@Truthexplorer, I stumbled onto the flat earth videos on YouTube a while back, and to be honest some of the arguments flat earthers make are slightly compelling, though not convincing, and my research into flat earth theory was purely for entertainment and curiosity.
That being said, there are (at least) 2 questions I've found that no flat earther has been able to answer. I've asked these questions in the comments section of 6-10 YouTube videos.
1. If the earth is flat, and we're on a flat plane, why is the moon upside-down to someone who is standing on the southern hemisphere? It should be right side up for everyone, unless people in the southern hemisphere are literally standing upside down on the bottom of a sphere, looking at the moon which retains its original orientation in the sky.
2. Where do tides come from? If the sun and moon are flat, and the same size (32 miles across and 3000 miles away) what causes tides? If it's still the moon causing them, why doesn't the sun cause them too?
So far I haven't gotten a single reply to these questions.