Tuesday, April 8, 2014

"There is no possibility whatsoever that the image on the Shroud is a scorch. . . ....". Who says? Ask to see the experimental evidence - and check scientific credentials.

 Who else recalls that celebrated self-mocking (1973) roadside ad for Guinness stout ale:

Guinness ad: "I've never tried it because I don't like it

(It took quite a while  to track down an image of that memorable ad on internet  files. Methinks Guinness may have had second thoughts about its ability to attract new custom!)

I was reminded of it when reading the latest posting on shroudstory.com, to give it a polite appellation on this bright sunny morning in the UK, now the Saharan smog and rain have passed over (see previous posting).

Yes, how many times have we seen those words in my title, quoted by shroud-authenticity promoters, the latest being from a gent with a leading role in the post-STURP, cat-that-got-the-cream $TERA. That's the "$hroud of Turin Education and Research Association" ho ho ho in case you didn't know. Sounds of cash registers ringing...

I've lost count of the number of big cheeses in the Shroudie Land who have solemnly incanted those words. Yet the vast majority have never bothered to produce a single contact scorch. I have - hundreds of them. While I sadly lack the technology to prove it, I invite others to disprove my contention that a contact scorch on linen can be as superficial as one likes, right down to the molecular scale at surface (primary cell wall) level. I see no theoretical or practical objections whatsoever

(ed: I've been taken to task elsewhere for that "prove me wrong" challenge. I've been accused of the very thing I condemn on this site (pseudoscience). Methinks the gent concerned should acquaint himself with the history and practice of science before attaching the p word to a published scientist, albeit long retired. He could do a lot worse than read up on the Higgs boson, whose existence was first predicted  by Peter Higgs in 1964, but it was needed as a vital component of the Standard Model (explaining why subatomic particles have extraordinary mass over and above relativistic mass that is predicted by e = mc squared). Higgs did not have the technology to prove the existence of his particles, nor did anyone else, until CERN's LHC proved its existence in 2012. Nobody condemned Higgs or anyone else for assuming the particle was there, if only to maintain the most all-embracing Theory of Nearly Everything. (except Gravity Dammit). Indeed, Higgs was awarded a Nobel Prize last year, despite having no hand in the experimental confirmation.  Homo interneticus, bereft of any formal scientific qualifications or research experience,   likes to think he understands the scientific method, but in my experience rarely appreciates the respect accorded to hypotheses and theories that unite a lot of existing disparate observations, but which still await the kind of experimental data that banishes most lingering doubts held by (fair-minded) sceptics. I exclude the flat-earth tendency from that final description, like those who think the radiocarbon dating MUST be wrong because it conflicts with their dossiers of "historical" and other evidence. It never seems to occur to them that the radiocarbon data conflicts with their self-serving agenda-driven quest for "spy clues" to the existence of the TS pre-14th century. Some of those spy clues, like tiny ink-drawn circles on an otherwise obscure Hungarian codex being evidence the illustrator  was signalling he had seen the Shroud  with his own eyes are frankly risible, indeed, faintly ludicrous, but to many in Shroudie  Land they constitute incontrovertible evidence against a 14th century provenance, and woebetide anyone who suggests otherwise. No, I'm not and never will be a Peter Higgs, with a 360 degree view of his chosen area of research. Mine's more like the standard 45 degrees. But I'm not a pseudoscientist either, like so many others I could mention who have dabbled in Shroudology, playing to the same old gallery).

So to STERA promoters and others: kindly cease recycling the same old mantra that the Shroud image cannot be a scorch. STURP never said that, as many folk seem to imagine. Read the STURP summary in full* and a reasonable person, free from preconceptions, religious or otherwise, might conclude precisely the opposite, namely that an image created by pyrolysis of linen, i.e. thermal degradation alone, is FULLY CONSISTENT with contact scorching. Elsewhere, in the course of some 200 and more postings,  I have addressed the many previous attempts to dismiss that notion, but they were either lacking in experimental support, or, one one occasion, accompanied by a risible and hamfisted demonstration of how to over-scorch.

