The Shroud of Turin, a linen cloth that tradition associates with the crucifixion and burial of Jesus, has undergone numerous scientific tests, the most notable of which is radiocarbon dating, in an attempt to determine the relic's authenticity.
The development in the 1970s of new techniques for radio-carbon dating, which required much smaller quantities of source material,[8] prompted the Roman Catholic Church to found the Shroud of Turin Research Project (S.Tu.R.P.
[9][10] A commission headed by chemist Robert H. Dinegar and physicist Harry E. Gove consulted numerous laboratories which were able at the time (1982) to carbon-date small fabric samples.
[27] Harry Gove, director of Rochester's laboratory (one of the four not selected by the Vatican), argued in an open letter published in Nature[28] that discarding the blind-test method would expose the results – whatever they may be – to suspicion of unreliability.
We are faced with actual blackmail: unless we accept the conditions imposed by the laboratories, they will start a marketing campaign of accusations against the Church, which they will portray as scared of the truth and enemy of science.
Also present were Cardinal Ballestrero, four priests, archdiocese spokesperson Luigi Gonella, photographers, a camera operator, Michael Tite of the British Museum, and the labs' representatives.
The labs were also each given three control samples (one more than originally intended), that were: Tucson performed the tests in May, Zürich in June, and Oxford in August,[38] and communicated their results to the British Museum.
[1] The uncalibrated dates from the individual laboratories, with 1 standard deviation errors (68% confidence), were as follows: As reported in Nature, Anthos Bray of the Instituto di Metrologia 'G.
"[3] He speculated that these products may have been used by medieval weavers to match the colour of the original weave when performing repairs and backing the shroud for additional protection.
Based on this comparison Rogers concluded that the undocumented threads received from Gonella did not match the main body of the shroud, and that in his opinion: "The worst possible sample for carbon dating was taken.
Gove has written (in the respected scientific journal Radiocarbon) that: "Another argument has been made that the part of the shroud from which the sample was cut had possibly become worn and threadbare from countless handlings and had been subjected to medieval textile restoration.
"[6] In 2010, statisticians Marco Riani and Anthony C. Atkinson wrote in a scientific paper that the statistical analysis of the raw dates obtained from the three laboratories for the radiocarbon test suggests the presence of contamination in some of the samples.
They examined a portion of the radiocarbon sample that was left over from the section used by the University of Arizona in 1988 for the carbon-dating exercise, and were assisted by the director of the Gloria F. Ross Center for Tapestry Studies.
They found "only low levels of contamination by a few cotton fibers" and no evidence that the samples actually used for measurements in the C14 dating processes were dyed, treated, or otherwise manipulated.
"[57][58] Barrie Schwortz, a member of the original STURP investigation team, commented on Fanti’s theory: "But it would be more convincing if the basic research had first been presented in a professional, peer-reviewed journal.
Others contend that repeated handling of this kind greatly increased the likelihood of contamination by bacteria and bacterial residue compared to the newly discovered archaeological specimens for which carbon-14 dating was developed.
Rodger Sparks, a radiocarbon expert from New Zealand, had countered that an error of thirteen centuries stemming from bacterial contamination in the Middle Ages would have required a layer approximately doubling the sample weight.
[59] Because such material could be easily detected, fibers from the shroud were examined at the National Science Foundation Mass Spectrometry Center of Excellence at the University of Nebraska.
Additionally, laser-microprobe Raman analysis at Instruments SA, Inc. in Metuchen, New Jersey, also failed to detect any bioplastic polymer on shroud fibers.
[61] The Russian Dmitri Kouznetsov, an archaeological biologist and chemist, claimed in 1994 to have managed to experimentally reproduce this purported enrichment of the cloth in ancient weaves, and published numerous articles on the subject between 1994 and 1996.
[77] Christopher Ramsey, the director of the Oxford University Radiocarbon Accelerator Unit, took the theory seriously and agreed to collaborate with Jackson in testing a series of linen samples that could determine if the case for the Shroud's authenticity should be re-opened.
The producer of the 2008 documentary, David Rolfe, suggested that the quantity of carbon-14 found on the weave may have been significantly affected by the weather, the conservation methods employed throughout the centuries,[80] as well as the volatile carbon generated by the fire that damaged the shroud while in Savoy custody at Chambéry.
[81][82] In March 2008 Ramsey reported back on the testing that: "So far the linen samples have been subjected to normal conditions (but with very high concentrations of carbon monoxide).
These initial tests show no significant reaction – even though the sensitivity of the measurements is sufficient to detect contamination that would offset the age by less than a single year.
Specifically: Philip Ball, a former editor of the science journal Nature, wrote in 2019 that "Nothing published so far on the shroud, including this paper, offers compelling reason to think that the 1989 study was substantially wrong – but apparently it was not definitive either.