Hi, this is my first post and I think all this Flat Earth discussion is quite interesting because it shows that people accept many things without thinking and even scientists sometimes make bad arguments and don't listen to the other side. Of course the same happens with flat earthers, so to me one has to avoid tricky arguments that are not strong enough (I'm tired of the Eratosthenes shadows argument, clearly does not disprove a flat earth with a close sun but scientists love it anyway) and I will leave a couple of arguments I cannot possibly explain with a flat earth. I've lived all my life in the southern hemisphere, so these things I can attest, and you could come and see.
1) There are flights from South America to Australia that last less than 15 hours and you see only water and sometimes Antarctica. I've seen this discussed lately but no satisfactory answer yet.
2) In the South we have also a celestial pole, a region around where all stars revolve (in the opposite direction than in the northern hemisphere), you cannot possibly explain this with a dome, so I've observed the 2 celestial poles myself.
I won't mention sunsets, satellites and eclipses, which are very strong round earth arguments, but I've seen flat earth answers to them that are very bad since require warping reality basically, but I'll leave them out anyway, for now.
Question: if you were to send some flat earther you trust to go to the South Pole and observe/record the 24h sun cycle around him/her, would you stop believing the earth is flat? If that is so, you should start some kind of crowdfunding...