26-04-2024, 07:02 PM
Hi Mark: I'm not entirely understanding all your points on this, or to what opinions or statements of mine, if any, they apply, but I'll try to answer...
When looking at the historical use of radiocarbon dating to determine the age of parchments, I had come across this:
https://proto57.wordpress.com/2011/05/13/c14-dating-of-parchment-testing-the-test-in-72/
From the above, "C14 Dating of Parchment: Testing the Test in ’72", I wrote,
"The procedure they used, discarding results based on known dates, actually showed that the tests alone could not be relied on. They would, in effect, have been clueless with undated samples. In fact, although the testers seem to present the results as though “C14 works for vellum”, they actually have this very telling passage:
Italics are mine. But the point is, this whole test of the test could be summed up as follows: “If you don’t know the date of a vellum document, C14 will not give it to you. It could be well over a hundred years off."
No doubt there have been many refinements of the process for radiocarbon dating of parchment since 1972. But from what I can tell, from the beginning, the accuracy of these tests rely a great deal on additional, outside evidence and assumptions. And usually, in the case of parchment, one has a date written on the document, or some other expert verification to buttress the results of the test. But in the case of the Voynich, the only thing we had, other than the test results, was a raft of expert opinion which overwhelmingly disagreed with the dates!
So what to do? Well you know well what I think about all this. But your point is a very good one, and also one I never couch: How good are those dates? I have found myself necessarily accepting that the raw results are correct, and would not deign to question them, as my full understanding of the methods, process and math required is short of what would be valuable. So I agree with those dates. It is a case in which I must rely on the experts, like when going into surgery or having a root canal. Not time to second guess them, no time for eight years of surgical training.
But again, a good question. How do we know? How do we know that the dates ARE correct, and this manuscript does not, indeed, match the overwhelming number of expert opinions, which I think would place it somewhere in the 17th century (not sure, I'd have to do the means and averages and all that)? And a question which I've also avoided asking... I have bigger fish to fry... Is about the change in f68 from "uncleaned" to "cleaned", and the resulting huge swing in resulting dates. Well, what got cleaned off, to change the dates? Were the other samples cleaned? If so, did their dates change? If not, why not?
We may not know the answers to all these things, but some might be found, or implied to, in the actual radiocarbon reports, which after a years-long struggle, finally shook from the tree: https://proto57.wordpress.com/2021/05/14/the-long-awaited-voynich-radiocarbon-report/
It can be downloaded from a link on that page.
TLDR: I don't know the answers to your questions, and the implications of all the unknown and possible answers are endless. Therefore, if an until there is more information forthcoming, which I doubt (forgive me), I must needs accept the raw C14 data. And, anyway, it (IMHO) supports forgery anyway.
Rich.
(26-04-2024, 06:21 PM)Mark Knowles wrote: You are not allowed to view links. Register or Login to view.Where is the evidence that error and variation in dating of historical documents like this is not commonplace? Is getting a date 100 years out quite normal when dating medieval objects without readable text? There seems to be an assumption that a higher precision in dating is normal, but where is the evidence for that? How accurately do you expect someone to be able to date an object like this without the assistance of carbon dating and on what basis do you expect that degree of accuracy?
When looking at the historical use of radiocarbon dating to determine the age of parchments, I had come across this:
https://proto57.wordpress.com/2011/05/13/c14-dating-of-parchment-testing-the-test-in-72/
From the above, "C14 Dating of Parchment: Testing the Test in ’72", I wrote,
"The procedure they used, discarding results based on known dates, actually showed that the tests alone could not be relied on. They would, in effect, have been clueless with undated samples. In fact, although the testers seem to present the results as though “C14 works for vellum”, they actually have this very telling passage:
Quote:It is interesting that the radiocarbon dates after correction and calibration for secular variations correspond to thier known historical ages. But the nature of the calibration curve first developed by Suess sometimes permits age ranges or alternative dates rather than unique dates. Consequently, for samples of unknown age it may be necessary to use independent criteria to narrow the choice.
Italics are mine. But the point is, this whole test of the test could be summed up as follows: “If you don’t know the date of a vellum document, C14 will not give it to you. It could be well over a hundred years off."
No doubt there have been many refinements of the process for radiocarbon dating of parchment since 1972. But from what I can tell, from the beginning, the accuracy of these tests rely a great deal on additional, outside evidence and assumptions. And usually, in the case of parchment, one has a date written on the document, or some other expert verification to buttress the results of the test. But in the case of the Voynich, the only thing we had, other than the test results, was a raft of expert opinion which overwhelmingly disagreed with the dates!
So what to do? Well you know well what I think about all this. But your point is a very good one, and also one I never couch: How good are those dates? I have found myself necessarily accepting that the raw results are correct, and would not deign to question them, as my full understanding of the methods, process and math required is short of what would be valuable. So I agree with those dates. It is a case in which I must rely on the experts, like when going into surgery or having a root canal. Not time to second guess them, no time for eight years of surgical training.
But again, a good question. How do we know? How do we know that the dates ARE correct, and this manuscript does not, indeed, match the overwhelming number of expert opinions, which I think would place it somewhere in the 17th century (not sure, I'd have to do the means and averages and all that)? And a question which I've also avoided asking... I have bigger fish to fry... Is about the change in f68 from "uncleaned" to "cleaned", and the resulting huge swing in resulting dates. Well, what got cleaned off, to change the dates? Were the other samples cleaned? If so, did their dates change? If not, why not?
We may not know the answers to all these things, but some might be found, or implied to, in the actual radiocarbon reports, which after a years-long struggle, finally shook from the tree: https://proto57.wordpress.com/2021/05/14/the-long-awaited-voynich-radiocarbon-report/
It can be downloaded from a link on that page.
TLDR: I don't know the answers to your questions, and the implications of all the unknown and possible answers are endless. Therefore, if an until there is more information forthcoming, which I doubt (forgive me), I must needs accept the raw C14 data. And, anyway, it (IMHO) supports forgery anyway.
Rich.