By Steven Saint

Physicist tries to prove Shroud of Turin's authenticity

The Colorado scientist's theory may overturn scientific dating of cloth to medieval times

As scientists continue to examine how greenhouse gases affect global climate, one researcher believes too much carbon in the atmosphere might be masking the true age of the Shroud of Turin.

Physicist John Jackson, long-time head of the Turin Shroud Center in Colorado Springs, Colo., wants to reopen the 1988 radiocarbon tests on the shroud.

Those tests, performed by three different laboratories, indicated the relic was made between 1260 and 1390.

Vatican officials did not dispute the 1988 findings but maintained the shroud's value as an icon. Jackson, however, suspects that increased levels of carbon monoxide in the atmosphere have enriched the cloth with carbon, skewing the carbon-14 date.

If he can demonstrate this effect on linen in the reaction chamber of his basement lab, Jackson will get the University of Oxford's Radiocarbon Accelerator Unit to join in a new study.

"You only need a 2-percent contamination from carbon monoxide in order to move the date back 1,300 years," Jackson says. "That's a real revelation to us in the shroud world."

Case for the shroud

The shroud world is populated with people debating whether or not the Shroud of Turin, which has been exhibited in various churches since 1357, is the burial cloth of Jesus. Jackson, 62, believes that it is -- but, as a physicist, he wants to see if science can verify that claim.

In 1978, Jackson led a team of U.S. scientists who went to Turin to examine the shroud and catalog data. The Shroud of Turin Research Project (STURP) studied the image of a man, whose front and back views on the 14-foot-long linen cloth were best seen by the naked eye in a photographic negative.

The team was stumped on how the image had been made, but ruled out paint or pigment of any kind in favor of discoloration caused by the dehydration of fibers in the image area.

They also found Type AB blood stains that correspond with the wounds of a crucifixion victim -- hands, feet, forehead and a larger stain on the side.

Jackson was particularly impressed that the hand wounds appear in the wrists. This detail about crucifixion is better known to modern researchers than it was to medieval artists, who universally painted the wounds in Christ's palms.

Researchers found flower and pollen from species consistent with the Middle East and even associated with herbs used in Jewish burial practices.

Jackson found himself spending most of his spare time studying various aspects of the shroud with the scientific method, creating three-dimensional models from light-intensity ratios and even suspending himself from a cross to check blood-flow data.

Then in 1988, the Vatican allowed a small strip from the edge of the shroud to be subjected to radiocarbon dating. Three labs dealt a blow to shroud-hopefuls by returning a medieval age for the cloth.

"The carbon dating didn't fit the rest of the evidence," Jackson insists. "Thirty years of historical and archeological research say the shroud is authentic, but the carbon dating did not. How do you resolve this?"

Carbon science

Radiocarbon dating is a system of measuring the precise decay in certain radioactive isotopes found in carbon. While the method is universally accepted by scientists, there is a margin for error and the possibility that materials can become contaminated, skewing the results.

One theory advanced by scientists soon after the 1988 lab results was that the sample from the shroud had been inadvertently cut from a medieval repair section. Recent research by STURP veteran Raymond Rogers corroborated the idea that the sample area was not part of the original shroud.

Other experts have argued that bacteria could have contaminated the sample cloth and skewed the dating results. The cloth's edge had been handled by human hands for centuries as the shroud was folded, packed, displayed and repaired.

For these reasons, many have called for a chance to test another section of cloth, but custodians at the Cathedral of St. John the Baptist in Turin say they won't consider such requests until at least 2010, when the stored shroud is scheduled for its next public exhibition.

In the meantime, Jackson is testing for carbon monoxide contamination. These experiments involve creating a laboratory environment where linen can be exposed to carbon monoxide and methane, to see if the gases "interpenetrate" in the cloth. One experiment, requiring an infrared laser to heat cloth samples or a spectrometer to analyze material, can take a month to complete as Jackson and his colleagues labor two nights a week in his lab.

"Our samples will eventually be sent to Oxford," Jackson says. "This will have wider implications than just for the shroud."

Indeed, Oxford is following Jackson's progress. Jackson met Radiocarbon Acceleration Unit Director Christopher Ramsey during the filming of a BBC documentary on the shroud, which aired in March in the United Kingdom.

Ramsey admits that so far, cloth contamination has only been shown to skew radiocarbon dating results by 100 years or so.

"This is just a theory," Ramsey told OSV. "We have yet to see any evidence that this reaction produces significant levels of contamination. Tests continue to see if under any specific circumstances such reactions do occur."

Seeing is believing

As Jackson points out details on the life-size replica of the Shroud of Turin that takes up one wall in his office, it's clear he's a true believer. He says he relates to his namesake, the Apostle John, who writes in his Gospel that he saw wrappings on the ground of the empty tomb and believed.

"The Gospel says he 'saw' -- which is science -- and then 'believed' -- which is faith," he says. "Science and religion come together in an exceptionally profound way in the shroud."

Jackson wants to prove with science that the shroud is the burial cloth of Jesus. He's enlisted the aid of his wife, Rebecca, a Jewish convert to Catholicism, who is fascinated by the history of the shroud and its roots in Jewish custom. The couple have joined the Knights of the Holy Sepulchre, a fraternity that advocates for Catholics living in the Holy Land.

For Jackson, the shroud, as a cloth that held the body of Christ and was physically altered during the resurrection, is a version of the Holy Sepulchre. It is an archeological site imprinted in cloth.

"The Catholic Church has never made a pronouncement except to say it's up to science to show them what they've got," he says. "It's definitely reasonable to say what we've got is a radiation image of a body on cloth."

Rebecca Jackson, who runs the center on private donations, is eminently practical about it.

"Let's get this thing solved," she says, "One way or the other."

Icon of human suffering

"The shroud is a challenge to our intelligence. ... Since it is not a matter of faith, the Church has no specific competence to pronounce on these questions. She entrusts to scientists the task of continuing to investigate. ...

The imprint left by the tortured body of the Crucified One, which attests to the tremendous human capacity for causing pain and death to one's fellow man, stands as an icon of the suffering of the innocent in every age: of the countless tragedies that have marked past history and the dramas that continue to unfold in the world. Before the shroud, how can we not think of the millions of people who die of hunger, of the horrors committed in the many wars that soak nations in blood, of the brutal exploitation of women and children, of the millions of human beings who live in hardship and humiliation on the edges of great cities, especially in developing countries? How can we not recall with dismay and pity those who do not enjoy basic civil rights, the victims of torture and terrorism, the slaves of criminal organizations? By calling to mind these tragic situations, the shroud not only spurs us to abandon our selfishness but leads us to discover the mystery of suffering."

Pope John Paul II, May 24, 1998

Steve Saint writes from Colorado.