Apologies for the necro, but it's not worth starting a whole new thread for this.
Getting back to the geometry involved with a flat Earth, I have a question. Assuming the typical FE model, with all the continents on one side of the disc centered on the North Pole and Antarctica making a ring around the edge, how is it that people in Australia see a completely different night sky than people in North America?
I can see Polaris from NA, but I cannot see the Southern Cross. Someone in AUS can see the Southern Cross, but cannot see Polaris. There are a number of stars and contellations that are visible to one location but not the other.
Geometrically, that simply isn't possible if all land masses are on the same side of the disc. Depending on how far away you want to say the stars are, they'd appear at different heights above the horizon, but they would both have to be visible at the same time for all observers on the Earth's surface.
But they aren't. You cannot observe the Southern Cross from NA, Europe, or Asia. You cannot observe Polaris from Australia, Antarctica, most of South America, and a good chunk of Africa.
Now, that's not proof that the Earth is (roughly) spherical, but it's an observation that the typical FE model cannot explain, whereas a spherical model can. The FE model would have to be modified such that some land masses are on one side of the disc and other land masses are on the other side.
Which doesn't work either, but for a different set of reasons.