The Turin Shroud elicits ever more bad science... which the media dutifully reports as cutting-edge...

Why did those Italian scientists choose the uv region of the spectrum to model their improbable hypothesis for the Turin Shroud's image?

Nothing, apart from the Blair/Brown legacy,  infuriates this retired scientist more than seeing New Age so-called scientists straying over the line between science and religion. Yet that is what a group of Italian scientists have done in spectacular fashion. What’s more they have done it in such a manner as to create confusion and misunderstanding as to precisely what role they see for (wait for it) supernatural processes having produced the image, allegedly of the crucified Christ, on the Shroud of Turin. 

On the one hand their spokesman says he is unwilling to go beyond the science, yet that is precisely what he proceeds to do with his references to “philosophy and theology”. OK, so he is not the first to do that – Stephen Hawking did so in his “Brief History of Time”, but he is a cosmologist who, usually in the absence of hard data, and dependent as he is on mathematical modelling,  has to think the unthinkable.  The Turin Shroud, on the other hand is a physical object, much damaged by the 1532 fire, the subject we are told of repair processes (that have conveniently “falsified” the carbon dating of 3 independent laboratories due we are told to contamination)  yet here we have scientists speculating, yes speculating on intense flashes of ultraviolet light with all the implied supernatural intervention from on high..

Is this objective science?  I say no. It’s in the same league as Uri Geller’s spoon-bending (and I say that in the knowledge there are those who still think that was “magic”, as distinct from a conjurer’s trick, using  suggestion, distraction etc.).

Why did those Italians - ostensibly employed to research new technology in the public sphere -  break off to beam ultraviolet light from a laser at linen?  Why that particular region of the electromagentic spectrum (see diagram) , given that whatever findings they made, or claim to have made, there would be the inevitable conclusion that no medieval forger had access to a coherent beam of uv light? Does it not sound like a placing of a conceptual cart in front of a well-flogged,  indeed knackered horse?  Their credo is  "Let’s discount any technology that was available to medieval forgers , because it would be unable to simulate the peculiar properties of the shroud revealed by 20^th century science – the superficiality of the image on the cloth, its appearance on the reverse side too (whether cloth of individual fibrils is not clear)?  Let’s skip a whole raft of experiments that might be performed with accessible regions of the em spectrum, notably non-coherent infrared, visible or uv light, with or without the presence of putative photosensitizers".  (See note at bottom re importance of photosensitizers in any discussion of cellulose and ultraviolet radiation)*. You know the sort of thing:  certain drugs in the body -  tetracyclin antibiotics, statins etc. - can sensitize certain susceptible folk to uv rays from the sun, producing phototoxicity, skin lesions etc.  How can those Italians be so certain that there is not a more mundane explanation for that faint sepia image on the shroud. Why rush straight to a uv light, and state-of-the-art coherent uv light at that, from a laser, with all the wave peaks and troughs in perfect hi-tech step?

Here’s a question to ponder: why even contemplate uv light as a candidate for producing superficial images on fabric?  That flies in the face of what we know about the interaction between uv light on organic molecules. Ultraviolet light covers a range of frequencies whose energy corresponds with the bond energies (C-C, C-H, C=O, O-H etc) in organic molecules. In other words, uv light causes those bonds to rupture - by promoting electrons to higher non-bonding molecular orbitals – resulting in reactive free radical being formed – i.e. atoms or functional groups carrying an unpaired electron.

Uv light penetrates to the very heart of molecules, breaking them up from within.  Think of it like a torpedo aimed at a warship’s store of weaponry. That’s as distinct from infrared rays say, say, which do not carry enough energy to break bonds directly. What they do is cause  chemical bonds (shared pairs of electrons)  to vibrate in various modes, not break, but a small proportion of that energy can so agitate molecules as to make some collide. If the collision energy exceeds the activation energy required for chemical reaction (needing bonds to be broken before new ones can be formed) then infrared radiation can producing the kind of reactions that producing scorching (dehydration, chemical condensation reactions etc).

