Does the cotton contamination affect a much bigger area of the Turin Shroud than first thought (say 4.4 x 1.1m)?

Here’s a comment I posted half an hour ago to Dan Porter’s shroudstory.com site:
October 22, 2013 at 2:15 am | #44

Cotton is now the fashionable marker for modern(ish) C-14 contamination, it would seem, but if I’m not mistaken the attention being focused on one tiny area of interest – the 1988 radiocarbon sample – vastly exceeds that for any other comparable area. Yet we read that cotton contamination is peculiar to the radiocarbon sample, that it’s not feature of the Shroud per se. How can we be so sure? Has anyone looked as hard and critically at a range of randomly-selected control samples?

It would be ironic, would it not, if the upshot of all this sudden interest in cotton were to lead to the discovery that the Shroud is only approximately linen, that it’s really a blend of a lot of linen (flax) fibres with a little cotton, the precise amounts of which remain to be discovered?

jaic43-01-007-ch7fg16Note the distinctive ‘twisted ribbon” appearance of cotton fibres, and the distinctive nodes of flax. In other words, the two are easy to tell apart.

Could there be a rationale for linen having a significant cotton fibre component by design rather than accident? One has only to look at the wiki entry on linen to see that there could be.

One reason for linen being a lot more expensive than cotton is the difficulty of working with flax fibres – they tend to break easily, being less elastic we are told than cotton. Might it be possible to admix enough cotton fibre with flax to get something that behaves better on the loom, but which still looks and feels like linen (cool on the skin in hot weather etc). If so, when and where might that knowledge of using lightly ‘cottonised’ thread for linen manufacture have been adopted – 1st century Palestine or medieval Europe? Is anyone else thinking what I’m thinking? Does the militant cotton-contamination wing of the pro-authenticity tendency need to be careful about what it wishes for?

Postscript: 09:38. Have just entered  (turin shroud cotton) into a search engine, and have encountered on http://www.historian.net/shroud.htm  an especially telling sentence (italicized):

****************************************************************************

FACT: The shroud is a herringbone twill with a 3:1 weave, of probably 1st century Syrian design. The flax fibrils contain entwisted cotton fibrils from a previous work of the loom. The cotton is Gossypium herbaceum, a Middle Eastern species not found in Europe. (Raes, G.: La Sindone, 1976; Tyrer, J. Textile Horizons, Dec, 1981)**************************************************************************

How can the writer be so certain that the cotton is carry-over from previous weaving, especially as cotton fibrils are “entwisted”? Would the latter n0t suggest that there was co-spinning of flax and cotton with the deliberate intention of producing a blend?

Irrespective: why all the song and dance right now on that other site about cotton in the radiocarbon sample when it seems clear from above that cotton has long been recognized as a component of the Shroud’s weave (whether there as a contaminant or purposeful addition)?

Update 12:16: am still searching under (turin shroud cotton). Here’s another finding that folk should know about if they don’t already:

The Linen

The weave of the Shroud’s linen is three-to-one herringbone twill, resembling the weave used today for denim material (Hoare 16). Ancient textile experts have repeatedly examined the material and the weave, looking for clues of its origin. Generally it is agreed that analysis of the weave itself is inconclusive; the herringbone twill weave is characteristic of both First Century and Medieval textiles alike. However, in 1973 Belgian Professor Gilber Taes (sic better known as Gilbert Raes methinks) of the Ghent Institute of Textile Technology examined the Shroud and found traces of cotton throughout the linen threads. This suggests that the equipment used to weave the Shroud had also been used for cotton. The specific cotton found within the Shroud, Gossypium herbaceum, is found only in the Middle East (Wilson 71). Even more important is the absence of any wool fibers, which certainly would have been present on any European loom. Therefore the Shroud is not of European origin (Hoare 17).

Update at 14:15: my reply to lawyerly John Klotz on shroudstory.com

October 22, 2013 at 7:46 am | #5

John Klotz: “I think I cam agree with Berry and Freeman: the C14 area contained medieval cotton and linen inter woven. To prove that it is not anomalous, demonstrate were else on the Shroud such interwoven fibers exist? Do they exist throughout the Shroud? Note, there are other patches but only some are documented.”

Whoa there. Nobody should be expected to prove that the radiocarbon area is “not anomalous”. It has first to be shown that it is anomalous! I can’t speak for NY courts of law, but that’s how science operates (onus or burden of proof etc). Declaring the radiocarbon sample to be a late intruder on account of cotton contamination is simply not evidence of it being anomalous, given that it has long been recognized that there are at least traces of cotton throughout the entire Shroud.

