First test of the quicklime hypothesis (Turin Shroud image) - in pictures

For background, see the posting that immediately precedes this one.

I'm restricting this post to pictures only - maybe with a caption or two. I need time to explore some more, and get thoughts together.

Oops. Underside of the polythene container is melting.

Let's try earthenware instead, and skip the temperature monitoring. Just tip quicklime onto linen and cotton, add water, and see what happens.

Do I see thermochemical scorches (no applied heat - just a chemical reaction between quicklime and water)?

Yup, scorches alright. Cotton on left. Linen on right.  Oh, and that's the knackered container from the abandoned experiment. But why are the scorches so localised? That's the question being asked in the next experiments.

Other postings in the pipeline: response to questions raised on shroudstory.com (Piero and daveB); does the TS man really have a beard and moustache?

Afterthought. there's a related thermochemical system that is maybe worth some consideration. It's the setting of Plaster of Paris (calcium sulphate hemihydrate, 2CaSO4.H20) when mixed with water to form the dihydrate., CaSO4.2H2O.  The reaction is admittedly not as exothermic as that between quicklime and water, and its questionable whether it would ever get hot enough to scorch simple linen (treated linen is another matter). But there's a big advantage in the context of the TS: one could create a mould from a living (or dead) person using death mask technology, the subject of a previous posting on my WordPress site, and use that to make a 3D replica with a slurry of Plaster of Paris. Might there be sufficient heat thrown off when the plaster fully sets to leave some kind of imprint or image on a sheet of linen thrown over the top?  You read it here first (probably last as well).


Update: Sunday 29 June
 It's said that one picture is worth a thousand words. On that basis, the blog posting so far should be worth 8 thousand words. Yet nothing could be further from the truth. To convey the truth where quicklime and its possible relevance (or lack thereof) to the Shroud of Turin is concerned, I would need a lot of words, maybe not 8000, but a lot. Why? Because I have (deliberately) committed the cardinal sin in science reporting by being highly selective so far in what I have chosen to report. Thus far, anyone looking at the pictures might think to themselves  "Wow, that's a lot of heat coming from that reaction between quicklime and water- so much so that plastic pots are melting, linen is being scorched. OK, so there's no image as yet, the starter experiment not being set up to produce an image, but the system clearly has great potential."

No it doesn't. It's actually of exceedingly limited potential. That I know already, not just from the highly localised nature of the scorching (reported) but from events (notably up-and-down thermometer readings) that preceded the spectacular meltdown of the plastic container.

Nope, I haven't been dishonest, just selective in the nature of my reporting, and later in the day I shall start to fill in the gaps, using up my quota of 8000 words to describe the profound limitations of the quicklime model, and why already I suspect it to be non-starter. It's to do primarily with the two physical states of water in this system (liquid or gaseous, hint hint).

I see my little punt has been flagged up on shroudstory.com. No comments as yet, which is perhaps just as well. I'll now do the decent thing and copy and paste what I've just added here.

Moral: beware selective attention to particular details, indeed selective reporting in general. Trouble is, you don't know when it's being done (but with long exposure to gee-whizz press announcements etc one can develop a nose for it. Indeed, it was that "nose" that 'attracted' this science bod into shroudology some 30 months ago. The amount of selective reporting that goes on in shroudology is nobody's business (except mine - see blog credo above).

Back again .

OK, now for some of those details that were omitted from the preliminary account, basically because I was puzzled and needed time to ponder.

The experiment began by adding water one drop at a time through a hole in the lid (just visible in my pictures). I had expected an immediate response on the thermometer, but that was not to be. There was a lag, and several more drops were needed to start a sluggish rise in temperature. The needle would rise a bit, then stop, and start to fall back. That was the signal to add more water, but there was a downside - the temperature then initially fellback a bit, and one had to wait a while for the 'new' water to react with the quicklime, as indicated finally by a new upward surge in temperature. But I then found I was having to add water not just 1 drop at a time, but an entire dropping-bottle full, simply to keep the temperature rising (but still with that annoying yo-yo effect).

Things were looking hopeful when the temperature reached some 80 degrees Celsius and higher, but that's when the bottom of the reaction vessel began to melt  (below the thermometer probe)  dropping its contents onto the garage floor (just as well I didn't try the experiment in the house).

So why was there not a smooth and continuous rise in temperature, and why were the scorches in the second quickie experiment so localised?

Here's my explanation: water is needed to start the reaction, and the heat of reaction quickly changes some or all of that water into steam. However, not only does each new addition of water 'undo' some of the previous temperature rise through the new water being cold,  but there is another effect operating due to the high latent heat of vaporisation of water. For as long as there is liquid water present, it will boil at 100 degrees C (maybe a little higher due to soluble calcium products) and prevent the temperature rising above 100 degrees C.

So how were the scorches produced, given that temperatures approaching 200 degrees and higher are needed in conventional hot metal experiments to produce scorching? I suspect that there is a brief 'wndow of opportunity' in pockets of quicklime in and around the linen that allows scorching when the last of the liquid water has been vaporised, but there is still "water" avalailable. But the latter would be gaseous water, probably superheated steam.

The equation for the slaking of lime is conventionally written with reactants and products in their standard states at 15 degrees C (298 degrees K), with the symbols s, l and g used to indicate those states.

CaO(s)  +  H2O(l) =   Ca(OH)2 (s)

But to see scorching, I believe the relevant equation is:

CaO(s) + H2O(g)  = Ca(OH)2 (s)

(It's testable, needless to say, e.g. by placing quicklime/linen in the steam above boiling water, and expecting to see more even scorching  In fact, I've just done that experiment, enclosing some quicklime in a linen pouch and suspending it over steam from a boiling water in a saucepan. The quicklime becomes slaked, judging by inertness towards water when the pouch is later reopened. I had hoped the linen would scorch, but that was not to be. Maybe the steam carries away excess heat, preventing the temperature rising sufficiently to scorch linen.)

But there one sees the practical pitfall of the mechanism proposed - namely that one is slaking the lime with liquid water, not gaseous water, i.e. steam. So it's only spasmodically and in localized 'hotspots' that the temperature is able to get much above 100 degrees C.

That makes the system almost impossible to design and manage predictably.

New addition: 19:10 Sunday June  29

And finally (for now, at any rate) here are my belated responses to a question  raised by a  commentator on shroudstory.com in response to my first quicklime posting.  (It should probably go on the post before this one since that was the one they were responding to, but it's overlong already).

Here's the comment from daveB of Wellington, NZ, divided into points (my responses in blue):

  

daveb of wellington nz

June 21, 2014 at 5:16 am

Read your posting, saw the video, all quite clear. You’re going to have to do some experiments, and probably several reruns before you strike any gold. Obvious questions arise: 1) Image is said to be superficial, maybe resident only on impurities layer; Can such an imaging process be so superficial? Or will it penetrate the fibres (flax medullas on TS not affected by process!)

