Shroud of Turin

The Shroud of Turin: modern photo of the face, positive left, negative right. Negative has been contrast enhanced.

The Shroud of Turin or Turin Shroud (Italian: Sindone di Torino, Sacra Sindone) is a linen cloth bearing the image of a man who appears to have suffered physical trauma in a manner consistent with crucifixion. It is kept in the royal chapel of the Cathedral of Saint John the Baptist in Turin, northern Italy. The image on the shroud is commonly associated with Jesus Christ, his crucifixion and burial. The origins of the shroud and its image are the subject of intense debate among scientists, theologians, historians and researchers. The Catholic Church has neither formally endorsed nor rejected the shroud, but in 1958 Pope Pius XII approved of the image in association with the Roman Catholic devotion to the Holy Face of Jesus.
The image on the shroud is much clearer in black-and-white negative than in its natural sepia color. The negative image was first observed in 1898, on the reverse photographic plate of amateur photographer Secondo Pia, who was allowed to photograph it while it was being exhibited in the Turin Cathedral. In 1978 a detailed examination was carried out by a team of American scientists called STURP. They found no reliable evidence of forgery, and called the question of how the image was formed "a mystery".
In 1988, a controversial radiocarbon dating test was performed on small samples of the shroud. The laboratories at the University of Oxford, the University of Arizona, and the Swiss Federal Institute of Technology, concurred that the samples they tested dated from the Middle Ages, between 1260 and 1390. Three peer-reviewed articles have since been published contending that the samples used for the dating test may not have been representative of the whole shroud.
Scientific and popular publications have presented diverse arguments for both authenticity and possible methods of forgery. A variety of scientific theories regarding the shroud have since been proposed, based on disciplines ranging from chemistry to biology and medical forensics to optical image analysis. According to former Nature editor Philip Ball, "it's fair to say that, despite the seemingly definitive tests in 1988, the status of the Shroud of Turin is murkier than ever. Not least, the nature of the image and how it was fixed on the cloth remain deeply puzzling". The shroud is one of the most studied artifacts in human history, and one of the most controversial.