A question for atheists about the origins of life and the universe

This is a science section, not an atheist section. Science, by definition, does not consider any kind of supernatural explanations, including explanations of the origin of the universe. Science does not compare Biblical accounts with data, although individual scientists are as free as anyone else to express their own personal opinions on any subject.

Few scientists are Biblical scholars, so this section is not a good place to seek comments on the unified content of the Bible or Biblical predictions.

The shape of the earth has been known since very ancient times, possibly as early as 7,000 years ago when sailors in the Mediterranean noticed that the mast of an approaching ship became visible before the hull became visible. The significance of the curved shadow of the earth on the moon during an eclipse was also understood by some ancients, i.e., before Biblical times which started in approximately 1,800 BCE. Since the water cycle was understood by Thales, an ancient Greek, it is fair to surmise that it was understood by even earlier civilizations.

The big bang was not, as you say, an explosion. Initially there was no space for anything to explode into; the big bang created space. The singularity from which the universe emerged was probably much smaller than an atom, and certainly not the size of a grape. If it pleases you to call the expansion of the universe "creation," then by all means do so; what you call it will change nothing.

Your vague claim about atheists claiming to know something that they can't prove belongs in the R&S section. In case you're curious, science does not deal in proofs. Science deals in probable explanations and the weight of evidence. Proofs are found only in mathematics and formal logic.