Hi abucs,
- The Chronological Gradient. Each of the three laboratories divided its sample into sub-samples, so that in the end twelve pieces of cloth were individually dated. In a well explained statistical article, Riani, Atkinson et al showed how the twelve dates indicated a chronological gradient along the sample. I think this is probably reliable. However:
a) A chronological gradient does not indicate that the Shroud is not medieval, nor that the dates found were incorrect. Quite the reverse, as a gradient may be more explicable than randomly distributed figures. The 14th century finding is not in any way refuted by the statistical analysis, nor is there any “the mathematically statistical test used to judge the acceptability of radio-carbon dating.”
b) Attempts to show that surface contamination were responsible for the chronological gradient foundered when it was shown that the further away from the corner (and therefore perhaps the less contaminated the Shroud), the younger the date, implying that contamination made the Shroud appear older, not younger, than it really is. One way in which that could be possible would be if the contamination contained mineral oil, or some other compound containing carbon with no C14 in it all. Such contamination would have to be such that it was not removed by the cleaning processes carried out by the labs prior to testing.
c) There has been speculation that some unknown physics resulting from the Resurrection itself may have altered the C14 content of the cloth, along a gradient related to the distance from the body. There is no justification for such speculation, and anyway, if the Shroud is the result of supernatural intervention, then conventional scientific investigation is pointless.
- Cotton in, or on, the Shroud. It is apparent that cotton fibres occur all over the Shroud, as observed by McCrone, Heller and Adler, Lucotte, Raes, and anybody else who has looked at the samples derived from it. The discussion centres around how much cotton there is, and whether it is merely surface contamination, from any age, or interwoven into the threads of the Shroud. The STuRP team, of course, could only observe fibres on sticky tapes, and were therefore unable to say where their observed cotton came from, while a few researchers, such as Rogers, Heimburger and Fanti, could study thread fragments from the Raes or radiocarbon samples. However, since they culd not compare their threads against threads from the rest of the Shroud, they could not say howe typical they were. Estimations of the amount of cotton vary hugely, from 5% (Fanti) to 100% (Villarreal), so that no definite conclusions can be drawn from these observations. Furthermore, the term “spliced” is extremely misleading. A splice suggests an interweaving of individual strands of two pieces of thread, for which there is no evidence, either scientific or historical, on the Shroud. There are two popular photographs of these pieces of thread, each only a few millimetres long, which authenticists frequently use to justify the idea of ‘splicing’. One simply shows a single piece of thread, which varies slightly in colour and texture along its length, as artefacts of the lighting and the handling of the thread. It is thus claimed that the two ends must be made of different materials, which is unjustified. The other is of two pieces of thread separated, and a blob of some sort of gum, which appears to have held them together. The two pieces are not unravelled, so there is no indication of a true ‘splice’ here, and I do not think the blob of gum was sufficient to have given the glued join any tensile strength at all. This was the thread fragment of which Robert Villarrreal identified both ends as being of cotton, which was rather brushed under the carpet, as it was hoped he could show that it was a cotton/linen join.
As this post is getting too long, I’ll discuss your subsequent points in a subsequent post!
