You try to link a very focused discussion to silly deflections like the Great Wall of China or Petra, you twist my words (I never said no one in the world knew how to quarry granite at that time), you change the meaning of what I say (I never said Romans didn't built the Pantheon or that they didn't carve ornamentals into what might be repurposed columns). It's very difficult to carry on a discussion under such 'moving target' conditions.
The books you cite admit many shortcomings and extrapolations in interpretation right down to contradictions between what appears to be luxurious baths in the midst of a water shortage. They acknowledge that the interpretations of the meaning of those artifacts is in constant flux. There is no credible explanation of the engineering methods used. Simply calling those columns "blanks" doesn't make it so. Comparing the repurposed temple entrance to Petra is insultingly absurd and shows the extremes you are willing to dive into to force your point on others.
The fact is, I see evidence there that indicates that many of the objects that have been interpreted to be quarried for shipment elsewhere may have been used by the site itself to serve its own infrastructure. The fact that there is evidence of at least one settlement (5th century monastic) repurposing stonework from the fortress opens the possibility that there may have been earlier layers of civilization at that site. The list of contradictions goes on and on but you cling to your photos and extrapolations between them without really knowing the true origins of anything.
I may post something from time to time just as I've just done in reply to your "At Emperor's Edge" post (an excellent citation), but your technique of using goading intimidation as a ploy to extract a reply from another user does not work with me.
To answer the question put to me, the evidence I find acceptable is physical evidence that makes logical sense and does not contradict the hypothesis. So far, the arguments from others in these discussions contain very little of that.
PS: I do love your photobombing, the difficulty it introduces to those trying to focus the discussion, notwithstanding.
Post Edited (16-Jun-15 19:20)
How can any of us ever know, when all we can do is think?