I’ve been exchanging emails with Hugh Farey recently. He’s been sending some impressive photographs of linen fibres, before and after scorching. There’s currently the beginnings of an exchange of views on the importance or otherwise of the primary cell wall (PCW) in capturing the Shroud image (well, scorch imprints anyway).
Regular visitors to this blog will know by now that my preferred working model for the faint yellow/brown TS body image is a contact/conduction scorch aka thermal imprint, with no role for radiation of any kind, while keeping an open mind on other possible mechanisms that are capable of being investigated by the scientific method, i.e. model-testing.
Hugh’s comments have prompted me to spend a few more hours with the new microscope. Trying to arrive at firm conclusions as to what one can really see and what is an artefact is tricky, given the (double) light refraction, i.e. birefringence of internal cellulose fibrils, that makes it exceedingly difficult to focus on fibres, the latter being being macroscopic 3D entities.
visible-to-the-naked eye unsectioned 3D entities (big and plump in other words). What’s more, at the risk of getting overly techy, my microscope lacks crossed-polaroids, handy for detecting those nodes, as well as regions of high crystallinity, such as the highly-organised cellulose fibrils of the thick internal secondary cell wall and generally giving a sharper, crisper image.
But I have seen enough to make me realize that I have up till now been operating with an over-simplified model, one that imagines that the secondary cell wall (SCW) is entirely cellulose, and that TS image-acquisition must ipso facto have been confined exclusively to the primary cell wall (PCW). That simple model has its advantages in theoretical terms, i.e. in pursuing a link between the (allegedly) highly superficial Shroud image – estimated as 200 – 600nm thick and a scorch confined to the PCW – assuming the latter were of approximately the same thickness.
But that model now seems hopelessly – and misleadingly – simplistic, and indeed may be placing a constraint on developing hypotheses re the mechanism of imprinting of the TS image, not just the scorch model.
Here’s a graphic I have just cobbled together on MS Paint which summarises the new thinking. Note the importance attached to the fact that some 15% of the linen SCW is NOT heat-resistant cellulose, but chemically-more reactive non-cellulosic polysaccharides (NCPs) which should (in theory) be just as capable of acquiring a scorch – albeit a faint one if interspersed with cellulose – as the PCW.
I’ll stop here for now, while I do some back- of- envelope calculations on what proportion of the Shroud image intensity might be on a faint and difficult-to-
spot be- sure-about coloration of the interior SCW, as distinct from a more readily visible intense coloration of the enveloping but highly superficial PCW. Get my drift? Yes, we really do need fibre cross-sections, as per diagram above. That needs embedding in wax and microtome sectioning, probably, nay almost certainly beyond my means. Hugh? Thibault?
I’ll be back later to post Hugh’s pictures and comments, as well as some more thoughts on the revised model above.
Now then, what’s that formula for the volume of a cylinder, 4pi r squared as I recall.
Late addition: (now the arithmetic, are you sitting comfortably?) there are two ways of approaching the question of how much incident light is absorbed by the PCW (or, more optimistically, the Shroud image, determining how each “looks” to the observer, and also where the image would appear mainly to be situated when viewed under the microscope in “as-is” (unsectioned) specimens. The first is by using scattered light, with incident light beamed onto the surface of the specimen, the other is transmitted light, with the light source behind or underneath.
The latter is by far and away the easier to analyse, so I’ll deal with it first, even though I think it the less realistic of the two scenarios. Light from behind encounters a maximum light path that is first a thin PCW, then the thick SCW, then the second PCW. Let’s make a few approximations, i.e. that the PCW is 200nm thick, and the SCW has 50 times that figure as diameter/light path. Let’s further assume that 80% of the PCW is easily-scorchable polysaccharide, and the comparable figure for the SCW being 15%, representing the non-crystalline non-cellulosic polysaccharide. The ratio of visible light absorbed by PCWs to SCW is then 1:4.7, or, roughly speaking, 5 times as much in the SCW as the PCW. But as the diagram above shows, it is the PCW that might seem to be the major absorbing layer based purely on image density, and the fact that the observer always sees the SCW through the PCW, i.e. the latter is the face that leaves the greater impression on the senses. So “SCW” light absorbance and thus image density could easily be mistaken as part of the PCW’s. (N.B. everything here refers to viewing an undamaged fibre; the Adler/Heller/Rogers experiments, where “clean” and reportedly colorless fibre cores are stripped away, leaving coloured impressions (“ghosts”) in sticky tape adhesive are another matter that will be scrutinised more closely soon, not necessarily on this post. For the moment, one has to ask whether a surface colour many times more intense than the interior might not have led to a false conclusion from those ‘strip-away’ tests that ALL the Shroud image colour was in the topmost layer, despite the latter being too thin to resolve under a light microscope, giving rise to that “200nm” figure, or as others, notably Adrie, see her recent comment, prefer (<200-600nm).
For that reason, the analysis based on light that is reflected/scattered off the image is likely to be skewed even more in favour of the more superficial PCW envelope, even if the SCW were to account for the majority of scorched polysaccharides, in terms of total amount. But don’t expect any quick estimates of the proportion of reflected light from PCW and SCW respectively. Performing that calculation almost is going to need some outside help.
