I didn't hear what's the refractive index of the atmosphere they are building in their 3d model. That would have been of great help to do some math.
The only reference to data in the video is "entered the data from the internet" and "he found out his program is capable to model the atmosphere"
Exactly! He just says that they model all the layers of the atmosphere and it all works. Usual FE logic.
Well, I just did my bit of modelling - on the back of an envelope (yes, one from Westpac Bank) plus Excel for the number-crunching.
It is a bit rough (envelope was not big enough - that's my excuse, and I'm sticking to it).
I took the atmosphere extending to 8.5 km, the typical "scale-height" of the atmosphere, with the refractive index
nair = 1.00029.
These figures mean that at the time of the geometric sunset the sunlight touches the top of the "effective" atmosphere about 330 km away and at about 3° to the upper atmosphere.
Snell's law shows that the sunlight would be refracted by about 0.3°.
As I said before, this is very rough, but it should be enough to show that the light can be refracted by only a fraction of a degree,
not the 20° or so needed to make the Flat earth sun set.That video completely misleading rubbish, still it might keep a few Flat Earthers happy!