Well, I don’t know about your, dear reader, but I for one had never previously seen those superb photomicrographs of Shroud image areas. I refer to the four that appeared in the second half of the (pdf) paper of French physician Thibault Heimburger MD.
I’ve seen inferior versions of those pictures, and used those inferior versions in at least one previous posting from February this year when comparing my experimental scorches with the Shroud image. If those pictures had been freely available online, I’m sure I would have found them in my hours of searching image archives. I shan’t say yet whether I would have adopted a different position, had the new pictures been available back then. In fact I’m still debating that in my mind. Thus the “thinking aloud” nature of this paper (see title).
They are labelled as having come from the ‘Mark Evans’ archive, and described as STERA copyright, that’s Barrie Schwortz’s $hroud of Turin Education and Research Association. I’ve already expressed my opinion on the hoarding of essential resource material by that one-man- band, and propose to say no more on that score right now, or the circumstances in which they now suddenly become available as part of a paper that attempts to dismiss the scorch hypothesis.
All that concerns me right now is that one has to assess the new pictures, and the claims based upon them, under a degree of time pressure. (Yes, there are folk on another site saying that a detailed response is required from me personally; others seem to assume that Thibault Heimburger has demolished the scorch hypothesis already with those pictures of his, to which I say: “please be patient”).
Well, I have in fact been drafting a response – indeed several – these last few days. But the task very quickly becomes unwieldy. Why is that? Answer: because the scorch hypothesis is assumed by Thibault and others to be a simple matter of altering a few highly superficial threads and fibres, and that any evidence from the Shroud of greater complexity and subtlety must demolish the scorch hypothesis. To which my response is: “Oh dear, where does one begin?” We may call it the “scorch hypothesis”, but the effect of pressing hot metal against linen is perhaps a lot more complex than Thibault and some others would have us believe.
Yes, where does one begin? Well, I have already prepared the ground with two recent postings that addressed the macroscopic aspects of Thibault’s study, focusing on that choice of template which, I say again, I regard as simply not fit for purpose. Use a crude and simplistic template, then it is hardly surprising if one is rewarded with a crude and simplistic scorch.
It’s time now to address those Shroud micrographs, the ones finally released from that squirreled-away STERA archive. I shall do it here, in my own good time, “thinking aloud” so to speak, trying to be thoughtful and undogmatic. There is far too much dogmatism already in Shroudology; Thibault Heimburger has regrettably just added to it with his paper. While acknowledging that the new graphics and factual content are welcome, I say “shame about the inherent bias, the all-too-apparent pro-authenticity agenda, the attempt to deliver a knock-out blow” based on what I see as his toe-in-the-water studies so far.
Yes, I shall be assembling a response here in the next few hours or possibly days even, and as I say, doing so as and when I feel I have something that needs saying. But I shall not be rushed into making possibly rash comments that I would then need to withdraw later.
First, I shall put up a screen grab of one of the new photomicrographs, and return later with some initial ideas that helped me at least to integrate it into what one has previously seen in lower magnification photographs. I’ll be using terms like warp, weave, herringbone twill etc etc.
Copyright considerations? The source is acknowledged (see graphic below). I consider I am making ‘fair use’ of the pictures for research purposes (some 120 previous postings to date), as well as flagging up my intentions previously, to which no objections, indeed, no response, have appeared so far.
“Fig 20” in Thibault’s paper, but my Fig.1
08:42 Note those rectangular-shaped horizontal threads and the pattern they make:
What one is seeing are what in a lower-magnification picture, would be the parallel diagonal ribs of the weave, which in an even lower magnification picture would be part of the herringbone twill.
My Fig.3 (above)
For comparison: textbook diagram showing structure of a 3/1. i.e. “3 up, 1 down” herringbone twill weave. Note that the white horizontal threads pass over three vertical grey thread, then under 1 grey thread, the pattern then repeating itself.
The Shroud weave above might at a first casual glance be mistaken for a 2/1 weave, but look closely and one can see it is indeed 3/1.
