unprecedented access to the shroud. this is one of my more fascinating mysteries. john jackson, can you tell me after so much scientific testing, thousands and thousands of hours that people have dedicated, why don't we know more, since we're so good at science? >> well, we do our science as best we can. but we can only do our science on the data that is available to us. there is certainly more information we would like to have. but based upon what we have, i think we have a good case, in my mind, from the data and correlating with the gospels that we are given -- are given to us by christianity as well as some documentary evidence in roughly 10th to the 12th centuries in constantinople, that there was a cloth similar