ColinB thinks I’m evading the question. This is enough until he does some reading on his own.

ColinB aka writes back:

OK Dan, so I can understand why you dislike the claim that the reweaving of the sampled regions took place after the fire, as a response to the fire. Who in their right mind would go the trouble of invisible, or near invisible reweaving on an inconspicuous corner of the cloth, given the damage elsewhere. But you have still failed to address my original question. Why would anyone, Margaret of Austria included, have commissioned repair by reweaving BEFORE the fire? What would be the point? It’s only an inconspicuous corner of the cloth, after all.

Here is some helpful reading.

1. [PDF] Historical Support of a 16th Century Restoration in Shroud C-14 … (2002)

2. [PDF] New Historical Evidence Explaining the Invisible Patch in the 1988 … (2005)

3. [PDF] Invisible Mending and the Turin Shroud: Historical and Scientific … (2008)

One good explanation is that Margaret bequeathed a piece of the shroud to her church. Remember, this was private property. Remember, too, that relics or even pieces of relics were thought to have special, even magical qualities (many still think so). She then arranged to have the spot rewoven.

Why do it so expertly that even the scientists and Vatican overseers some 6 centuries later imagined it was the original shroud that was being sampled? Why would Margaret etc interfere with a supposed Holy Relic? Why risk compromisinmg its authenticity in any way?

Call it medieval souvenir collecting. It was very common with relics. Cloths of saints were divided among many church and private owners. It still goes on.

Sorry, but for all your welter of words, punctuated with those inevitable putdowns that seem par for the course on internet forums, you have failed to address the objections I raise, ie. to your “contamination by reweaving” hypothesis . Yes, hypothesis. But I need hardly remind you that the onus is not on the scientist to prove the fabric was not contaminated. No one should be asked to prove a negative. The onus is on you and others to prove that it was contaminated, which you have so far failed to do… I can see that it is a handy out for those who want to rubbish the C-dating, but it’s hardly scientific, is it, to conjure up red herringss, and expect others to prove you wrong. Can you prove that Kepler-22b and all the other exoplanets are not made of green cheese?

Actually, it is not contamination by reweaving that needs to be established as a scientific hypothesis. Rogers (and others) proved that the material of the sample area was chemically different than the rest of the cloth in two significant ways. Reweaving is a plausible explanation from history.

1. There were significant quantities of cotton, madder root dye, aluminum (likely from alum mordant) and gum (possibly Arabic gum) in the sample area. These materials do not exist in significant or measurable quantities throughout the whole shroud. That is proof of material intrusion, in this case or more precise terminology than contamination. 2) The sample area contained significant amounts of vanillin. The rest of the cloth contained no detectable vanillin.
2. Microchemical tests reveal vanillin (C₈H₈O₃ or 4-hydroxy-3-methoxybenzaldehyde) in an area of the cloth from which the carbon 14 sample were cut. But the rest of the cloth does not test positive for it.  Vanillin (vanilla) is produced by the thermal decomposition of lignin, a complex polymer, a non-carbohydrate constituent of plant material including flax. Found in medieval materials but not in much older cloths, it diminishes and disappears with time. For instance, the linen wrappings of the Dead Sea scrolls do not test positive for vanillin. (The kinetics constants for calculating the loss of vanillin from lignin are E = 29.6 kcal/mole and Z = 3.7 X 10exp11/second). Quantitative counts of lignin residues show some large differences between the carbon 14 sampling areas and the rest of the Shroud. Where there is lignin in the sample area it tests positive for vanillin. Other medieval cloths, where lignin is found, test positive.  The main body of the Shroud, with significant lignin at the fiber growth nodes, does not have vanillin. The Shroud’s lignin is very old compared with the radiocarbon sampling area.

Here is a collection of reading for you:

1.  Thermochimica Acta (Volume 425 Issue 1-2, 2005, pages 189-194, by Raymond N. Rogers, Los Alamos National Laboratory, University of California) – The peer-reviewed article is available on Elsevier BV’s ScienceDirect® online information site. The abstract reads:

The combined evidence from chemical kinetics, analytical chemistry, cotton content, and pyrolysis/ms proves that the material from the radiocarbon area of the shroud is significantly different from that of the main cloth. The radiocarbon sample was thus not part of the original cloth and is invalid for determining the age of the shroud.

Ironically, Rogers was trying to prove that the “results are accurate and the samples came from the shroud.”

2.  Microscopical Investigation of Selected Raes Threads from the Shroud of Turin by John L. Brown, retired Principal Research Scientist at the Georgia Tech Research Institute’s Energy and Materials Sciences Laboratory. This is a 2005 independent, by-different-means  confirmation that the carbon 14 dating was flawed.

3. The 2008 work of Bob Villarreal and a team of nine scientists at the Los Alamos National Laboratory which confirmed that the carbon dating of the Shroud of Turin is wrong. According to Villarreal:

[T]he [1988] age-dating process failed to recognize one of the first rules of analytical chemistry that any sample taken for characterization of an area or population must necessarily be representative of the whole. The part must be representative of the whole. Our analyses of the three thread samples taken from the Raes and C-14 sampling corner showed that this was not the case.

4. Chemistry Today (Volume 126, Number 4, pages 4-12, July-August 2008 by M. Sue Benford and Joseph G. Marino). Discrepancies in the radiocarbon dating area of the Turin shroud. 

5.  A 2009 paper, Cotton in Raes/Radiocarbon Threads: The Example of Raes #7, by Thibault Heimburger; published on the STERA site.

6. A 2010 paper, Carbon Dating of the Shroud of Turin: Partially Labelled Regressors and the Design of Experiments, co-authored by Marco Riani, Anthony C. Atkinson, Giulio Fanti and Fabio Crosilla; recently published on the website of the London School of Economics. The abstract reads:

Bottom line. There is sufficient reasonable doubt about the carbon dating. It was the British Museum and the labs who failed to do a good job, failed to account for apparent material intrusion, failed to chemically characterize the samples, etc. Red Herring, my ass.