1. Rory

    Rory Senior Member

    Youtube user 'The Bloody Truth' is a flat earther who posts 'proof' and 'globe debunking' videos. In marked contrast to most flat earthers, he invites challenges, sometimes admits when he's wrong, and apologises for using insults - plus goes against well-established flat earthers when the evidence convinces. He even debunked a D. Marble 'proof' that he had previously agreed was a 'globe killer'.

    His latest video is another 'globe killer' showing how a video of the full moon and sun in the Dublin sky at the same time would be 'impossible on a spherical earth'. He has made a scale computer graphic to back this up:

    Source: youtube.com/watch?v=PBgvzzv1btA&t=5m32s

    The top red ball is the moon on the ecliptic plane - ie, where it would be during a lunar eclipse - and the bottom red ball is where he estimates it was in the Dublin video. The yellow 'plank' is the 5.14° angle of lunar inclination, and the yellow square represents the terminator.

    There are two reasons he believes this represents an impossibility on a globe: 1. There's no direct line between any place the moon could have been and Dublin (ie, Dublin is on the sunny side of the terminator); and 2. When he draws in the Tropics of Cancer and Capricorn - the purple lines in the diagram below - most of the moon's possible positions extends beyond these:

    Source: youtube.com/watch?v=PBgvzzv1btA&t=7m30s

    The second claim is of course comically easy to debunk: he's drawn his tropics parallel to the ecliptic plane, rather than parallel to the equator, even though he shows the 23.4° axial tilt elsewhere in his video.

    The first claim, meanwhile, is because he hasn't taken into account atmospheric refraction, which allows us to see both the sun and the moon when they are physically located beyond the horizon, as show in this video:

    Source: www.youtube.com/watch?v=c9y5nwok1to

    What's most interesting about his video to me is what it demonstrates about flat earth thinking. Throughout his commentary he disparages science and NASA, sighs at their stupidity, and fully believes that he has successfully challenged the work and understanding of millions of people over thousands of years:
    It's not massively different to the kinds of things other flat earthers might say - but interesting in that he is one of the few who has something of an awarenes of having been wrong about these things before, and therefore might be expected to possess a little caution and humility in leaping to such conclusions. Yet there's not of that: this latest 'proof' is presented with apparently utmost conviction.

    The comments, meanwhile, reveal the usual instant support and congratulations of flat earthers - "Another 100% globe killer!" - "Awesome work, just perfect!" - (as his now self-debunked previous 'proof' received, and presumably still does), while those who point out the flaws in his model are aggressively dismissed - so not quite as open to "challenges" as claimed. ;)

    This I find strange, as this particular error isn't something that can be debated with perception or perspective, but is due to the simple fact that he has drawn the tropics in the wrong place. That his viewers don't check the model is one thing; but that someone with some obvious smarts, who knows he's been wrong before, can display such enormous confidence in his abilities as to believe he's overturned established science, while resisting those who point out the elementary flaws in his model, is something altogether different.

    I shall leave it to someone else to reference the famous study and effect.
    Last edited: Nov 23, 2017
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  2. Retman

    Retman New Member

    What would the moon's path around the orbiting earth look like from a perspective above the orbiting plane?
  3. Mick West

    Mick West Administrator Staff Member

    The moon's path is an ellipse, but of low eccentricity so it looks roughly circular. From above the orbiting plane and viewpoint fixed above the CoG of the Earth it looks like this:


    From a sun fixed viewpoint it's more of a wiggling cycloid, but hard to see as the orbit of the Moon is so small compared to the orbit of the earth.

  4. Retman

    Retman New Member

    As the moon circles the earth, it gets in front of and behind the earth in its path. Does this necessitate the moon speeding up to get in front of and slowing down to get behind the earth?
    Last edited by a moderator: Dec 2, 2017
  5. Mick West

    Mick West Administrator Staff Member

    Depends on your frame of reference. If we ignore the elliptical variations in orbit then it's orbiting the earth at a fixed speed, and the center of gravity of the Earth and Moon together orbit the sun at a fixed speed. If you look at the position of the moon relative to the sun then it will seem to have variations in velocity. It's all relative.

    However it's not speeding up and slowing down like a car accelerating and braking.
  6. Rory

    Rory Senior Member

    From stackexchange:
    That whole thread is pretty fascinating. Here's their animation of the moon's orbit around the sun:

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  7. Mick West

    Mick West Administrator Staff Member

    The Earth actually follows a similar, but much less wiggly path. It's the barycenter of the Earth/Moon system that orbits the sun. The Earth and the Moon then orbit the Barycenter. The barycenter is inside the Earth, so that just translates to a bit a very minor wave in the orbit.

    You can see why people get confused. I know I do.
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  8. Retman

    Retman New Member

    They showed the path of the solar eclipse of August 2017 going from Idaho to Carolina on a stationary United States. Shouldn't they have had the map rotating? Faster than the moving shadow thereby in effect going west relative to the surface which is how we see the moons movement.
  9. Tumeni

    Tumeni New Member

    I really don't have any difficulty in visualising someone ON the terminator, having a sightline to both Sun and Moon ...
  10. Mick West

    Mick West Administrator Staff Member

    No, the movement of the Earth is factored into the movement of the eclipse shadow. The map simply shows (correctly) where they shadow will be, and at what time.
  11. Z.W. Wolf

    Z.W. Wolf Senior Member

    Take a look at this thread. There's a GIF that shows a model earth in motion.

  12. ConfusedHominid

    ConfusedHominid New Member

    I just built this model myself in Maya.
    Sphere + earth texture timeanddate (timeanddate data from may 10 2017)
    23.44 tilt
    Duplicated the sphere, scaled it down by a factor of 0.25 to get the moon (.25 x 4 = 1).
    Duplicated the Earth 30 times to get the earth-moon distance in there.
    Made sure the moon's plane was 5.14 degrees off set from the ecliptic (not the equatorial) and rotated above where timeanddate said it should be (matched up nicely).


    Lowered the camera to around Dublin aaaaaand:

    No refraction needed I think.
    Last edited: Dec 5, 2017
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  13. Rory

    Rory Senior Member

    What's the altitude of the camera?
  14. ConfusedHominid

    ConfusedHominid New Member

    I'll check it now but it's pretty much clipping the terrain of Dublin as you can see. Those blue lines in the bottom left corner is the wireframe of the other side of the globe.
  15. ConfusedHominid

    ConfusedHominid New Member

    Okay, so I've checked again and I hadn't saved my camera. So I had to redo that part. The following image is dead center, as in pretty much 0 feet and 0 inches above the terrain:
    Note, the focal length (100) was for zooming in. Also, my globe is using a limited number of polygons, so it appears slightly more blocky than I'd like personally. This will inevitably raise the terrain of each edge of a sphere a bit more than it would be if it was a perfect sphere of greater detail.

    So yes, there would've been indeed some refraction going on to raise the apparent altitude of the moon.