There has been some controversy concerning the authenticity of the Shroud of Turin. Here are some pieces of evidence in favor of the shroud.
First, dirt. On the shroud in the areas of the nose, knees, and soles of the feet, geologists have found a specific kind of dirt. This dirt, known as Travertine Aragonite, is unique to Jerusalem and very few other places. More particularly, Travertine Aragonite is found on the steps of the temple in Jerusalem, which were preserved after the temple’s destruction in 70 AD. The nose, knees, and soles of the feet are areas in which one would expect to find dirt if one had fallen. Jesus Christ is reported to have fallen while carrying his cross to Golgotha. Since he was wrapped in the shroud shortly after his journey, the dirt from his journey could have been transferred onto the shroud.
Second, pollen. Pollen can tell the observer where something was and at what time of the year it was there. In 1978, the shroud was examined by Dr. Max Frei, who found, in 204 different pollen grains, 49 different kinds of pollen. Among these, 13 were unique to Jerusalem and several others were unique to Constantinople. This says that the shroud spent some time in both places, which is consistent with the history of the shroud given in an earlier blog.
Finally, dating the shroud. The process of dating of the shroud tells us in what century the cloth was produced. There have been a few attempts at dating the shroud. Only one is radically different from the others. In 1988, an attempt at radiocarbon dating a piece of the shroud was made using the most contaminated corner of the shroud (the upper-left corner in the photo above). This test placed the shroud somewhere between 1260 and 1390. However, 3 other tests (2 chemical and 1 tactile) made using separate methods placed the shroud around 33 BC plus or minus 250 years. The results of the three methods overlap in the first century AD.
Resource: our Virtual Pilgrimages on the Shroud of Turin parts 1 and 2 (coming soon to YouTube)