Shroud of Turin is fake, official confirms.

Shroud of Turin is fake, official confirms

A centuries-old body of controversy wrapped up in the Shroud of Turin seems at last laid to rest. Luigi Conella, scientific adviser to the Archbishop of Turin, has confirmed that radiocarbon dating showed that the shroud -- a linen relic believed by many to be the burial shroud of Jesus Christ -- was woven in the 14th century.

Although the three scientific teams conducting the first-ever carbon dating of the shroud swore to keep the results secret until the Church announced their findings, repeated rumors surfaced that those scientists had dated the shroud to a time far later than the 1st century AD. At press time the Church had yet to announce the official findings, but Gonella's comments to the media last week were widely interpreted as an official verification of those rumors.

Carbon dating of the shroud ends an era of dogged detective work by historians and intense scrutiny by scientists looking for clues to the yellowed cloth's true origin. Doubts about the shroud's origin were expressed only a few years after the cloth containing the image of a crucified man first surfaced at the opening of a new church in Lirey, France, in about 1357. Scientific investigations began in earnest in the early 1970s, when Church officials allowed scientists to stick tape on the shroud and analyze the few particles pulled away as the tape was peeled off. A more complete investigation came with a widely publicized 1978 effort by an international team of scientists, almost all of whom found no evidenced of forgery.

The 1978 tests failed to include perhaps the most definitive test, carbon-14 dating, because it would have required the destruction of a piece of cloth about the size of a pockethandkerchief. After some controversy, the Church agreed to carbon-14 dating by teams at the University of Arizona in Tucson, the Federal Technical Institute in Zurich, Switzerland, and the University of Oxford in England. They subjected the samples to mass spectrometry using a newly refined method that requires only milligrams of material (SN: 4/16/88, p.245).

Carbon-14 dating is based on the principle that the atmosphere has a small, fixed ratio of the radioactive isotope carbon-14 to the much more common isotope carbon-12. The constant circulation of carbon atoms keeps this ratio static in all living plants and animals, but after death the carbon atoms become locked in place and carbon-14 decay begins to change that ratio. Knowing how many centuries the flax in the linen shroud has been dead is simply a matter of measuring its ratio of carbon-14 to carbon-12.

The carbon-14 results are something of a vindication for one member of the 1978 team who dissented from the others by deciding the shroud was a forgery dating from 1356. After subjecting residue peeled off the shroud with sticky tape to analysis under a light microscope, Walter C. McCrone of the McCrone Research Institute in Chicago concluded the shroud was a very thin watercolor painting done in a style common to the 14th century.