These days one sees the expression “to beg the question” used wrongly to mean “to invite the question” when it really means to give a response that merely rephrases the question in a different form, e.g. "Opium induces sleep because it has a soporific quality”.

Those Italian scientists have (temporarily I hope) forsaken the objectivity that is expected of scientists. Their beaming of ultraviolet rays at cellulose - and the way they have reported their results to the media - in order to preempt or dismiss  other scientists is, to put it mildly, merely “begging the question”.

*  "Cellulose undergoes auto-oxidation in the presence of UV radiation  leading to bleaching of the surface. Cellulose itself does not absorb UV, however, lignin, hemi-celluloses and some dyes and pigments act as photo-sensitizers. (Photo-sensitizers absorb UV radiation and transfer the energy to the cellulose, initiating a reaction.)  As a result some of the long molecular chains break up, lowering the degree of polymerisation, and weakening the material."

Taken from: link 

It is important to keep this is mind when one reads of so much emphasis, possibly over-emphasis on the Shroud image being superficial, exceedingly thin, or present on opposite faces of cellulose fibres/fibrils but not in between. Any photodynamic action involving visible or uv light is likely to be confined to a very small distance from the interface between putative photosensitizer and cellulose. 


In my recent previous posts (see link to posts with the keyword thermo-stencilling), I have described the use of "charcoal paint", subsequently washed out after heat-irradiation, to produce a thermo-stencil. It has just occured to me that the charcoal might be described as a "thermosensitizer", producing a highly localised scorch mark. A thermosensitizer would be to the infrared region of the em spectrum what a photosensitizer would be to the visible or uv regions. 

Did the production of the Shroud image require the presence of sensitizer? If so, was it a photosensitizer or thermosensitizer?

Weblog: further experiments to reproduce, albeit approximately, the Turin Shroud by non-supernatural means, e.g. by thermo-stencilling

I ended the previous blog, posted earlier this morning, with the following words:

"Experiments are underway, which I shall report in real time, i.e. as a (web)log, which was the original meaning and intention of the “blog”, with new items being added to the top, rather bottom.  It’s a little self-indulgent, I grant you, since it supposes that visitors come back for a second or third look. Neither is the end product terribly user-friendly to someone reading a reverse chronology, so to speak. But it’s a suitable format for a reporting a lot of bitty experiments in real time – as evidence that one is still busy and interested – and more user-friendly summaries of chief findings and conclusions can come later. I’ll call it : Weblog: further experiments to reproduce, albeit approximately,  the Turin Shroud by non-supernatural means, e.g. by thermo-stencilling."

So here we go with the weblog, posted in reverse chronological order:



Experiment 2: Given that starch (from white flour") did not increase the charring of cotton by charcoal-mediated thermo-stencilling in Experiment 1, does further addition of glucose have an effect?

Here you see a 4g tablet of glucose (Boots, 92% glucose plus additives) ready to be added to the white flour suspension.

Here's the result, hoping that my make-shift labelling is legible (click picture to enlarge). Note the brown fringe on the glucose+starch area, irradiated with charcoal in columns 1 and 3, but not in the centre column 2. The enhancing effect of glucose was much clearer when viewed from the oppposite side of the cloth, without being obscured by charcoal:

Glucose/starch had a major effect, allowing an intense char patch to form after just 1 minute under the ceiling spot, not seen with starch alone How will the cloth look after washing out the charcoal?

Here's one of the strips after rinsing in cold tap water and drying. One is looking at the top surface, i.e. the one to which the charcoal was applied, the one that was irradiated. With just 1 minute irradiation, with scarcely any charring in the starch/no glucose control (upper half) there is heavy charring in the starch/glucose impregnated area.