I know of no hard evidence that the image is on a man-made superficial layer, e.g. starch or saponins etc (based on citations from the Pliny!).  It all seems highly conjectural to me. The behaviour of the sticky tape samples under the microscope when fibres are pulled out (leaving those allegedly sub 200nm ghosts) is open to different interpretations, and in any case there is a big risk of artefacts when viewing whole fibres, especially when immersed in an adhesive hydrocarbon.
The PCW is reckoned to be 200nm thickness plus or minus. Why was that not considered first before invoking an impurity coating?


2) Do we know whether or not there’ll be an alkali corrosive effect on the CaO side of the linen?

Alkali is a standard treatment for cotton (mercerising). It changes the physical structure of the fibres. It also makes cotton more resistant to scorching, according to some experiments I did a while back, with less effect of linen.. Quite why that should be so I cannot say. It’s tempting to think there are differences in the PCW, but one cannot discount the possibility that modern fabrics have coatings that are more or less resistant to scorching, and that alkali acts on those. Suffice it so say that any effects one sees with quicklime have to be interpreted with caution on account of calcium hydroxide being a fairly strong alkali ( as anyone who has handled wet cement will know to their cost).


3) What would be the signature residues of CaO on the backside of the linen, any? No one’s noticed any such residue signature so far.

It’s been a while since I looked at the mineral analysis of the TS, and I’ve mislaid the references. I seem to recall that there were substantial amounts of calcium (as CaCO3?) on the TS, but stand to be corrected.


4) Process will necessary take some finite time, so perhaps a heat process would affect subject and its appearance with consequent distorted image on cloth, but no such distortion appears on TSM (no “corruption” evident).

Yes, quicklime is a desiccant, so any model that envisages a long-term process might need to explain why the TS image is not excessively  skeletal in appearance (while noting the boniness of fingers).

 5) Maybe it’s not a scorch but something else, so that you could still be on to something.

A “scorch” to me is simply a discoloration due to chemical modification of linen components, primarily carbohydrates, but not excluding lignin. It may be the result of thermal processes that require no added substances, but the latter are possible, provided they leave nothing substantial behind that would conflict with the STURP finding (claim?) that there are no pigments etc that would suggest the TS was some kind of painting.

Even if one envisaged an “invisible ink” effect, produced with say lemon juice, leaving minimal residue that escape normal chemical tests for unusual chromophores, etc., then heat is still needed to produce the scorched look (which incidentally can be seen with lemon juice alone, needing nothing else present).  So in a sense it’s still a “scorch” albeit not a pure thermal effect with or without  chemically assistance.

 6) It might not be quicklime, but it could still be alkali from body products or even Max’s red-heifer ash.

Yes, he used to refer to limestone and red heifer ash as sources of alkali. That’s not true re limestone. While limestone (calcium carbonate, CaCO3) is capable of neutralising acids, it has scarcely any effect on the pH  of pure (CO2-free) water, and does not fit the definition of alkali as a soluble base, since bases are defined as reacting with acid to make a salt and water only (carbonates make CO2 as well). Animal ash? Yes, it may be an alkali, though that’s as likely as not to be due to accompanying wood ash – a good source of potash , i.e. potassium carbonate, that accompanies the animal bones. Contrast with calcium hydroxide from the slaking of quicklime, which as we’re agreed,  has powerful alkali properties that fit all the chemical definitions relating to base character,  solubility and ability to produce a big increase in pH (typically above 11 or 12).


 7) You’re looking for lots of heat, but if only impurities layer is affected, maybe you don’t need the same heat as is necessary to scorch linen (image is said to be resident only on crowns of fibres).

Yes, it’s a lot harder to explain selective scorching of the fibre crowns in  chemical or even thermochemical systems, although Rogers as we know attempted to do so with his arguments based on capillary action. Indeed, it is the predominant (though not exclusive) location on the crowns that makes pure thermal scorching by contact with an applied template the most realistic model in my view.

I recall someone’s ribald comment a year or two back, that you’ll end up proving the Resurrection! You still have to end up with an image that looks like crucified Jesus, complete with crucifixion marks, scourge marks, bleeding head, and lanced chest wound. Don’t think they did that sort of thing in medieval times, more into hanging, drawing and quartering! Look forward to seeing pictures of your chicken legs! Hope the family cat survives!

Yes, but you don’t know that the image we see today was formed all in one single event. Indeed, if you look at the Lier copy, it has L-shaped poker holes and nominal blood stains (yes, I’m aware of the cop-out argument based on contemporaneous viewers' sensibilities etc, but it’s evidence for authenticity we are seeking, not explanations for why that evidence is all too often less than convincing).

Hanging, drawing, quartering certainly. But aren’t you forgetting something else (burning at the stake). Where’s the evidence, say, on the Lirey badge that the figure depicted was (a) Jesus (b) crucified. I see little if any. Who’s to say it was not (a) Jacques de Molay  (b) burned at the stake – slowly?  Posture, non Christ-like appearance and some other details would seem to favour the second of those hypotheses.
Yes, I am doing something  like a chicken leg experiment (with a pork sausage – all I  had to hand, and now on its, er, third day). Disappointing result. No scorching – insufficient water presumably.

Might the Shroud image have been produced as a thermochemical scorch on linen? Quicklime?

World's worst schematic diagram - a 5 minute job in Windows Paint. It's a cartoon to provide an instant idea of what's being proposed as a possible image-imprinting mechanism to explain the Shroud of Turin. The corpse (pink) lies on an up-and-over  linen sheet (yellow) such that upper and lower surfaces of body only (not sides) are in contact with linen, There is quicklime (grey) surrounding the shroud and contents. The red line shows where heat is generated through contact between migrating moisture from the corpse where it meets the quicklime on the OUTER surface of the shroud, creating, with time, a thermochemical imprint ("scorch").

While I believe the Shroud image to be a contact scorch on linen, due to chemical dehydration and yellowing of linen carbohydrates, I still try to keep an open mind as to the source of heat.

Given that a dead body does not produce sufficient heat to scorch linen (for which a temperature of 200 degrees Celsius or more is required) then the thinking so far has been that an effigy of a real person, e.g. a bronze statue, was deployed. However, I'm as conscious as the next man of the practical difficulties of imprinting successfully off a life-size effigy. Mistakes would be costly, given the price of quality linen,

So this morning, I got to wondering about alternatives to metal templates that have been heated, say, over coals. Might an exothermic reaction using a chemical have been used instead - but a common one available in medieval times?