Oh, and let's not forget the occasion when the $TERA top man no less deployed the nuclear option : ... there is no possibility whatsoever that the image on the Shroud is a scorch because ...   drum roll ..  it fails to show obligatory fluorescence under ultraviolet light. Yeah, right...Thanks for the chemistry lesson. Sadly I missed out on the photography module at University, having to do tedious and irrelevant stuff like 2 years of subsidiary organic chemistry. Uv fluorescence is a property of certain specific molecules. Those molecules are not necessarily permanent fixtures. They can oxidise, polymerise, volatilize etc. Lack of fluoresence, centuries after formation, proves nothing, ABSOLUTELY NOTHING., except maybe to photographers-turned-organic chemists and/or other $hroudie-circus showmen.

Postscript: here's a link to a posting I did over 6 months ago -  admittedly not my finest hour re concise reporting of new experimental findings - that I suspect gives the strongest clue as to why fabrics like linen and cotton (cotton especially) can take a scorch-imprint without falling apart.
Basically, what I found was that cotton can be scorched more easily than linen at any given temperature, but that the difference is reduced by pre-treatment of the fabric with strong alkali.

I interpret that as cotton having a greater concentration of fragile (thermolabile) non-cellulosic polysaccharides in the outermost primary cell wall, due either to genetic differences, OR the fact that cotton requires no retting to separate fibres, and that alkali targets those fragile polysaccharides (hemicelluloses etc) leaving cellulose largely intact, at least chemically. That leaves less target-material ON THE SURFACE for imprinting an image.  The underlying cellulose (especially the highly crystalline inert  variety in the core of the fibre, representing the secondary cell wall) seems to be largely irrelevant where contact scorching is concerned, at least where imprinting of a highly superficial image is concerned - one that attempts to model the faint image on the Shroud.

Here's a graphic from that posting, showing how alkali-treated cotton gives a less intense scorch than control(untreated cotton).

The difference seems to be greatest in the second-from-left imprint where the template was still very hot and held longer against the fabric, before 'serially imprinting' while progressively cooling (images to the right). That's suggestive of there being more than one chemical species qualifying as 'more thermolabile than cellulose'. There's a largely unexplored world where knowledge of contact scorching is concerned,  one this kitchen-experimenter can only hint at.  Who would know or even suspect it -  looking all those categorical and dismissive comments made in Shroudie Land, like the one in the title.

When in doubt - experiment. It's the sure way to experience the buzz of real science - as distinct from received wisdom/dogma, all-too-often pseudoscience.  Not for nothing is this site called "sciencebuzz".  As the song goes: "It ain't necessarily so..."

*A Summary of STURP's Conclusions

Editor's Note: After years of exhaustive study and evaluation of the data, STURP issued its Final Report in 1981. The following official summary of their conclusions was distributed at the press conference held after their final meeting in October 1981:

No pigments, paints, dyes or stains have been found on the fibrils. X-ray, fluorescence and microchemistry on the fibrils preclude the possibility of paint being used as a method for creating the image. Ultra Violet and infrared evaluation confirm these studies. Computer image enhancement and analysis by a device known as a VP-8 image analyzer show that the image has unique, three-dimensional information encoded in it. Microchemical evaluation has indicated no evidence of any spices, oils, or any biochemicals known to be produced by the body in life or in death. It is clear that there has been a direct contact of the Shroud with a body, which explains certain features such as scourge marks, as well as the blood. However, while this type of contact might explain some of the features of the torso, it is totally incapable of explaining the image of the face with the high resolution that has been amply demonstrated by photography.
The basic problem from a scientific point of view is that some explanations which might be tenable from a chemical point of view, are precluded by physics. Contrariwise, certain physical explanations which may be attractive are completely precluded by the chemistry. For an adequate explanation for the image of the Shroud, one must have an explanation which is scientifically sound, from a physical, chemical, biological and medical viewpoint. At the present, this type of solution does not appear to be obtainable by the best efforts of the members of the Shroud Team. Furthermore, experiments in physics and chemistry with old linen have failed to reproduce adequately the phenomenon presented by the Shroud of Turin. The scientific consensus is that the image was produced by something which resulted in oxidation, dehydration and conjugation of the polysaccharide structure of the microfibrils of the linen itself. Such changes can be duplicated in the laboratory by certain chemical and physical processes. A similar type of change in linen can be obtained by sulfuric acid or heat. However, there are no chemical or physical methods known which can account for the totality of the image, nor can any combination of physical, chemical, biological or medical circumstances explain the image adequately.
Thus, the answer to the question of how the image was produced or what produced the image remains, now, as it has in the past, a mystery.
We can conclude for now that the Shroud image is that of a real human form of a scourged, crucified man. It is not the product of an artist. The blood stains are composed of hemoglobin and also give a positive test for serum albumin. The image is an ongoing mystery and until further chemical studies are made, perhaps by this group of scientists, or perhaps by some scientists in the future, the problem remains unsolved.
Brief summary/update of my own position re the scorch hypothesis after some 2 years/200+ postings.