The broad horizontal threads are all part of the warp of the weave; the vertical threads over or under which they loop are the weft. It is those warp threads that are of primary interest in assessing the credibility of the scorch hypothesis, given they are the highest, i.e. most superficial part of the weave. One can think of the fabric as comprising three overlaid planes. The top plane comprises warp threads passing over weft. The intermediate plane is the weft. The lowest plane comprises the warp threads looping under the weft. I shall try to find a cross-sectional diagram to illustrate that point, though it is not difficult to picture in one’s mind. Here’s a home made one to be getting on with. Note the three planes – upper warp-weft- lower warp:
Fig.6: Warp thread blue, weft threads (cross-section) in black to match colour-coding above
So, are the more superficial warp threads more highly coloured than the weft? Here’s the picture again. Make your own decision, while I go away and label up the lightest regions (partly subjective I grant you, not having an image densitometer to hand):
My Fig.7 (above)
Here’s a very simple (indeed simplistic) scenario, with a very flat heated template, shown in grey, pressing down lightly onto linen with a 3/1 weave.
Fig 8A: light downward pressure from hot template (grey) on 3/1 linen twill
The hot spots and regions for scorching by contact are shown in red. The next diagram models what to expect if/when higher pressure is applied, still with that flat template.
Fig. 8 Heavier pressure that compresses the weave
Here’s the same, but under higher contact pressure. The scorched area is now wider than before, occupying a greater width of those rectangular warp sections. Whether the scorch now begins to affect the oblique ends that are descending to loop under the weft is anyone’s guess (see Thibault’s paper for his apparent concern re oblique thread scorching). But I would make this observation for now: not all the oblique portions are coloured in his mark Evans photomicrographs, and only a few of the exposed weft threads. Already i am beginning to take issue with Thibault and his somewhat ascerbic observations on coloration that is not strictly confined to the most superficial, flat portions of the weft.
11:47 Hugh has just added a comment, drawing attention to the Shroud Scope images, and whether the herringbone weave we see there represents threads, or shadows between threads. It’s a subject we discussed earlier, and I don’t recall exactly what I said there, except maybe that it would require lateral lighting for furrows to look more prominent than ridges, and that I really couldn’t imagine that Durante in 2002 would have used lateral lighting, but instead have opted for an overhead bank of lights to avoid shadows (surely?). While I think some more about it, here is a Shroud Scope image I have just grabbed, to which I’ve given some extra contrast. Judge for yourselves, folks… It’s from the nose, mouth and chin, selecting an area with primarily body image, with some adjacent non-image area. Body image tends to show grey or red-brown.
Fig.9: Click to enlarge
The next step will be to add another entirely different source of thermal energy to the model so far. It is secondary, and it is convection as distinct from conduction. It acts at a distance, in contrast to conduction that requires atom-to-atom contact between template and linen. It is in fact forced convection, and may contribute to the subtlety and complexity of the Shroud image, even if the template, as above, represented so far as a flat sheet of metal, is unsubtle. I’ll address the possibilites that are offered by curved bas relief template over a flat sunk-relief metal plate last of all.
Watch this space – more to come.
Fig.10: Caveat: the above diagram is highly schematic, indeed impressionist, with no attempt to show the precise locations of the new additions.
More to come… with the focus on the above hypothesised ‘secondary scorching’ via forced convection of superheated gases (air and steam).
15:15 The natural moisture (H2O)content of linen is said to be 6.7%, although it can absorb up to 20% of water without feeling damp. It seems unlikely that linen will start to pyrolyse under a hot template at least until that physically-associated water has been driven off as steam. Where is it to go? If there’s a metal template on top, it has little alternative but to exit through the pores of cloth to the underside of the latter. What happens then will depend on the underlay – whether it’s a hard surface or an absorbent cloth say.