I got to thinking about quicklime, chemical name calcium oxide (CaO)  and googling quickly led to this fascinating WordPress site:

 

 Having a Wordpress ID, indeed blogsite,  I quickly bashed off this comment (too quickly, sorry about the typos) which now awaits moderation, that being the cautious way that WordPress deals with newbie commentators.

Link to comments thread.

"The best know property of quicklime is not so much its reversion to limestone (by reaction with CO2) so much as its reaction with water (the so-called slaking of lime). That creates a great deal of heat in a short space of time. The classic lab demonstration is to drip a little water onto a biggish chunk of quicklime. It quickly soaks in, there's often a deceptive lag before anything happens, then then the lump suddenly starts to swell, to develop fissures, cracks open and disintegrates releasing torrents of steam. Spectacular

Calcium oxide + water  = calcium hydroxide + heat

Maybe the theory was a body placed in quicklime would cook and disintegrate, but conditions would have to be just right for that to happen, and it's maybe not surprising that one ends up with a preserved body, especially as calcium hydroxide (slaked lime) is highly alkaline with antiseptic properties.

I got to thinking about slaked lime and bodies this morning, through being interested in the Shroud of Turin. Thus far I've been inclined to think the image is of medieval origin, consistent with the radiocarbon dating (1260-1390) and maybe produced by 'branding' linen from a heated bronze statue or similar. Might there be a chemical component too, one that produces heat in contact with water, or even a moist corpse? Suppose a body of a fallen crusader knight have been wrapped in linen and then encased in quicklime to preserve it on its journey back from the Holy Land? Might that have left an image on the linen that is what we now call the Turin Shroud, or maybe implanted the idea of how an image might be produced to order by thermochemical action?"

I'll see if  I can find a YouTube clip of quicklime being slaked.

No sooner said than done...   (Poor choice of title methinks - it's calcium oxide that is the chief interest, not the precursor calcium carbonate).

Addendum: for those interested in the entire limestone/quicklime/slaked lime/limestone cycle, here's the full works.

1. Take natural chalk or limestone (calcium carbonate). Kiln-roast to decompose, driving off CO2 gas to leave residue of quicklime (calcium oxide)

      Calcium carbonate  + strong heat   = calcium oxide + carbon dioxide gas

2. Slake the quicklime with water to get slaked lime (calcium hydroxide):

       Calcium oxide +  water  =  calcium hydroxide (highly exothermic reaction)

3. Slow reaction (months, years even)  between slaked lime and CO2 of air to revert back to calcium carbonate:

      Calcium hydroxide +  CO2  =  calcium carbonate +  water

 

Lime kiln, La Rochelle, France, reckoned to be 2nd - 6th century. Much is now missing, like the top part, usually hemispherical,  that served as a hopper for the limestone.

Link

Update 10:50am, 20 June 

Hey, look what's just turned up. A 13th century French recipe (originally) for cooking without fire, using the heat from slaking of quicklime with water. (The same reaction is still being used today in camping kits).

Click on image to enlarge. It's the last paragraph that is especially interesting ("to cook meat without fire"). The medieval French and no doubt others knew all about the extraordinary properties of quicklime  and uses to which it could be put - notably an easily portable source of  instant heat, needing only the addition of a little water - the stuff that extinguishes conventional fires.

Further thoughts - 11:40am

OK, so it's blue sky thinking at this stage. Suppose the geometry were as follows  (top down): corpse, linen sheet, bed of quicklime.

Now where's the MAIN image likely to be formed when moisture from the drying corpse meets quicklime? Answer: not on the conventional interface between body and linen, but on the OPPOSITE side. In other words, moisture would need to migrate through the thickness of the linen first, and only when it meets the quicklime would heat be generated to create a thermal imprint via chemical dehydration of the linen. Might this mechanism go some way towards explaining the curious superficiality (to say nothing of fuzzy character!) of the TS image?

 What's being conjured up here is a scenario that might be described as 'reverse-side imaging'.

Might it even help to explain (don't ask me how) the "second face", that being where the body IS in direct contact with the linen?

More thoughts: 13:00

OK, so we know from the YouTube clip that the reaction between quicklime and water generates sufficient heat not just to bring water to the boil, but to convert it instantly to steam. That suggests a temperature considerable in excess of 100 degrees C, which is needed, of course, to produce scorching of linen. But how much greater?

The wiki entry on calcium oxide provides some clues (my bold/italics)


"Quicklime is also thought to have been a component of Greek fire. Upon contact with water, quicklime would increase its temperature above 150 °C and ignite the fuel (ref)..

Because of vigorous reaction of quicklime with water, quicklime causes severe irritation when inhaled or placed in contact with moist skin or eyes. Inhalation may cause coughing, sneezing, labored breathing. It may then evolve into burns with perforation of the nasal septum, abdominal pain, nausea and vomiting. Although quicklime is not considered a fire hazard, its reaction with water can release enough heat to ignite combustible materials."

Me again:  the temperatures quoted are maybe lower than those required for rapid scorching from a heated metal template,  but  in the scenario imagined here, it is a slower process that gradually produces a visible yellowing of linen and final image production. What's more, the production of the alkaline calcium hydroxide would almost certainly allow chemical dehydration and yellowing to occur at lower temperatures, due to base catalysis by hydroxide (OH-) ions..

And finally, to bring this shroudological derring- do to a close, none too soon some might feel, one has to ask the crucial question: is the idea testable?

Why yes. The first thing to do is buy in some quicklime, which I see is available though Amazon.

One then gets a jar with a well-fitting lid. One places a bed of quicklime on the bottom. One then adds a layer of linen, and then adds something that is organic of high moisture content, to model a human corpse, preferable with intact skin. It could be a chicken leg or wing, say. One then covers with a second layer of linen, and adds more quicklime on top. One then screws the lid on firmly, to exclude moist air and CO2 (which would  inactivate the quicklime)  and then leaves the jar. For how long? No idea. It might be days, or it might be weeks. Ideally one ought to set it up in such a way that the progress of any imaging can be monitored without having to open the jar or disturb the contents. A thermometer inside might also be a wise precaution.

