What If The Earth Was Flat?
According to our understanding of physics, a planet such as Earth couldn't be a flat disk, as the force of its own gravity would cause it to collapse into a ball. But, for a fun hypothetical's sake, let's assume a disk-Earth is possible. In this case, gravity would prevent you from simply walking to the edge. Its pull toward the center would become stronger as you walked away from it, eventually causing you to feel as though you are climbing a steeper and steeper hill. Reaching the edge itself would be near impossible, because at that point, "down" and "behind you" would be the same direction.
Key Facts In This Video
If the Earth was a flat disk, approaching the edge would feel like climbing a hill that becomes gradually steeper. (0:44)
Modern "Flat-Earthers" believe that the Earth is flat, and that photographs taken from space are all elaborate hoaxes. (5:04)
To a cosmic ray proton traveling at nearly the speed of light, Earth appears to be a mere 56 feet (17 meters) thick. (7:50)