or The Universe is Flat
The three density ratios (Ω omega) and the corresponding cosmological morphology. (Goddard Space Flight Center WMAP Cosmology)
Therefore, brethren, having boldness to enter the Holiest by the blood of Jesus, by a new and living way which He consecrated for us, through the veil, that is, His flesh, and having a High Priest over the house of God, let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water. (Hebrews 10:19-22)
The “firmament” is the most troublesome element of the Creation week. Even when we understand its symbolic counterpart in the Tabernacle (the veil), how do we account for its description as a physical part of the world?
On Day 4, God created the governing lights and put them in the firmament. If this refers to some sort of “water canopy” that later came crashing down in the Great Flood, the language referring to it as a home for stars is then visual. The Adam-to-Noah pattern puts the floodgates of heaven at “Atonement,” which means the opening of this original “proto-veil” brought men face-to-face with the Ark/throne of God and washed away the sin of the world, quite literally. All flesh was cut off. All sin was covered. And it was the end of that Covenant. The sky was rolled up like a scroll. In Noah, God founded a new heavens and a new (mediatory) Altar-Land. Symbolically, the old sun, moon and stars came crashing down. They were the “mighty men” of Genesis 6. Symbolically, God put new rulers in the firmament: a body of men and animals in a covered vessel.
But, of course, the actual governing lights remained. So, there remains something beyond this original watery “sea.” The word translated “firmament” means something flat, beaten out like metal. It is architectural. Cosmologists now tell us that the universe may well be both spherical, hyperbolic and/or “flat,” a bit like the surface of the earth, I guess.  God speaks of the mediatory Land as flat because it is an Altar.  Space is a veil between men and the throne of God. Filled with lights, it pictures for us the Holy Place before God’s throne, which is populated with angels and the redeemed. This cosmic hall of government resembled a crystal sea.
But there is something strange about the account of the creation of this veil, this dark garment stretched out on Day 2. Like the “waters above” of the original Covenant, space itself has a built-in obsolescence.