Time and again one finds it is the presence or absence of proper controls that distinguishes genuine science from inferior imitations. So much for the basic principles and MO of science. As for the practice, no one should underestimate the difficulty of instituting proper controls for quantifying the amounts and distribution of cotton contamination, given we are dealing at the level of individual fibres, not whole threads (there being typically 200 or more fibres per thread that would each have to be examined to check whether they were cotton or flax).

Methinks the ball is in your court, John, if you still wish to maintain that the radiocarbon dating was wrong due to contamination, at least by an exceptionally cotton-rich patch. You may find it jerst one big, cotton-pickin’ nuisance… 😉

Update: 16:30 (in response to John Klotz):

October 22, 2013 at 9:37 am | #9

Klotz:  “I believe the enormous volume of literature demonstrating the anomalous nature of the C14 sample area has shifted the burden.”

What matters is the weight and quality of evidence – not its volume.

Controls are vitally important, as also is comparing like with like. Hugh (below) mentions the use by STURP of sticky tape samples, but when you read Rogers claim that the Raes corner was more cotton-rich than his rare sightings of cotton from the rest of the Shroud you find he is comparing Raes threads with sticky tape surface extractions only (in other words, not like-with-like, since tape tends to extract surface fibres, not whole threads).

So before anyone adduces or tries to adduce cotton as evidence of patching, they have show they have searched thoroughly for it outside the radiocarbon region, and to have done so by dissecting threads, not relying on sticky tape samples. It’s not enough to say that it was not seen, if there was no systematic attempt to find it among all the flax fibres. Surface cotton fibres, being much shorter than linen fibres, may tend to be preferentially shed with age and handling, and thus be poorly represented on thread surfaces. They are also harder to see against the Mylar adhesive under the microscope than flax fibres (due to refractive index differences, or lack thereof, and thus weaker birefringence under crossed-polaroids), Repeat: one has to tease out the entire thread into its scores of separate fibres..

Update Wednesday (Day 2 of same comment thread)

October 23, 2013 at 3:05 am | #28

There is no interwoven cotton on the Shroud in chief. That is the quite positive determination of the STURP team.

I would have described it as a quite negative determination , i.e. that STURP was unable to confirm previous claims for a cotton presence. But determining whether cotton was present, and if so, in what amounts, could hardly be said to have been major part of STURP’s mission. Why should it – when there were no big controversies at the time regarding the significance, if any, to attach to cotton (they having come post radiocarbon dating). In any case, STURP’s sticky tape sampling of surface fibres could only have detected a major presence of cotton, and been hard pushed to distinguish between, say, 1% and 5% cotton, and even then we are assuming that there is no difference between flax and cotton fibres in their relative ease of detachment (by no means self-evident).

I for one will keep looking for pre-STURP references to cotton, considering that STURP is/was not the last word on the subject (and certainly not the first).

*******************************************************

October 23, 2013 at 5:09 am | #31
Radiocarbon area of Shroud, as excised by Riggi in 1988. Note the sizeable unused (retained) portion.

Radiocarbon area of Shroud, as excised by Riggi in 1988. Note the sizeable unused (retained) portion.

Why not get that retained (unused )piece – approximately half of what Riggi snipped from the corner – then punch out small discs, say 5mm diameter, of fabric along two dimensions at right angles? Each disc would be subjected to close scrutiny under the microscope (crossed polaroids etc) to determine their relative content of linen v cotton fibres.

If there’s any truth in the patch theory (which I doubt somehow) there should be some kind of systematic trends or maybe abrupt transition zones. That’s assuming the entire retained fragment is not 100% patch. If there’s been no patching, the cotton/linen ratio should show no systematic transitions or trends.

Oh, and repeat the radiocarbon dating on that same (oddly neglected) retained strip, but using a single clean-up procedure to minimize statistical noise. When the new results are announced, John Klotz, Stephen Jones etc should be allowed to subject the messenger and supporting lab staff to lie detector tests. They could also insist on the new dates being followed by a ? rather than ! mark, to avoid sending wrong signals re objectivity. 😉

*********************************************************

Advertisements

About Colin Berry

Retired science bod, previous research interests: phototherapy of neonatal jaundice, membrane influences on microsomal UDP-glucuronyltransferase, defective bilirubin and xenobiotic conjugation and hepatic excretion, dietary fibre and resistant starch.
This entry was posted in Uncategorized and tagged , , , , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s