While reading the bendy light threads, I thought of another phenomenon that requires some explanation on the part of FET'ers to explain the difference between what we should expect from a Flat Earth model, and what is observed.
Take the situation where the sun is rising on the Spring of Autumn Equinox, and the observer is on the equator. What is observed is that the sun rises directly in the east.
But consider a flat earth map. On an equinox, the sun lights half the earth at a time. So the light from the sun would cover exactly 1 half the circle. For an observer at sunrise, at the point when the light from the sun first reaches them the sun is 1 quarter of the way around the circle. An observer looking due east would not see the sun due east, as their view would be tangent to the east-west circle at the point where they stand. They would see the sun rising far to the north. As the day progresses, the sun will move further south until noon when the sun is directly overhead. Then through the afternoon the sun will move north again.
This means that bendy light must not only account for the difference between the expected and observed angle of the sun to the horizon, but also for the difference between the expected and observed position of the sun north-south in the sky. Except at mid-day, the sun will always appear much further north than it should be. And the difference between expected and observed changes constantly thought the day, and each day of the year. Bendy light must account for all these changes to be a valid theory. As far as I can tell, the equation on the wiki only attempts to account for the difference in angle from the horizon, but does nothing to account for the difference north-south.
And for those of you FET'ers who discount Bendy Light and rely on perspective effects to explain the setting sun, how exactly do your perspective effects account for the difference in position of the sun north-south?
EDIT: I realize that all is a bit garbled. Will try to clarify if anyone doesn't understand what I mean. In short, on a flat earth, because east-west is a circle around the north pole, when we look east we aren't really looking east, but in a direction tangent to east. But the sun circles from the actual east, which would make it appear far north of east from an observer's point of view. But what is actually observed is that the sun rises along the line tangent to east. Neither the Bendy Light formula in the wiki, nor the perspective effects described in ENaG make any attempt to explain this.