Once the linen itself begins to pyrolyse at high temperatures – typically well in excess of 200 degrees C, probably nearer 25o degrees C, then there will be more steam from the chemical dehydration of organic compounds. What’s more it will be superheated steam, probably hot enough to affect linen constituents that are not in direct contact with the template.
I used the term ‘forced convection’ earlier. It’s worth bearing in mind that heated air, steam etc expands with temperature according to Charles’s Law. That means there will be a rush of hot gases from under the template that will have to force their way through the pores of the fabric in order to escape, so the area immediately under the template will be a complex physical and chemical environment which will be reflected in the nature and distribution of the scorching.
In passing, I might mention the “twinkling stars” effect I have seen when my scorch marks are held up to the light.
Does anyone know if the Shroud shows a similar effect in its image areas? Might those twinkling stars be a signature for a scorch, produced presumably by a combination of mechanical and thermal insults.
Note then the orange coloration that I have added to the last but one figure showing hot gas-induced pyrolysis extending into surrounding area, and probably concentrated in the interstices of the fabric between threads. So it should come as no surprise if on studying the Shroud photomicrographs one finds occasional coloration of the oblique fibres that descend into the interstices. The pyrolysis gases may also contain volatile carbon compounds. The most likely are carbon monoxide and carbon dioxide.
15:50 OK, so we now have two levels of complexity, arising from scorching via primary conduction, and scorching via secondary convection. We now need to factor in the third source of complexity – the nature of the template, primarily to do whether it is a flat plane – or a simple sunk relief, i.e. two stepped planes – as used by Thibault, or whether it is a bas-relief with more or less curvature in addition to scattered and maybe isolated protuberances.
More to come:
Again, a highly schematic diagram that now includes two new elements – a bas relief template and an underlay that permits a degree of moulding of linen to bas relief contours when the latter is pushed down vertically. A diagram does not easily allow one to convey the additional complexity and subtlety that comes form using a curved rather than flat template. suffice it to say that scorch image intensity is likely to be greatest at (a) prominences (b) flatter planes that impact with an incident angle of 0 degrees, ie. “square one”, giving compression of underlay over a wide area, resulting in maximum resistance to penetration of the underlay, and maximum pressure of contact between linen and template. Other things being equal the higher sides of a bas-relief template will imprint less well than the lower “square on” planes.
Put all of these factors together – conduction, convection, bas relief and underlay and it’s clear that far from being simple, the scorch hypothesis can produce images that are subtle and complex. It is a mistake to dismiss scorching on the basis of a few experiments that fail to incorporate the most elementary features that a medieval forger could have adopted with with or without conscious thought processes, but almost certainly with a degree of trial-and-error to achieve and end-result intended to impress and no doubt intrigue viewers if given no hint as to the kind of technology employed. The superficial negative image alone might have perplexed, given that negative images are uncommon even now, yet it is thermal imprinting that in my humble opinion explains the negative image far better than any rival hypothesis, certainly not radiation or obscure chemical processes that require a score of more of conditions to be just right.
With this admittedly lengthy preamble I am now in a position to comment on, and interpret, the Mark Evans microphotographs that introduced this posting.
My Fig.13 (above)
My Fig.14 (above)
My Fig.15: Click to enlarge
Not finished yet: the results above now need to be interpreted in relation to my newly tweaked conduction/convection model discussed earlier…
That will have to be tomorrow, I’m afraid. Congratulations/commiserations to all of you who have stayed with me this far (quite a fair few, judging by WordPress’s visitor meter)…
Wed 31st October am
OK. Let’s make a real effort to be as objective, as icily-detached as is possible. Scroll back to that first photomicrograph in this postings without labelling. Imagine, as I have just done, that one is seeing it for the first time, and asking oneself – “Are there any clues from the distribution of colour, especially between warp and weft (i.e more and less superficial components of the weave) as to how that image may have come in to being? Think about it. I’ll be back shortly.
Can anyone seriously doubt or question that warp threads are more strongly coloured than weft? Yet the difference between them in terms of superficiality is tiny, probably nor more than a mm or so. That difference has to be the major feature of the Shroud image – it is predominantly warp- located. It is the difference that has to be accounted for in any explanation for the Shroud image.