Conclusions (and discussion) so far: 

There is a rapid browning reaction dependent on free glucose (as distinct from  starch or cellulose) that requires both the charcoal and the source of radiant heat. It may or may not require oxygen. The brown product seems to adhere firmly to the fabric, i.e. does not strip off with adhesive tape, so one still does not have a match with the reported properties of the Shroud image, but never mind, these are early days. It may well be that the product is simply caramelised sugar, comparable to what is obtained by holding a spoonful of sugar (sucrose) over a flame.

But simulating all the characteristics of the Shroud image is not the sole objective. I used an analogy on another site involving cheese, addressed to an individual who called himself “MouseinaHouse”. If one had discovered, say, Stilton cheese for the first time, and knew nothing of its origin, one might start by discovering how the pale component was formed first, from what ingredients, which starting materials, and worry about the blue veins later.

Why even bother trying to simulate anything regarding the Shroud? Why not let those who wish to regard it as the real Shroud of Christ, and formed moreover by supernatural processes (by no means axiomatic, even if it were Christ’s) ?   Three reasons. Firstly, it was the investigations by scientists back in the 80s that lent a great deal of credibility to the idea that the Shroud may be authentic – that was before the C dating. Secondly, the reasons given for rejecting the C dating that fixed it as 14^th century seems perverse to this individual – e.g. to claim that the Shroud had been repaired at the one tiny area that the Vatican had allowed to be sampled.  Thirdly, and the last straw, so to speak, was the manner in which the research by the Italian group was reported to the media, and subsequently received by the blogging community. To say that I am disheartened by the “imaginification”  (provisional term) of science is an understatement to say the least. There are times when modern so-called science, at least in the hands of certain individuals with an over-developed, some might say lurid  imagination seems determined to take us back to pre- Renaissance era.  The fact that the RC Church seems to be playing some kind of role in this, even a relatively non-aggressive one ( I hesitate to describe it as passive) comes as no surprise, given its stick-in-the-mud stance on so many other key issues, notably contraception.

The immediate aim then is to scotch the idea that because “science has not explained the Shroud ” then it’s somehow defied science, and ipso facto there must be a supernatural explanation. For a start, science has much better ways of occupying its time, now that the Shroud has been dated to the 14^th century. (Those who claim the sample was contaminated with more modern carbon should realise that the ball is in their court on that one). Secondly, it is unrealistic to expect science to explain every centuries-old item, artefact or otherwise, given no clues as to the materials used, given that age and original processing can alter the characteristics of familiar materials out of all recognition (a cooked onion is an entirely different eating experience from a raw one, and stale bread, even 10 days old, entirely different from bread that is still fresh).

Experiment 1: Does cotton char more quickly under a source of radiant heat if impregnated with a medieval source of "starch"?


What to use a source of starch? Potato starch is ruled out (Sir Walter Raleigh coming along much later). There is one reference I came across suggesting that starch for "starching" clothes in medieval times, and perhaps earlier, might have come from wheat bran. That would makle sense, given that bran has adhering flakes of starchy endosperm, i.e. white flour  - which is not pure starch, needless to say, having some protein there as well. But i was not too worried about the latter, since protein would be necessary if the browning effect with impure starch depended on protein as well to generate Maillard type reaction products. So a level teaspoonful of white flour (self-raising, since no plain flour in cupboard) was added to 250 ml water, heated just to boiling with stirring, then cooled to room temperature. I then steeped half a cotton square in the cloudy suspension, allowed to drain, then dried over the radiator, and then applied my charcoal "paint" as previously described, i.e. a slurry of powdered barbecue charcoal. When the charcoal paint had dried, each black circle was held for 1 minute under a 60W ceiling spot. The charcoal was then washed out with tap water, and the strip of cloth dried and photographed.

Result after 1 minute of irradiation:  the charred area was if anything lighter in the lower flour-impregnated half than the upper control (no flour). That admittedly qualitative result was confirmed a second time.

