Friday, December 23, 2011

The Argument From the Shroud 2-A: The Carbon Dating

I have to admit that I wasn't entirely sure if I should write this essay. There already exists many other presentations on this subject and I felt that perhaps I could save time if I had simply linked to one of them instead of writing my own. However, since I already have all the notes in front of me, I figure that at least for the sake of my own writing I should follow through. With this said, at the end of this post I'll link some of the other presentations that I've mentioned (though only Dan Porter's comes to mind at the moment).

Carbon Politics

There has been perhaps nothing more hindering for those who believe that the Shroud of Turin is the authentic burial shroud of Jesus Christ than the carbon dating tests of the 1980's. It's easy to understand why; the Shroud stands out as if it is almost proof of the central miracle of Christianity – the Resurrection. The weave of antiquity, the dirt particles and possible pollen data that links the Shroud to 1st century Jerusalem, it's absolute correlation with the Gospel accounts of the Crucifixion, and it's still mysterious and seemingly explanation-defying image can leave many a Christian, myself included, with a strong reassurance that Christ is truly Risen.

Yet, when the Shroud was finally dated, it seemed that all this evidence was moot. The dates came in and the Shroud was Medieval in origin: ‘1260-1390!’1 as is seen scribbled behind Doctors Michael Tite, Robert Hedges and Professor Edward Hall.2


It's as if on the last 100 yards of a race a wall suddenly materialized in front of you, halting all the momentum of the final dash. It didn't make sense: all of the evidence pointed towards a date of antiquity and yet the carbon dating flew in the face of it all.

This, of course, is the first problem with the carbon dating, or rather how one uses carbon dating. Any piece of evidence in science must be utilized alongside the entire body of evidence – one piece cannot overturn all of the evidence unless the latter group is found to be faulty in some way. So in the case of the carbon dating of the Shroud, it alone can not nullify what we already know (the herringbone weave, the dirt, the pollen [though I have yet to get to these two], etc). On the flip-side, we cannot immediately discard the radiocarbon dating because it doesn't match up with either the evidence that we do have or our own a priori convictions. It is fitting then to evaluate the carbon dating in order to spot any mishaps of procedure. There needs be some exposition to all of this.

First, what is radiocarbon dating? Taken from Ian Wilson's The Shroud:

“The principle behind it [carbon dating] is that all living things, animal or vegetable, take in the very mildly radioactive isotope carbon 14, but only while they are alive. When they die this isotope ‘decays’, or loses its radioactivity, at a steady rate relative to the stable carbon 12. Libby’s brilliant achievement, for which he was awarded a Nobel Prize, was to develop a form of Geiger counter to measure this decay in organic materials such as bone from an ancient skeleton, or wood from some historic boat, or linen from what had once been a flax plant. As if from an atomic clock, Libby’s counter could ‘read’ the date on which the once living organism died.”4

The early years of carbon dating were not as refined as they are today; there are certain adjustments that are performed in every procedure that are now done routinely that were not when it was first developed.5 At this period of time using it to date the Shroud was specifically advised against by top scientists in the field of expertise.6

However, in June of 1977, AMS, accelerator mass spectroscopy, was announced.7 It was to be a more efficient way to carbon date material, both requiring a smaller sample size and having roughly the same precision in dating.8 Even here, though, scientists felt it was too soon to use the method on an object such as the Shroud of Turin.9

Those of the Libby camp purported that they too were working on a new version, one that was just as efficient as AMS.10 Furthermore, the Libby laboratories had decades of experience – the AMS laboratories did not.11 The Shroud, due to it's legendary status, became the prize crown in this “bloody war”12 between Libby and AMS advocates.13 It seemed to not be as much about the science as it was about being the victor.

When the then owner of the Shroud, “ex-King Umberto of Italy”, died in 1983, the cloth changed owners to none other than Pope John Paul II.14 Debate soon ensued in the Vatican on how to appropriately test the date of the Shroud.15 Though Professor Carlos Chagas had put forth 7 laboratories, a range that would utilize both the “old Libby method” and “the new AMS method”, Cardinal Ballestrero's reduced list of 3 AMS laboratories won out.16 The justification for the latter's was that the listed laboratories had the most experience in the field.17 This fact, however, was entirely false, as “the rejected Harwell alone [had] vastly more experience than all three of the chosen [labs] put together.”18

The Inadequacy of the Choice

One may not care that the AMS laboratories won out. Indeed, though a laboratory may be young and inexperienced, such facts cannot be used to rule out their results. However, the situation only seems to get worse the more we learn.

