|There be more where this came from - read on if you dare|
One often sees or hears the Shroud image being referred to as “enigmatic”.
|A "Multifaceted" Enigma, no less...|
Let’s suppose it is medieval. Then how come the image is “enigmatic” if man-made, not supernatural? What features cause it to have acquired that tag, and why has science allegedly been unable to explain its peculiarity, far less to model it in the laboratory? Or can it? Is it really “enigmatic”? Or is that self-serving hype, the kind to which TV documentary makers are so enamoured?
I shall now post the graphics, then hit the "Post" key. My own interpretation (and hopefully that of others) can wait till tomorrow or later.
|Fig.1 This image is not a real rubber stamp, needless to say, but made using ImageJ to look like one. It's entirely man-made, deliberately so, to be used as a 'thought experiment' in what follows.|
|Fig.3 As I say, negative image and mirror image are not inseparable (see above). One can easily restore the initial left-right configuration with photoediting software (ImageJ used here) while retaining the negative image.|
|Fig.7: One can always use a photoediting program to convert grey into jet black, so as to reduce still further the possibility of a coloured (yellow or other non-black) imprint behaving unpredictably in further image processing.|
|Fig.8 So what started as a yellow-brown rather than black imprint has now been converted to one that is virtually indistinguishable from the black imprint of Fig 2, especially as it has now had a left-right flip too. Any enigmas so far?|
Longstanding quote from the sidebar of Dan Porter's shroudstory.com: my bolding
"No one has a good idea how front and back images of a crucified man came to be on the cloth. Yes, it is possible to create images that look similar. But no one has created images that match the chemistry, peculiar superficiality and profoundly mysterious three-dimensional information content of the images on the Shroud."
Er, what's so profoundly mysterious Dan about 3D-rendering? Any 2D image can be 3D rendered, provided there's some appreciable stepped gradations or (better still) smooth gradients of image intensity. The 3D-rendering programs such as ImageJ simply convert image intensity to apparent height above a base plane to create pseudo-3D. The settings one selects are entirely arbitrary and indeed subjective if one has never seen the template from which the 2D image was derived., as is the case with the Shroud of Turin, where all we have is the imprint, comparable to Fig.2 above, with no Fig.1
Image superficiality? (Sorry, no graphics).
See this link from my posting immediately preceding this one.
Rembrandt thickened paints with flour
It quotes the typical thickness of oil paint on old Rembrandts as being approximately one-thousandth of a mm, i.e. 1 micrometre, or 1000nm. Granted, that's greater then the 'guesstimated' thickness of the TS image. (Not measured directly, I hasten to add, simply assumed to be of the same order as the wavelength range of visible light, being based upon inability to "see" i.e. resolve the image in cross-section under the microscope). Now then, if highly visible artist's paint with flour thickener can be as thin as 1000nm, it's not difficult to see how an image layer at the limit of visibility could be even thinner. What if the image layer were a faint scorch, or, better still me(currently)thinks Joseph Accetta's DYE imprinting (now this blogger's preferred hypothesis in place of a previous fixation with thermal imprinting aka scorching.) That's even supposing that the image today is still that of the chosen dye bonding to linen. As suggested here previously, it's not impossible that what we see now is merely a 'ghost' image that survives after the dye has faded. How might that happen? One possibility is that alum (potassium aluminium sulphate) was used as a mordant to attach the dye to the linen. But alum is strongly acidic (it hydrolyses in water to form sulphuric acid). The latter could gradually cause faint but permanent discoloration of the most superficial part of linen fibres via chemical dehydration (a process that mimics scorching by heat) and those coloured caramelised products might survive long after the dye has faded.
Already there seem no good reasons for describing a 200-600nm image thickness as "enigmatic". "Not beyond the realms of expectation" would seem a more fitting less hyped-up description - hardly the stuff of enigmas.
Conclusion so far: there is really nothing in the Shroud's image - at least at the macroscopic level - to justify describing it as "enigmatic". Its properties are entirely consistent with those of an imprint obtained from a 3D or bas relief template - namely a negative (with obligatory light/dark reversal), a mirror image (left/right reversal, due to a template being turned through 180 degrees towards linen, away from operator*), non-directional character (being an imprint, not a portrait relying on light/shade to hint at form, i.e "3D-ness", and probably superficial, given that a dye (or less probably a scorch) was used instead of paint to simulate the faint aged imprint (sweat?) that a deceased victim of crucifixion might have left on linen many centuries earlier.
