Flat Earth and Dome of the Earth proof if proof were needed. What shape is a rainbow, is it a semi circle?

Indeed. The rainbow starts in the South of the flat Earth and 'curves' itself around the dome of the Earth and lands in the the North, this forms a 'semi circle' if you will. This This proves that the Earth is flat because if it was not rainbows would be circles...

Of course this is just a creation science hypothesis devised by the great and the good of of this particular discipline of science, but I feel the reasoning on this one is will clearly form our scientific model moving forward.

Thoughts?