The evidence is not just in books. These sources speak of the earthly evidence still carved in the land. The uncertainty will always be in the details, for any book, because we were not there.
We certainly do know that there were civilizations thriving around the world at the same time as the Babylonian one. There were civilizations thriving around the world at the same time as the Roman one. There is physical evidence. From what I can tell, Schizm, you have challenged my understanding of history from two angles. First of all, that it is possible that these nations could have conquered these parts of the world, because how did those people get there? You are theorizing that the Romans/Babylonians followed the same route. Or second, if that did not happen, that these peoples did not exist at all, and rose up after the Babylonian/Roman ones. I've challenged you in two areas. 1. Continuity of culture and literature. These other civilizations, Chinese and Mayan, (but there are hundreds of others) did not absorb any features of the Roman or Babylonian cultures; either in language, food, or any other feature. There are no monuments in these countries in the style of Babylon or Rome. 2. Proof of existence pre-Babylonian. Their calendars go back before the Babylonians. This is certain, even if minor features are not. Others have asked you why these admittedly vast empires built walls. You have not addressed any of that. You would not be required to make these gymnastic hoops of logic, schizm, if you re-examined your interpretation of the whole world. As a matter of perspective, It is very likely that for the Romans and the Babylonians, their empires were close enough to the whole world. To them.