So despite starch being chemically more reactive than cellulose, there was no enhancement of charring by impregnating with starch. Indeed, there was possibly a little less charring.  I am relieved in a way, since the fewer variables from hypothesised pre- treatments of ancient linen, e.g. during weaving, the better.

The next experiment will be to see whether a simple reducing sugar, e.g. glucose  would affect the outcome. For that I decided to add glucose to the flour suspension, rather than test glucose alone (isolating variables one at a time can come later).

Overview - attempts to reproduce the image on the Shroud of Turin with simple technology available to medieval forgers

Is it still worth attempting to reproduce a Turin Shroud-like artefact with modern materials and techniques? Could thermo-stencilling be a valid approach?

Scorching the charcoal image onto fabric using ceiling spotlight

Appearance after washing out the charcoal - drying in progress

We have been told repeatedly that the image on the Turin Shroud has features that have never been satisfactorily reproduced. Increasingly the message has become one of: “Don’t even think about it. That image could only have been made by supernatural means”

Whilst not verbatim, words to that effect have come recently  from a group of Italian scientists no less (YES SCIENTISTS would you believe it?) who are talking about  a miraculous corona discharge, producing ultraviolet or maybe some other high energy radiation. That shows the extent to which magic is now permeating into science. (We shall overlook the tiny fact that forming an image requires not just a source of light, regardless of which part of the electromagnetic spectrum – infrared, visible, uv etc. but in addition a means of focusing that light – see my previous post). 

Am I the only one to be deeply disturbed by the blurring of the boundary between science and magic? And whilst the Vatican, to its credit, has never claimed that the Shroud is the burial cloth of Christ, or indeed of anyone from that era (its first response being to dismiss it as a fraud) is it not time for the Vatican to stop treating it as if it WERE a holy relic, and allow scientists access to more of the fabric. Is it not absurd that the C dating should be rubbished on the grounds that the sample was from a corner of the cloth that had allegedly become contaminated by frequent handling or, with even more brass neck, that it was not the original fabric, but a repair job that had used “invisible re-weaving”. It is quite simply ludicrous that scientific time and resources should be wasted in this manner.

This series of posts began with a prediction – that an image could be scorched onto linen (or other cellulosic fabrics, e.g. cotton) by drawing or painting with a black pigment, exposing the image to radiant heat, and then washing out the pigment, leaving just the scorch mark, and no clue as to its origin. That prediction was quickly confirmed using lump charcoal as the pigment initially applied dry, i.e. drawing, and then more effectively by applying as a  pasty slurry in water, i.e. as charcoal paint.

So straightaway some pretty elementary science (black things absorbs heat) could be used to undermine one of the key claims made re the Shroud, namely that it was not “painted” on the cloth, that there are no brush marks, there are no residual traces of pigment.  Using the ‘thermo-stencilling’ procedure I have described, one can indeed paint with a substance that can then be removed, leaving nothing except scorched cellulose with NO CLUE AS TO ITS ORIGIN.  

That is just a beginning. There are further claims regarding the shroud (based it has to be stressed on that tiny, possibly unrepresentative sample of material). The crucial one is that the image is not a scorch mark, at least not a typical one (whatever that is – my own reading suggests that scorching of fabric has not been a major preoccupation of carbohydrate research). We are told that the coloration does not extend the entire width of the cloth, i.e. the total diameter of cellulose fibres- that it is confined to each of the external surfaces, with no coloration in between. We are told that the coloured material can be stripped off the surface with adhesive tape. We are even shown phase-contrast microscopy of a supposed coating on the surface of the fabric, with suggestions that it represents something acquired or added in weaving, possibly starch and simple sugars used as a processing aid for weaving, and that the image is confined to that layer.

Once you envisage the image being on an applied  or accidentally  acquired coating, rather than the cloth itself, then the number of formative mechanisms increases exponentially, and it becomes increasingly less worthwhile as a scientific exercise to explain images, if one does not know the starting materials. Indeed, some might say, especially in view of the C-dating, that the onus now rest entirely on the magicians to explain how the image was formed if wishing to prove a supernatural origin, as distinct from placing the onus on scientists to disprove a supernatural origin. Scientists do not like being asked to prove negatives, i.e. that there is no known non-supernatural means of reproducing the image, that exoplanets are not made of green cheese.

