In 1898, with the first photograph, a new phase began for the Shroud, that of scientific investigations to answer a few more questions about the most famous cloth in the world.
How was the image of the Shroud formed?
How is it possible for a corpse to leave an imprint with similar characteristics on a sheet.
During the hundred years of research, various theories have been advanced and numerous experiments have been conducted to try to reproduce an image similar to the one present on the Shroud, both using cadavers and through artificial methods. Some have hypothesized that the footprint was generated by the chemical reactions between the ammonia vapors emitted by the corpse and the scented vegetable substances such as aloe and myrrh, used in ancient times to honor the dead. Others have hypothesized the presence of radiation coming from the body itself or from an external source. Some experiments have harnessed the thermal energy generated by a heated metal statue, while others have attempted to paint a picture using red ocher on a bed sheet.
However, none of these experiments succeeded in producing an image similar to that of the Shroud in a satisfactory way. Furthermore, some features of the Shroud image still remain unrepeatable to this day. Despite this, the results obtained made it possible to state with certainty that the image was produced by a natural process deriving from the corpse of a human being, excluding the intervention of an artist who would have used conventional reproduction techniques.
In 1978, the American research group called STURP (Shroud of Turin Research Project) conducted direct experiments on the Shroud. Through a complex series of tests, the scientists determined that there were no pigments or dyes present on the sheet, further demonstrating that the body image is absent under the bloodstains (indicating that it formed after them). The imprint extends only for a thickness of a few hundredths of a millimeter in the superficial fibers of the fabric and was found to be “due to an oxidation-dehydration of the cellulose”. The process of forming such an imprint still remains unknown and was definitely not caused by artificial means.
What biological traces can be found?
In two different years, 1973 and 1978, some micro-traces were taken from the Shroud by applying adhesive tapes, revealing pollen grains belonging to 58 flowering plants. Since some of them come from plants that grow only in Palestine and Anatolia (in present-day Turkey) it can be concluded that the prolonged permanence of the Shroud is highly probable, as well as in Europe, also in these regions. Further research, also conducted by Israeli scholars, allowed the discovery of other types of plants, a discovery that confirmed the aforementioned hypothesis.
What can you tell from bloodstains?
The analysis of the red spots visible on the Shroud has always led to consider them as bloodstains. However, to have absolute certainty, it was necessary to conduct a thorough examination of the material present on these stains. In 1978, two teams of researchers (one Italian and one American) took samples of this material and the tests conducted in the following years confirmed the presence of human blood of group AB.
What can the Shroud fabric material tell us?
The Shroud features a fabric woven on a rudimentary treadle loom, with a herringbone twist that was common in the Syrian-Palestinian area during the time of Christ. Its dimensions correspond to the Syrian cubits.
Traces of “natron” have been found on the Shroud, a substance used in Egypt for embalming due to its property of absorbing water. Also in Palestine, it was used for the dehydration of corpses. Furthermore, the presence of aloe and myrrh on the cloth has been identified, substances used in Palestine during the times of Christ for the burial of the deceased.
Spores, fungi and mites similar to those found in tombs of the same period were also found on the Shroud.
What can be deduced from the image studied with modern means?
In 1977, a group of American scientists subjected the image of the Shroud to electronic processing, carrying out a special scan. This process revealed that the image contains unique three-dimensional characteristics not found in traditional paintings or photographs. A year later, a team of scholars from Turin independently obtained high-definition three-dimensional images, revealing numerous otherwise invisible details. For example, the traces on the right eyelid have been highlighted, left by an object that most likely corresponds to a Roman coin minted in the first half of the first century AD.
Furthermore, images of the face free of wounds and drippings of blood were obtained, allowing to obtain a realistic representation of the face of the man of the Shroud. Subsequently, the scholars conducted a comparative electronic elaboration between the face of the man on the Shroud and the main icons depicting the face of Jesus dating back to the first millennium of the Christian era. This comparison highlighted a large number of similarities, strongly suggesting that the face of the man on the Shroud may have been used as a reference image for icons since the 6th century.
What research can be done on dating?
In 1988, three tissue samples were taken from the Shroud in order to submit them to dating using the radiocarbon method, commonly known as C14. The results obtained by three laboratories in charge of the examination indicated that the Shroud fabric dated back to a period between 1260 and 1390 AD. However, these results are still the subject of a large debate among scholars regarding the reliability of the use of the radiocarbon method to date an object with such particular historical and chemical-physical characteristics as those of the Shroud.
The medieval dating obtained contrasts with various results obtained in other fields of research. Furthermore, it is difficult to establish whether over the centuries there has been an accumulation of new C14 compared to that present at the time of cutting the linen used to weave the Shroud. Studies conducted on ancient fabrics have further reopened the scientific debate on the dating of the Shroud, noting that contamination of a textile, biological and chemical nature can significantly alter the radiocarbon age of a fabric.
Given that the Shroud was clearly subject to contamination of a biological nature (as demonstrated by the microtraces found) and chemical (due to the fire suffered in Chambéry), the aforementioned experimental results deserve careful analysis and verification through an extensive research program and new exams. This would make it possible to evaluate the problem of introducing an adequate correction factor to the radiocarbon dating of the Shroud fabric.
What conservation systems are adopted today?
In 1992, an international commission of scientists was charged with developing a new and modern system of conservation for the Shroud. After years of study and testing, two new display cases were designed: one for maximum security, used for the exhibitions of 1998, 2000 and 2010, and a lighter one for ordinary conservation.
In the display case, the Shroud is positioned horizontally, completely stretched out, immersed in argon, an inert gas. It is protected from light and maintained in constant climatic conditions of temperature, humidity and pressure, monitored by a computerized system. Storage inside an inert gas such as argon, which does not react with common chemical elements, is essential to prevent the development of bacteria and slow down the progressive yellowing of the fabric caused by natural oxidation due to atmospheric oxygen. This yellowing is responsible for the gradual decrease in image visibility.
The two new display cases have the shape of a parallelepiped, with the lateral and lower surfaces made of a metal alloy and the upper surface in scratch-resistant glass.
In 2002, the Shroud underwent an important and indispensable restoration. The patches sewn in 1534 to cover fire damage have been removed, and the holland fabric used for the stitching has been replaced. This restoration made it possible to remove the polluting materials present under the patches, the residues of the Chambery fire of 1532, which were carefully collected in sealed and cataloged containers.
