The Greek Septuagint describes the earth’s atmosphere using the word stereoma. This is usually defined as ‘a solid body, a support, strength, firmness,’ and is used to mean a foundation, something immovable and solid. Some Bibles translate it as firmament. Yet Genesis 1, and some other verses, uses the word to refer to our planet’s gaseous atmosphere. Why?
The ancient peoples of the Near-East understood the sky to be a solid arch, or dome, made of metal.
Some Bibles translate this term as space or expanse, because the equivalent Hebrew word carries the meaning of to expand. However, scholars say that this meaning comes from the thought of hammering out metal into an expanded solid surface, not an empty space. In other words, to create a solid arch or dome.
So does the Bible teach that there’s a solid metal dome above the earth? No. It’s just what the ancients called our atmosphere because they didn’t know how it worked. They had no idea what an atmosphere was; so the Bible just used the name familiar to its readers. It would be difficult to call it anything else, because that’s what it was called back then.
As for Genesis 1, it was originally a poem or a song. It wasn’t meant to be a scientific document, it was meant to roughly convey how God created the world, speaking in terms that people back then could understand, in a few short verses. And it does that very well.
Mankind later discovered that the ‘firmament’ is not a metal dome, but an atmosphere made of gas, made possible by the earth’s magnetic field. However, just like a strong protective dome, the atmosphere and magnetic field do protect us from solar flares, cosmic radiation, and meteors.
Also, perhaps what Genesis called the ‘waters above,’ is just the blue we see in the sky, caused by the atmosphere filtering the sunlight. Some have speculated that earth once had a water canopy, which later came down during the Great Downpour. However, Psalm 148:4 indicates that the water above the skies is still present, so it could indeed refer to the blue reflection.
Interestingly, modern cosmology tells us that at one time, earth may have been a water-world without an atmosphere. The waters below (our oceans) had to, at some point, gain a new neighbor: the waters above (the blue reflection), separated by an atmosphere in between. Could the creation of our atmosphere be the event alluded to here? Perhaps.
The point of Genesis 1 is to convey, in song, that God created everything we see, by using terms familiar to its original audience.