So why is Paolo and his ‘out-of-normal- working hours’ “ENSA” team continuing to promote their wacky laser beam uv model, claiming that it somehow explains the superficiality of the Shroud image? Why should a high-energy photon (of mysterious origin) produce a colour change in the surface of a warp thread, while an adjacent weft thread, every bit as exposed to the incident laser beam, remain unaffected, or virtually so? That’s all I have to say on the subject of the laser beam theory – it’s simply not worth the time of day… (And I have not forgotten Paolo Di Lazzaro’s patronizing attempt to summarily dismiss the scorch theory with that silly one-off sustained contact scorching with an over-heated coin posted to the Other Site – one that guaranteed excessive scorching).
11:00 Here’s some light relief – a screen grab from the Other Site as it appeared a few minutes ago.
Yes, that’s my ‘lemon juice’ posting you see there, which yesterday drew some mean-spirited comment, yet again, from one of the Usual Suspects saying it was unbecoming of a proper scientist to post without numerical data ( has he never heard of a qualitative discovery, e.g. like the discovery of oxygen, or a preliminary announcement). But it’s those Comments that do that site absolutely no favours. I speak as the individual who first suggested to Dan Porter that he create a “Recent Comments” feature for the sidebar, but look how it has been abused by one obsessional attention-seeker with too much time on his hands(to whom I have just addressed a comment in my own sidebar).
More to come…
Next step: could the pattern be due to scorching by contact/conduction? Obviously yes – the template making best contact with the most superficial part of the weave, i.e. the warp in this instance.
Is there any other mechanism that could produce selective coloration of the warp threads and fibres? Possibly. STURP’s Raymond N. Rogers attempted to incorporate that into his Maillard theory, proposing that reducing sugars were originally in solution and migrated to the highest part of the weave, where they were deposited by evaporation. There are so many objections one could make – but one will do for now. While Rogers claimed that he had a positive test for starch or starch fragments, he did not (to the best of my knowledge) ever test for reducing sugars. What’s more, it’s said there is no excess of nitrogen in the image areas that one would expect if the image has resulted from a Maillard reaction between reducing sugar and any kind of amine (ammonia, putrescine, cadaverine etc). Rogers’ hypothesis needs rather more in the way of underpinning experimental evidence if it is to be taken seriously by this sceptic.
OK, so it’s not uv, it’s not a Maillard reaction. What does that leave? It leaves some kind of thermal scorching. So let’s take that as our working hypothesis and look critically at it in the light of the other photomicrograph evidence. What about those interstices?
More to come…
Oh, one other thing before we move on. I must flag up a crucial aspect of the scorch imprinting model – contact pressure. Contact pressure that is sufficient to get a good imprint off a template is likely to flatten the weave. If the weave is flattened, reducing the height difference between warp and weave threads then a greater width of those warp threads will be scorched, and indeed there may be some scorching of the weft weave as well. Maybe we have here a means of testing the hypothesis. How? It’s a well known fact that certain parts of the head of the Man in the Shroud are imaged better than others, notably the nose, chin, mouth etc. In the scorching-off-a-hot-template model, that’s because those prominences give good contact. Ipso facto, one might expect better imprinting, leaving a wider-than-average impression on the threads, maybe even beginning to imprint on the recessed weft threads. That should be a testable hypothesis, once the copyright holder(s) of the Mark Evans and other photographic archives can be prevailed upon to place the ENTIRE high-resolution archive into the public domain.