Postscript: This posting was quickly spotted by shroudstory.com while still in gestation (yes, I generally take a working day to assemble a posting by instalments in 'real time', it being my preferred MO), and appeared under the title:  "Maybe a new image hypothesis"

 Sadly, the discussion there was side-tracked (yet again) by someone proselytising his own "limestone" scenario, one I don't pretend to understand, given his long-expressed belief, predating current references to ammonia as well,  that limestone is an alkali.  Things went rapidly into the mire, given (one suspects) that a lot of folk do not know (or care) that limestone and quicklime are two entirely different substances. Limestone is natural, and a major surface rock. Quicklime is man-made (yes, from limestone) and is a vicious chemical that burns skin and eyes, due to its avidity for water, and the heat that is generated when it reacts with that water, forming calcium hydroxide, a strong alkali. It is also increasingly apparent that folk on that site plunge into comment and indeed criticism without bothering to check with the originating site (this one!). At least two commentators appear to imagine that the corpse is in direct contact with the limestone, and would become attacked and decomposed. They have had to be disabused of that idea. The corpse is wrapped in linen, and the shroud and its contents placed on or in a bed of quicklime. The putative scorch imprint is formed when moisture from the corpse migrates across the thickness of the linen, and on meeting quicklime on the outside, reacts instantly with the calcium oxide to generate local heat and alkali. It is the combination of the heat and alkali that produces the thermal imprint on the OUTSIDE of the shroud, leaving the body inside largely unaffected (while slowly drying out, and perhaps mummifying). 

Tongue-in-cheek finale

Speaking of which (shroudstory.com) today's posting has the title:  Discussion about the Pray Codex and its relation to the Shroud of Turin is over".

(A Guest Posting by "OK", a Polish Shroud scholar).

Am I the only one to be overawed by the sophisticated nature of the probability calculations that led to OK's conclusion, namely that it is the Shroud of Turin that is being displayed in the late 12th century (1192-1195)  Pray Codex (outside the range of the Shroud's radiocarbon dating, 1260-1390)?

Taking a leaf from OK's book (of probability and statistics) I've just made two amazing discoveries.

First I shuffled a pack of cards, then dealt them from the top of the pack onto a table. The resulting order in which the cards emerged had an amazingly small probability, one that was 1 in 52 factorial (52!), i.e. 1 in 52x 51x 50x 49 ...  x4x 3x 2 x1.  See link for the infinitesimal answer from a calculator. Isn't that just incredible, though I have to admit I thought that probabilities were supposed to be computed BEFORE one did one's trial, not after.  ;-)

I've also been experimenting with his "points of correspondence" criteria for determining whether two items are related or unrelated in space and time, and have made yet another amazing discovery.

Look closely at the two pictures. (Naturally, I chose the one of Queen Victoria that had a Mona Lisa-like enigmatic smile, the way that textile restorer Mechthild Flury-Lemberg and historian Ian Wilson chose the Pray Codex with its "L-shaped poker hole". (Selection bias gets one ahead of the game when wishing to make claims for real as distinct from spurious cause-and-effect relationships). Notice anything else about the pictures? NEITHER OF THE TWO LADIES HAS A FULL SET OF DIGITS (either a thumb or finger is missing).  And as everyone knows there are no thumbs on either the Shroud image or the Pray Codex which simply HAS TO BE TELLING US SOMETHING, and COULD NOT POSSIBLY BE ACCIDENTAL.

Yup, there's no doubt about it. Queen Victoria could not have been born in 1819 as historians would have us believe. She must have been around much earlier to have served as Da Vinci's model for the Mona Lisa, painted 1505-1507.

See my critique from two years ago  and that of others of the claims made for the Pray Codex, with links to a particularly long and trying discussion on shroudstory.com .(It was clearly a waste of time, given the way that folk return time and again to their entrenched positions, failing to acknowledge the points that one has researched, e.g. that what is being interpreted as a shroud with a herring bone weave and "poker holes"is in fact a sarcophagus lid with a stepped pattern).

Update 13:51

OK has come back to someone with this comment:

O.K. commented on Discussion about the Pray Codex and it’s relation to the Shroud is over?.

in response to Thomas:

Other similarities that could be mentioned include a seemingly high set chest and long arms

Perhaps, but I only included those that the sceptics cannot dispute in any way.

 Note to OK and others: please don't refer to me as a Codex "sceptic". Someone (apparently the textile restorer Mechthild Flury Lemberg)  spotted a manuscript illustration with a sarcophagus lid bearing a complex pattern of stepped pyramids and holes, and  decided it depicted the Shroud of Turin with herringbone weave and L-shaped holes. She, Ian Wilson etc are entitled to believe what they wish. Personally I find their entire case too ludicrous for words, so please don't describe me as a sceptic. I'm a scoffer. Those people should read up on the phenomenon known as "selection bias". It's exceedingly common when scientists (or would-be scientists) venture out into the real multi-variate world, and imagine that phoney statistics, with a sample size of 1, constitute a scientific survey.

Thibault Heimburger is incorrect. A linen thread CAN be scorched from a heated metal template on ONE SIDE ONLY.

My previous post had the title "Thibault Heimburger is correct ...".  That was on the question of whether the Shroud image was created by a stochastic mechanism, i.e. incorporating a random element. We both of us agree that cannot be the case, simply from looking at magnified pictures of the TS image-bearing weave. But I also reminded readers that TH is strongly opposed to my contact scorch hypothesis, and has written 2 detailed pdfs, links to which are prominently and permanently displayed in the side bar of shroudstory.com

For my trouble, this terse comment appeared from TH yesterday:. See especially the tail-end, which I've enlarged and highlighted in RED.

Thibault HEIMBURGER

June 18, 2014 at 4:06 pm

Reply

Anoxie wrote: “Thibault Heimburger : “If there is a stochastic process, it is at thread level and not only at fiber level.”
Stochastic process at a thread level, seriously ?!?”
I agree that this particular sentence is misleading. But reading my entire comment, you should have understood what I meant.
I do not think that the image formation process is a stochastic process.
The true question is: how can we explain the surface distribution of the color ?
You wrote:” But “stochastic FM screening” is misleading, it is not a stochastic process but a PSEUDO-RANDOM distribution of dots.” and “….”varying threshold” and “fibers properties”
Could you please explain in detail ?

In addition, I completely disagree with Colin.
I repeat: the distribution of the image color is not consistent with any kind of scorch, even if one takes into account ageing etc..
This has been shown in :

http://shroudofturin.files.wordpress.com/2014/04/scorch-2-eng-final.pdf

That's the second of TH's two anti-scorch pdfs. The first was the subject of an in-depth critique(s) from this blogger some 2 years ago, none of which was responded to on the grounds that I had been "insulting", and indeed the site that displays TH's pdf  never once flagged up the fact that I had challenged TH, notably on his bizarre choice of template.


Result: anyone who googles (shroud turin scorch) sees the following return, with my TS site listed first, followed by TH's first pdf, but will not know that the latter has been criticized.

That pdf is also given prominence on the wikipedia page on the Shroud of Turin, but again with no critique, or facility for posting critical comment.

How can it be called scholarship to write papers that never receive peer review (about which this blogger is relaxed) but are never open to online criticism either, despite being exposed and promoted online?

