Religion: Debunking The Shroud of Turin

Since the Middle Ages multitudes have believed that a piece of linen enshrined in Turin, Italy, is the burial shroud that Jesus Christ left in the tomb when he rose from the grave. But last week Turin's Anastasio Cardinal Ballestrero calmly announced that scientific testing proves the yellowing 14- ft.-long fabric is only six or seven centuries old and could not have dated from the time of Jesus. Thus ended the most intense scientific study ever conducted on a Christian relic.

The new findings may please skeptics, but the shroud saga is not a major embarrassment for the Roman Catholic Church. Shortly after the earliest known exhibit of the shroud, in 1354, a French bishop declared it to be a fraud. Through subsequent centuries the church refused to confirm its authenticity. The examination that finally discredited the shroud was conducted with the full blessing of the church, in an unusual alliance between honest faith and objective science. When Pope John Paul was informed of the negative report two weeks ago, he ordered, "Publish it."

Ballestrero had initially agreed to an extraordinary series of scientific tests on the shroud in 1978, but refused to permit carbon 14 testing, which was crucial to determining the fabric's age. Handkerchief-size samples needed to be cut out, which, to Ballestrero, was unthinkable for such a revered historical item. After technical improvements made it possible to use samples the size of postage stamps, however, the Cardinal allowed cuttings to be taken last April.

Testing was done simultaneously at the University of Arizona, Britain's Oxford University and Switzerland's Federal Institute of Technology in Zurich. Each laboratory received four unmarked samples: a shroud cutting and three control pieces, one of which dated from the 1st century. The samples were chemically cleaned, burned to produce carbon dioxide, catalytically converted into graphite and then tested for carbon 14 isotopes to fix the date by calculating the amount of radioactive decay. Only London's British Museum, which coordinated the testing, knew which samples were which.

Arizona's Physicist Douglas Donahue says that the three laboratories reached a "remarkable agreement," all estimating dates within 100 years of one another. Averaging of the data produced a 95% probability that the shroud originated between 1260 and 1380 and near absolute certainty that it dates from no earlier than 1200. However, some Catholics held out the slim hope that there was a scientific oversight and the shroud might be redated someday.

The dating dispute may be settled, but the shroud remains as mysterious as ever. Reason: it bears an inexplicable life-size image of a crucified body, which is uncannily accurate and looks just like a photographic negative -- occurring centuries before photography was invented. The elaborate 1988 testing failed to produce any agreed explanation of how the image, which is indistinguishable from close up, could have been imprinted. There is, for instance, no evidence that it was painted.