I stand by
my premise …
… I do not accept that the fact that Rome knows that there is "something out there" means that Rome knows it.
Is the Oort cloud part of the known world? Was the far side of the moon part of the known world before anyone had even seen it? Was Mars part of the known world before Voyager (or was it Enterprise?
) visited it and started to map it?
Socrates (Roman ambassador to the court of Alexander the Small, ruler of Asia Minor) said something like "Who is wise? Only he who is aware of his own ignorance."
Romans were well aware that they did not
know the Han empire?
And is there any way that Rome could possibly have been in debt to the Han empire?