The Shroud of Túrin was carbon-dated to the Middle Ages, which certainly counts as debunking. Certainly, there was nothing fishy about the carbon-dating procedure - it was done by multiple labs along with other samples of linen, and the researchers were not told which sample was from the Shroud. Some of the linen samples tested were of known age, and those came out correctly.
However...there are some questions that remain. First, was the sample contaminated with anything prior to the testing being done? There was a fire in 1532 that damaged it, and it was patched with new linen 2 years later. If any of the 'patch' material (including the backing) contaminated the samples, the date would be skewed. To a lesser extent with something growing on the shroud (bacteria or mold contamination, etc.) This is not really enough to call the carbon dating into question, but rather would leave open a door for retesting at a later time (if permitted). After all, to carbon date, you have to burn up the linen, and no one's in a big hurry to cut up the Shroud and do that.
Secondly, how was the image made? After all, if this was a hoax/fake from the 1200's, the method used should be
somewhat straightforward to identify. It's not like there were a lot of options available beyond...wrapping up a dead guy and leaving some stains, or 'enhancing' the effect with paint/pigment of some sort. But in both cases, there are some issues.
One - the image on the Shroud is rather...interesting...when it comes to photography. The photographic negatives of the shroud reveal all sorts of detail not visible to someone just looking at it. If it is assumed to be a fabrication from the 13th century....that does raise some questions as to how they even knew to bother with that!
1999 article And then just a few days ago, a study of how to discolor linen (as seen in the Shroud), was reported with the conclusion that, yes, high energy light does this, but no, we can't actually replicate it and it would be difficult to see how a 13th century (or 1st century, for that matter) forger could have done so without seriously anachronistic technology. (Articles:
NY Daily News,
Huffington Post)
Two - the details of the man crucified in the shroud match accurate details of Roman crucifixion. The nail marks are in the wrists, etc. Popular artwork from the Middle Ages seldom portrays the crucifixion in this way, so it would be...unusual...to choose to portray a crucified man this way at a time removed from both the 'current' practice of crucifixion and modern research into ancient times.
Three - the pollen found on the cloth places it in the Middle East, not Europe. Of course, someone could have taken a forgery to the Middle East, or it could have been made there and brought to Europe later. So, it's not like that proves anything. But it is...interesting...that Danin was able to identify pollen from plants that would have been found near Jerusalem in the spring from the Shroud.
All that being said, for all I know some medieval knight crucified some guy out in the Middle East, used some sort of pigment to enhance the image, and then wrapped up the guy in the cloth. I'm not saying that the Shroud of Túrin is definitely authentic, merely that it is not definitely a fraud, either. I've never heard of anyone making their own, for instance, so it's not exactly
easy to fake.
I only brought up the Shroud in the first place because it's the first thing that came to mind as a 'portrait' of Jesus. I suppose I could have referenced iconography as well, but of course, those weren't painted from life