1. At the outset I could see scarcely if any scientific merit in non-contact scorch hypotheses, notably those involving radiation or of putrefaction products leaving a chemical imprint. But then advocates of those hypotheses seem content to assume them correct, while failing to seek and provide experimental confirmation. In short, those ideas are nor scientific, and it is thus pseudoscience to maintain that they are.

2. I initially envisaged the scorch technique as one of heating a metal template, probably bas relief, and pressing it down into linen spread out of a yielding material, e.g. bed of sand. But there were difficulties with that, notably that one could not easily monitor the progress of scorching, thereby risking over-scorching. There might also be excessive tenting of the linen between extremities, say between the kneesand the tips of the toes, with minimal imprinting of everything in-between,

3. When experimenting with a brass crucifix as template, I reversed the geometry, laying the heated template down on a hard surface, covering with linen, then, quickly, with a damp overlay, and manually moulding the two apposed fabric layers to the major surface contours. That procedure, which I call the LOTTO method (Linen On Top, Then Overlay) allows one to monitor heat flow (touchy-feely technology!), makes it harder to over-scorch (in fact, near impossible), gives a fuzzier, arguably more Shroud-like image,  and seemed the right answer if one were aiming to develop the TS image in a single step.

4. However, the LOTTO method does not account for some alleged subtleties in the TS image at the microscopic level. While one has to take much on trust - much that is written being little more than anecdotal - one might with the eye of faith describe the TS image as showing a half tone effect, where apparent differences in image intensity are not due to continuously varying scorch intensities between neighbouring fibres, but to differences in a chosen area between numbers of fibres that are scorched to a particular maximum level OR unscorched, with no in-in betweens. The half-tone effect could be described as digital as distinct from analogue imprinting. Some might consider chemical precedents for "digital imprinting" are few and far between, encouraging one to seek explanations that involve two or more steps, rather than a single one.
Recently I have proposed just such a two step mechanism involving: 1. Intense analogue scorchimg as a primary step, i.e. at point of manufacture centuries ago. 2. Subsequent loss of all scorched fibres, except those that are minimally scorched, e.g. by selective pyrolysis of the outermost PCWs, that does not impair the mechanical strength of the whole fibre. The half-tone effect then gradually appears via a 'survival-of- the-fittest' process leaving finally just two (main) classes of fibre - minimally-scorched versus unscorched.
The transition from intense to fainter scorch could have been entirely natural and unaided, Alternatively, it may have been accelerated at some point early on, in order to 're-invent' a deliberately-contrived scorched image, representing say, a martyred Templar, as one of the crucified Jesus, with a fainter attenuated scorch being promoted as a Veronica-like sweat imprint.  See the more recent postings on my now dormant specialist Shroud blog for more details on the "reinvention" hypothesis.

5. As hinted at earlier (but still little more than conjecture so far) I'm toying with the idea that that the LOTTO method was used, and, at least for the torso, might have used a 3D bronze that was half-embedded in sand to make it effectively a bas relief at the imprinting stage. What's more, the sand bed itself could be hot (used in fact to heat the template) relying on the fact that contact between linen and sand, far from being undesirable, might help to provide an instant  aged yellow look to the Shroud linen, with a smaller contrast difference between image and background for your more authentic-looking Shroud .

Initially I considered  that a bronze of the crucified Jesus might have been chosen, even if intending the image to be promoted, at least initially, as that of a more modern martyr, notably a Templar (Jacques de Molay?), the chemically pyrolytic/artistically pyrographic art form signalling the manner of execution (slow roasting at the stake). Another possibility has since occurred to me. Were there life-sized bronzes available in medieval times of St.Lawrence of Rome, who also was put to death by slow-roasting (258AD), with much medieval art work (painting) depicting him horizontally on his grid iron, often held  down by men with tridents or pitchforks, with or without cords?

Artist and date still unknown to this blogger, despite the above picture of St.Lawrence appearing in many different internet sites.

The advantage of using an effigy of St.Lawrence, if available, is that hands may have been in the right location to start with, if the contemporaneous 2D representation in art were anything to go by.

