don't see the point... strong interaction/electroweak are short distance interaction. You can't hold 2 piece of macroscopic material by these forces. (and even then it wouldn't make the earth flat for simple reason of symmetry (action of these force are symetrical, which means you end up with sphérical shape at a point or another. You never end up with a flat disk.
Anyhow can buy a telescope and watch jupiter rotate on its axis, so at least by analogy that proof the earth is flat (even though you don't want to believe anything but your eyes)