(Continued)
We wind the clock back for a few years here. STURP initially planned to conduct a range of different studies on the cloth, including radiocarbon dating. A commission headed by chemist Robert H. Dinegar and physicist Harry E. Gove (under the prodding of the Rev. David Sox, then secretary of the British Society for the Turin Shroud) consulted numerous laboratories which were able at the time (1982) to carbon-date small fabric samples. The six labs that showed interest in performing the procedure fell into two categories, according to the method they utilised:
Brookhaven (New York) and
Harwell (Oxfordshire) used a proportional counter approach (the old Libby method), while Rochester,
Oxford,
Tucson (Arizona), and
Zurich used the newly-developed accelerator mass spectrometry or AMS. To obtain independent and replicable results, and to avoid conflict between the laboratories, it was decided to let all interested laboratories should perform the tests at the same time.
Under the traditional method, radiocarbon-dating the Shroud would not have been feasible since it would have required at least one pocket handkerchief-sized piece of the Shroud to be destroyed for sampling purposes, and indeed, Harwell advised against such a prospect in the 1960s. The development of AMS in the late 70s, wherein smaller samples (about the size of a postage stamp) could be tested, and with much the same precision as the old method, is thus a godsend.
STURP published the list of tests which would be performed on the Shroud in 1982; However, a disagreement between STURP and the candidate laboratories devolved into a P.R. rift: STURP expected to perform the radiometric examination under its own aegis and after the other examinations had been completed, while the laboratories considered radio-carbon dating to be
the priority test, which should be completed at the detriment of other tests, if necessary. There was also the behind-the-scenes rivalry between the laboratories themselves: the inception of AMS, which needed some heavy investment and some lengthy installation time for laboratories opting for it (like Oxford), was hotly followed by traditional laboratories (like Harwell) developing a rival version which claimed to be nearly as capable of accurate radiocarbon dating from very small samples.
By 1986, the Turin protocol drafted with the help of Dr. Chagas offered a compromise. It was decided that
(1) carbon-dating would be the only test performed;
(2) as a blind test, original and control samples, indistinguishable from each other, would be provided;
(3) the test would be performed concurrently by seven laboratories, under the joint supervision of the Pontifical Academy of Science, the archbishop of Turin, and the British Museum;
(4) both dating methods would be adopted;
(5) the sample offered to each laboratory would weight 28 mg, equivalent to 9 sq. cm. of cloth;
(6) the British Museum would manage the distribution of the samples; and
(7) laboratories would not communicate with each other during the analysis, nor divulge the results of the tests to anyone but the three supervising authorities.
Of course, the events both at the front and backstage (public violation of the protocol on four counts, the feud between Chagas and Gonella and their sides, etc.) led to the eventual scrapping of this protocol, as mentioned. In 27 April, a spokesperson at the Vatican announced that contrary to the stipulations, the test likely be performed by two or three laboratories at most, which is confirmed by Cardinal Ballestrero’s 10 October reply to the laboratories.
At the end, there were three laboratories chosen on the basis of their “
experience in the field of archaeological radiocarbon dating”: Oxford, Zurich, and Tucson, all of which are AMS laboratories. The traditional proportional counter method was apparently rejected because as mentioned, it would require too much Shroud material. However, this decision was hardly perfect: the rejected Harwell alone has much more ‘experience’ than all three chosen laboratories put together. Since the Pontifical Academy of Sciences was struck out of the project (only being invited as an observer) the sole supervising institution ended up being the British Museum under Michael Tite.
This decision attracted some controversy. Gove, then director of Rochester’s laboratory (one of the rejects), argued in an open letter that discarding the blind-test method would expose the results - whatever they may be - to suspicion of unreliability. We don’t know what really happened behind the scenes, but Gonella, it seems, had had his way.