we must remember; this present universe came forth from the previous universe which was not fertile and could not bear children. The previos universe was like water with the "visible particles" floating in the "atmospheres". Because it was infirtile the big bang followed to make it fertile by way of the male/heaven's atoms impregnating the infertile female atoms.
the female atoms used to keep this universe alive but she "lost" het energy and became a heap of nothing Gen.1:2. These particles were then "sucked" into a vacuum which formed a tornado/huricane and then became top heavy and fell over from noth to south and dexploded as a result of atoms "touching each other" resulting in the explosion. this demolished the previous universe completely to create the present one. we must remember that God/the universe is still busy creating itself. The whole proses of creation started off with atoms dividing and "growing", before and now.
logically then after the explosion the scattered visible particles made it "dark" and obscured until these paticles combined into different atoms forming different "things" and because of this the atmospheres became clear, logically so. Gen.1:and God divided the light/the cleared sky from the darkness/the visible objects. hope this will help. johan.