Postscript (correction: ‘prescript‘) added July 2019:
You have arrived at a 2014 posting. That was the year in which this investigator finally abandoned the notion of the body image being made by direct scorch off a heated metal template (despite many attractions, like negative image, 3D response etc. But hear later: orchestral DA DA! Yup, still there with the revised technology! DA DA! ).
In its place came two stage image production.
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Stage 1: sprinkle white wheaten flour or suchlike vertically onto human subject from head to foot, front and rear (ideally with initial smear of oil to act as weak adhesive). Shake off excess flour, then cover the lightly coated subject with wet linen. Press down VERTICALLY and firmly (thus avoiding sides of subject). Then (and here’s the key step):
Stage 2: suspend the linen horizontally over glowing charcoal embers and roast gently until the desired degree of coloration, thus ‘developing’ the flour imprint, so as to simulate a sweat-generated body image that has become yellowed with centuries of ageing.
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The novel two-stage “flour-imprinting’ technology was unveiled initially on my generalist “sciencebuzz” site. (Warning: one has to search assiduously to find it, and it still uses a metal template, albeit unheated, as distinct from human anatomy):
So it’s still thermal development of sorts, but with a key difference. One can take imprints off human anatomy (dead or alive!).
A final wash of the roasted flour imprint with soap and water yields a straw-coloured nebulous image, i.e. with fuzzy, poorly defined edges. It’s still a negative (tone-reversed) image that responds to 3D-rendering software, notably the splendid freely-downloadable ImageJ. (Ring any bells? Better still, orchestral accompaniment – see , correction HEAR earlier – DA DA!))
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This 2014 “prescript” replaces the one used for my earlier 2012/2013 postings, deploying abandoned ‘direct scorch’ technology.
Thank you for your patience and forbearance. Here’s where the original posting started:
Original posting starts here:
Appended below is latest example of trolling on shroudstory.com from one “Andy”, who like so many others on that site simply can’t let go. He came back today after lying low for a month, to renew his attack on me with his trumped- up charges as if there had been no cooling-off period.
I’ve been blogging long enough on this and other sites for folk to know my beef. I detest pseudoscience, especially when it’s agenda-driven, relentless and systematic. I detest the way that Shroud authenticity is being pushed by the ideologues who constantly seek to impugn one’s motives. (Today there are references to Hades, the Devil etc etc). I will openly criticize the work of any research investigator, living or dead, whom I consider to have resorted to pseudoscience in order to push Shroud authenticity or merely Shroud mystique. (I would be equally hard on anyone pushing Shroud ‘inauthenticity’ if I suspected the science were rigged to produce the desired answer).
This, as I say, is just the latest example, and by no means the worst, merely symptomatic of the tactics and strategy deployed – starting with the targeting and provocation that is the modus operandi of internet trolls. Later, I shall cite a much earlier instance, almost 2 years ago, in which the site’s host allowed a complete ‘newcomer’ (?hmmm) to launch a hit-and-run attack on me and my credentials, attempting to trash one of my most treasured hot-from-the-presses research findings .
Onion inner-scale leaf epidermis experiment. One cell thick layer, mainly two primary cell walls ( +desiccated cell membrane and cytoplasm) protects the fabric against scorching (blue area)c despite having sufficient heat afterwards (red area) to scorch. Scorching by contact can be highly superficial AND localised.
Porter gave that troll a guest-posting (one of his favourite tactics that has been deployed against me time and time again), always setting up the hard cop/soft cop routine, he himself switching between hard and soft cop. Sorry, Daniel. I spotted YOUR modus operandi a long time ago.
Enough is enough. From now on, I shall cease referring to shroudstory.com as “The Other Site” or “Across the Way”. Henceforth it will be “Troll Central” and will remain so until such a time as Daniel R.Porter calls off his ideologue hounds and cleans up his site.
Here’ s the thread in question. Note the dates, and that one month gap before “Andy’s” renewal of hostilities :
February 3, 2014 at 8:56 pm | #20
Honestly Dan, I don’t expect any non sentimentality from Colin when it comes to STURP members, scientists or anyone else. He has lambasted Rogers (among others) when he was not able to defend himself. It seems to me Colin simply doesn’t like Rogers. He may pretend its scientific, but his character assaults of him in these blogs of which I am a witness gives him no credibility at all in the issue. I will not listen to Colin. There are many real scientists who can at least be honest and fair, even if they disagree with conclusions (anyone’s).
