One of the most frequent pieces of evidence I get from round earthers is that since a ship disappears over the horizon the earth must be curved. This is wrong. The reason a ship looks smaller and smaller until it disappears is simply just a matter of perspective. The further a ship goes away from the observer the smaller it appears eventually the the viewer cannot determine ship from sea and there fore the viewer wrongly concludes that the ship "sailed over the horizon"
You can see that in the diagram above the further away a ship goes the smaller it appears. Eventually line w will intersect line E and the viewer will perceive the ship as disappearing. All round earthers have to do to test this theory is watch ships leaving a harbor. Eventually the round earthers will see that the ships get smaller and smaller until they cannot see the ship anymore. Round earthers feel free to debate me in the comments I look forward to debunking them.
You should all also follow my twitter @chadoakhill https://twitter.com/ChadOakhill If you follow me I will follow back