That is not right. It's surely an abuse of the internet to attack other people's ideas, offering no means of redress. The fact that my name does not appear in pdf1 (and only briefly in pdf2) is hardly relevant. Most folk who read TH's epistles will know who is being targeted for having resuscitated the scorch hypothesis, buried some might say with indecent haste by so many earlier Shroud investigators, STURP especially,  some of whose work now looks distinctly biased and non-objective.


I don't wish to dwell on this matter, having more important, more constructive matters to attend to. I'd just make two points.

First, I believe that the owner of the site that promotes TH's (and others') pdfs in the side bar should set up a post for each of them to which comments can be sent.

Secondly, I would use this opportunity to point out an egregious error in the second of TH's pdf's.

I refer to this passage in particular:

Heimburger April 2014 pdf

Page 11 of 23, just below Fig 13, we read:

The cross section experiments show clearly that a light scorch, which is able to give a superficial imprint at fabric level is not superficial at all at thread level: the entire thickness of the threads in contact with the template is colored  (while the threads or portions of threads which are not in contact with the hot template are not colored). On the Shroud, only the 2 or 3 surface layers of fibrils at the surface of the image threads are colored. 

Nothing could be further from the truth. Anyone with access to a piece of metal, tongs, a cooker hob and linen can find that it's possible to scorch just one side of a linen thread, and indeed scorch it heavily, without visibly affecting the fibres on the opposite side. Here are some pictures I took this morning:

 

The single thread was pulled from the lower border, laid on the linen, then scorched with a hot metal template.

Here's the same thread, rotated through 180 degrees. The reverse side is NOT scorched, contrary to TH's generalization.

Here's an attempt to show both scorched and unscorched faces of the same thread. Click to enlarge this and other pictures. Look at the left side of the thread near the end.

Note that those parts of the thread  that were not in immediate contact with hot template were unscorched.  (Click to enlarge).

 Oh, and here's how things looked immediately after scorching, and removing the template. Note the way that the individual pulled threads protected the underlying weave.

There are other details in TH's pdf2 to which I take exception, notably the claim that it is not the flax fibres per se that are are scorched, but the middle lamella and its surviving pectin cement substance that binds bast fibres of flax together in the intact plant, prior to retting (microbial digestion of pectins etc). I would like to see thin transverse sections of real scorched linen, as distinct from schematic diagrams, before buying into that particular idea. I have to say, looking at TH's photographs, that the linen  he used has a coarser appearance than mine, and lacks the lustre for which optimally-retted linen is famed.

 I have a hunch that his linen was sub-optimally retted, having indeed a lot of "technical fibres" that are bundles of elementary fibres that failed to disaggregate in retting and which may indeed have an excess of highly heat-susceptible, easily scorchable middle lamellar pectins.  But most folk who have examined the TS closely remark on the high quality of its linen.


Update: Aug 15 2014

I have just hit on a simple way of photographing scorched linen in cross section. I attach sticky tape to both sides of the fabric, over a scorched region naturally, then cut out a narrow strip with fabric sandwiched as it were between layers of tape. then bend the strip round to make a "ring" that can be laid onto the microscope stage.

Ring of scorched fabric (reinforced both sides with sticky tape)

Ring on microscope slide, positioned to view cut fabric in cross-section

Note the superficial scorching on the contact side only. The scorch does not penetrate the entire width of a thread (the latter being the approximately circular white area in the centre of the photograph.

These results are in total opposition to those reported recently by Thibault Heimburger, who claimed it was impossible to scorch on one side of the fabric or thread only.

"The cross section experiments show clearly that a light scorch, which is able to give a superficial imprint at fabric level is not superficial at all at thread level: the entire thickness of the threads in contact with the template is colored (while the threads or portions of threads which are not in contact with the hot template are not colored). On the Shroud, only the 2 or 3 surface layers of fibrils at the surface of the image threads are colored." 

See especially his Fig 13 of the most recent pdf.

 Maybe there was a something not right in the illumination of the specimen, giving the impression that the entire width of the thread was scorched.There was less coloration in his Fig 12, but he omits to mention the difference between one photo and another.

Irrespective: the conclusion is obvious. The 'scorch hypothesis' simply cannot be dismissed on the basis that a scorch from a heated template can never be as superficial as that of the TS. That claim, that presumption, that now monotonously oft-repeated mantra  is simply not borne out by the facts (above).


So what is the theoretical basis, if any, for scorching to produce so superficial in image on linen, when the annals of shroudology tell one it's not possible ("oh yes it is").

See my current posting for what I consider after long reflection (and a fair amount of experimentation) to be the reason.

In brief, it's to do with accelerated heat loss from a hot metal template stamped onto linen which is not simply via heat conduction. There is additional cooling due the fact that scorching reactions require heat (i.e. are endothermic). It's that absorption of heat in the superficial fibres that protects the underlying fibres from being scorched. Not many people know that.

Afterthought: the endothermic nature of pyrolysis (scorching) reactions can now provide an explanation for my finding some two years ago that the gossamer-thin dried epidermis stripped from onion scale leaves, just one cell thick, with primary cell walls only, was able to offer complete protection to underlying linen against scorching.

http://shroudofturinwithoutallthehype.wordpress.com/2012/02/21/modelling-the-image-of-the-turin-shroud-an-interrupted-experiment/

There may well have been additional pyrolysis or other caramelization reactions taking place, judging by the intensity of scorching of the epidermis per se, but it's the principle that matters. One cannot hope to interpret the superficiality or otherwise of scorching purely on the basis of heat conduction alone, treating the plant material as if it were chemically inert, which it clearly is not (it wouldn't scorch if that were the case). One has to consider the thermochemistry as well, specifically the endothermic nature of scorching reactions that introduce a 'hidden' heat sink into the system. or more prosaically, an exit route for heat in the form of steam and other pyrolysis gases, thereby protecting the underlying fibres, threads and fabric from deeper scorching.

Thibault Heimburger is correct - Shroud photomicrographs lend no support to the notion of a 'stochastic' imaging mechanism.

The difference between those areas within the blue and red rectangles may possibly have theoretical significance as regards the mechanism of imaging (stochastic v deterministic, if you'll pardon the jargon). Why? Read on...

I won't pretend that I understand the papers by Giovanni Fazio and his colleagues in Sicily, claiming that the Shroud image is the result of 'stochastic' processes, ones that rule out certain image-forming mechanisms, and render others more probable  (see link below).

So what are stochastic processes? One could give a textbook answer and say they are the opposite of "deterministic" ones, that they incorporate an element of randomness, as distinct from being totally predetermined. The analogy that is generally given is that of rain falling on a pavement. Gradually a pattern of drops develops, but the location of each drop is not pre-determined, but random.

