The Data and the Dateby Emanuela MARINELLI - Naturalist and Geologist
(from "Collegamento pro Sindone" - September/October 1988)
Reprinted by Permission
E. Hall, M. Tite and R. Hedges during the press conference
at the British Museum on October 14, 1988
© 1988 Saint-Pares-les-Vaudes
Finally the result of the 14C has arrived, and the mass media have broadly reported and commented it. It's a result in blatant contrast with all the elements supplied by the other scientific researches. Beyond the emotional reactions, we try to examine the facts serenely, confirming our trust in the scientific means that, when are honestly and correctly used, can take only to the truth.
Not being yet the publication on a scientific magazine, we must base ourselves only on the announcement of Card. A. Ballestrero spread in Turin last October 13.
The statement "the Shroud is false" or still worse "the Shroud is a forgery" doesn't exist in this announcement. One reads that to the Shroud it has been "assigned" by this investigation an interval of date between 1260 and 1390 A.D. and that one refers to science the evaluation of these results. In the meantime the problem of the image, still unsolved, will demand further researches.
Waiting for that the "good brains" will set work again for other investigations, we try a comment evaluating the elements in our possession and formulating some hypothesis.
FIRST HYPOTHESIS: The Shroud is really indeed medieval.
In a mosaic of tens and tens of concordant elements for the authenticity, this datum sounds false, extraneous. A wedge that doesn't agree with the harmony of all the others.
However the firm point that this sheet wrapped a real dead body and that it is not a handicraft work doesn't change. About this, scientists have provided incontrovertible proofs.
One should therefore hypothesize that a man was expressly tortured and killed simulating Christ's Passion in its slightest details, also those unknown in the Middle Ages, like the nails in the wrists, the crown like an helmet, the transport of the only "patibulum", etc. This dead body, removed then from the sheet with extreme caution after few hours, there would have let engraved on it this image still inexplicable.
Certainly, nothing is impossible, however this hypothesis is in evident contrast with the logic, and makes the mystery of the Shroud still thicker, with possible exceedings toward the hypothesis of a miraculous origin of the image.
SECOND HYPOTHESIS: There was a "plot" against the Shroud.
This hypothesis, reasonably little reasonable, was however nourished by the disagreeable and little clear facts happened during last months. The experts of the laboratories had to act separately; they had to date the pieces of cloth blindly and instead they have identified the Shroud samples (otherwise the indiscretions now resulted found could not have spread out); they didn't trust in the Cardinal and they wanted to be present during the taking, but they didn't invite representatives of Vatican during the proofs; they made instead enter extraneous like H. Gove and D. Sox, this latter well-known like relentless enemy of the Shroud's authenticity. With which cheek then Prof. E. Hall, director of the laboratory of Oxford answers to the indiscretions affirming a month ago (Il Tempo, September 10, 1988) that "the date is not that one..." and then he joins the other two laboratories in declaring that the Shroud is medieval and didn't dislike this?
The polemics broken out following all these facts have left much disgust and so many doubts in the public opinion. How could one trust in the work of people with a so incorrect behavior?
THIRD HYPOTHESIS: The 14C missed.
It is known that this method, propagandized as "infallible," "the casting out nines," is not always so precise and reliable as one would like. It bases itself on the existence in nature of radioactive carbon that forms in the atmosphere because of the bombardment of the cosmic rays on the nitrogen nucleuses. This radioactive carbon, the 14C, combines with the oxygen and forms radioactive carbon dioxide that is assimilated by the living beings in very little quantities together with the normal carbonic dioxide, formed by the most common and calm 12C.
When, as the death of the organism, biological metabolism stops, there it is no more assimilation of carbon of the environment. But while the carbon 12 existing in the dead organism remains unchanged, the 14C suffers the radioactive "decay", changing into nitrogen 14 and giving out a beta particle and a neutrino.
More time goes by, less 14C remains in the rests of the organism. The dating, that measures how much 14C is still present, and in proportion attributes a date, counting the particles beta given out by the sample in exam for a certain time, bases on this phenomenon. In substance one estimates how much 14C is present, assuming that it all derives from the biological exchange that the organism had when was alive. If then, the sample was contaminated by other 14C of various origin, this too goes into the calculation; the sample results in this way more radioactive, and, in order to the dating, "younger."
