Archive

Posts Tagged ‘Radiocarbon Dating’

A Guest Posting by Joe Marino: If another C-14 test is ever done . . .

November 29, 2014 49 comments

At the recent St. Louis conference, there was an open discussion regarding future testing of the Shroud, with participation by Prof. Bruno Barberis.  Naturally, one of the topics discussed was another possible C-14 dating.

After hearing comments there and after rereading some material, especially Ian Wilson’s chapter "Carbon Dating:  Right or Wrong" in his 1998 book The Blood and the Shroud, I’m becoming more and more convinced that another C-14 test would be unwise and moreover, that the Shroud is simply not, and never has been, a suitable item to carbon date.

Wilson points out in his book (pp. 190-191) that in the 1960s, 2 Harwell lab scientists warned Vera Barclay, a British proponent of having the Shroud carbon dated, of pitfalls.

Dr. J.P. Clarke told Barclay,

There appears to be some doubt as to whether the carbon content of the material has remained constant over the years.  It would be an assumption of any dating that the addition of something at a date later than that of the fabrication of the Shroud.

P.J. Anderson told her: 

The history of the Shroud does not encourage one to put a great deal of reliance upon the validity of any C14 dating.  The whole principle of the method depends upon the specimen not undergoing any exchange of carbon between its molecules and atmospheric dioxide, etc.  The cellulose of the linen itself would be good from this point of view, but the effect of the fires and subsequent drenching with water . . . and the possibility of contamination during early times, would, I think, make the results doubtful.  Any microbiological action upon the Shroud (fungi, moulds, etc., which might arise from damp conditions) might have important effects upon the C14 content.  This possibility could not be ruled out

Wilson himself goes on to say: 

That such concerns have been far from eliminated by more modern methods is quite evident from a recent booklet by Dr Sheridan Bowman, Michael Tite’s successor as Keeper of the British Museum’s Research Laboratory, in which she lists the sorts of conservation and packing materials that archaeologists should avoid using when sending their samples for processing by a radiocarbon-dating laboratory: ‘Many materials used for preserving or conserving samples may be impossible to remove subsequently:  do not use glues, biocides . . . [etc.]  Many ordinary packing materials such as paper, cardboard, cotton, wool and string contain carbon and are potential contaminants.  Cigarette ash is also taboo.’  It is worth reminding ourselves here of the variety of already listed carbon-containing materials with which the Shroud maintains daily contact, e.g., a sixteenth-century holland cloth, a nineteenth-century silk cover – quite aside from the innumerable candles that have been burnt before it, the water that was thrown over it at the time of the 1532 fire, and so on.  And those are merely the events we know about.

One other excerpt worth noting here (pg 193):

Archaeologists, who routinely call upon radiocarbon-dating laboratories’ services, tend to shy from openly criticising the results they receive, even if they do not necessarily agree with some of them, but one who certainly has no qualms is Greece’s Spyros Iakovidis, speaking at an international conference in 1989:  ‘In relation to the reliability of radiocarbon dating I would like to mention something which happened to me during my excavation at Gla [in Boeotia, Greece].  I sent to two different laboratories in two different parts of the world a certain amount of the same burnt grain.  I got two readings differing by 2000 years, the archaeological dates being right in the middle. I feel that this method is not exactly to be trusted.’ [Italics in original]

Because of such opinions–and keep in mind the above ones are by people who actually used the C-14 technique, it was all the more unfortunate and detrimental that the C-14 test wasn’t at least done as one of many other tests at the same time.  Those other tests may have provided overwhelming evidence that the Shroud was from the 1st century, and since it’s not uncommon for C-14 dates to be disregarded in some instances***, there would not be as much ink being spilled on the Shroud C-14 results.

If another C-14 test is ever done, it will take a lot more background study, and hopefully it wouldn’t be done in isolation from other multi-disciplinary testing.

***Rogue dates are common in archaeology and geology . . . Such has been my experience as an archaeologist who has excavated, submitted and interpreted more than one hundred carbon 14 samples from Neolithic, Bronze Age and Early Historical sites.  Of these dates obtained, 78 were considered credible, 26 were rejected as unreliable and 11 were problematic.  I mention this merely to inform the non-specialist . . . —William Meacham, archaeologist, Centre of Asian Studies,University of Hong Kong, 2000

* * *

Joe

Paper Chase: The Shroud of Turin and its Radiodating

November 23, 2014 18 comments

The proportion of the "youngest" threads is 32.23 % – almost a third of the total
– on the whole SAMPLE. In the case of the "cleaned", radio dated sample,
it increases to 41.65% – approaching the half.

imageIt was one of those things I had put in a stack of things to get around to. Don’t believe me if I say I didn’t have the time. I did. Maybe the best excuse I can invent is this: Those stacks, these days, are virtual, electronic reminders that buzz and beep at all the wrong times. I have developed many ways of ignoring electronic reminders. It was easier when papers piled up in stacks so high you could use them for footrests.