Reactive postscript:

Message to the gent on Troll Central. aka shredstory.som, who is trying to stick the charge of pseudoscience on this pro-scorch, anti-authenticity investigator.

You’re wrong, just plain wrong, indeed about so many things.

You’re  one of these people who imagines that science demands instant experimental confirmation of a new idea, that nothing can proceed without that confirmation, and that there’s an obligation on the originator of an idea to deliver the confirmation, or otherwise keep his thoughts to himself. At least, that’s your position where this investigator is concerned, though I note you do not demand the same of those who are content to sketch out airy-fairy scenarios of mysterious bursts of radiation,  or of ammoniacal vapours that travel in straight lines to conjectural sugary targets in linen.

Sorry, all you and other like-minded 'more-scientific-than-thou' armchair philosophers. That’s not how science works, and never has been.

 Science is primarily about ideas. Ideas run in advance of experimental corroboration, sometimes by years, decades even.  It’s the ideas, shared freely soon after inception  that provide the buzz for many in science.  There’s as much interest in supporting or refuting other people’s ideas as there in one’s own. It’s a collegiate thing: ideas go into a common pool. They may be known by their originator’s name, as a courtesy, and less charitably, to prevent plagiarising by those with no ideas of their own. But once an idea is out in the open, the genie’s out of the bottle, and there’s a sense in which it then belongs to science, rather than its originator. There is no shame in having one’s idea proved (or even disproved) by another scientist, the essential test of its scientific merit being whether it shows predictive utility, and whether or not it stimulates new lines of investigation, hopefully productive, that might otherwise not have been tried.

It’s time the world of shroudology ceased pretending that the scorch hypothesis was ruled out of contention  by the tendentious lines of argument advanced by Raymond N.Rogers and others, least of all by STURP (see previous posting).  It was not. While wishing no disrespect to someone who has sadly passed on, Rogers seemed to regard linen fibres as if they were composed entirely of cellulose. He made scarcely any reference to the chemically more reactive non-crystalline matrix of hemicelluloses, except as an “impurity”. Neither did he make reference to the superficial PCW (primary cell wall) that I can recall. Indeed he seemed to have no knowledge or even interest in the nature of the linen fibre as a botanical entity. To him, it was simply cellulose fibres, scarcely any different from his chemist’s filter paper.

  Those who have survived him have even less excuse to ignore the likely role of PCW hemicelluloses in scorching, given it’s now over 2 years since I posted a reference to Yang et al, emphasising that hemicelluloses pyrolyse  in a much lower temperature range than cellulose.

“…the pyrolysis of hemicellulose and cellulose occurred quickly, with the weight loss of hemicellulose mainly happened at 220–315 °C and that of cellulose at 315–400 °C….

 As I say, absolutely no excuse.  The facts speak for themselves. One cannot turn a blind eye to the facts. One cannot claim to be investigating the Shroud image scientifically, making vague references to some kind of “radiation”, usually unspecified, and failing to recognize the existence of the superficial PCW with one or more components prone to contact scorching.  Scorching by direct contact (zero air gap)  explains so much (the negative image especially, its preferential location on crown threads, its chemical and spectral  properties  which though poorly characterised thus far are consistent with pyrolysed, i.e. thermally-degraded carbohydrates, with no direct evidence that I’m aware of that it might represent a non-enzymatic browning product due to Maillard reactions requiring  an exogenous source of amino- nitrogen AND reducing sugars.

It’s time the world of Shroudology woke up and smelt the coffee. It’s the roasting of coffee beans that gives them their aroma. It was almost certainly the roasting , or rather scorching of linen carbohydrates due to direct contact with a heated  object that gave them their physical and chemical fingerprint, albeit presently lacking in detail and a facsimile negative image.

 (But why is that? I’ll tell you why. It’s due to wilful and chronic neglect following a  premature rejection  of a commonsensical proposition – thanks in no small part to what can only be described as agenda-driven pseudoscience, of refusing to give proper consideration to a particular IDEA). 

Which is where we came in. Science is the world of ideas. Ideas have to be addressed fairly and squarely - not swept under the carpet- citing anti-idea arguments that lacked credibility, to say nothing of objectivity, right from the word go.
Update: 22:30 Wed 9 April

April 9, 2014 at 4:26 pm | #5
CB: ” Yet the vast majority have never bothered to produce a single contact scorch. I have – hundreds of them. While I sadly lack the technology to prove it, I invite others to disprove my contention that a contact scorch on linen can be as superficial as one likes, right down to the molecular scale at surface (primary cell wall) level. ”
Colin, you have “hundreds of them”..
Me too.
You have a microscope. You could easily demonstrate that a ” a contact scorch on linen can be as superficial on linen as on likes..”
At least at thread level.


