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.