* Whilst inconvenient, one could deploy a rubber stamp in a manner that did not requiring turning it away from one, e.g. by pressing a sheet of translucent paper DOWN onto the ink-coated stamp face-side UP, and then viewing the result through the thin thickness of paper, with a sheet of glass as support. In that situation, the image, while still a negative of the original, would now be the "right way round". The negative and mirror images are entirely different phenomena arising for entirely different reasons.
Afterthought: coin imprints! There one has the template (coin) face up, with paper on top, so there's no mirror image reversal:
|Negative imprint, but NOT a mirror image due to imprinting geometry.|
|As above, after tone-reversal.Now back to a positive image, the highest relief looking more light-reflective.|
|Yes, they can be 3D-enhanced needless to say. But it's PSEUDO-bas relief, guided by knowledge of coins.|
Taking all these points into consideration, I repeat: there appears to be nothing in the least bit enigmatic about the Shroud image. It's exactly what one would expect of a contact imprint, as can be modelled, as above, with a rubber stamp, real or imaginary, as distinct from a painting or with coin-rubbing (manually assisted to ensure best contact between relief and surface). When was a rubber stamp imprint or coin-rubbing ever described as enigmatic?
Addendum: as stated here and elsewhere, this blogger now aligns himself with Joseph Accetta in thinking that the TS image was probably dyed onto the linen, rather than heat-scorched. (I would not have rated dyeing per se very highly, but for the fact that dyeing onto linen is difficult without use of a mordant, that the most common mordant - alum - is highly acidic, and that sulphuric acid from slow alum hydrolysis may explain the faint ghost image we see today (so I've gone beyond Dr. Accetta somewhat). So how does printed fabric respond to the conversions outlined above?
I've chosen a printed fabric that obviously has no 3D history, but which shows some stepped changes in image density.
Here we go:
|Printed cotton from image files|
|As above, after light/dark reversal in ImageJ (yes , I should maybe have converted to B/W, but these images are prettier).|
|As above, after 3D enhancement in ImageJ.|
Yes. I have some alum on order, and yes, I shall be attempting to model a ghost image on linen offcuts using alum and water pastes in varying proportions, or even dry powder, followed by exposure to moist atmospheres. There's still everything to play for in 'experimental Shroudology.'
Further thoughts: the chief drawback with any wet ink or dye technology was the risk of seepage through to the reverse side and, as we all know, there's no reverse image, at least not one that is visible to the naked eye (digital enhancement, as per Fanti et al, has revealed a 'second face' but it's hard to know whether that is real or artefactual).
The game changer is the possibility that a mordant was used. ("mordre" - French verb, infinitive, to bite). Yes. anyone can quickly "dye" linen or cotton, but will the intense colour still be there in a year or two, especially after laundering? Mordants give the dye a real "bite" on the cloth such that the coloration is essentially permanent. (Whether still visible after the passage of centuries is another matter).
Might we finally have a handle on the Shroud-imprinting technology by assuming Accetta is correct with his dyeing, but taking it a stage further? Suppose alum had been used as a mordant, applied first to impregnate the linen. Then suppose the dye imprinting was done, so that the dye attached quickly to the surface mordant, so there was no appreciable reverse-side coloration. Suppose the dye gradually faded, but the mordant slowly released sulphuric acid on exposure to moist air, and that the concentrated H2SO4 produced as a result of subsequent evaporation then proceeded chemically to dehydrate and discolor the surface fibres of the linen, such that, centuries later, what we see is primarily those "ghost" yellow fibres. Might it be possible to model that process (see above)? We shall see.
Reminder: This blogger, being impressed initially by the ability of contact scorching to reproduce many of the crucial Shroud properties (but annoyingly not alleged absence of fluorescence under uv) had found a rationale for scorching through the linking by Noel Currer- Briggs of the de Charnys of Lirey (Geoffroi and Jeanne née Vergy) genealogically to an alleged Templar uncle (Geoffroi de Charney) and thegruesome events of 1314 (slow death by roasting over hot coals). Some curious features on the Lirey Pilgrim's badge sustained that 'symbolic scorch' model.
