According to the Genesis story, after the flood God placed the first rainbow in the sky as a sign of a new covenant that he would never flood the earth again.
Now, one can reasonable conclude therefore that there were no rainbows until after the flood. How can this be?
Could it have never rained? No, it rained
during the flood.
So we are left with just two possibilities - that light didn't refract before the end of the flood, or that water didn't refract, reflect or otherwise was altered so as not to produce a rainbow. Either way it requires a pretty radical alteration of the laws of physics.
So then, literalists, what is your explanation? Is there another way? Or did life somehow go on just the same in this wildly different world?