For the calculation one needs very sophisticated apparatuses of revelation, because the beta particles given out by the carbon 14 have a low specific activity (about 13 disintegrations for minute for a gram of carbon) and a low energy.
The precision of the method depends also by the sample quantity at disposal. To have satisfactory results on a skeleton it would be necessary to sacrifice around a kilogram of bones. It's obvious that more the samples are small, more the result is unreliable.
Moreover, it remains however an "uncertainty of measure" due above all to the statistic fluctuation of the calculations in successive intervals of time. Other factors of uncertainty are the extent and the fluctuation of the "leading radiation" (environmental radioactivity and cosmic rays), residual impurity, the contamination in the preparation of the sample, the uncertainty about the constancy of 14C decadence, the uncertainty about the joined quantity of 12C. All these factors are considered overall inferior to the statistic error and they provoke an uncertainty in the dating of the order of ± 100 years.
The problem is that some postulations on which the method bases itself (constant rate in the years of the 14C in the atmosphere, constancy of the rate of 14C decay) today are discussed.
We haven't the certainty that the cosmic rays in the past were constant, and from calculations it results that there is not equilibrium between the quantity of 14C that forms and that on of 14C that decomposes. Moreover it is much discussed the speed of decomposition of 14C; the dating system is valid only if this speed is known and constant. But the studies have ascertained the presence of anomalies.
The time of "halving" of 14C (that is the necessary years so that in a sample the quantity of 14C is reduced to a half because of the decadence) was estimated by W.F. Libby, the inventor of the method, around 5568 years. In 1962 was fixed a time of 5730 years, officially used yet; but some laboratories propose even periods between 7200 and 4700 years (Marco A. Politi, La datazione al radiocarbonio, Scienza e Vita Nuova n. 3, March 1988). It must be finally considered that as from the 60's the nuclear explosions in the atmosphere have provoked an increase until 100% of radioactivity in atmospheric carbon.
There are in the scientific literature clamorous cases of fake datings. We quote only some examples.
- The prehistoric station of Jarmo was dated 4700 B.C. New proofs have provided like approximate epochs 10000, 7000 and 6000 B.C.
- In the case of strong atmospheric pollution exceptional cases could verify: plane leaves picked in Rome a year before appeared old of 400 years because they had absorbed carbon from the air due to the combustion of oil, ancient hydrocarbon and therefore poor of 14C.
- Archaeological finds attributable to historical precise periods (for example dated back to any dynasty of the ancient Egypt) with the 14C appeared younger than any hundreds of years.
- Yet unsolved the problem of the Man of Lindow, dated in a first time to 300 B.C. by Harwell laboratory with the conventional methods and subsequently, with the new method that can date small samples, attributed by Oxford to the I century A.D. and by Harwell to the V century A.D.
- In 1983 six laboratories dated two samples with age already known by other way, and one of the two resulted with more recent date than the known one.
Other cases are quoted in an exhaustive article published by the American archaeologist W. Meacham.
FOURTH HYPOTHESIS: The 14C has done its duty, but the Shroud is a particular thing.
This hypothesis is to consider with still more attention. The alterations of a sample can weigh heavily on the dating, and there are contaminations practically uneliminable. It's enough to consider that normally the samples to examine with 14C must not be handled in the open air with smoke of cigarettes and they must not come to contact with labels of paper and with fabrics that contain recent carbon. We could imagine then what kind of weight could have the historical vicissitudes of the Shroud!
The transformations on molecular level suffered by the Shroud during the fire of Chambéry can have been determinant. If one considers then the contamination due to the moulds, to the smoke of the candles, to the sweat, etc. and to the secular narrow contact with the cloth from Holland and other cloths still more recent, one can conclude that before rushing to support that the Shroud is of the Middle Ages would be preferable to conduct further, different and more complete investigations.
Someone could, at this point, object: "Why didn't you write all this before? Do you shut the stable-door when the horse has bolted?" or "You tell this deliberately, because you want that the Shroud is authentic whether it is or not!" To us of Collegamento pro Sindone this accusation cannot be moved at all. Personally I reminded the existing problems with the 14C in the conclusion of an article appeared on Il Messaggero on November 12, 1986. We have devoted ample space to the problem of the 14C in the number of September/October 1986. With our usual impartiality we quoted the favorable voices and those contrary, the hopes and the doubts. We will continue to occupy ourselves with the problem of the Shroud with unchanged interest and we will give space in the next numbers also to the problem of the dating.