God tells us He made a firmament or boundary of the first heaven on the 2nd Day.
Genesis 1:6-8 This defines heaven since God called the firmament heaven.
The firmament was empty, containing only air, since we are told in the New Testament that it was "in the water and out of the water" which indicates that it was floating in water.
2 Peter 3 (Blue Letter Bible: KJV - King James Version)
God spins the water from under the firmament and brings it into the enclosure.
Gen 1:9 And God said, Let the waters under the heaven be gathered together unto one place,
The water is contained in the bottom of the Biosphere.
and let the dry land appear: and it was so.
Gen 1:10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good.
We know that God spun the water to bring it into the firmament because He called the waters "Seas" which in Hebrew means a roaring, the sound made when the waters were twisted in order to bring them into the Biosphere.
The dry land was placed into the firmament and was on top of the water, with the sky above. This Earth, the Earth of Adam, was
FLAT. It's highest point is only about 22 1/2 feet above sea level,
Genesis 7 (Blue Letter Bible: KJV - King James Version) and the entire Earth had only 4 Rivers while the present Earth has thousands, indicating it was much smaller than our Earth.
Is there any wonder that ancient man believed the stories of a Flat Earth? Put dry land on top of water in an enclosed Biosphere and you will also find that
Genesis 1:9-10 describes a Flat Earth. It's the Flat Earth of Adam which was "clean dissolved" in the waters of a Universal Flood.
Isaiah 24:19