The Shroud of Turin—a nearly 2,000-year-old relic or an exquisitely clever forgery? The mystery has recently attracted a small army of detectives that would make any police department crime lab jealous. Organized as STURP (the Shroud of Turin Research Project), these “detectives”—state-of-the-art specialists in an array of scientific disciplines—rendezvoused at the Royal Palace of Turin in October, 1978. Their mission: to don white gloves, spread the 14-foot-long linen cloth on a special, rotating test table, and probe the shroud (or photos of it) with X-rays, spectroscopes, a VP-8 Image Analyzer, ultraviolet fluorescence, macrophotography, phonomicrography and other space-age tools and techniques.
The genesis of STURP dates to 1974, when two U.S. Air Force scientists, John Jackson and Eric Jumper, intrigued by some 1931 photographs of the shroud, decided to process the photos with a VP-8 Image analyzer. A kind of fancy computer, the analyzer takes satellite photos of the moon and planets and turns them into three-dimensional topographic reliefs.
To the scientists’ shock, the analyzer produced a relatively undistorted, three-dimensional image of the man of the shroud. This transformation would have been impossible if the shroud image were a standard two-dimensional painting.
Other scientists heard about Jackson and Jumper’s work. In March 1977, a meeting was arranged in Albuquerque, New Mexico, and the project was underway. Soon the scientists got permission to conduct nondestructive tests on the shroud at the close of the public exhibition scheduled for the fall of 1978.
However, approval did not come through for one critical test, carbon dating, which might have fixed the age of the cloth within a range of 120 years. The Archbishop of Turin, although in favor of carbon dating in principle, was not convinced that the test could be done with enough credibility.c
But the STURP team was undaunted. For five days, more than 30 American scientists worked with Italian colleagues and a Swiss criminologist on a precisely choreographed 24-hour-a-day schedule. They photographed the shroud more than 500 times, vacuumed it, pressed it with sticky tape, subjected it to X-rays, ultraviolet radiation and infrared light.
What were the experts able to measure, detect or discover? Ultraviolet and X-ray fluorescence produced clues to the shroud’s chemical makeup. Since whole blood does not fluoresce, some STURP scientists believe that the stains around “wound” images on the shroud are serum, the thin liquid that separates from blood. X-rays of the stains also revealed a level of iron compatible with blood.
The vacuum and the strips of tape seized bits of fiber that could be scrutinized back home in the lab. Most scientists who analyzed the red stains on the cloth have now concluded that the stains are human blood, but two team members dissent. Microscopist Walter C. McCrone contends that the stains are iron-oxide paint applied, he suggests, by someone who wanted to enhance the image on the shroud. Most of the team members, however, agree that the shroud image shows no signs of brush marks; in other words, the image was not painted on.
Samuel Pellicori, an optical physicist and spectroscopist, says that the color of the supposed bloodstains “is startlingly reminiscent of recent blood and not at all what one would expect after a minimum of 600 years.” But chemist Ray Rogers says that the shroud may have been washed in soapwart, a plant used in antiquity as a detergent, which has the property of maintaining blood cells.
Obviously, the team has not reached a consensus. Each scientist, in his or her own lab or office, has continued working since returning home, but as some problems are solved, new ones are revealed.
