Let’s start with a quick botany lesson (apologies to those who already know what I’m about to say).
On the right is a 3D model I’ve made of the typical young plant cell, before it has acquired a secondary cell wall.
The primary cell wall is depicted as a network of cellulose fibres (red) embedded in a non-fibrous ground substance (hemicelluloses). See end of posting for more details on how the model was constructed (using net bag, polythene bag, Vaseline, red bean, pepper, inky water).
First, one can represent a linen fibre in cross section with 4 concentric circles.
What one is seeing is the cross-section of what originally was an elongated bast cell in the stem of a flax plant. The part that was originally living, with streaming cytoplasm, cell nucleus and other organelles, is shown coloured in the next diagram.
The hole in the middle, aka lumen, was the fluid (cell sap) filled centre, typical of most plant cells, with dissolved mineral salts,sugars etc.
The first formed cell, aka protoplast, simply has a fragile cell membrane, similar to that in animals, which is exceedingly thin (typically 4nm for a lipid bilayer prior to embedding of proteins). Plants waste no time in producing a primary cell wall (PCW):
Why is it on the outside? Because it’s only a temporary envelope, one that can stretch as the cells and tissues are growing and expanding, providing a measure of support and stiffness that depends on cell turgor, ie. uptake of water that expands cells like balloons until the PCW is fully stretched. But that alone is not enough to prop up a tall flax stem. The flax bast cells that comprise the long fibres are intended for support of the entire stem, so need to be reinforced. That happens as a result of formation of the much thicker secondary cell wall (SCW), packed with crystalline cellulose and usually lignin too. Result – the PCW, now largely irrelevant, is pushed to the outside, and is very, very thin (typically 100nm). The diagram below (schematic, needless to say, like all the others) shows the workhorse SCW, the feature that makes linen linen.
There are important differences between the PCW and the SCW that have to be understood if one is to understand the nature of progressive scorching of a linen fibre by heat, e.g. contact with hot metal template.
What follows is a thought experiment.
Contact with hot metal and PCW leads to pyrolysis (thermal alteration and yellowing due to chemical change). The PCW consists of cellulose fibres embedded in a matrix of hemicelluloses (non-crystalline xyloglucans etc) The latter are more susceptible than cellulose to pyrolysis (Yang H et al, 2007)
So initial scorching is confined to that superficial PCW (reckoned to be a mere 100nm thick, It may or may not propagate around the entire diameter of the fibre, as shown in the next diagram (about which more later).
So what would be the next target for pyrolysis, as more thermal energy is conducted by atom-to-atom (or molecule-to-molecule) transfer of kinetic energy of vibration/oscillation. There are two possibilities.
The first, perhaps more probable, is yellowing of the SCW, due to its appreciable hemicellulose content, said to be approximately 15%.
However, there is another possibility, namely that the cytoplasmic remnants – ‘fossilized life-stuff’ so to speak – may be more susceptible than SCW hemicelluloses to pyrolysis, given the assortment of biomolecules that may be present, notably proteins, sugars etc etc (Maillard reactions?).
Finally, and without a single cellulose molecule being implicated, one has this more advanced stage:
So that’s the thought experiment. (Yes, let’s stop there without going on to imagine charring of the bulk cellulose which is of no relevance to the faint and “ultra-thin” (200-600nm?) thick image layer on the Shroud. Where do we go from here?
First, the easy bit (at least for those who have a reasonably well-equipped microscopy lab at their disposal).
The first priority is to subject linen to increasing inputs of thermal energy, initially by contact scorching (which accounts for the negative image and much else besides – like ‘encoded’ 3D properties, but so far not fluorescence, or lack thereof) and to monitor the sequence of scorching in the 3 zones indicated.
One then needs the cooperation of the Shroud’s custodians to do high grade microscopy on a few Shroud image fibres. The latter would not be confined to entire threads, where artefacts of light refraction etc may produce a wrong impression of coloration or darkening. One MUST section Shroud threads in order to view in cross-section.
Are there available transverse photomicrographs at a sufficient level of magnification to see whether the Shroud image fibres fit any of the stages in the model scheme above?
