The Shroud of Turin, a linen cloth bearing an uncanny, blood-stained image of what appears to be Jesus Christ, is held as an object of devotion by Christians worldwide. For centuries, countless Christians have considered it the authentic historical burial shroud of Our Lord, out of which He rose from the dead some 2,000 years ago. Today it resides at the Cathedral of St. John the Baptist in Turin, Italy. The Church has never declared it to be the real burial shroud of Christ, although it does take the mysterious image to be worthy of Christian devotion.
As with any allegedly miraculous religious artifact, the Shroud is subject to a high degree of both faith and doubt. The image clearly seems to depict Christ, as the body is that of a man wrapped in linen after being scourged, crucified, stabbed in his side and made to wear something like a crown of thorns. In addition, the origin of the image itself is scientifically inexplicable. It manifests on the shroud in the form of a photo negative, yet it's been known to exist since about 1360 at the latest, long before producing photo negative images was understood.
The Shroud has come to be regarded with its most severe doubts in the last few decades. In the 1980s, Church authorities gave permission to a team of scientists to test a piece of the cloth with radiocarbon dating techniques. When the scientists announced the results, they rather triumphantly declared that its history goes back only to medieval times, from between 1260 and 1390 AD.
And yet the shroud remains an object of devotion, particularly because the radiocarbon dating leaves so much unanswered about the enigmatic Christian icon. There's still no known way of reproducing the image on the cloth using medieval technology. It couldn't have been painted, as the fibers on the cloth are not stuck together by any sort of paint. The coloration on the cloth is actually a change in shading on the fibers themselves. Embalming methods have similarly been discredited as possible ways the image could've been produced.
Further, the image contains three-dimensional properties in the varying intensities of its shading. As Nello Balossino of the University of Turin explains, "The image on the Shroud contains this information, which is codified in a series of nuances. In other words, what we have before us is an image formed through a three-dimensional process, which cannot yet be explained and simulated in practice in order to obtain replica images of the Shroud."
In addition, soil and pollen specific to Jerusalem have been detected on the cloth of the Shroud, even though it hasn't been to that area in its known history.
There's also evidence in art and devotional history of Christians being aware of the Shroud prior to the radiocarbon dating of the 13th century, as documented in this BBC documentary.
And what about the dating tests conducted on the cloth that assign its origins to the late medieval years? Some experts on the Shroud believe the results could have been skewed by the fact that scientists tested only the edge of the corner of the cloth. Doing so could have produced a sample that was part of a medieval repair to the cloth, or that was contaminated by bacteria or carbon monoxide.
More recent tests have also been performed that date the Shroud to a period well before the 13th century. Giulio Fanti, professor of mechanical and thermal measurement at the University of Padua, led a team of researchers through three tests of Shroud fibers that were in the piece of cloth used in the 1988 radiocarbon tests. The tests used infrared light and Raman spectroscopy as well as a way of analyzing mechanical parameters related to voltage. The tests' conclusion dated the Shroud to some time between 300 BC and 400 AD.
The new body of evidence in favor of the Shroud of Turin, while not enough to convince hardened skeptics, has at least been sufficient to keep the question alive.