The Shroud of Turin

In this article, we are answering, in a brief fashion, three questions that naturally come to mind when we look at the Shroud of Turin:

- What is it?

- Where does it come from?

- Who is the person represented?

What is it?

The Shroud of Turin appeared for the first time in history, and in a way that we are absolutely certain of, when it was exhibited in 1357 in the collegiate church in the village of Lirey, near Troyes, France. It is a piece of linen cloth 14 feet 3 inches (4.36 metres)long and 3 feet 7 inches (1.10 metres) wide. The linen had been bleached after being woven. The cloth depicts two images of a man, of normal height, from head to foot, one of the back and one of the front. Certains details which we can see on the cloth, have linked it with the Passion of Jesus, and the layout of the two images have led to its being identified as an actual burial shroud. At the time of Jesus, in fact, the dead were buried (notably those who were condemned to death) by wrapping them in such a piece of cloth, placing the body at one end of the cloth and then pulling the other end down over the body. The body was positioned by tying it up at certain points with bands. Thus it was believed that the image of the body had been imprinted following a process to be defined.

The images are dark yellow. They are very superficial. They actually appear on a single side of the cloth and on only a few dozen microns (the diameter of the threads being about two hundred microns). Various physio-chemical analyses excluded the presence of a foreign substance added to the linen to create this colour. It was shown that the colour was due in fact to acid oxidation that caused dehydration of the cellulose of the linen creating a certain browning effect.

Other coloured surfaces can be distinguished. There are darker stains that might be identified as blood stains when taking into account their placement with respect to the body. After physio-chemical analysis, we have good reason to believe that the stains are indeed those of human blood. One remarkable characteristic of the blood stains is the absense of gradation or disturbance of the fibres of linen around them, as if the drops of blood had been traced, then very delicately removed from the cloth. Pieces of cloth vaguely triangular were added to the shroud by Poor Clare nuns in 1534, at Chambery where the shroud was kept. In 1532 the Shroud had been saved from being destroyed by a fire during which the heat melted a corner of the silver reliquary in which it was contained. The molten metal burned through layers of the cloth folded over several times. We can also see various marks of folds and dark stains which may have been caused by other fires. In addition, specialists in the treatment of images from Orsay confirmed the discovery of Italian researchers regarding the existence of very faint inscriptions in Latin and Greek on the bands of cloth enveloping the base of the face.

The images of the body reveal surprising characteristics which make the cloth absolutely unique from an iconographical point of view. First of all, they give a negative image in a photographic sense. This was discovered when the first photograph of the shroud was taken a hundred years ago by Secondo Pia. The images are more real when we look at the negative. Secondly, the images are clean, in the sense that the edges are clean (without gradation). The possibility that the colours were produced by gases or by impregnating a liquid is excluded because, apart from the fact that this process could not create an image that is so superficial, it would not give such a resolution of image. Thirdly, the image gives three dimensional information. The greater the distance of the cloth from the body, the weaker the intensity of colour. Thus, it was possible to reconstruct the image of an undistorted face by computer. This could not be achieved by photography (because of the shadow) or by painting (because of the saturation of colour). Actually, a fine analysis of the density of the colour does not reveal the existence of micro-faults or imperfections which would indicate utilisation of a tool for creating the image.

The superficial nature of the image led physicists to think that it is possible to produce a similar colouring with a very light bombardment of radiation. This was confirmed by J.B. Rinaudo who irradiated a piece of linen with protons (the approximate energy of 1 MegaV). The colouring and superficiality of the image are in fact comparable with what we can observe on the Shroud. The resolution of the image implies that the protons have proceeded from the same direction. In the same way, the three-dimensional character of the image can be explained by the movement of the charged particles through the humid air between the body and the cloth. To say the least, this kind of unidirectional radioactive bombardment would be difficult to explain if it originated in the Middle Ages.

To be continued...