I had a geography teacher when i was young that kept saying the earth is flat, and when people started doubting her and calling her out for her shit she said "prove it, prove im wrong". Best geography teacher to date, we all passed with flying colours because we all tried to find ways of proving her wrong and learned geography techniques while at it. i used coordinates and distances between cities on national maps to prove that either the maps we used are wrong and cannot be used to navigate in any respectable manner. orrrrr... connecting the national maps together, respecting the distances between the cities either the earth was round, or the inside of a ball. looking at the horizon proves its not the inside of a ball, so -> earth is round