Back in November last year, I tried deliberately, with no success, to ‘over-scorch’ using my LOTTO procedure.The best I could do was to produce faint scorches on linen that might reasonably be described as Shroud –like on that basis. But expecting me to show that those scorches are highly superficial at the thread level, which may sound reasonable to the uninitiated,  is not as simple as it may seem. 

Why not? Because scorches that are exceedingly faint at the macroscopic level become almost impossible to detect when viewing individual threads or fibres under the microscopic. One is in effect asking the impossible – at least where a kitchen lab is concerned -  to produce faint scorches that can then be studied at the microscopic level. 

Don’t believe me? Then check the several photomicrographs in the posting linked to above. It becomes virtually impossible to distinguish between individual coloured and uncoloured fibres under the microscope, which is what one has to do in order to determine superficiality even at gross thread level. The colour one sees, such as it is, the merest hints of yellow or brown coloration, comes from seeing bundles of fibres packed closely together. It is asking too much to expect one to categorise individual fibres by colour, say by probing with a needle. A subtle scarcely visible scorch is just that – a subtle scarcely visible scorch.

Put another way: if one is asked to produce scorches that are highly superficial at the macroscopic level, judged on the basis of faintness to to the unaided eye, it is unreasonable to ask for visual proof of superficiality at the microscopic level.  The human eye is a wonderful thing - but cannot be expected to perform miracles. The better the model in terms of faint image, the progressively harder the model becomes to probe microscopically.

All of this needless to say distracts from the real issue, namely that it is ultimately against the spirit of science to attempt to dismiss or even marginalize scorching by contact, when the facts speak for themselves: contact scorching accounts for the major characteristics of the Shroud image. 

Where there are gaps or discrepancies, the first thought should be to account for  them in terms of precise scorching technique - LOTTO etc- or maybe secondary ageing effects. It is hardly scientific to nitpick or snipe at a model that explains so much, when there are no other credible models on offer, at least not ones that fulfil elementary scientific criteria  of theoretical feasibility and experimental testability..

Ray Rogers - along with several others - attempted to strangle the scorch hypothesis at birth.  But the case for immediate euthanasia was full of holes, as I have repeatedly pointed out. It was hardly one of the more glorious chapters in the history of science.

But the baby somehow survived, and is now a rebellious and unruly teenager, riding around on a noisy motorbike.

The successors of Ray Rogers, kindred spirits in detesting any idea of a medieval provenance, never mind scorching, are now attempting to set up road blocks, or, as in the cartoons, to paint what could be mistaken for dark tunnel entrances onto roadside outcrops of solid rock.


Hugh Farey said...

I ran out of linen the other day, so got some more off ebay. Raw unbleached linen, it said, but it was much thicker and heaver than my previous sample. So in curiosity I chopped off a 1m x 10cm strip and weighed it, and to my surprise, it has an areal density of 16 mg/cm2, which is not only vastly more than my previous sample, but vastly less than the shroud, which is usually reckoned at about 25 to 30 mg/cm2.

This puts a whole new complexion on the "only on one side" argument, as it is now ridiculuosly easy to produce a scorch which doesn't reach the other side, and almost impossible to get thick paint to seep through unless it is really smeared about.

I wonder what the areal density of "Edgerton" linen was? Or Thibault's? We're often told how 'fine' the weave of the cloth is, and how worried the STURP team were that their sellotape experiments might pull it apart, but if it was half as dense again as mine it was more like canvas than the silk hanky I'd misbelieved it to be.

How heavy are your "experiment" fabrics? You might be surprised!

sciencebod said...

That's very interesting Hugh, and definitely worth following up. Unfortunately I don't have access to a microbalance to check my linen or cotton. One thing I might try doing is to find the number of fibres per thread. Do you think that might be a factor in explaining such big differences between one piece of linen and another? The individual fibres are, after all, single cells in cross-section so one would not expect a huge difference at that level.

Btw: my wife asks if you have considered the weight of modern coatings on newly-purchased linen.

I'm heading off to Switzerland tomorrow to look after a friend's pets so won't be doing experiments of any kind for a while.