As ever, this blog is to be viewed as a work-in-progress, not written on tablets of stone (meaning I shamelessly add on new bits, and occasionally change or delete the first part). Yaboo sucks to Shroudie news aggregators/news managers who might have preferred a fait accompli from which selected passages could be quoted, – to say nothing about omitting the troublesome bits that might offend those regulars seeking reinforcement of a certain agenda, one that views the TS as a handy aid, a prop, in bolstering and/or proselytising their own brand of religious belief. 😉
As promised, here are cut-and-paste accounts from my email inbox of Hugh’s recent researches together with attached photographs, inserted into text close to – but not always right next to – relevant text.
The first: dated Wed 9th Jan:
“To be honest I’m not sure what birefringence is, but I think it may be a definitive test for impurity layers!
I enclose two photos from a bit of linen, clean at one end and scorched on the other.
I stuck a piece of sellotape firmly down over the whole thing, pulled it off and then stuck it to a microscope slide. The dark blue bubbles are from the sellotape. Anyway, with bits of polaroid below and above, and a magnification of 40X, this is what we see. The linen fibres show up brightly against the dark blue, and stuff which isn’t linen (any other impurity) doesn’t. You can see on the ‘scorched’ slide lots of regularly spaced patches of little lines, representing shreds of fibre (not, I think whole bits of broken fibre, but shreds from the surface of fibres – your beloved PCW?) torn off by the sellotape. The ‘clean’ slide shows no such patches, as the linen is not sufficiently degraded to pull fibres apart.
So – if the image is on an impurity layer, which does not show up in crossed polarisers, then an ‘image’ tape will look like a ‘non-image’ tape, and rather like my ‘clean’ slide. But if the image is on the fibres themselves, then an ‘image’ tape will look like my ‘scorch’ tape – even if the image is not a scorch.”
Are there any tapes out there which haven’t been returned to the Vatican? Do encourage anyone who has got one to try the test!”
2nd email: Thur 10th Jan:
“I think the thin coloured layer is really there.
The first two pictures are of the same fibre (the right side of the coloured one overlapping the left side of the white one) at 400X, and the colour is clearly present between the nodes.
It also shows the variation in colour possible along the length of a single fibre. The third photo (40X) shows those patches of separated fibre fragments I showed in the polarised photo, coming off the uppermost surfaces of the uppermost fibres of the uppermost threads, which, again, are coloured throughout.
Notice that even in a 1/1 ordinary weave, on one side the warp threads are prominent and the weft threads depressed, so only the upper surfaces of the warp thread fibres have broken away, which is why all the patches have lines pointing the same way. On the other side, the cloth appears much flatter, and I dare say if I had singed that side the patches would have been closer together and alternated directions at right-angles.
4) Sticky tape sample of scorched linen (as photo 1) in transmitted light – X40
By rubbing hard on the sellotape after it is stuck to the slide (with the principal intention of being able to focus at high magnification), it is quite easy to smash individual fibres (I think these are ‘bast’ fibres) apart into their ‘elementary fibres’ (see the diagram at http://www.agrofibrecomposites.com/process.htm), and the fourth attachment shows a scorched (bast) fibre literally bashed to bits. These bits are roughly cylindrical and 10-20um wide (I read).
5) End of a single scorched fibre showing broken microfibrils – X1000
This is considerably thicker than Rogers’s putative 200-600nm, but I am not convinced by his photograph (in his FAQ paper) of two ‘troughs’ in a layer of sellotape glue. I think it possible that the colour difference is an artifact of the focusing, and I’m afraid that if that is the best image he can produce, its not sufficiently convincing for me. My idea of the ‘image layer’ (of broken off ‘elementary fibres’) is much more clearly discernible and speaks for itself.”
Third email, in response to my: “Superb pictures – and thought-provoking comment too. May I use this and your previous email, pictures included, as topics for posting – thus helping to keep the kettle on the boil so to speak?”
Hugh: “Yes indeed, help yourself, as usual. I normally post direct to your blog anyway, as you know; it’s just sending photos that I use email for.”
Final note: for now, at any rate: I’m aware I have not really addressed the reference in the title to the Shroud image per se, and explained fully why I consider these thoughts on PCW v SCW NCPs to be relevant. I could do so, though it would involve expressing (still further) irritation with Ray Rogers’ compressed style of exposition, and having to analyse it line by line, sometimes word by word, in an attempt to extract his precise meaning. All that takes up more space. I’m now minded to make a separate posting of it, linking to this one, but if anyone’s keen to know my thinking re the Adler/Heller “ghost” experiments with sticky tape and their “image colour on surface layer only” conclusion, one that was supported by Rogers, then I would be more than happy to discuss that under comments.
PS: Hugh’s observations above are based on some highly adept handling of his sellotape, crossed polaroids etc. There’s some fascinating detail packed into those summaries, and he may well have hit on a method for distinguishing between an image on the surface as against one that is more integral with the fibre (some convergence there?). Since my head is buzzing right now with some of the new interpretations based on my own “impure SCW cellulose” model above, and on Hugh’s, placing a question mark against exclusive PCW imaging, I’ll hold off saying any more about Hugh’s findings right now, and give all the new perspectives, Hugh’s and my own, time to digest. Sorry about the wordiness – but there are some tricky issues here. Oh how I wish we had cross-sections to examine, as mentioned earlier. Does anyone know if the STURP investigators (Adler? Heller? McCrone?) ever sectioned and examined cross-sections of, say, wax- embedded threads and/or elementary fibres?