However, there is still some science that can be done, based on some rudimentary info we have re the nature of early linen, whether it be medieval in origin, or even 1^st century AD. It is said that it was treated with starch, accompanied perhaps by simple sugars, which are, needless to say, close chemical relatives of cellulose.

Experiments are underway, which I shall report in real time, i.e. as a (web)log, which was the original meaning and intention of the “blog”, with new items being added to the top, rather bottom.  It’s a little self-indulgent, I grant you, since it supposes that visitors come back for a second or third look. Neither is the end product terribly user-friendly to someone reading a reverse chronology, so to speak. But it’s a suitable format for a reporting a lot of bitty experiments in real time – as evidence that one is still busy and interested – and more user-friendly summaries of chief findings and conclusions can come later. I’ll call it : Weblog: further experiments to reproduce, albeit approximately,  the Turin Shroud by non-supernatural means, e.g. by thermo-stencilling.

More progress in improving my thermo-stencilling technology for simulating the Turin Shroud

Previously I used a charcoal stick to sketch pictures on cloth, prior to fixing those images with thermal radiation (charcoal absorbs heat and light rays). But the images were rather faint, and it was difficult to remove all the charcoal by washing (thus disguising the methodology) probably because of pressure needed to draw with a stick.

As suggested earlier, I figured that a better result might be obtained by painting with  aqueous charcoal suspension ("charcoal paint") , and that has indeed proved to be the case, as should be apparent from what follows.

The lump charcoal was first reduced to a powder with a hammer, and then a little water added to the powder. That did not give a satisfactory "paint", with a lot of charcoal floating on top. As soon as a few drops of detergent were added (washing-up liquid) a relatively homogenous paste was obtained that could easily be applied to fabric with a brush as if painting.

The following pictures should be self-explanatory:

 Charcoal painted onto cloth, with paint pot in background

The next step is to dry the paint over a radiator.

Each letter of the painted word was then exposed to a few minutes radiant heat from a 60W ceiling spot lamp, and here it is viewed from the rear before washing out the charcoal "stencil". Faint smoke was visible during the roasting procedure, but nothing burst into flame. The pyrolysis (charring) seems to be self-limiting, and greatest in the regions with most paint.

Here it is, back on the radiator, drying off, after washing out the charcoal with soap and water (which proved exceptionally quick and easy). So that's a scorch image that is visible now, instead of the original charcoal.

Here we are, back on the dining table. looking at the thermo-stencilled image,and  with no trace of charcoal visible that might give a clue as to how it was formed. Painting is definitely the way to go, as distinct  from drawing, allowing one to build up the  density of heat-absorbing pigment in stages until one gets the desired intensity of  scorching. And it's much easier to wash out the charcoal, due presumably  to far less pressure from painting with a brush.Could this be how the Turin Shroud was produced?

Next experiment? It is said that the image is not formed on the cellulose fibres, but on a surface coating of starch, the latter having been used as an aid to weaving:

Link

Evidence for this is that the image can apparently be stripped off physically with adhesive tape (which is certainly not the case for scorched cotton) or reduced chemically with diimide, N2H2.

So the next step is to repeat the experiments with a starch-coated fabric. It's my guess that scorching will occur more readily with starch, which is chemically more reactive alpha-linked glucan, than with cellulose (beta-linked glucan), the latter having more extensive crystallinity due to  multiple intermolecular hydrogen bonding interactions. If scorching can be achieved quickly, then it may indeed be possible to strip off a superficial scorched layer from underlying cellulose, simulating more closely the characteristics of the Shroud. I shall have to think of an authentic (historically credible) source of starch. It certainly won't be potato starch!