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)
    20120618_startrails-1024.
    Image Source: http://www.rc.au.net/blog/2012/06/26/kirribilli-sydney-harbour-trails/
    From Re├║nion
    upload_2016-3-4_10-5-45.
    From ESO, Chili
    upload_2016-3-4_10-6-21.
    So, instead of this
    upload_2016-3-4_10-8-15.
    We must assume this

    upload_2016-3-4_10-9-51.
     
    Last edited by a moderator: May 24, 2017 at 7:46 AM
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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.
    20170512-093943-58fvu.

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

    20170512-094239-0v45h.


    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:
    All_In_A_Spin_Star_trail.
    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)
    20120618_startrails-1024.
    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.
     
  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.

    20170512-111625-wb2eh.
     
  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...
     
  7. Astro

    Astro 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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