While writing my first article about the dome, I proved the physical need for a rigid vault acting as a ceiling. In the lack of an enclosure top, the atmosphere would diffuse, with all its gases, in the outer space. Hence you can understand the absolute necessity of the presence of a dome. It’s the only way to obtain a stratification, with the lighter gases rising to the upper layers under the top. That is a clear demonstration of the existence of a solid top over the flat earth.