(08-03-2026, 05:30 PM)eggyk wrote: You are not allowed to view links. Register or Login to view.The merging/averaging of the different C14 results by treating the different folios as "a single object measured 4 times" is, in my opinion, nonsense. They are different pieces of parchment, and could very well have been created decades apart from eachother.
Well it's not completely nonsense -- There is a straightforward and mathematically precise approach to combine the probability distributions to form a proper combined distribution. It does, however, require additional information (without which, one must resort to the adopting of specific assumptions.). Once one adopts the specific assumption that the separate samples are all from a single source (i.e. all the parchment samples are indeed from the same animal slaughter), then the mathematical combination of probabilities is deterministic. But the technicians really should have been explicit about the fact that this was an adopted assumption, and that it is under that specific assumption (and only under it), that a combined probability distribution can be derived.
But I don't think the technicians in this case have been clear in what assumptions they are adopting. As I recall, they have only implied that they are only considering a single-source possiblity. And, even under that assumption, they have not made the correct rigorous combination of test results to arrive at their 1404-1438 range. They seem to have taken a simplistic approach.
Of course, they have also not incorporated uncertainties associated with the C-14 technique itself, but it is not an uncommon practice with tests like C-14 dating to make the implicit assumption that those uncertainties are all negligible. Still, it would be more appropriate to take several more samples, and then assume some contamination errors and throw away the most extreme outlier samples.
But, on the other hand, it is not like there is a long spread of dates with some of the very few samples tested indicating the 14th century and others indicating the 19th century. They are all from roughly the same era of being "really old" and they do still indicate a pretty reliable bound for the earliest date that the VMS could have been created. Beyond that, little can be said, since there is no reason to assume some or all of the parchment could not have been stored for years -- or centuries -- before being used.
(Before the usual complaints start getting posted that "But it is not believable that parchment would have survived unused for a very long time": Remember that the parchment for the infamous Vinland Map forgery, which was created in the 20th century, was also carbon dated. That parchment was found to have been from a date range AD 1423–1445 ... directly overlapping the date range reported for the VMS.)