call people up on the, er, other side of the world and it is day time, whereas it is night where you are.

    One of these has to give. For Flat earthers, it's (2). The stars are on a flat plane.

    Hope that makes more sense.
  26. Z.W. Wolf

    Z.W. Wolf Senior Member

    It confuses people who:
    -struggle with expanding a concept
    -have difficulty dealing with metaphors and analogies
    -are overly-literal
    -have poor spatial reasoning

    Especially a group that is aggressive, engages in motivated thinking and rationalization, and unconsciously places themselves in a mode of thought that exaggerates all the four above problems.
    Last edited: Jun 4, 2018
  27. Z.W. Wolf

    Z.W. Wolf Senior Member

    I've made some changes.

  28. Z.W. Wolf

    Z.W. Wolf Senior Member

    There were steps between the Ptolemaic model and the modern heliocentric model.

    -The Copernican heliocentric model placed all 5 known planets in circular orbits around the sun while retaining epicycles and deferents. [Still quite flawed.]
    -The rival Tychonic system placed the earth at the center, with the sun and moon orbiting the earth and all 5 known planets orbiting the sun. The inferior planets were in small orbits that never circled the earth and the superior planets were in large orbits that did circle the earth but were not orbiting the earth. Retrograde motion was explained with no need for epicycles and deferents. Interesting.

    Both retained the celestial sphere model.

    Astronomers in Tycho's time were doing naked eye observation, they didn't fully grasp atmospheric effects, or know much about optics of the human eye or optics in general. They swore they could see stars with shapes and sizes. (Many people still do and will draw stars confused as UFO's with complicated shapes.)

    -Kepler refined the Copernican system with his first and second laws of planetary motion:The Law of Ellipses and The Equal-Areas Law.

    The Tychonic system hung on for awhile in the 17th century but faded. I don't think there were many astronomers who believed in it much past 1650.

    By then the Tychonic system was a quaint footnote. Did anyone still find it relevant? I don't know. The last nail (if it was needed) wasn't the measurement of parallax in 1838. It was the discovery of stellar aberration in 1727 by James Bradley while he was searching for evidence of stellar parallax. By that time mainstream astronomy assumed parallax would someday be found with better instruments.
    Last edited: Jun 4, 2018
  29. edby

    edby Member

    Not sure. I agree at any point in time it looks like a dome, i.e. a hemispherical object. But a rotating dome? What happens at the next point in time when stars have risen in the East? Have we annihilated the ones that set in the West, then created a new set of stars that have ‘risen’? That seems counterintuitive. When we see the top part of a person’s body above a hedge, do we assume intuitively that only the top part exists? Do we intuit that a person facing us has no back, and that when he turns away from us his front is destroyed and a new back part created?

    Regarding (3), the time zones, I agree this is not intuition. Yet we have to explain somehow why Zetetic astronomy moved from the intuitive idea of a celestial dome/sphere, to that of a disc.
  30. Z.W. Wolf

    Z.W. Wolf Senior Member

    The Egyptians and Mesopotamians thought the sky was a fixed dome, not a rotating one. The heavenly bodies were in the fabric or body of the dome but their motion did not come from the motion of the dome. They moved about inside it. The sun and moon traveled over the earth and then under it or through a tunnel in its lower depths. Thus sunsets had a more logical cause than modern flat earth theory. In this model the earth would enter night at the same time everywhere. Later the Greeks postulated that this was not true, but they had no way to prove it.
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  31. edby

    edby Member

    Surely the idea of a tunnel implies a sphere rather than a hemisphere? Or did they think the tunnel was completely flat or straight? How do we know they believed this?
  32. edby

    edby Member

    However a check on A History of Ancient Mathematical Astronomy By O. Neugebauer p.577 suggests you are right.

  33. Z.W. Wolf

    Z.W. Wolf Senior Member

    The Egyptians and Mesopotamians were much more concentrated on the religious and prophetic meaning of astronomy and less on cosmology. We're talking about a very long history and there is no one completely standard model, but very generally the Mesopotamians believed that the flat world was afloat in an infinite ocean; not on the surface, but in the midst. There were waters above the dome of the sky as well. This belief was shared by the Hebrews and scraps of this flat earth cosmology show up in the Old Testament.

    The Egyptians believed the earth is flat and oval with a vast Underworld with different levels, gates, and passages. Ra, the sun god, had to make a difficult journey through the Underworld each night. He entered in the west and emerged, reborn, in the east. This cosmology makes some sense if you stay at home and don't travel about. I've never seen an explanation for setting and rising stars, but it makes sense that they too dipped below and rose above the edge after an Underworld journey. I don't know if the Egyptians felt it necessary to even think about that. I do know that they had a special reverence for the circumpolar stars which never set, either during a complete day or the year. They were eternal.

