Is there any validity believing that a lack of vanillin says anything about the shroud’s age?

imageTopic drift is a fact of life in this blog and almost every blog I’ve encountered. It is not a problem; it’s a useful feature. We were talking about radiation models for the images on the shroud and the subject of vanillin came up; it’s not important why. This caused Colin Berry to respond in the weeds – that is over in his blog – with an unrelated update to a posting on a different subject. Anyway that is how we got to this yesterday:

Vanillin is not a separate component from lignin. In fact it’s not even a component of  flax or linen. It’s a degradation product of lignin, derived from oxidation, side-chain shortening (loss of 2 carbons)  and detachment starting with one particular  monomer in the complex resinous polyphenol that is lignin, ie. coniferaldehye. See my earlier posting on the subject, this site.

Ray Rogers no less described and discussed vanillin as though it were a preformed component of lignin that gradually reduced with age. Nope: as the lignin oxidizes, the vanillin is newly formed, and being a relatively small molecule, gradually evaporates away, being responsible for the distinctive aroma of old lignin (the ability to detect it by smell being a sure sign that molecules are escaping into the air).

Anyway, if you haven’t read [Colin’s] earlier posting on the subject, you should. Do we really understand if the vanillin claim is valid?

And if you want to know what in the weeds means, it is this: In golf, when a shot lands on the fairway, it’s in plain sight in easy-to-play short grass. When a shot lands to the side, it’s in unkempt grass, and the golfer wastes time trying to find the lost ball. He’s literally "in the weeds".  And Colin wants to know why Google and people don’t find what he writes about on his blog.  There is a practical limit to topic drift.  What does comments about vanillin have to do with Here’s an updated version of my ‘iconoplastic’ modelling of that Turin so-called “Shroud” (probably a misnomer)?

Anyway, NOW, the topic is vanillin and the question is this: Is there any validity believing that a lack of vanillin says anything about the shroud’s age?

“Tell me this,” Colin writes:

What is the use of a clock that is either running, or has stopped completely? That is the situation with the Shroud linen. We are asked to believe that it’s the absence of Wiesner-reactive lignin that is the reason, ie that it is incredibly aged.

Sorry, I don’t buy that. The “vanillin clock” is so poorly documented that I decline to believe that the absence of a positive test is necessarily to do with age. It could be due to any number of factors….

And Colin gives us an alternate possibility, the sort of thing lawyers like to do to make us have reasonable doubts about a defendant in a criminal trial:

… someone decided to fumigate the reliquary (see my earlier comment). They removed the TS, then inserted a lit sulphur candle. Later the candle was removed, and the TS replaced, with its long sides folded in towards the middle before folding or rolling. Residual SO2 made better contact with the central regions of the TS than with the edges. So the reactive aldehyde groups of lignin in the initially peripheral Raes threads were better protected from the SO2 than the more central threads.

I’m not suggesting this was the actual process that gave the difference between Raes v the rest, but it’s an indication of the uncertainties that attach to using a chemical as distinct from radioactive clock, where one is at the mercy of environmental conditions that one can only guess at, as I am guessing right now.