February 4, 2014 at 3:27 am | #21
If you don’t mind my saying, you seem fairly proficient in the character assault department yourself, Andy, especially as my comments regarding Rogers have been confined largely, if not entirely, to details of his science, with just occasional asides re the failure to maintain strict scientific objectivity on his part. He was, to put it colloquially, rooting for authenticity, albeit a chemist’s version thereof, with chemical, rather than radiation or thermal imprinting. In other words, we were allowed to have any scorch we liked, provided it’s a Rogers’ approved chemical “scorch”.
Ray Rogers, to put it mildly. showed a distinct pro-authenticity bias and was clearly piqued when the radiochemical radiocarbon dating was announced. Maybe you consider my saying that to be “personal” or disrespectful to a dead scientist. I don’t, since the chief requirement one expects of any SCIENTIST given privileged access to the TS and with no obvious specialist skills to contribute (why recruit a thermochemist, unless to investigate pyrolysis and scorching with an open mind?) was transparent objectivity, whatever the underlying religious beliefs or otherwise.
I am not going to respond in kind to YOUR character attack, Andy (Andy Weiss?). What I shall do is assemble a list on my own site of the numerous instances in which Ray Rogers simply got it wrong, of failed to properly support his often over-dogmatic assertions which again and again were more expressions of hunch or opinion, NOT closely argued science. See my recent post on the sloppy way that he employed the term “vanillin” that has since been adopted as the assumed gold standard in Shroud literature. But Rogers was NOT measuring vanillin. He was supposed to be measuring components of undegraded lignin that were NOT vanillin – albeit with his simplistic unfit-for-purpose spot colorimetric reagent (why did he not use his pyrolysis mass spectrometer?).
ONE MONTH GAP
March 2, 2014 at 8:08 pm | #25
That was clearly not a character assault. You did that yourself, Colin.
March 2, 2014 at 8:06 pm | #28
Glad you can walk the dog again, Dan. No doubt Colin is thinking and gets others doing the same, which is good, but his character assaults he has made completely tuned me out from what he has to say. It’s a shame really, but I don’t have the time to waste. I am far too busy.
March 2, 2014 at 9:45 pm | #40
You’ve waited a month, just to have another go at me Andy? See my #21.
Daniel R Porter: if you continue to allow this kind of trolling to occur on your site, I may feel obliged to devote a posting to it. I’m even toying with the idea of referring to this site in all future postings as Troll Central.
March 2, 2014 at 10:34 pm | #41
Colin, do what you must, but do it elsewhere.
March 2, 2014 at 10:58 pm | #42
Your comment is awaiting moderation. (Here we go again – Daniel R.Porter back in censorship mode for about the 3rd or 4th time)
Systematic trolling, trumped-up charges, demonisation.
What an ugly site!
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Have just submitted this long-overdue raspberry to Daniel R.Porter re that appalling posting he allowed, nay cajoled, Paolo di Lazzaro to place on his site.
Your comment is awaiting moderation.
Classic Porter. He invites this clown to present still more so-called science, to which I respond with REAL SCIENCE (the onion epidermis experiment). He then allows same clown to run off, unwilling to be criticized on a truly pathetic (INDEED, RIGGED) experiment.
Porter and his site are an utter disgrace .
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Your comment is awaiting moderation.
“Colin, you cannot escape the ownership for the burden of proof or the responsibility to experiment. That is absurd fallacy. It is not how responsible science is done. ”
http://shroudstory.com/2012/02/20/image-by-scorching-heat-or-science-by-hot-air/
Wrong, Daniel R Porter. You clearly don’t have the first idea about the way science operates. Did Higgs back in the 60s have to personally demonstrate the reality of his mass-conferring bosons in order to be taken seriously? Of course not. It’s taken the world’s biggest most expensive hadron collider to date to prove his ideas were correct.
It’s what you and other armchair cynics and debunkers consistently fail to recognize – that science is primarily about ideas. Those ideas have only to be testable in principle. There is no pressing obligation on the originator of a scientific idea to personally put it to the test. If the idea is good, then others will be falling over themselves to test it, especially those who have the wherewithal to do so.
I don’t expect this and other comments to be posted. I don’t particularly want them to be. I just want you to know that I consider you totally unfit to be hosting a Shroud site, Daniel R.Porter. You simply lack the grasp of fundamentals, and try to make Aunt Sallys of those of us who are equipped to think our way through the morass of bad science, most of which in Shroudology is tainted with agenda-driven selectivity and bias.
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Later today I’ll insert a section here showing how Daniel R.Porter allowed that guest troll who called himself “Leland of Boston” to use a previous exchange between me and another commentator calling himself “Chris” to accuse me of ‘ad hom’ . “Chris” had entered the thread, calling me “the old boy” and then dismissing me as an “attention seeker”. Yes, great isn’t it, but par for the course on Troll Central.