 Here's another attempt to convey the difference between the situations, free from as distinct from incorporating a random element, cribbed from internet image files: chess v snakes and ladders (the latter requiring dice)

So how is that relevant to the Shroud image? Again, I don't pretend to follow the authors' line of reasoning, but gather it's related to what's been called the 'half-tone effect', a topic I was discussing not so long ago. The half-tone effect is a shorthand term for a peculiar feature that is claimed for the Shroud image, namely that regions of  differing image intensity do not have linen threads and fibres of differing colour intensity. There are either uncoloured fibres, or fully-coloured ones with no in-betweens. A region that looks dark has a higher proportion of coloured to uncoloured fibres  compared to one that looks pale. Think of it if you like as comparable to analogue versus digital stereo. The analogue audio signal can take a whole range of values across a smooth continuum, whereas the digital signal is simply a series of binary digits, either 0 or 1.

So where does Thibault Heimburger MD, Paris-based French physician and member of the Shroud Science Group enter this story? Some might be surprised to find his views being favourably received on this site, given there is so much on which we differ, notably the contact scorch hypothesis (one that TH rejects). But that does not mean he's wrong - or right- on everything, far from it, as my follow-up to a recent comment on his on shroudstory.com will now show.

TH appeared on the recent thread, the latter flagging up the presence of a Fazio et al  paper recently published in Mediterranean Archaeology and Archaeometry.   He queried the claim (or supposition?) that yellowed  fibres were randomly distributed across Shroud image-bearing regions, stating that they could appear together in bundles   (see copy/paste below). Were that correct, it would deal a devastating blow to any theory that required the coloured fibres to be randomly distributed (though occasional clumping is not totally ruled out, albeit being of low expected frequency).

I recalled that TH had recently acquired from STERA's Barrie M.Schwortz a collection of Mark Evans photomicrographs of Shroud  magnified close-ups, e.g. x64, and have just spent the last few minutes perusing them, and selecting one in particular for enhancement in my MS Office Picture Manager.

Here's one in particular that backs up TH's claim for "bundles".

That's an "as-is" image, from the TS nose region, magnified x64.

It seems fairly clear that one has two adjacent threads, one comprising mainly yellow fibres, the other largely uncoloured ones. The chances of that happening via random processes must surely be vanishingly small.

Here's the same picture after adjusting brightness and contrast that makes it easier to see the difference.

Sorry, Dr.Fazio, but I think your focus on supposed "stochastic" processes is simply unwarranted, and have TH to thank for making that point. Apologies to the latter for possibly pre-empting him, had he been intending to publish pictures from the same Evans archive.

But there's a sting in the tail for TH: juxtaposition of coloured v non-coloured threads, such as we see above, is I believe entirely consistent with contact-scorching, e.g. from an apposed heated metal template, and is difficult if not impossible to fit into any other of the proposed models that I'm aware of, especially ones that involve radiation of some sort, or diffusion of gases.

Copy/paste of TH comment. 

June 14, 2014 at 4:10 pm 

In my opinion this paper needs to be read carefully.
I do not not if the term “stochastic” is the best one.
The main problem comes from the fact that the surface distribution of the color in the Body image areas is not easy to describe.
With the help of the analogy with the effect of low doses of radiations in a large population, one can understand what the authors have in mind.
It is true that low doses of radiations have the properties described by the authors:
1) There is no minimal level of radiations (except zero, which does not exist) without effect
2) The number of tumors increases with the time/level exposition
3) it is impossible to predict who will have a tumor in this population.
This is only an analogy.
Is the TS image color distribution like a “stochastic “process ?
In my opinion, not exactly.
Why ?
It is true that the color distribution in a given image area depends only on the number of colored fibers having the same density (+/- 10%) and not on the density of the fibers (the half-tone effect).
But the colored fibers are not randomly colored.
In a colored thread, there are BUNDLES of colored fires adjacent to bundles of uncolored fibers
If there is a stochastic process, it is at thread level and not only at fiber level.
In other words, a stochastic process at fiber level does not explain the fact that the colored fibers are bulked together in bundles adjacent to uncolored bundles of fibers in a given image thread.

Update: Tuesday 17 June.  One of the difficulties I have with the proposed  (or should that be "prescribed") stochastic mechanism, apart from the problem already noted on overt non-randomness in pigment distribution, is the paucity of chemical detail. The thesis appears to depend primarily on a blend of physics and statistics, leaving the reader to fill in the chemical gaps as best he can with little more than hints re the essential chemical detail. Matters are not helped by the authors' carelessness with the chemical detail where, rarely, it does make an appearance. For example, they cite the active oxygen species-  singlet oxygen - as playing a role at some point or in some instances, but with precise details being omitted. But they refer to singlet oxygen "atoms" or to it being a "free radical". It is neither. There is no such thing as a singlet oxygen atom. It is only intact oxygen molecules, O2, in which  bonding electrons can be promoted to the excited singlet state. No, it's not a free radical either, despite the chemical reactivity of singlet oxygen, in which all the electrons are spin-paired (free radicals by definition have one or more unpaired electrons).


Despite the simplicity of its chemical formula, oxygen (O2) is a peculiar molecule. We tend to think of it as being chemically reactive, based on its role in combustion and respiration, but the oxygen around us is reluctant to enter into chemical reaction, except slowly in most instances, until it is activated in some way. In the case of combustion, that requires raised temperatures to give the reaction a kick-start. In the case of respiration it is the iron-containing cytochromes of the mitochondria that are needed as catalysts.

Curiously, it is ground state unreactive oxygen that is the free radical, more correctly a diradical (with two unpaired electrons per molecule) and with three degenerate molecular orbitals for the so-called p-type bonding electrons. Thus the description of ground-state O2 as triplet-state oxygen. In singlet oxygen the two unpaired electrons are promoted to an excited higher-energy level, but in the process become paired.

Red spots represent electrons able to flip between two energy levels. Note the two unpaired electrons in ground state (triplet) oxygen at the top. The arrows show they have "parallel spins". In singlet oxygen the corresponding electrons are paired, i.e. have opposite spins.

So how does one convert triplet to singlet oxygen? There's a very simple and pretty way of demonstrating the conversion in the laboratory. One bubbles chlorine gas through an alkaline solution of hydrogen peroxide in the dark.

The reaction mixture becomes chemiluminescent, i.e. light-emitting, giving off a red glow. That's due to production of singlet oxygen which then slowly reverts back to triplet oxygen by a complex mechanism, emitting visible red light in the process. The typical survival time of singlet oxygen as a gas can be an hour or more - in contrast to most free radicals that exists for a fraction of a second.

