Hello everyone. I trust you all enjoyed the festivities so far as much as I did. However, a surfeit of mince pies and much else besides has left this blogger in a near-vegetative state.
Consequently I shall try to keep this posting short, hoping for some informative feedback that will keep me awake – to say nothing of explaining things I may have overlooked.
Here’s the conundrum/brain-teaser/glaring contradiction – call it what you want.
Much has been made of the extreme superficiality of the body image on the Shroud of Turin. One well-cited estimate, albeit based on some less-than-impressive methodology – puts it as little as 200nm thick. (That’s just one 50,000th of a cm – roughly the thickness of gold leaf).
Here’s a diagram that shows how an image-bearing outer layer (yellow) might look in relation to the entire width/diameter of a linen fibre (blue) – of which there may be some 200 or so fibres per thread.
(As I say, “schematic” – and highly so. The individual fibres are in fact polygonal rather than circular, and the cellulose is present not as a homogeneous mass but as a series of concentric helical bands with interspersed non-crystalline material. See the (free) diagrams in a useful paper, especially as it addresses the issue of tensile strength and fibre fracture, the text of which, bar the abstract, is however behind a paywall.) In passing, beware the diagram on page 15 of Raymond Rogers FAQs, described as the ‘gross internal composition of a flax fibre’ which initially perplexed this blogger. It is not. It is a botanist’s diagram showing the internal structure of the bast fibre BUNDLES in a flax stem.
coating image-bearing layer could correspond with the primary cell wall (PCW), according to some authors, comprising mainly celluloses and hemicelluloses , OR could be Rogers’ “impurity layer”. That is a question that can probably be left in abeyance for now, given that the spotlight here is on differences in relative size of core to outermost layer in particular, given that the core is always predominantly tough old cellulose regardless of the chemical nature or composition of that outermost layer..
So any effect on the fibre core should be slight, should it not, especially as the core consists mainly of highly crystalline cellulose which is well known for its physical and chemical resistance?
So what do you make of this statement made as recently as 2010?
From: Microscopic and Macroscopic Characteristics of the
Shroud of Turin Image Superﬁciality
G. Fanti et al
Journal of Imaging Science and Technology
How can the Shroud image be described as ultra-superficial, too thin to have been formed by any conventional form of energy (thermal imprinting etc) – having presumably negligible effect on the integrity of the fibre as a whole – only to be told that fibres that bear that image are mechanically-weakened across the entire cross-section – so much so that they BREAK EASILY?
Is there not a glaring contradiction here? Either the image-forming process is not as superficial as we have been led to believe, and in some way affects the entire fibre – not just a superficial surface layer – OR – the above model of a linen fibre is over-simplistic, in which case more research needs to be done to discover weak points on the linen fibre that might also be compromised by the image-forming process. But if the latter were true, we would need to ditch a lot of the baggage that presently accompanies the alleged “superficiality” of the Shroud image.
PS: I have deliberately avoided mentioning the L word. Was that wise? 😉
And here’s a clue to some potential weak points in a flax fibre.
Further clue: note this fascinating observation in one of Adrie’s papers (pdf):
“Note that the ghosts are also continuous over the joints of fibre cells – also called growth nodes – which seems to suggest the ghosts weren’t (only) primary cell walls. The thickness of the ghosts (200-600 nm) perhaps also precludes that they only consist of the primary cell wall of the linen. More recent experiments estimated the thickness of the colored layer to be 200 nm +/- 200
nm; a primary cell wall would be only about 200 nm thick.”
Thanks Adrie. Yours is one of the few informative statements I have been able to find so far in this important aspect of flax fibre microstructure, especiallly as it related to Rogers’ “ghosts” – to say nothing of that allegedly “impossible to account for” image superficiality.