The YEC camp doesnt seem to have any explanation for how the universe could be young.
Genesis 1 is not theory, and it is fact, and it is God's science.
Just read it and see that there was nothing, no creation, no universe, nothing.
God made the heavens and the earth. Six days later, they were completely finished and all their laws were ordained, and all creation followed them.
On day 1 God called light into being; divided the light from the darkness and the revolving heavens around the earth made night, and day -one whole Day completed, from sunset to sunset- as the heavens bearing that light and darkness revolved over the entire globe.
On day 2 God cut the waters in two. Waters is Hebrew mayim.
God stretched out the firmament between the divided waters and named the stretched out firmament sha-mayim -basically two/cut/divided mayim.
-the forces of heaven/shamayim operate electro magnetically. Stars are conductors of the electric power of the universe.
The waters of division are still above the stretched out heavens, above the stars, the sun, and the moon. They are there, and they were created right here, as part of this earth. Everything in between them is stretched out from the earth, and in the stretched out expanse, the stars, sun, and moon have their orbits/paths to follow, according to divine plan, in the revolving around the heavens earth.
On day 3, God proceeded to call the waters of earth below to be gathered into one place, and for the dry/יבשה
yabbashah to appear. He named the dry "eretz". and the gathered waters "seas/yam".
On day 4, God made the Menorah/the sun, and the moon; and set them in the stretched out heavens on day 4 of creation week to govern the light by day and by night.
On day 5, God commanded the earth to bring forth grasses and fruiting plants to fill the earth and multiply after their kind, each.
Then, God commanded the waters to bring forth flying creatures to fly in the face of heaven, and to bring forth sea creatures to fill the waters and to live in the waters, abundantly, and all were to multiply after their own kind.
Then on day 6, God commanded the earth to bring forth beasts and creepy crawlies, after their kind, and to multiply after their kind, and it was so.
Everything was perfect, and everything was finished, and everything was completed in six evenings and mornings; in six revolutions of the heavens around the globe, which was covered with one great gathering of waters, and one continent. The continent did have smaller bodies of water on it than the oceans we have today, but after the rebellion of Babel, the earth was divided up, and mankind was scattered over it with 70 tongues, so as to keep man separated and not "one people", in their evil state of fallen nature, Adam being, creatures, until God regenerates the heavens and the earth, back to its first state.
The divisions of the one continent came after the rebellion of Babel, equally, with the scattering of the tribes over the earth.