|How does Carbon 14 dating work ?|
|What is the situation today ?|
The announcement, by Professor Tite, in October 1988, that the Turin Shroud was a fake, dating only from 1260 to 1390, was a shock for all who believed that the Shroud was authentic. Let us evaluate this finding without prejudice, and as dispassionately as we can.
This announcement did not encumber itself with details and did not try to explain why it was in total contradiction with all the other scientific results to date. Naturally, there was a public outcry by many who could not understand this, and who questioned the honesty and competence of the experts who had conducted the Carbon 14 dating analysis. Others tried to find out what elements, factors, or test conditions might have interfered with the carbon 14 dating to produce erroneous results. Based on all the other evidence to date these were valid questions, and questions that needed answers. There were many theories on what might have gone wrong, but this is not the place to discuss them. We have restrained ourselves to facts so far, and will continue in the same manner.
It would be tiresome to mention again all the arguements that we have already worked through in this study and which have eliminated absolutely the possibility that the Shroud, and the images on it, might be a man made fake.
We have seen and demonstrated that the the Shroud could not be the work of a medieval forger. This is completely impossible. And it does not become possible just because the carbon 14 dating would like to conclude that the object was made between 1260 and 1390.
It is therefore not enough for the authors of the Carbon 14 study to claim that the Shroud is a fake. By all accepted scientific conventions, if the result of an experiment is in contradiction with all the previous results that have been reached and rigorously tested and verified, then it is the anomylous new result that is suspect and needs to be proved, before the others. This seems to be the direction that events are finally moving, and discussions are now taking place on revised sampling and analysis procedures for a new Carbon 14 dating of the Shroud.
In the 1950s, W F LIBBY developed the theory of Carbon 14 (C14) dating. It is based on the fact that living organisms (animals, plants, etc) are composed of organic molecules which contain Carbon atoms. This Carbon is part of the Carbon cycle, one loop of which goes from the Carbon dioxide in the atmosphere, to plants (through the process of photosynthesis), to animals who eat these plants. Most of this Carbon is the normal, stable atomic form known as Carbon 12. A tiny portion of the total Carbon however, is the unstable isotope Carbon 14 which is formed in the upper atmosphere as a result of the day to day bombardment of the upper atmosphere by cosmic radiation from space. It is assumed that periodic surges in cosmic radiation, or any peaks or troughs of localised concentrations will have balanced out by the time the C14 gets to the lower atmosphere.
This unstable C14 isotope has a half life of 5 700 years. In other words through a process of radioactive decay it changes slowly back to its original form of Nitrogen 14 so that the amount of C14 reduces by half over 5 700 years, and then by half again over the next 5 700 years, and so on. LIBBY assumed that the percentage of C14 had been constant in the atmosphere for the past 50 000 years. He surmised that its rate of disappearance due to decay was counterbalanced by the constant creation of fresh C14. In the same way, living organisms are constantly replenishing their carbon, so the ratio of C14 to C12 in them remains constant as long as they are alive. But from the moment that any organism dies, the C14 to C12 ratio starts to fall, and this should fall at a rate governed by the normal half life of C14. By measuring the ratios of C14 to C12 it is possible, in suitable samples. to calculate how much time has passed since the organism ceased to live. It is a method commonly used by archaeologists to date to materials such as wood, seeds, hair, bones, paper, cloth, etc. The principle is simple and this gives the impression that this is solid law of physics.
It usually gives good results, but it has been known to fail. Two notorious examples are reported by A.A. UPINSKI in his book "L'Ènigme du linceul" :
-- Some live snails when analysed, actually gave a date of 24 000 years before Christ, (The oldest living snails we know!);
-- A Viking horn, made around the year 500, was dated by Carbon 14 at 2006 AD (5 years into our own future !).
Apart from these two caricatures there are countless other examples where Carbon 14 dating has given weird results, ranging from the dubious to the impossible. Like any other test method, there are times when something goes wrong. C14 dating is normally used to confirm what the rest of the scientific evidence indicates. When it contradicts that, the C 14 dating tests need to be repeated using fresh samples.
The critics of the result have claimed there were a number of irregularities in the analysis procedure.
The results :
The critics therefore claimed that this Carbon 14 dating was not carried out according to the normal and recommended scientific procedures, and that the results obtained were in absolute disagreement with all the other results obtained by dozens of internationally renowned scientists working in other specialisations.
The Symposium Scientifique International de Paris in September 1989 concluded that the Turin Shroud was an authentic winding sheet and not an article produced by a counterfeiter. One week later Professor Tite, coordinator of the Carbon 14 dating tests sent a letter to Professor Gonnella telling him that he had never considered that the C14 dating showed that the Turin Shroud was a counterfeit. This new approach to the C14 result was confirmed on the 23rd of August 1990 by a letter from the British Museum, which had prepared an exhibition which implied that the Shroud was a fake, and who had now decided to correct the catalogue of the exhibition, eliminating every allusion to a falsification.
The authenticity of the Turin Shroud, as a shroud, has therefore been accepted by the scientific world since 1990. The Turin Shroud is therefore a real shroud, but whose body had it contained?
This question was what the Symposium Scientifique International de Rome, 1993 set out to answer. Its conclusion, unanimous from the members of CIELT, (the organiser of the symposium), was clear : "The man in the Shroud was truly Jesus of Nazareth".
Therefore, since June 1993, the scientific world has been absolutely certain that the Turin Shroud is truly the shroud or winding sheet of Jesus of Nazareth. The date given by the C14 dating is rejected : the results published, for one reason or another, had been wrong.
It has been sincerely regretted by all concerned that passions overtook reason in this matter, and that some people, including eminent scientists, had by imprudence ? or by prejudice ? or by a taste for sensation ?, ignored that most elementary of scientific principles -- When results conflict with what has already been established, go back and do the tests again and again before publishing any findings.