Carbon 14 Dating Problems:
1988 C-14 Results: A tiny piece of the Shroud (.0014%) was Carbon-14-dated to the period 1260 - 1390 AD
There were Significant Flaws with the Process and with the Sample Area tested:
Inaccurate: Carbon dating of textiles in general has problems with accuracy: an Egyptian mummy-wrapping showed an age 700 years younger than the body.
Inconsistent: A Government test of 38 C-14 labs, which used both conventional dating method and the newer Accelerator Mass Spectrometer (AMS) method, showed actual errors 3 times greater than claimed. Only 7 labs had satisfactory results, and the AMS method did badly.
Unscientific: Original agreement was to take cloth samples from multiple places, tested by 7 labs using 2 different methods. After political maneuvering, the Church changed it to only 3 labs, with the 3 samples to be taken from only one small area. Only AMS dating was used.
Secretive: The crucial moment of placing Test Samples and control samples into metal cylinders, observed by only 3 people, Dr. Tite of the British Museum, Cardinal Ballestro of Turin, and the Cardinal’s scientific advisor, Professor Gonella, was not filmed.
Invalid: The Test Sample was too small to be statistically valid. The 3 labs tested a postage-stamp-sized area that came from the worst-contaminated and most-repaired area of the Shroud (1 sq. inch out of total Shroud’s 7,400 sq. inches).
Non-Representative: Test Sample data did not pass the “Chi-Squared” statistical test, which shows how samples in a test relate. The Chi-Squared value must be lower than 6, but the Samples’ value was 6.4; therefore, the 3 sub-samples cannot be considered to be from the same overall sample.
Non-Representative: The Weight of the Test Samples was about 42 milligrams per square centimeter, almost double the normal Shroud linen weight of 25 milligrams per square centimeter, therefore the Test Sample pieces must have contained extra material in them.
Contaminated: The Test Sample Area had been dyed with Madder Root Dye applied in a plant-gum medium, to hide repairs made after the 1532 Fire; the gum-and-dye mixture is not found elsewhere on the Shroud.
Misleading: The Test Sample had significant amounts of cotton mixed with the linen to help dye adhere (from the 1532 AD repairs). However, the Main Body of the Shroud linen has only a very small trace of cotton impurity, and it is not part of the weave. If there was merging of cotton from the year 1532 into the Test Sample Area, it would definitely have skewed the carbon-dating towards the Middle Ages.
Sorry, no. AMS was the only protocol considered as the others would have consumed too much of the Shroud in testing. The Church did not do any politicking about this. The choice of sampling change was done at the last minute, literally, and was made by one person, the person making the cuts, and was done unilaterally. These facts are well documented.
The AMS method is quite accurate. The problem was on WHAT was tested. Not on the accuracy of the tests. In fact, the accuracy of the tests is part of the proof that the sampling was completely flawed in that each of the tested sub-samples reported differing dates that were proportional to the percentages of contaminating 16th Century French Cotton they contained in relation to the original Linen Flax of the Shroud material, with the more original material reporting an older provenance, and with less original material reporting a younger provenance. Thus the sample closest to the main-body, sub-sample E, tested by the Arizona Lab, reported an origination date of 1260AD with a mix of 60% old, 40% new, while the same lab, testing sub-sample A, with a mix of 40% old, 60% new, reported an origin date of 1390AD, 130 years later. Adding in the spread of the plus or minus 25 years range of confidence, that could have been as much as 180 years difference.
The other tested samples, B and D, tested by Oxford and Zurich, ranged between the two extremes tested by Arizona, yet neither of those two sample overlapped the others. Their percentages of contamination correlate linearly to their age dating.