The area of the cloth that was chosen to be tested wasn't decided upon before it's viewing by the lead scientists Luigi Gonella and Giovanni Riggi. They argued on spot what area of the cloth should be used.19 Such lack of planning could hardly be called scientific. After this, the

“approved ‘referee’ of the exercise Dr Michael Tite of the British Museum, together with Cardinal Ballestrero, then took the three portions to a side room where, with no camera present, they placed them, together with the pre-arranged ‘controls’, into sealed canisters carefully labelled for the laboratory representatives to take away with them. A 135-milligram portion of the sliver that was surplus to the laboratories’ requirements was left over.”20

After the tests, the now infamous results were reported, leading the world to believe that the Shroud of Turin was another medieval fake. However, as we can see already, the experiments' procedure didn't seem to be the meticulous and rigorous process that science is known for. This is even more evident when we start to view the quotes of many of those involved with the Shroud. For instance, the same scientist Giovanni Riggi said: “I was authorized to cut approximately 8 square centimetres of cloth from the
Shroud…This was then reduced to about 7 cm because fibres of other origins had become
mixed up with the original fabric …”.21 Similar comments were made by “Italian author Giorgio Tessiore”, “Professor Edward Hall” (who was also the head of the Oxford Lab at the time of the testing), “Professor Raes” and. “Dr. Alan Adler”.22

Dr. Adler's contribution was especially significant as he showed there was a difference in “chemical composition” between “the radiocarbon samples” and “the non-image samples that comprise the bulk of the cloth”. That the sample was not representative of the cloth was further supported by the work of “statistician Bryan Walsh” who “showed that the data indicated that there was a 97.7% chance that the C-14 subsamples themselves are from different populations...” He also found that there was more C-14 the further distance away “from the edge of the Shroud”. Furthermore, the work of Van Haelst showed that the sample failed to pass the Chi Square test, scoring above a 6 (a 6.4 specifically) instead of below. This indicated that “the subsamples cannot be...from the same representative sample.”23

Many hypothesis were put forward as to why the Shroud turned up with a medieval date. Anything from chemical contamination, radiation, sabotage, and after-effects due to a miracle were put forward. They were all subsequently shot down for either lack of evidence, or for not being provable by science.
However, in the year 2000, Joseph G. Marino and M. Sue Benford put out the paper “EVIDENCE FOR THE SKEWING OF THE C-14 DATING OF THE SHROUD OF TURIN DUE TO REPAIRS” in which they argued that the Shroud was “patched with medieval material”, causing the subsequent date in the C-14 testing.24 Besides giving many quotes which supported their hypothesis (including all the above cited), they also provided the results of 3 blind analysis experiments in which all 3 subjects separately agreed that their was an anomaly where the Shroud cloth and the purported re-weave connected.25 They also supplied a historical reason as to why such a re-weave would have been done.

However, it wasn't until 2005 that the re-weave hypothesis became as widespread and accepted as it did. This is thanks to the work of chemist Raymond N. Rogers.

Raymond N. Rogers

When Benford and Marino presented their paper, STURP member Barrie Schwortz, the person behind www.shroud.com26, was shocked: “...this is the first credible, easy-to-understand explanation that does not require a miracle or some unknown science. I was excited.”27 Needless to say, Schwortz received permission from the authors to post their paper on his website – it didn't take long before he received a quite heated call from his friend and STURP chemist Raymond N. Rogers. Rogers claimed that the two were “'shroudies'” – those of the “'lunatic fringe'”.28

However, when he ran his own tests on some “strands of the Raes sample” he found that “clearly distinguishable cotton fibers begin appearing amongst the linen fibers” which had to have “been spliced in” since “there was no cotton elsewhere interwoven with the linen.”29 Rogers took another look at “the 1978 ultraviolet and X-ray photos” and noticed that in the corner from where the sample was taken, the color as well as the contrast stood out compared to the rest of the Shroud, indicating a difference in chemical makeup.30

Looking at his samples in greater detail, Rogers found there was an “'encrustation' on the unraveled cotton fibers” that wasn't found elsewhere on the Shroud. Furthermore, the seemingly reckless way in which it was encrusted clued Rogers in that it “had been applied as a liquid and had flowed down the threads”. This, combined with the presence of “madder root in a gum arabic base” was evidence that it had been dyed. This makes complete sense with Benford and Marino's hypothesis; since linen is very resistant to dye, anyone trying to match the color of a reweave would dye the patch so it looked similar to the rest of the Shroud.
In addition to all this, Rogers found what appeared to be a splice in the very area that “Benford and Marino believed...the patch to be.”31

