And here's an experiment you can try yourself to confirm the flatness of the earth. Go outside to a wide open space. Look down at the ground. Tell me if you see that you are standing on the top of a giant sphere, or if you are standing on flat ground.
This is a childish comment, have you ever taken into account how huge the earth is? Just under 25,000 miles (assuming that you believe in a round earth). But consider this, why is it that when observing a ship through a telescope, travelling away from/towards you, the mast is the last thing to disapear (if the ship is departing) and the first thing to appear (if travelling towards you)? At this point i feel i may be told to read the FAQ and may find something about there being a slight curvature to "the flat earth" so i will put this to you, how is it possible for the sea to follow a curvature?
Another issue that i have not seen whilst briefly scanning these forums, is the Aurora Borealis/Australis. How could these two acts of scientific phenomena occur on a flat earth? I have seen maps of "the flat earth" and a magnetic field would simply not arrange itself in a pattern that is congruent to that of the north and south poles on the "flat earth".