Units of time
God may have created lunar months to be exactly four weeks (28 days), and a year to be exactly 12 lunar months (336 days or 48 weeks). Then solar years god slightly longer and days slightly shorter as a product of the Fall of Sin, but lunar months stayed more or less the same.
Einstein’s Theory of Relativity
Contrary to popular belief, the speed of light is not constant, it’s actually decreasing. The speed of light may have been ten billion times faster on the Fourth Day than it is today. Alternatively, the speed of light was ten billion times faster during the Planck Era or Inflation Period than it is today. Reference: In the Beginning: Compelling Evidence for Creation and the Flood, by Walt Brown. https://www.creationscience.com/
Where did the speed of light come from? Are cosmological constants eternal? How could the speed of light just HAPPEN to be what it is?
I posted something similar last week: https://wqscience.wordpress.com/2023/04/15/the-speed-of-light-is-not-constant/
Quantum mechanics
String theory postulates that there are ten dimensions, 11 if you count time. But seven of them are small.
Could even living things have seven additional dimensions, so small that they (including us humans) cannot sense or perceive them?
Maybe God created the world to be ten dimensions, not three. Then after either the Fourth Day, the Fall, or the Flood, seven dimensions shrunk greatly and three dimensions grew to cosmological scale.
The oceans were not created salty like they are today
One issue is that most of marine life cannot survive in freshwater. Most sharks, including great whites, require at least half of the salinity of the ocean.
Maybe before the fall, the oceans weren’t exactly created freshwater, but created less salty than today.
Maybe creatures were initially adapted to more freshwater.
Noah’s flood made the oceans saltier. Then creatures had to adapt to the saltier water.