Calling Scwhortz back, Rogers admitted “'they're right. I've found a splice...There's nothing like that anywhere else on the shroud.” He then turned to Dr. John L. Brown, a proficient forensic chemist who used to work for Georgia Tech Research Institute's Energy and Materials Sciences Lab. “Using different methods and technology” Brown confirmed Rogers' observations, and also noted that in areas “where 'the weave was tight enough,' the dye 'did not penetrate.'” This indicates that the dye was poured on after, compatible with a re-weave.32 To quote Brown: “this was 'obvious evidence of a medieval artisan's attempt to dye a newly added repair [in order]33 to match the aged appearance of the remainder of the shroud.'” Rogers' findings were verified yet again by Robert Villarreal of Los Alamos labs.34 “Using new high-resolution microscopes, a variety of spectroscopy and spectrometry, they found both the cotton in the sample and the 'cocoon shaped brown crust' holding the threads together.”35 Villarreal's statement is poignant:

“Apparently, the age-dating process [1988 Carbon 14]36 failed to recognize one of the first rules of analytical chemistry that any sample taken for characterization of an area...must necessarily 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. What was true for the [corner]37 was most certainly not true for the whole.”38

As for another way of dating the Shroud, Rogers used the compound vanillin which “is found in flax, the plant from which linen is made.”39 This compound “is known to dissipate slowly over centuries”. For example, the wrappings which covered the Dead Sea Scrolls, known to be about 2000 years old, “have lost all their vanillin – as has the overall shroud.” Rogers tested “Raes samples” as well as “samples of the Carbon 14 cut sent to him by Professor Gonella...and pieces of linen backing” that were “known to have been sewed [onto the Shroud] in the sixteenth century”. He “found significant amounts of vanillin in each.” In other words, the area that was purported to be a re-weave was consistent in its vanillin with other items of a medieval origin but not the Shroud itself. This further indicates that said area is indeed a re-weave. While the lack of vanillin on the Shroud by no means automatically points to a date of antiquity (since there are many variables that could affect vanillin content) the significant difference between the two do suggest different origins.

The results of the Carbon-14 datings done in 1988 are simply not acceptable when we take into account all of the above. The haphazard selection process which lead to a inadequate sample skewed the results. Thus, a medieval origin of the Shroud cannot be posited viably.

1Ian Wilson The Shroud: The 2000-Year-Old Mystery Solved, 2010. Kindle Locations 1747-1748
2Ibid, kl. 1746
4Wilson, kl. 1677-1681
5Ibid, kl. 1682-1683
6Ibid, kl. 1686-1688
7Ibid, kl. 1692-1693
8Ibid, kl. 1693-1694
9Ibid, kl. 1695-1699
10Ibid, kl. 1702-1703
11Ibid, kl. 1703-1704
12Ibid, kl. 1704-1705
13Ibid, kl. 1704-1706
14Ibid, kl. 1707-1708
15Ibid, kl. 1709-1711
16Ibid, kl. 1714-1717
17Ibid, kl. 1715-1717
18Ibid, kl. 1718
19Ibid, kl. 1723-1724
20Ibid, kl. 1728-1731
21Joseph G. Marino and M. Susan Benford EVIDENCE FOR THE SKEWING OF THE C-14 DATING OF THE SHROUD OF TURIN DUE TO REPAIRS, 2000. pp. 1 citing Riggi di Numana, Giovanni: 1988. Rapporto Sindone. Milano: 3M Edizioni. English translation by John D’Arcy (unpublished).
22Ibid, pp. 2
23Ibid, pp. 3
24Ibid, pp. 1
25Ibid, pp. 4. Subjects were Thomas Ferguson & Co. Ltd, David Pearson, and Louise Harner
26Authors note: Easily the best website on the Shroud of Turin on the internet
27Robert K. Wilcox, The Truth about the Shroud of Turin: Solving the Mystery, 2010. pp. 214
28Ibid, pp. 215
29Ibid, pp. 215-216
30Ibid, pp. 216
31Ibid, pp. 217
32Ibid, pp. 218
33Wilcox's brackets
34Ibid, pp. 220-221
35Ibid, pp. 221
36Wilcox's brackets
37Wilcox's brakets
38Ibid, pp. 221-222
39Ibid, pp. 218