Assuming we go off the fact that plate tectonics some how work on a flat earth, we must also assume that under the surface is magma. So...what's under the magma? How would that connect to the surface? And if there is something under it, how does it not crumble away into the abyss below the accelerating disk? And if we assume there isn't magma under the surface, how do plate tectonics work? Are those even possible on a flat earth, the way they work on a round one? If they are, can anyone describe how they would fit together to give the same affect they would on a round earth?