His first premise was wrong, therefore his entire thesis was wrong.
"If it were flat, the stars would rise and set for all people together and at the same time. "

http://bertie.ccsu.edu/naturesci/Cosmology/Ptolemy.html

He did not yet have knowledge of the law of perspective, which is how star rise, moon rise, and sunrise and set are explained on the flat plane of earth.

His first premise was wrong, therefore his entire thesis was wrong.
"If it were flat, the stars would rise and set for all people together and at the same time. "

http://bertie.ccsu.edu/naturesci/Cosmology/Ptolemy.html

He did not yet have knowledge of the law of perspective, which is how star rise, moon rise, and sunrise and set are explained on the flat plane of earth.

Tell us or show us how there can be a fixed Pole around which the stars revolve only visible to those who live in one part of a flat earth, and another Pole around which the stars revolve visible to people in another part of a flat Earth.

In a global geocentric Earth both these poles are easily explained. Try as I did I cannot find a relative explanation for a flat earth. 

The difference in constellation appearance in the south is due to the law of perspective, owing to its exceedingly great distance from the north pole at earth's center.

With the greatest respect Smedley, I think I will stick to the simple global version. If trying to understand what is in this video is what it takes to be a flat-earther, then do not expect too many converts.

With the greatest respect Smedley, I think I will stick to the simple global version. If trying to understand what is in this video is what it takes to be a flat-earther, then do not expect too many converts.

The flat earth is much easier to believe in than the freemason globe earth.

You are choosing to believe globe earth error.

The horizon always appears perfectly flat 360 degrees around the observer regardless of altitude. All amateur balloon, rocket, plane and drone footage show a completely flat horizon over 20+ miles high. Only NASA and other government "space agencies" show curvature in their fake CGI photos/videos.

The horizon always rises to the eye level of the observer as altitude is gained, so you never have to look down to see it. If Earth were in fact a globe, no matter how large, as you ascended the horizon would stay fixed and the observer / camera would have to tilt looking down further and further to see it.

The natural physics of water is to find and maintain its level. If Earth were a giant sphere tilted, wobbling and hurdling through infinite space then truly flat, consistently level surfaces would not exist here. But since Earth is in fact an extended flat plane, this fundamental physical property of fluids finding and remaining level is consistent with experience and common sense.