    Later, the Greeks had a different, analytical, mindset and were interested in the physical nature of the universe in its own right. Through analysis, and an awareness of what the sky looks like from different parts of the earth, they found evidence for a spherical earth, inside a celestial sphere.

    I'll let Aristotle speak for himself:

    "Again, our observations of the stars make it evident, not only that the earth is circular [spherical], but also that it is a circle [sphere] of no great size. For quite a small change of position to south or north causes a manifest alteration of [what is visible in the sky at] the horizon. There is much change, I mean, in the stars which are overhead [in the sky], and the stars seen are different, as one moves northward or southward. Indeed there are some stars [e.g.Canopus] seen in Egypt and in the neighborhood of Cyprus which are not seen in the northerly regions; and [circumpolar] stars, which in the north are never beyond the range of observation, in those regions [Egypt] rise and set. All of which goes to show not only that the earth is circular [spherical] in shape, but also that it is a sphere of no great size: for otherwise the effect of so slight a change of place would not be quickly apparent."

    Simple geometry; which should be intuitively obvious.

    Aristotle was just one of many. He was speaking of a standard model that was emerging. One of the arguments for this model was that if the earth were flat, the entire earth would enter night at the same time. They believed it didn't. But this was circular logic, because they had no empirical evidence for "time zones." They weren't perfect.

    In the Egyptian model the sunset intuitively looks "right." The sun is falling below an edge. The 19th century Zetetics couldn't ignore time zones and had to modify the more logical Egyptian model, and posited a sun making a circle above the the FE. This makes no analytical sense, but neither does it make intuitive sense. That's not what the sun looks like it's doing. It's an example of how the modern Flat Earthers have to concoct elaborate theories that violate their own philosophy of trust your own eyes.

    At first, 21st century FE Believers simply ignored the two celestial poles; (mostly because they didn't know about them). Now they can't. They are now engaged in concocting more and more elaborate theories to explain the two celestial poles. Some of them involve refraction through the dome, some with reflections in the dome of two counter-rotating disks, others more mystical, and some that rely on simple confusion. The modern heliocentric model is much more intuitive, it looks as if we are inside a celestial sphere. The FE Believers are once again violating their own philosophy.
    Last edited: Jun 5, 2018
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  34. edby

    edby Member

    Thanks for this, v helpful. Incidentally, slightly off topic, but do you have a sense of when people started thinking that stars were really a very long way away? I read that Herschel suggested this about the Milky Way, but couldn't find a reference.
  35. Trailblazer

    Trailblazer Moderator Staff Member

    Tyco Brahe used parallax measurements in 1577 to show that a comet was further away than the moon. He also tried and failed to observe parallax with the stars, so concluded that either the Earth was motionless at the centre of the universe, or the stars were a really really long way away.

    He chose the wrong option, unfortunately.
  36. Mick West

    Mick West Administrator Staff Member

    It's kind of a necessary conclusion from heliocentrism, given the very large orbit of the Earth. One of the earliest heliocentrists was Aristarchus of Samos (b 310 BC) . Wikipedia says of him:
  37. edby

    edby Member

    This book looks good.

  38. Mick West

    Mick West Administrator Staff Member

    Archimedes wrote:
    That seems to suggest that the stars are at 2 AU (1 AU = distance from sun to earth), which it would seem to be obviously incorrect even back then, so maybe I'm misreading it?

    Ah, later it is clarified:
    Metabunk 2018-06-06 08-20-37.

  39. Dan Ly

    Dan Ly New Member

    I own a copy of this book and would highly recommend it. It's a fascinating tale detailing the working of many astronomers who toiled over centuries trying to find stellar parallax. It basically became the equivalent of the space race. If I recall correctly, it was actually Thomas Henderson who first successfully detected stellar parallax from observations of Alpha Centauri but he was cautious to publish because of a number of false positives from work by others. In the end it is Friedrich Bessel who gets the credit because he published first! Anyway, I don't want to get too off topic I just recommend reading this book :)
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  40. edby

    edby Member

    Thanks, and just as well you posted that as I had already ordered it from Amazon.

    It's kind of on-topic as it relates to the question of what the celestial sphere looks like. It doesn't look as though all the stars are different distances. Yet they are, or at least that's what 'science' says.