This is the same question that I myself asked myself, and the reason why I registered here.
According to the FAQ, the sun and moon are spotlights, and their apparrent rising and setting on the horizon is merely an optical illusion. Could someone please explain how that is supposed to work? Right now that explanation seems completely arbitrary to me, just like most of the other "explanations" provided by FE'ers. After all, every single piece of observable evidence shows that the earth is round. The distance to individual stars can be measured trigonometrically, which has proven that they are definitely not 3000km away. The curvature of the Earth's surface is easily visible from a height or when the horizon is not obstucted. There is an overwhelming amount of images and video material showing that the Earth is in fact spherical, and not only from those evil government agencies who are allegedly trying to hide the true shape of our planet from us. The spherical nature of the Earth and all other planets in the solar system, not forgetting the sun, explains logically and comprehensibly why we see what we see when we look up at the sky.
So, again, how can the rising and setting of the sun and moon possibly be explained away as an optical illusion when the most logical explanation is also the most obvious: the Earth is round. The Flat Earth theory provides no proof at all, instead resorting to the wonderful explanations of "it's an illusion" and "it's a conspiracy". Though we see no comprehensive motives for the conspiracy, no scientific proof for the so-called illusions and absolutely no logical arguments whatsoever against the widely accepted fact that the Earth is round.