Trolling doesn’t get much nastier than that when Troll A initiates the mudslinging, and then Troll B is allowed to use that previous exchange to totally misrepresent what was said AND then demonise, and all as an open-door, anything goes guest-posting.
Fortunately, it’s all still on record to show how that bear pit of a site operates, either with the blessing or active connivance of its host, allowing newcomers of dubious bona fides to exploit the site as a platform for character assassination.
Ugly, ugly site – and getting worse with each passing day.
Insert extract here (later)
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Trolls
It is totally wrong that someone new (or apparently so) to an internet forum or other site should be allowed in solely to have a rant against a site regular. It’s an unfair contest. He (or she) can mine one’s scores of hundreds of comments in order to construct, or as often as not, concoct, a diatribe. One has nothing on them, and can only guess what their real motive might be, especially if or when the troll displays a remarkable subject knowledge for one who is “new” to the site.
It’s pointless taking them on – being invariably a no-win situation. As they say, “Don’t feed the trolls”. One is always on a hiding to nothing. That’s why responsible site owners should identify and expel trolls – and not go giving them a free platform – or actively recruiting them through a network.
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It’s bad enough when trolls suddenly appear in a comments thread. It’s 10 times worse when they are given a guest slot, and when it’s quite clear that the site’s host is taking their side, even when one’s comments are being shamelessly manipulated.
Turning to more constructive matters, newcomers to this site (or others who have not looked in recently) may be interested to see the conclusions this retired (biomedical) scientist has reached after researching the Shroud these last two years or so.
Here’s a link to a recent posting, with a flow chart and summary:
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Next task: may take a few days to complete. Give some more background details on that onion epidermis experiment, showing how those cells are likely to behave on desiccation to create a thin double-skin comparable to the reported dimensions of both the Shroud image layer and (importantly) the similar thickness of the PCW sheath on the linen fibre. (Being rich in chemically-reactive glucoxylans and other hemicelluloses makes the PCW the prime target for contact scorching, as well as the most superficial, first-encountered layer). It’ll be an opportunity to post to my long dormant sciencebuzz* site initially, showing how a typical plant cell can be modelled using a polythene bag, a string bag, Vaseline and water. I showed the model some years ago to a couple of schoolteachers who seemed impressed, saying it was not something they had encountered before. Whether it’s still “original” or not remains to be seen. One good visual aid is worth a thousand words, methinks.
* Here’s what I said over 4 years ago when setting up the sciencebuzz site (the aims – and the prime target of those aims – not having changed one iota):
My sciencebuzz site (still going, just)
Hello
Sat Aug 22, 2009
Some people keep a old boot handy when watching TV – or is that a cartoonist’s creation? Irrespective, I feel the need for a virtual old boot when perusing the media’s handling of science. Think of this new blog on the block as that “old boot”, but don’t be surprised if some constructive comments creep in from time to time, or even new, highly questionable, indeed suspect hypotheses. What is science if it’s not sticking one’s head above the parapet?
Never is my spectator ire more keenly felt when there’s no facility for readers to post responses, or when one’s gems of wisdom/vitriol/jaundice fester unpublished in the moderator’s in-tray during three-hour lunch breaks, or fail to appear at all.
Think of this, then, is a talking-shop for making sense – or nonsense- of the science we read on the main sites. The ones I track on a regular basis are the BBC, the Telegraph, The Times, The Independent and the Guardian. Yep, up-market anglocentric, I grant you, (do I hear groans) and I’ve no time for the dumbed-down underbelly. But I’ll broaden my sweep if folk can suggest some wider reading which, in estate agents’ argot “repays closer inspection”.
“Sciencebod” as I then was.
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Here’s a C&P , currently displayed on Troll Central, of what Professor Giulio Fanti is quoted as having said re dating methods.
Fanti: “Today, we have thus five different dating methods: the radiocarbon method, my three and those of Rogers. Also, we could have been wrong. But four different independent methods, reach the same result, but then speak a clear language. As long as these results are not refuted, and I can not imagine how this should be possible, these results have scientific validity. So that has first Century after Christ the greatest probability as emergence period for the Turin grave cloth. This dating corresponds exactly to the time Jesus of Nazareth lived in Palestine. We now await the reactions from the rest of the science world. So far we received only affirmative and affirmative responses, but no refutation.”
