Watch Flat Earth - Fake As Wizard Of Oz Factor - Documentary Debate video on DTube
If the Earth were a globe, there certainly would be - if we could imagine the thing to be peopled all round - "antipodes:" "people who," says the dictionary, "living exactly on the opposite side of the globe to ourselves, have their feet opposite to ours: - people who are hanging heads downwards whilst we are standing heads up! But, since the theory allows us to travel to those parts of the Earth where the people are said to be heads downwards, and still to fancy ourselves to be heads upwards and our friends whom we have left behind - us to be heads downwards, it follows that the whole thing is a myth - a dream - a delusion - and a snare; and, instead of there being any evidence at all in this direction to substantiate the popular theory, it is a plain proof that the Earth is not a globe.
So the biggest evidence that the Earth is round is that you can fly around it in an airplane. Like for $1500 USD you could buy a plane ticket around the world, and you could see for yourself that it's round.
If you still think it's flat, then you're forced to entertain the absurd notion that every pilot who has flown around the world has been "in on it," and that every air traffic controller has also been "in on it," and probably many others as well. We're talking about millions of people throughout history.