So far my knowledge on that score is restricted largely to a few words in the Fanti et al paper on macroscopic v microscopic properties of the Shroud image fibres, ones that have acquired wide currency in the Shroudie world, and inspired (in my view) far too much premature and misguided excursions into exotic forms of energy input (uv laser beams, corona discharges, neutron bombardment etc). Why wasn’t conventional energy studied first in model scorch systems, to see if alleged ‘super-superficiality’ really was explicable or otherwise in terms of conventional physics (and botany and pyrolysis chemistry)? Was proper consideration ever given to the physical and chemical structure of the flax fibre that could have accounted for image superficiality? I say not, and I say it’s an appalling display of what happens when engineers turn their hands to science, and proceed to engineer results that just happen to fit with their agenda-driven preconceptions, and which are guaranteed newspaper headlines, concluding with the researchers’ pious hope that readers will be prompted to think about theological and philosophical considerations. They might as well have carried a banner reading “We do pseudoscience better than anyone else”. That “we hope” comment alone brands them as practitioners of pseudoscience, or as I would prefer to say “Mickey Mouse” scientists. One of those comedians even responded to an invite on Porter’s ‘Troll Central”* to report his one-off hot coin scorch imprint – pressing on the coin until it produced, surprise, surprise, a reverse-side image – one of the most mirth-provoking interventions imaginable. The screaming title claimed that scorching was “untenable” (with my name attached, natch). Garbage. Complete and utter garbage, to say nothing of hit-and-run trolling, brought to you by the Mickey Mouse Institute of Instant One-Off Scorching, recruited by the mysterious string-pulling Shroud-promoter Daniel R.Porter.
I responded with my onion epidermis experiment – real science. The silence was deafening, and really tells folk all they need to know about the scientific bona fides of the people who engineer results in order to to “get us thinking about theology and philosophy”.
Engineers should stick to engineering, and leave science to the scientists – folk who can generally be relied upon to design and execute disinterested experiments regardless of their ‘theological or philosophical’ beliefs.
It’s high time the Italian equivalent of the UK’s Royal Society stepped in, and began blasting those agenda-driven Shroud-obsessed engineers who posture as scientists , who do huge damage to the reputation of real science and real scientists.
* Enter “Colin Berry’s idea is untenable, and heat cannot produce a superficial coloration” into one’s search engine. I shall not dignify that execrable instance (one of many) of hit-and-run trolling on Porter’s site by providing a link, and have merely informed the host that it’s been flagged up here as abuse of site.
For another instance of egregious trolling, see the September 12 2012 posting entitled “What is Colin Berry talking about?” Note the Aunt Sally attack from the site’s host, plastering my name in the title (which he has done so many times before and after). Then see the way that the Usual Suspects (persistent trolls) pile in.
Why did I not respond? Well, as I said yesterday, there’s the stock internet advice: “Don’t feed the trolls”.
But there’s another reason – bemusement with the Shroudie group think, that makes any attempt at rational argument a waste of time. Roughly speaking, here’s how it goes. Someone reports a feature of the Shroud image that they consider “peculiar”, e.g. that it’s so superficial that only the top few fibres are coloured. That quickly becomes “there is something totally unique and mystifying about the Shroud image”, despite no one bothering to look at similar- looking light scorches produced experimentally. So when I produce a light scorch that is scarcely visible, with no reverse side image, I get mocked and ridiculed because I have not “understood the nature of Shroud image superficiality”. But I do. I know that its guesstimated 100-600 nm thickness is exactly what one would expect of a PCW that has been selectively-scorched, by virtue of its superficial location and complement of hemicelluloses. Do the Shroudie-mystifiers know that? Did they ever take the trouble to think as I have done at the microscopic and molecular level? Or was their narrative based on a handful of “trophy results” that can be intoned like mantra, and used in trolling attacks to belittle anyone who dares questions their self-serving, agenda-driven narrative?
The final insult is when the Shroudie pseudosciences finally get round to producing an experimental scorch, and do it in so crass a manner as to scorch the entire thickness of fabric, and then say “Look, I told you so”.
You really couldn’t make it up. For the record, I’m not in the least surprised that a faint scorch on the Shroud scarcely penetrates the weave. But that’s because I have no reason for thinking my experimental scorches would be any different. Sure, I may get round to probing with a needle, as indeed I have done already in a half-hearted fashion. Why half-hearted? Because the real test is to start with a transverse section (as stated above) so that one’s report can be accompanied by photomicrographs, instead of 1st person (“I did this, I saw that”) accounts, unsupported by any permanent record. Unfortunately I don’t have the wherewithal to do cross-sections, and my microscope has acquired some debris in the field of view. What I do have is enough knowledge of fundamental physical and chemical principles relating to heat conduction, and thermochemistry to know that relatively small heat ingress due to limited contact time, or temperature control or light pressure, or damp backing cloth is not in the least bit surprising. That’s because thermal energy is a continuous variable that can metered down essentially to zero. It would be physically impossible to produce a deep scorch by limited energy flux from brief contact with a hot template. Brushing against a hot electric iron may be painful, but does not produce 3rd degree burns.
Science is often more a matter of commonsense, requiring no recourse to intimidating theory and partial differential equations. Toasting bread usually takes minutes – not seconds. No pyrolysis (or Maillard reaction) can take place until most or all the water has been driven off.