So he claims a score of 4/5, conveniently ignoring the fact that radiocarbon dating is vastly less open to false positives and/or false negatives than any method that relies on chemical change. (Yes, we know about the “invisible mending”, but that is largely speculative, assisted by those scarcely credible results from Mr.Raymond Rogers RIP, explosives chemist, post-retitement kitchen microscopist/experimentalist (like me) using illicitly harvested and distributed threads.
But I know three different people who each maintain, on different approaches, that a medieval forgery involved heating of the linen that would have produced accelerated ageing.
1. The early owners of the Mark1 Shroud, who according to Antoine de Lalaing involved testing with fire, repeated laundering and “boiling in oil”.
2. Luigi Garlaschelli, whose powder frottage method involved heating in an oven at an elevated temperature (? 180 degrees C), this procedure causing ochre (iron oxide) with acidic impurities (made by heating green vitriol, i.e. hydrated iron (II) sulphate with release of acidic sulphur oxides) to cause etching of linen under the pigment AND generalized yellowing and degradation of fibres.
3. My recently revised scorch hypothesis that proposes the Mark 1 Shroud was an obvious and unsubtle contact scorch from a hot template that was subsequently toned down by the procedures listed by Lalaing. (They would have reduced the contrast between image and background, giving rise to those descriptions of image formation as one of “accelerated ageing”.
So while Professor Fanti claims a score of 4/5 for his 1st century dating, I would claim a score of 3/3 for the linen having been artificially aged, such that i is mechanically weakened and chemically altered in Fanti’ and Rogers’ chemical tests, but does NOT fool the radiocarbon dating. Come to think of, the score for non-authenticists is 4/4 if you include the radiocarbon dating. 4/4 beats 4/5 any day, especially with the realistically-appraised non-cuckoo-land radiocarbon data.
Professor Fanti cannot legitimately claim the evidence is in his favour, lacking as he does information on the complete environmental history of the Shroud. His (and Rogers’) dating methods are model-dependent. They start with the hypothesis that the linen is of 1st century provenance, and fail to envisage the various kinds of treatments, obvious and less so. that may have followed a 14th century provenance, apart from the obvious ones like the 1532 fire.
Frankly, I don’t have a lot of time for what clearly is agenda-driven so-called science. Rogers betrayed his agenda when he assumed that the linen had been spun and woven according to assumed 1st century methodology (citing Pliny). Fanti betrayed his agenda when claiming he could detect the ‘correct’ Biblical time sequence in the acquisition of different classes of bloodstain on the TS (scourge marks especially), despite there being no imaging of wounds directly.
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Am now toying with the idea of widening my attack on agenda-driven so-called science, systematically and shamelessly promoted via the MSM. I need a campaign slogan. How about this for starters?
“IF IT SMACKS OF PSEUDOSCIENCE, THEN SMACK BACK HARD – AND SWIFTLY”
My answer to the steeped-in-mystique Turin Shroud - evolving gradually from some 10 years of science-based experimental modelling. 
Colin,
Can you explain step by step your onion experiment ?
I am not sure to understand well, but I see no connection with the scorch hypothesis on the Shroud.
I’m a little surprised I have to explain (all over again) what to me seems self-evident. Never mind. Let’s start again.
Do you not consider it extraordinary that hot metal can produce an intense scorch on dried onion epidermis, while having virtually no effect on underlying fabric? Yet there was still enough heat in that metal to scorch the fabric when applied directly, without the protective epidermis, despite some cooling.
I find that extraordinary, and could scarcely believe what I was seeing. What is onion epidermis? It’s merely a sheet of plant tissue, just one cell thick, minus vacuolar water, having been dried, in which each individual cell is simply collapsed down to a pair of primary cell walls, each of which, it is estimated, is about 100nm in thickness ( not forgetting a small amount of desiccated cell membrane and cytoplasm separating them). In other words, the thickness of that protective epidermis is probably in the range 200-400nm, precisely that estimated for ‘ultra-thin’ Shroud image.
So there is no reason why the Shroud image cannot be a simple contact scorch that affects the first 200-400nm of exposed linen fibres. There are absolutely no a priori grounds for claiming as Paolo Di Lazzaro did with that simplistic hot coin experiment of his that a scorch cannot be imprinted on one side without it showing on the reverse side as well. A contact scorch can be made as faint as one wishes, with NO penetration to the opposite side (that should be plain commonsense).
He himself acknowledged the existence of the primary cell wall as an outer sheath on linen fibres . So why all the song and dance about the “peculiar” microscopic characteristics of the Shroud image that made he and his ENEA colleagues resort to (man-made) laser beams when simple botany/chemistry alone accounts for the superficiality of the Shroud image, and when conventional energy sources should have been studied first? A light scorch at least can surely be confined to that PCW, especially as the underlying SCW is primarily (though not exclusively) crystalline cellulose with a much higher pyrolysis temperature.
