The Shroud of Turin is purported to be the burial shroud of Jesus. Samples were removed under supervision of the Church that owns the shroud, and were analyzed by several different labs. The labs performed dating techniques independently and arrived at an age that doesn't square well with the storied death, burial, and resurrection of the Jesus character.
The quest to explain this discrepancy yielded some answers. Some answers may be valid, I've listed three below, but I'm sure this is not an extensive list. One answer was to talk about an "organic varnish" covering the fibres. This is under investigation, and may be a valid concern. In sufficient quantity this new organic material would skew the result the old organic material would yield. Another was to say the samples were altered by a fire. This fire is an historical event and, like the varnish, would skew the reading. The burnt cloth was repaired and the churchmen knew where the repairs were, they could have directed the scientists to an unrepaired section of cloth. No new, verifiably old cloth, samples have been allowed to be taken. Lastly, the church said it shouldn't matter to a believer how old the test said the Shroud was.
Personally, I would never question the last explanation. The other two are scientific and are under investigation. At any rate, all three of the above are outside any expertise I might legitimately claim.
Another tack to explain the discrepancy is to speak of it as a holy mystery. And I feel qualified to write, but not extensively, on this subject.
Did you know, I was asked, that no one knew what was on the Shroud 'till the invention of photography? The body and face are plain to see, although it's a "negative" of a positive body. Clearly, the reason to venerate the thing is because people could see the shape of a body and face. Of course people could see the image.
No one knew what a negative was 'till the invention of photography! Which makes sense in an emotional way, but not in a factual way. Consider engravings, which are as much negatives in their production as the Shroud image is. My favorite artist of this genre is Durer, no web page could do his "Melancholia I" justice, so find a book*. Notice that some of the numbers in the angel's "magic square" are backward. This is because Durer, and other engravers, worked "negatively".
The resurrection obviously created the mark, no other explanation makes any sense. Even if no natural explantion for how the image got there is uncontested, consider the implications of your "theory". If souls entering bodies release energy that burns cloth, and if life begins at conception, how do women (or embryos) survive conception? By your theory, the bodies should incinerate when the spirit enters.
It looks just like Jesus! How do you know?
It's obviously a crucified man! Consider a person hanging on a cross; the head and chest are tilted forward from their weight while the shoulders are thrown back. Now on a slab the shoulders are resting on the slab, elbows are resting on the slab, muscles are not under voluntary control, the body lies limp, but siffening.
Lay down on the floor and try to mimic the shroud picture...shoulders and elbows flat on the floor...hands over your crotch. Can't do it, can you? Consider also that dead bodies do not bleed, but the blood of Jesus is part of the power of the Jesus story, and is splotched on the Shroud.
Those are reasons why I'm most confidant in saying the Shroud is a hoax. It's too painterly, too reverential, too much like iconographic art for me to take seriously.
Click on the image below to visit the Shroud of Turin website. Maintained by a professional in medical imaging, this site presents all perspectives.
(c)1978 Barrie M. Schwortz. Used by Permission.
*You can find material on Durer at a library but Civilisation by Kenneth Clark is a readily available book. You can see "Melancholia I" on page 152 of the 1969 edition.
Notes on the original.