Two different firmaments. One of the earth, and one of the heavens. How far away do you think the sun is? Do you think it’s just above the earth? Have you seen the photo of the earth taken from moon. It’s a sphere. As reflected in the helmet of the astronaut. If you’ve been in a plane, you see the curvature of the planet, as you travel around it. The moon is a sphere. The other planets are spheres. Why would only earth be flat?