Raymond Rogers’ explanation for the enhanced imprinting of the nose, chin etc? His model attributred it to those putative (or as I would say, premature) putrefaction amines, escaping from each and every body orifice. Sometimes in science one needs more than ingenuity. Sometimes in science, faced with the unfamiliar or the unexpected, one’s first refuge should be the feet-on-the-ground commonsense that one hopefully was born with, or acquired through experience…
15:25 : Now for those interstices (Fig 14 above with the red circles). There does seem to be heavier coloration on the oblique ends of the warp threads than might be expected from a simple contact scorch model, even with a lot of applied pressure. However, that should not be an occasion – or pretext- for dumping that model, least of all when there is nothing credible to put in its place. There is a time-honoured alternative in science, which is to tweak the model (while trying not to incorporate so many refinements as to make the model over-embroidered and unrealistic).
I have pointed to one possibility – namely that steam and pyrolysis gases escape through the interstices of the cloth to the underside, and may colour up the oblique ends of the warp threads en route. Note especially my Fig 11, with its “starlight effect”, which are enlarged interstices that let through more light. One can’t be certain at this stage as to what caused them, but dehydration steam seems a likely possibility – with enough enlarged holes being created to relieve the pressure. Might such a star-studded effect be apparent if the Shroud were held up to the light and photographed? Might that star-studded effect be another signature of scorching?
Rogers himself, no friend of scorch models, postulated that superheated steam from pyrolysis could provide the activation energy for further scorching. But if it were pyrolysis gases that were extending the zone of pyrolysis and coloration, shown as orange instead of red in my schematic diagrams above, would that not also colour up the weft threads as well, given they too will feel a hot blast? Yet the weft threads, as mentioned above, have remained pale in colour and easily distinguishable from the more roasted appearance of the warp, even the oblique ends of the latter. Maybe there’s another explanation. One I recall suggesting elsewhere some months ago is that the threads that are most quickly scorched through immediate contact (i.e. “warp” though I did not use that term at the time) then contract due to partial dehydration, such that coloured portions retreat into the interstices making the scorch look less superficial than was really the case. That idea is only a possibility at this stage, and is one that needs testing experimentally. Unfortunately it would need a 3/1 weave for any results to be considered relevant to the Shroud, and that’s something I don’t have. Nor do I have a microscope. Maybe I could beg, borrow or steal Hugh’s, or, perish the thought, buy it off him when he’s done what he wants to do… 😉
Seriously, I might consider investing in my own microscope, but only when I feel that I am running out of things to do at the more macroscopic level. Neither do I wish to get too involved with the minutiae of microscopy right now. that would be inviting frustration while the Shroud photomicrographs are still jealously guarded by STERA and its pro-authenticity globe-trotting President, the man given to springing out the woodwork of the Other Site to personally slap down my ideas about scorching with stale STURP so-called science. It’s one thing to go cap in hand to a curator for access to artefacts – another thing entirely to go to the proselytising President of $TERA with his hoard of copyrighted material, having read his advisory note that high definition photographs are not available for display on the internet. Maybe Thibault Heimburger can persuade STERA to release its entire portfolio of photomicrographs – not just the one that serve his purposes…. I for one really need to know how those bloodstains look in relation to warp and weft (see my earlier postings on the Shroud Scope images of blood – or should that be “blood-substitute”?).
More to come: (probably not a lot more, but I must mention those “burned bits” that Thibault considers the signature par excellence for scorching).
Thibault Heimburger concludes his paper with this: “The “signature” of a scorch is found in all kind of scorches, even in very light and light scorches: even at the lowest temperature, some protruding burned fibers are observed and many small opaque brown to dark burned pieces of fibers are easily found everywhere in the sticky-tape experiments. This was not the case for the direct observations with the microscope on the Shroud in 1978 or on the sticky-tapes.”
No protruding burned fibres on the Shroud, eh Thibault? No dark burned pieces of fibres? Never mind the STURP samples for now. Have you looked closely, and I mean REALLY closely at the 4 Mark Evans pictures that you have liberated from the Evans/STERA archive. Have a look at my Fig 15 above. Are there not black bits in those circled areas. Have a look look at the circle on the right, which I have enlarged as Fig 0 (an afterthought) to introduce this posting. Here it is again:
Is that not at least one – possibly more carbonised fibres I see there?