So I appreciated hearing from Joe Marino:

Barrie’s October 5 update had a paper from the 1993 Rome symposium by the late archaeologist Maria Grazia Siliato titled "The Shroud of Turin and its radiodating".

I think you mentioned Barrie’s update at the time but no special mention was made of this paper.  I just reread it again this morning and although I’m biased, I think it’s an excellent article that didn’t get the notice it deserved at the time and still doesn’t, but in light of all the other evidence that has come out about the reweave theory since then, I think it is a most significant paper.  Give it another read and see if you don’t agree.

I agree. The Shroud of Turin and its radiodating by Maria Grazia Siliato, translated by Dr. Augusto Monacelli, demands the attention of everyone interested in the 1988 carbon dating. Here is a sample (pun intended):

We have come to the core of the problem.

At that time, product analyses carried out by experts Timossi and Raes calculated, with good accuracy, the MEDIUM WEIGHT PER SQUARE CENTIMETER OF THE SHROUD’S CLOTH.

It was also calculated with radiographs by Morris, London and Mottern in 1978, and the result was consistent with the previous ones. The lowest average weight was the one proposed on another occasion by the operator in charge of the sample to be radio dated.

Considering the irregularities of an ancient, handcrafted cloth, and in order to move within safer margins, we have applied a prudential, surplus tolerance to the measures indicated.

Let us therefore assume an average weight of 25.00 MILLIGRAMS PER SQUARE CENTIMETER of the SHROUD’S CLOTH.

Now, the following is what happened upon TAKING THE SAMPLE FOR RADIO DATING:

1) According to the official operator in charge of taking the sample, the sample measures cm 8.1 x 1.6, namely, cm² 12.96

2) In the video showing the taking of the sample, the weight measured on the scales is mg 478.1

3) Dividing the sample’s weight by its surface (mg 478.1: cm² 12.96), we obtain a WEIGHT of approx. mg 36.89 per cm².

Therefore, the sample weighs mg 11.89 per cm² MORE than the original cloth should – at most.

4) However, the operator in charge of taking the sample says that he removed some irregularities and some "free" threads from the sample. (Let us skip the singular procedure of "rethreading" and squaring such a precious, ancient sample, wasting further irreplaceable material). The operator reduced the sample’s measures to cm 7.00 x 1.00, namely cm² 7.00)

.

WEIGHTS OF THE SHROUD AND WEIGHTS OF THE RESTORATION WORKS

SHROUD → AVERAGE WEIGHT → 1 cm² (pict. of scales) mg 25.00 cm² 12%

WEIGHT mg 478.1

SAMPLE TAKEN → AVERAGE WEIGHT → 1 cm² (pict. of scales) mg 36.89 cm² 7.00

WEIGHT mg 300

RADIODATED PART OF SAMPLE → AVERAGE WEIGHT → 1 cm² (pict. of scales) mg 42.85

The sample bears recent restoration works of mg 17.85 per cm² – accounting for 41.65 % of the total

.

5) Then the operator reports the WEIGHT of the sample, "cleaned" and distributed to laboratories: mg 300

6) Dividing the weight of the "cleaned" sample by its surface of mg 300: cm² 7.00, we obtain a WEIGHT of mg 42.85 per cm².

The sample weighs mg 17.85 per cm² MORE than the original cloth should, at most.

This element is even more surprising and irregular than that of the "non cleaned" sample.

A few millimeters away, we find differences of nearly 6 milligrams per square centimeter. (Difference between 36.89 and 42.85 = 5.96).

7) AS A RESULT, WHAT EMERGES IS THE PROOF THAT THE SAMPLE WAS IRREGULARLY LOADED WITH FOREIGN, UNDETERMINED TEXTILE MATERIAL – in other words, MANY THREADS WERE ADDED FOR ITS MENDING with various techniques IN DIFFERENT, MUCH LATER AGES.

8) The proportion of the "youngest" threads is 32.23 % – almost a third of the total – on the whole SAMPLE. In the case of the "cleaned", radio dated sample, it increases to 41.65% – approaching the half.

%d bloggers like this: