The Second Day of Creation
On the second “day” of the world God created the firmament — that unfathomable space which stretches above us and surrounds the earth, that is, the heaven visible to us. The second creative command formed the firmament.
“And God said: let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. And God called the firmament heaven. And the evening and the morning were the second day” (Gen. 1:6-8).
The firmament is the atmosphere, or the visible heaven (sky). The origin of the firmament, or of the visible heaven, can be imagined in this way. The immeasurably vast mass of primeval liquid matter separated, at the command of God, into millions of separate spheres which revolved on their axes and were carried about, each on its own orbit. The space that appeared between these spheres became the firmament; for in this space the movement of the newly created worlds was made firm by the Lord on definite and irrefutable laws of attraction, so that they neither collide nor interfere with each other in their movements. The water above the firmament is the liquid spheres which later hardened and, from the fourth day of creation, began to shine and twinkle over our heads; and the water under the firmament is our planet earth, which is stretched out beneath our feet. All this still bore the name of water, because on the second day of creation it had not yet received a firm constitution and solid form.
It is worthwhile to note the point of one of the greatest teachers of the Church, St. John of Damascus, who lived in the VIII century. In the Irmos of the third ode of the fifth tone he says, “…Who by Thy command hast fixed the earth upon the void, and hast suspended its weight by Thine irresistible might.” Thus, St. John of Damascus discovered a scientific truth many centuries before the time when it became understood by science.