Just follow simple logic. If the earth was flat, how does GPS work? How can we have days if we didn't rotate spherically? How are there seasons? How can the moon, a much smaller mass, and everything else we've ever discovered at the critical level of mass (i.e. Large enough mass to become spherical and level out) be spherical? I'm sure I could think of infinite more reasons that just follow self reasoning and need no external proof.
English
-
Flat earthers believe that the moon is about 600 miles from the earth and that the sun is only about 5000 miles away and that they revolve around us. Trying to argue with them is just senseless at this point.