Thursday, February 28, 2008

Shroud of Turin Gets High-Def Scrutiny


The Turin shroud, the 14- by 4-foot linen long believed to have been wrapped around Jesus' body after the crucifixion, has entered the digital age.

A huge 12.8 billion-pixel image was made of the linen, on which the smudged outline of the body of a man is indelibly impressed. The image was made following a Vatican request to obtain the most detailed reproduction of the yellowing ancient cloth. The technology allows a level of scrutiny of the linen as never achieved before.

"The Shroud has been photographed in high definition for the first time. We have stitched together 1,600 shots, each the size of a credit card, to create a huge photo which is almost 1,300 times stronger than a picture taken with a 10 million pixel digital camera," Mauro Gavinelli, technical supervisor at HAL9000, a company specializing in art photography, told Discovery News.

According to Gavinelli, who also created the world's highest-resolution photo when he digitalized Da Vinci's "Last Supper," the technology allows researchers to analyze the shroud in unprecedented detail.

"It is like looking at the Shroud through a microscope. You can see the threads, the fibers that make these threads, the damage that the shroud has suffered over the years," Gavinelli said.
As hundreds of shots were taken using sophisticated equipment, the process, itself, was recorded by the British Broadcasting Company, which will be airing a program about the project on the Saturday before Easter.

"It was fascinating. Seeing the shroud within a few inches is a unique experience. The image is very visible, it isn't true at all that it is fading," said David Rolfe, director of the BBC documentary.

Kept rolled up in a silver casket, the shroud has been shown only five times in the past century. When it last went on public display in 2000, more than three million people saw it. The next public display will be in 2025.

Scientific interest in the cloth, which has survived several blazes since its existence, began in 1898, when it was photographed by the lawyer, Secondo Pia. The negatives revealed the image of a bearded man with pierced wrists and feet and a bloodstained head.

Venerated by many Catholics as proof that Christ was resurrected from the grave, the shroud was eventually dismissed as a brilliant, medieval fake twenty years ago. Carbon-14 tests at three reputable laboratories in Oxford, Zurich and Tucson, dated it to between 1260 and 1390.

After the tests, the Oxford laboratory's founding director, Edward Hall, told journalists: "Someone just got a bit of linen, faked it up and flogged it."

But shroud scholars, known as sindonologists, have always argued that no medieval forger could either have produced such an accurate fake or anticipated the invention of photography.
Speculation about the linen cloth continued as well as debates over the validity of the carbon-14 tests.

"There is the possibility that new carbon-14 tests today will produce different results. A new hypothesis has been formulated, and it deals with information that wasn't available twenty years ago," Rolfe said.

The new hypothesis, developed by "another contributor to the film," according to a University of Oxford press release, is being tested by Christopher Ramsey, director of the Oxford Radiocarbon Accelerator Unit. The results will be revealed in the documentary
Ramsey, a top expert in the use of carbon dating in archeological research, is skeptical the new theory will prove that the carbon dating tests were inaccurate.


"I keep an open mind--as I would about any scientific investigation. However, my strong intuition, based on my experience in this field, is that the new hypothesis will not challenge the accuracy of the original radiocarbon dating exercise," Ramsey said in a statement.

The new theory would only require two percent contamination to skew the results by 1,500 years--not much considering the shroud's long history, handling and exposure to the elements.
"There is nothing new, as far as I know, which would change the situation. These ideas have been raised previously and none has been shown to have any merit. Many hypotheses, such as contamination, fire changing the results and more dubious assertions have been made, but none has seriously challenged the 1988 dating," Timothy Jull, a professor in geosciences at the University of Arizona who specializes in carbon dating, told Discovery News.

Indeed, numerous theories, such as a plastic coating built up on the linen by millions of tiny micro-organisms, have been presented to explain how the radiocarbon tests could have been inaccurate. All have been rejected by the scientific community.

In 1998, Ramsey himself tested the possibility that carboxylation of the cellulose in the linen during the 1532 fire could have produced a younger dating, but concluded that "carboxylation is not a systematic source of error in the dating of cellulose-containing materials such as the linen in the Shroud of Turin."

The latest research, by the late Ray Rogers, suggested that the sample used to test the age of the shroud in 1988 was taken from a medieval rewoven area of the shroud.

Whatever the outcome of Ramsey's tests, the high definition images are expected to add new complexity to one of the most controversial relics in Christendom.

"The Shroud has yielded surprises each time it is subjected to a new form of reproduction. The first time it was photographed, it revealed its negative characteristics. Then it was scanned and turned into a tridimensional image. Now we have filmed it in high definition. We are already seeing some interesting effects," Rolfe said.



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