In everyday life, singlet oxygen can be formed more silently and surreptitiously by processes that involve sensitization to visible or uv light by the presence of dyes and/or other molecules, the classic one being methylene blue. It then attacks and degrades biomolecules (lipids, proteins etc) in the vicinity, the process being referred to as photodynamic action., Plants have to protect themselves against singlet oxygen formed "accidentally" during photosynthesis in chloroplasts. It's been suggested that accessory pigments like carotenoids are there to mop up singlet oxygen.

Singlet oxygen may be generated in the cytotoxic armoury of some killer immune cells that stop invading bacteria in their tracks. Sadly it has also been implicated in some cancer aetiology. Singlet oxygen is a big subject. Anyone proposing a role for it in Shroud studies should first take the trouble to get acquainted, if  not with its electronic configuration in molecular orbital terms, at least its broad chemical character and classification, certainly before referring to it as a "free radical", or oxygen "atoms"  or to others as "self-styled scientists".

Incidentally, anyone who has worked with singlet-oxygen mediated  reactions, as I did in Philadelphia, 1970-72, will know that far from inducing yellow coloration in organic matter, the end-result is usually to bleach it. It's not rocket science. Colour in organic compounds is often due to conjugated double bonds
( -C=C-C=C- etc). Singlet oxygen, by adding across the double bonds to form dioxetanes etc, destroys one or more double bonds that comprise a delocalised system of electrons resulting in LOSS of colour.

Conjugated diene (left side) reacts with singlet oxygen (above first arrow) to form an adduct that has only one double bond instead of two, with less absorption in visible or near uv spectrum. (In other words, the tendency is for singlet oxygen to bleach, not to make yellow).

Bleaching of fabrics, paper etc by light has been ascribed in some cases to self-sensitized production of singlet oxygen.

Here's an ad' for teeth whitener.

Note the ranking of 'active oxygen' species according to bleach power. Note which one tops the chart. Yes, it's singlet oxygen. It's especially effective the accompanying words say against the stubborn yellow stains of tetracyclin antibiotic.

PS: I see that Fazio et al are citing Mills et al* as the proponents for a role for singlet oxygen, which they describe as imparting "energy" to the fibres, resulting in yellowing  while being more circumspect themselves, They prefer to play safe, and refer to an "unknown source" of energy triggering off immediate and subsequent lag-phase reactions to produce yellowing maybe years or decades later. Would it be uncharitable to suggest that a hypothesis that depends on an "unknown" source of input energy hardly ranks as a hypothesis, or at any rate a scientific hypothesis?  Hypotheses in science have to be testable. How can one hope to test a hypothesis that is based on an unknown source of energy? 

* Mills, A.A. (1995):  Image formation on the Shroud of Turin. The reactive oxygen

intermediates hypothesis.  Interdisciplinary Science Reviews, vol. 20, 319 - 326.

Not all images that are 3D-enhancible have 'encoded 3D information'.

What was done to the Shroud image can be done to our flags too, with a few clicks in image-enhancement software programs (in this instance ImageJ).

The Turin Shroud image is famously 3D-enhancible, given the right software. Initially it was shown with the so-called VP8 image analyser that was allegedly space-age technology, and not surprisingly led to much over-hyped speculation that the TS image was different from any other. (Caveat: the article has "multiple issues" according to wiki. I would concur with that, it being less about the VP-8, and how it works, and arguably more a vehicle for "Shroudie" propaganda).

This  blogger pricked that particular balloon some 2 years ago, pointing out that the 3D- enhanced images not only brought the man's image up out of the page, but the 1532 scorch marks as well. (Wikipedia credits me with making that finding, but I'll try not to let it go to my head).

There's more talk right now about what the modern day digital equivalent to the analogue VP-8  (notably the freely downloadable ImageJ software) does or does not do to the TS image that is meaningful. In other words, what are the 'correct' settings that gives a valid image?

Again, I've expounded on that question in the past, and shown how one can 'normalize' ImageJ settings by taking a scorch imprint from a bas-relief metal template, and then enhancing it in ImageJ to get the closest possible match to the original. If one then applies those same settings to the TS image, one gets a very realistic-looking semi-3D image of a bearded man.

("Normalised" 3D-enhanced image from a 2012 posting - see link below)

But inevitably there will be those who reject that approach, denouncing it as self-serving, a means of selling my "scorch" hypothesis.

Are there other ways of deciding on the optimal settings?

Here's a simple experiment one can do that brings home the arbitrary nature of ANY settings one applies.

Select any flat, non-3D image that shows a gradient of colour intensity. The one selected here is a colour palette, aka shade chart,  from MS Paint (click on the menu's Custom colour).

Now enter that image into Image J.

Here's one result that shows a gentle 3D enhancement that reflects image intensity:

So there is no question that the 3D enhancement is entirely artefactual, inasmuch as there was never a 3D object to begin with, simply a planar colour chart.

What if the image intensity rises to a peak, and then falls back again?

Above you see the (fairly predictable) result of overlapping two shade charts, end-to-end, then 3D-enhancing in ImageJ.


Incidentally, the ImageJ settings used were approximately those that I used many moons ago to get the best match between a horse brass (a handy bas relief template) and its scorch imprint on fabric.

Left: original brass. Centre: scorch imprint (left-right reversed). Right (with artificial colour which seemed a good idea at the time): optimized 3D enhancement in ImageJ intended to achieve the closest match with original, thus establishing 'normalized' settings.


Yes, they were what I called 'normalized' settings and which later produced that pleasing result shown earlier with the Shroud Scope/Durante 2002 Man on the TS.

Link to my March 2012 posting

But those same settings can be used to endow many 2D images with 3D or, more correctly,  pseudo- or virtual 3D character.

A week ago, working at home on my main computer, I constructed the chart as a series of concentric circles, with lightest shades on the outside, becoming darker towards the centre. When entered into ImageJ the diagrams were converted to pleasing cones that telescoped so to speak out of the page. The model system allowed one to see precisely what effect could be achieved by twiddling the various controls, especially z (for more or less 3D) and smoothing (which in simple terms can be thought of as the 3D equivalent of converting a bar chart into smooth curve). The fun part was to create irregularities in the sequence of shade intensity, so instead of a smooth progression like 1,2,3,4,5,6,7,8, one had 1,2,3,6,4,5,8,7.  One might have expected the relief to respond up or down with each change in shade. but that was not the case. Abrupt changes of shade in the sequence 'forced' the overall relief such that expected micro-changes elsewhere in the local topography were suppressed.  Sadly I did not save to memory/thumb stick, but will add the graphics onto this posting (and more besides) later when available.

Update: I've been able to produce the same effect on this older travel laptop in MS Paint, despite its Windows Vista having less functionality in Paint than Windows 7.

Here's a series of images that hopefully speak for themselves obtained just now when a colour-graduated series of closed contour lines are manipulated in ImageJ. (Why is it I can't get Madonna out of my head right now?)