Everything then changed with detailed descriptions from Ian Wilson and others of the recently discovered Machy mould for a second Lirey badge, with an additional motif that I (and perhaps I alone, c'est la vie) consider to represent the Veil of Veronica. Might that be a hint that the Shroud was to be seen, not as a scorch imprint, but a sweat imprint? If so, how might a medieval artisan set about simulating a sweat imprint? It might have used light dry scorching to simulate an ancient sweat imprint, but was more likely - one would have thought - to have used some kind of wet chemical treatment, if only dyeing, while still needing a template to account for negative imprinting etc. That's where my thinking began to dovetail with that of Joseph Accetta's, except I see an additional role for a sulphuric acid 'impurity' in producing a secondary faint but more permanent ghost image, one that in passing has a resonance with Luigi Garlaschelli's ideas (sulphuric acid-contaminated artist's red ochre).
Pomegranates have been used as a source of yellow dye for millennia (there's said to be a mention in the bible!).
Here are two fascinating images I've discovered through googling. They show the effect of dyeing with pomegranate extract, either used "as is", with no further additions, OR with a mordant. The latter? Alum of course!
|Pomegranate dye, without mordant (left); with mordant,right.|
See this article of the 'Folk Fibers' site.
Update: have today bought a real date stamp from my local branch of Poundland for the princely sum of ... yes, £1 (oh what a lovely recession).
This scan of the imprint, followed by B/W reversal in ImageJ, followed by 3D enhancement. says it all.There was serial stamping from top to bottom without reloading with ink. Note the way that the 3D response falls off with image intensity.
Update: 13th March
The alum has arrived, express delivery (parcel postage 3 times the cost of the chemical!). Have seen its mordanting action with my own eyes, tested using a home-made dye extract from pomegranate rind.
Have hit on a simple way (in principle, assuming no unforseen hitches) in discriminating between the dye and any H2SO4-induced "scorch" forming underneath the dye/mordant combination. One adds diluted sodium hypochlorite after treatment /storage that selectively bleaches the overlying dye, but not the underlying scorch. These are early days, and the odds against getting a result are slim if the "ghost" image is one that is age-related or depends on lots of other things coming together in the correct sequence. Nothing ventured, nothing gained.
The new line of experimentation is underway.
The dye is a boiling water extract of pomegranate rinds (rich in tannins, gallates etc).Used on its own it gives linen a yellow-brown to orange colour (top left) When used on alum-mordanted linen one gets a greyish-green colour (top right).
Most but not all the dye can be bleached out with hypochlorite solution. Interestingly there's a faint brown remnant that tends to be more intense on the alum pre-treated side. It may or may not be relevant to the Turin Shroud, these being early days.
Another result (today's):
Top (inside yellow box): a wet imprint from a brass crucifix that has been painted with a syrup from boiled/semi-evaporated pomegranate rind extract almost to dryness, after (a) conversion to negative image and (b) 3D enhancement in ImageJ.
Bottom (inside blue box): the dry imprint obtained/reported many months ago by pressing the same crucifix (heated) into linen. It was not my best scorch imprint (much of the face being invisible) but was chosen for a preliminary rough comparison between rival wet and dry imprinting technologies.).
See the banner at the top of my specialist Shroud blog for other scorch results obtained from the same crucifix template.
Provisionally. let's call it the AMPS -imprinted model (AMPS = Alum-Mordanted Pomegranate Syrup).
|1. Prepare syrupy concentrate from boiled pomegranate rind.|
|2. Paint syrup onto template (am using same brass crucifix as used previously for scorch imprinting).|
|3. Imprint left by pomegranate syrup on linen, the latter having first been impregnated with alum mordant.|
|Here's the imprint after washing and drying to remove unbound syrup. It's turned grey-green! Well, I did say it was a model system. The mordant has certainly done its job.|
|Left: before washing. Right:after washing. The top image is the pomegranate imprint, without alum-mordanting. The lower is a contact scorch from a previous experiment with the same crucifix.|
|Extracts from new pomegranate. The tray on left has boiled concentrated extract from rind and pith only (not seeds). The one on right with the greenish tinge has added alum (potassium aluminium sulphate).|
Quote (STURP 1981) : 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.