Subsequently the shroud was made available for scientific examination, first in 19 by a committee appointed by Cardinal Michele Pellegrino .
Even for the first investigation, there was a possibility of using radiocarbon dating to determine the age of the linen from which the shroud was woven.
Since uranium-238 (the isotope comprising more than 99% of natural uranium) has a half-life of billions of years, it’s useful for figuring out the age of (among other things) zircons that crystallized billions of years ago. And, not for nothing, it’s also caused a thousandfold increase in lead contamination in the bodies (or bones at least) of everything that breathes and/or eats.
If you’ve ever wondered why gasoline should be “unleaded”: that’s why.
The reason carbon dating works is that the fresh carbon-14 gets mixed in with the rest of the carbon in the atmosphere and, since it’s chemically identical to regular carbon, gets worked into whatever is presently absorbing atmospheric carbon.In October 1987, the offers from three AMS laboratories (Arizona, Oxford and Zurich) were selected by the Archbishop of Turin, Pontifical Custodian of the shroud, acting on instructions from the Holy See, owner of the shroud. Samples weighing 50 mg from two of the three controls were similarly packaged.At the same time, the British Museum was invited to help in the certification of the samples provided and in the statistical analysis of the results. The age of the shroud is obtained as AD 1260-1390, with at least 95% confidence. The three containers containing the shroud (to be referred to as sample 1) and two control samples (samples 2 and 3) were then handed to representatives of each of the three laboratories together with a sample of the third control (sample 4), which was in the form of threads.First, that radioactive isotopes have a fixed half-life (totally independent of their environment).And second, that the elements they were before and after the radioactive decay have different chemical properties. If an atom doesn’t interact chemically in the right way, then it won’t be incorporated into a forming crystal.