To be continued: I shall be adding on some information re the hazards of attempting microscopy with whole unsectioned plant cells, and giving some further reasons for thinking my onion epidermis experiment argues strongly against misinformation that would have us believe that contact scorches are by their nature instantly deep and penetrating, and thus “untenable” for explaining the superficial Shroud image. As I said before – garbage- total, unmitigated, agenda-serving garbage.
Other instances of ‘mystification’
1. The Shroud is a negative image. Ipso facto, it must be a proto-photograph of the man depicted.
No, it’s probably a contact scorch, like a brand on cattle hide, with reversal of light and dark. So while not a photograph, a fitting description might be “thermograph”.
2. The Shroud has unique encoded 3D information.
But the 1532 burn marks also respond to 3D enhancement. There’s nothing at all unusual or unexpected about an image with differing intensity being converted to a 3D relief map with suitable software. In fact, a quick charcoal sketch of the Shroud image can be given a Secondo Pia makeover with ImageJ software.
3. Only minor lateral distortion in the image (and no imaging of the sides). Therefore the image was created by orthogonal projection of mystery radiation.
Alternatively, the image was imprinted thermally from a hot bas-relief template.
4. The Shroud image, observed under the microscope, shows fibres that are either uncoloured, or fully coloured (pale yellow) with no in-betweens. The appearance to the unaided eye depends on the relative proportions of coloured and uncoloured fibres, not on variations in individual fiber coloration.
This is a simple statement of what is now touted as the ‘halftone effect’ and a more pretentious terminology would be hard to find.
The term halftone effect was coined for the development in the late 19th century of a method for printing photographs that achieved the optical illusion of tonal contrast by means of dots of varying size and degree of closeness to each other. It was a purposeful, engineered effect.
To apply the term halftone to fibres that are either pale yellow or uncoloured while ignorant of , or indifferent to mechanism, and indeed attempting to imply there was some kind of mysterious process at work unknown to science is frankly pseudoscience at its very worst.
Who’s to say there were not fibres with differing degrees of coloration initially, and that over the centuries the more intensely coloured ones, being most compromised in terms of mechanical strength, have simply broken off, leaving pale yellow fibres of approximately the same intensity. The progressive stages of scorching modelled in my thought experiment above provide a ready explanation: those fibres that are darkest to start with probably have not only a maximally-scorched PCW, but scorching that penetrates to the SCW as well, rendering the entire fibre weaker, more brittle, and thus prone to break off on repeated handling. The end result may be survival of those fibres that have highly superficial PCW scorching only. That surviving population of lightly scorched fibres is now described by Shroudies as “the halftone effect” that sceptical scientists are required to reproduce, without benefit of a time machine.
The term”halftone effect” should be expunged from the Shroud literature. See the rationalwiki definition of pseudoscience.
“Pseudoscience is any belief system or methodology which tries to gain legitimacy by wearing the trappings of science, but fails to abide by the rigorous methodology and standards of evidence that demarcate true science. Although pseudoscience is designed to have the appearance of being scientific, it lacks any of the substance of science.
Promoters of pseudoscience often adopt the vocabulary of science, describing conjectures as theories or laws, often providing supposed evidence from observation, expert testimonials, or even developing what appear to be mathematical models of their ideas. However, in pseudoscience there is no real honest attempt to follow the scientific method, provide falsifiable predictions, or develop double blind experiments. Pseudoscientists often use the tactic of cheating the scientific method.”
5. From Thibault Heimburger (yesterday, comments, this site), my bolding:
You definitely failed to prove your hypothesis.
I (after many others) proved that the scorch hypothesis does not explain simutaneously the superficiality, the half-tone effect, the fuzzy borders etc….
Well, we’ve addressed the superficiality criterion, and just now the half-tone effect. So what about the ‘fuzzy borders’? Will lack of perceived fuzziness be the killer criterion that brings my 14th century provenance edifice crashing down?
I hardly think so. Look at this site’s banner, showing thermal imprints from a brass crucifix obtained by my new LOTTO method.
Here’s part of the image of the imprinted head magnified x8.
Looks pretty fuzzy if you ask me. (It’s almost as if it had been painted on with that burnt umber that artists use for their preliminary composition).
Invoking a”fuzziness” criterion is maybe not pseudoscience. But it’s not precision science either – not unless one has a system that assigns a number to an image that denotes degree of fuzziness.
Update: Friday 7 March
I’ve been asked by TH (see comments) if I have a higher resolution picture than the one above. The answer is probably no, unless I take my existing pictures and photo-edit to increase the contrast (which is hardly scientific). But I still have the original linen with the image, and have just re-photographed, without flash, in artificial light (admittedly not ideal). Here are the results. I will repeat again tomorrow in daylight.
Update: I said yesterday I would post a description of how a typical plant cell with primary cell wall only (like that in the onion epidermis) can be modelled in 3 dimensions. I have just this minute assembled the necessary ingredients: