Some fakes never die, and the Shroud of Turin is one of them. Despite the multiple, independent radiocarbon tests dating its fibers to the middle ages, the hope that it goes all the way back to Jesus stays alive. The latest attempt to resurrect the Shroud is described in a New York Times article by Elisabetta Povoledo, “Turin Shroud Going on TV, With Video From Pope“:
Skeptics say plenty of evidence corroborates a medieval dating, including carbon-14 tests done in 1988 by three independent laboratories. They dated the cloth between 1260 and 1390.
But others dispute that. Using infrared light, multiparametric mechanical tests and spectroscopy to analyze tiny fibers of material from the cloth, Giulio Fanti, a professor at the University of Padua, found they were compatible with fibers dating from around the time of Christ.
“Crossing the data from the various tests, we arrived at an average date” to the time of Christ’s death, plus or minus 250 years, said Mr. Fanti, whose findings were published this month in the book “Il Mistero della Sindone” (“The Mystery of the Shroud”), which he co-wrote.
Scientists have struggled to explain the image of the man on the cloth, which has markings compatible with the wounds of someone who was crucified. Mr. Fanti said he thought the image could have been created by a “very intense burst of energy,” which could have mutated the percentage of carbon-14 in the linen, leading some scientists to wrongly date it to the 13th century.
Well, I’m skeptical. I don’t know why a burst of energy at the moment of resurrection should mutate the precise amount of the Carbon-14 in the fibers to produce a medieval dating that just so happens to coincide with the first historical reports of the relic. It’s just too convenient.
We can estimate the dates of objects by the differential decay rates of various isotopes. Unfortunately, none of the new tests–infrared light, multiparametric mechanical tests, and spectroscopy–look at that. Rather, they analyze the chemical and structural composition of the fibers, which does not seem to be a promising avenue of dating the material, nor superior in its precision and accuracy to carbon dating.