Centrus speculates:
Moses wrote Genesis upon the inspiration of God. I guess the assumption is that Moses was curious as to how the Earth was created, and questioned God. Thus, God explained it to him, and Moses later recorded it for others to read. Moses simply wished to portray how he was told the world was created (and maybe he did so slightly inaccurately, who knows? But I choose to believe he didn't), and so complicated things like the fundamental structure of matter did not concern him, just as they would not concern (but confuse!) the majority of his readers.
Perhaps God answered Moses' questions at a level that Moses could understand, without going into the singularity, atomic structure, quantum physics, cosmology, geoscience, bioscience, etc.
Of course had the Bible gone into such details, even with God patiently teaching Moses, would it have been understood by the audience that Moses ultimately would have to confront? Would that portion of the Bible have even survived their incredulity short of divine intervention.
However, even the slightest hint such as providing the acceleration due to Earth's gravity, would have rendered athiesm and even this forum problematical. Guess too much truth was not part of the plan, or at least more truth than your average bronze-age mentality could handle.