2D image constructed in MS Paint

After applying ImageJ with low z axis value

Now with high z value

Low smoothing

Increased "lighting" (lateral, thus creating artificial shade effects)

.

Take away message for now: 3D enhancement of a 2D image does NOT necessarily mean that the image has "encoded" 3D information. It may simply have gradients or even abrupt steps in colour intensity which the program reads as more or less height on an artifically imposed z axis.

Joseph Accetta PhD, electro-optics/laser/imaging expert said as much at the 2008 Ohio Shroud conference, though you have to go patiently page by page through  his now hard-to-find Power Point presentation. See yesterday's Dan Porter posting, and an acknowledgement to this blogger for having unearthed it.

Further update:  Well, I've persevered, despite MS Paint not allowing me to create nests of concentric circles in Windows Vista, so I've had to make do with ovals. From earlier you may recall that the aim was to show the kind of anomalies that can arise when the stepped density gradient values are out of sequence.

Here's the 2D starter, with an irregular sequence of image density.

Here's the first result in ImageJ, where one sees that the program has failed to respond to the density gradient at the peak, due to there being a dominant intermediate zone of image intensity. But tweaking of settings, especially of z value and smoothing, can make the program respond to the peak, as the next graphic shows.

The peak within the 'crater' is now visible, but the overall image has a poor 3D enhancement, due to that out-of-sequence gradient of image intensity.

Late postscript: followers of this and my specialist Shroud blog will know who I believe is depicted on the Shroud of Turin via some kind of thermal imprint (maybe chemically-assisted). It's a historical figure, alright, but not Jesus Christ. Who?  Probably Jacques de Molay, last Templar Grand Master, executed on the banks of the Seine in central Paris by slow-roasting in 1314.Others before me (notably Knight and Lomas) have arrived at the same conclusion, even if their proposed imprinting scenario is totally different, involving in their case a still live subject, as distinct from bronze effigy or similar.

Here's an image of de Molay I've just found by googling, fashioned and described as a 'mascot' (don't ask me why).

Let's see how that 2D image responds in ImageJ. Does it  have what some might misleadingly describe as "encoded 3D information"? I leave you to judge dear reader:

Some of us get a feeling of déjà vu  when viewing artistic portrayals of Jacques de Molay, even modern-day ones as here.

Update: Sunday 8 June

In response to points raised elsewhere I may make additions or clarifications here, but won't be drawn into debate that has a backbiting nature, based on this free spirit being seen as one of "them" rather than one of "us". I'm only here for the science.

The question has been raised as to whether colour can endow 2D graphics with superior 3D-enhancibility relative to the TS image (the latter invariably viewed as the gold standard needless to say, whose alleged uniqueness is assumed, not posited).

I've just this minute taken one of my earlier graphics, the shade chart from MS Paint, and converted to gray scale before uploading to ImageJ. Here's the result - identical except for colour.

Now before exploring the substitution of gray scale for colour, here's a comparison which I bet you've never seen before of the behaviour of (a) the TS face in ImageJ (or similar) alongside (b) a model scorch (c) a model shade chart and (d) a painted portrait of our old friend Jacques de Molay. I'm showing it first WITHOUT and then WITH a tick in the ImageJ "Invert" box. Absence of a  tick brings up the denser image regions (seemingly) above the plane of the screen, whereas a tick in the box puts dense regions in hollows below the plane. Note especially the response of the shade chart, third from left, producing a cone without the tick, and a crater with. Click or double-click on images to enlarge.

There are some interesting differences there that need discussion, but let's deal first with the matter of gray scale, and see if that makes any difference to what you see above.

Please be patient. More to follow later today.

Resuming 12:49 pm local time:

OK, here are the gray scale versions of the two graphics immediately preceding this update.

Conclusions: both the TS image and the model scorch were enhanced better without a tick in the Invert box, such that the shade chart appeared as a peak rather than crater. But it seemed that the portrait responded better when there WAS a tick in that box. In other words, imprints, whether of 'mysterious' origin (the TS) or scorch imprints from a hot metal template seem to be qualitatively different from painted portraits in their response to image enhancement in ImageJ. (underlined words  unfortunately omitted from first draft)

All the tests so far were done on the 'as-is' images, without any prior "photographic inversion", i.e. reversal of light and dark, as per Secondo Pia. Does prior photographic inversion alter subsequent response in ImageJ, tested with an without a tick in that (somewhat confusingly named) "Invert" box. where invert in that instance means raising or lowering the vertical z axis above or below the viewing plane (something different from photographic inversion from "positive" to "negative" and vice versa.

More to come later in the day.

 

So, no surprises  there then. The monochrome results mirror the coloured ones, and graphics that are black/white reveresed give the same result, provided the Invert box is ticked or unticked to allow for the switch in tonal distribution.

The chief finding in these latest experiments is to confirm what I found over 2 years ago, namely that the settings in ImageJ that work best for 3D-enhancement of the TS, judged artistically, are essentially the same as those judged more objectively by matching up the 3D-enhanced scorch image with the template from which it was derived. You would not know this from reading much of the Shroud literature where, time and again, after searching diligently for the few references dealing with  model scorches, one finds derogatory references to their quality and/or response to 3D imaging, compared with the Shroud image. One also finds claims that the Shroud image is 'uniquely' responsive to 3D-imaging, which one sees above are patently untrue. There seems little to distinguish between the TS and a scorched-on image: STURP almost said as much in its 1980 summary.

Postscript: I have just this minute added a section to my earlier posting on the TS man's toes, those very elusive toes, deploying a new (desperate) ruse to improve 3D-imaging in ImageJ. It's been, well, moderately successful. 

Final gasp (on this over-long posting):  there was a curious and unexpected feature of those 3D images where 4 different images were tested together. Switching between Invert On versus Off in Image J did not produce so marked a transformation as expected (one expects the image to be turned inside out, like punching a hat to make a new one with the lining on the outside).

Here's what happens if one performs the switch on the TS image on its own:

Well, I never. The result is surely different from testing them singly. Must go and check the sequence again, make sure there's no mistake..

Nope, no mistake. On a quick glance they looked similar, especially if one holds one's laptop at arms' length. But they are clearly not.  Note the guide to "sense" in a topographical way - the convex pucker at the top of the head on the left, the indentation at the same location on the right. The ease with which the two can be confused is probably due to the relatively small z value used to get a pleasing result, giving relatively shallow relief above and below the base plane.

OK, let's compare the TS and scorch side by side with HIGH z setting to exaggerate relief, and then toggle between INVERT on and INVERT off.

INVERT on

INVERT off.

Note the identical response of the two images in Image J under these different settings. Go figure, as they say.