imageColin Berry is up with an interesting posting, Beware: with each passing decade and century, the Shroud image sheds vital evidence as to its origins.

[The idea is] part hypothesis, part common sense. It relates fading to the loss of degraded linen fibres (regardless of mechanism of image imprinting, whether by mysterious radiation, or as I prefer to imagine (see site banner) by contact scorching from a heated bas relief metal template).

or by some other means, neither radiation nor scorching heat.

The first fibres to break off and be lost would be those that are degraded all the way to the central lumen of each fibre, with visible coloration of what Rogers described as the “medullas”, i.e. the interface between empty central lumen  (“hole”) and secondary cell wall.  Coloured “medullas” probably represent scorched remnants of the long-deceased flax cell membrane and cytoplasm.

Less degraded fibres, with degradation confined to the hemicelluloses of the outermost primary cell wall (PCW, dark brown)  and thick secondary cell wall (SCW, yellow) would be next to fracture and detach.

The image we see today probably represents the population of minimally-degraded fibres, with damage to the highly superficial PCW only, with largely unaffected SCW cores.

It is something to think about, isn’t it.

If the truth be told, I should have done this post two years ago. Then, one the scores of occasions when the  sciency “200nm” card is played, I could have come back with this. The 200nm card, for the uninitiated is the one that was introduced to shroudology by the STURP team leader Raymond N.Rogers. He went to Turin i9n 1978, and pressed sticky tape onto  various Shroud locations, and took them back to New Mexico to analyse. One of his memorable and much cited findings was that one could grab the end of an image fibre with forceps, and when one pulled the coloured image stayed in the adhesive as a “ghost” and was so thin one could not resolve it by light microscopy. Given the range of wavelengths of visible light, the mantra was born that the Shroud image layer is a mere 200nm to 600nm thick – amazingly thin. (Reminder: 1cm = 10mm; 1mm =1000micrometres; 1 micrometre=1000nanometres).

Fast forward to Shroudie forums, and one is informed time and time again that no man-made scorch, at least off a hot solid template, could be so incredibly thin, and that one has to invoke some kind of radiation. (Cue uv excimer lasers, corona discharges, neutron bombardment from earthquakes and fracturing rock etc etc).

or some other means, neither radiation nor scorching heat.

OK, so it’s a tall order (maybe) to create a 200nm thick scorch that never goes deeper into the weave. But it’s not a tall order if one is then allowed to come back a few centuries later when all the more deeply scorched fibres have broken off, leaving just those with the PCW scorched. Reminder: the PCW of flax/linen fibres is reckoned to be of the order of 100nm thick!

It is something to think about, isn’t it? Is fading the right word? Or degrading? Does the same principle apply if an “impurity layer” is involved? Should we give more thought to non-scorching hypotheses ravaged by time?