My onion epidermis experiment showed convincingly in my view that an intense contact scorch can be confined to a depth of penetration corresponding to just one or two primary cell walls (again, ignoring debris of cytoplasm etc) without significant heat penetration into deeper layers. In other words, the much over-hyped ultra-superficiality of the Shroud image has been demystified. It’s merely a reflection of the superficial location of the PCW, packed with hemicelluloses that are highly susceptible to scorching by contact. It’s the heat-resistant cellulose core of the SCW that prevents deep scorching of linen, provided that temperatures or contact time and pressure are not excessive.
Afterthought: I’m presently preparing another posting that will list 4 prime sites on a linen fibre that are susceptible to scorching by contact with a heated template, and which will attempt to place them in (possible) order of susceptibility. The model could then be tested experimentally, using different contact times at the same temperature (or different temperatures with the same contact time) with a view to establishing a cumulative progression of thermal signatures against which the Shroud’s image fibres could be compared.
About the experiment itself:
Looking at your photo, I don’t see any scorch in the red area, except on the border (and the tiny burned area).
Moreover, although you wrote that your onion epidermis was dried. How ? It looks not so. There is probably (likely) a lot of water remaining in your onion epidermis.
But it is not very important.
What does your experiment show ?
It shows that a layer made of a 200-400 nm.thick layer of “primary cell walls” INSERTED between the hot template an the linen sheet “protects the fabric under scorching”
And then ??
And you conclude: ” Scorching by contact can be highly superficial AND localised.”
That’s true in your experiment.
But I still don’t understand the connection with your scorch hypothesis, in which a hot template had to be applied on the linen sheet itself.
“Looking at your photo, I don’t see any scorch in the red area, except on the border (and the tiny burned area).”
What on earth is that supposed to mean? There’s a scorch. OK, it’s mainly on the border. So what? It’s a scorch. There was sufficient heat left in the metal to produce a scorch on the linen. So it’s not a evenly distributed homogenous scorch. So what? It’s not a scorch beauty contest.
Here’s a link to my original posting, with the same photograph before I added the blue and the red.
https://shroudofturinwithoutallthehype.wordpress.com/2012/02/21/modelling-the-image-of-the-turin-shroud-an-interrupted-experiment/
The scorch is there, but it has to be viewed scientifically, not aesthetically.
Thibault: I really don’t wish to engage with you any further. You know the reasons why.
Colin,
One again, you failed to answer to my comment: “What does your experiment show ?
It shows that a layer made of a 200-400 nm.thick layer of “primary cell walls” INSERTED between the hot template an the linen sheet “protects the fabric under scorching”
And then ??” “But I still don’t understand the connection with your scorch hypothesis, in which a hot template had to be applied on the linen sheet itself.”
No answer.
This is your usual strategy.
The onion experiment has no connection to the TS image problem.
You definitely failed to prove your hypothesis.
I (after many others) proved that the scorch hypothesis does not explain simutaneously the superficiality, the half-tone effect, the fuzzy borders etc….
I don’t wish to engage with you any further.
If you wish people to respond to particular points of concern, then here’s some advice. Don’t preface them with matters of personal opinion that are not backed up with evidence – like your suggesting the skins were not fully dried – or saying you couldn’t see a scorch, and then admitting you could. You cannot expect to create an obstacle course, and then complain when the target of your petty quibbles grows tired of all the attempts on your part to claim superior knowledge and judgement.
I may have one more go at explaining the relevance of my onion experiment, but not tonight. Oh, and I have looked out the unused skins from the experiment back in February 2012 that look and feel exactly the same as the ones I tested, except for some yellowing. I may try repeating my experiment – and am reasonably confident of obtaining the same result.
As for your comment re simultaneous this or that – and how you have “proved” it, then I suggest you, sir, are a pretentious twit – and arrogant with it. Your departure will be no loss to this site. Go back to your ridiculous template and unassailable pdfs.
Update: Saturday 8th March
I have just repeated my onion skin experiment using the same batch of epidermis peels from 2 years ago, heating them first over the radiator for a few hours to be absolutely certain they were maximally dehydrated.
Result: exactly the same outcome as before, on both linen and cotton: the epidermis protects the underlying fabric from scorching, while itself acquiring an intense red-brown scorch off the hot aluminium template.
Pictures available if any one is interested.
” I may have one more go at explaining the relevance of my onion experiment, but not tonight. ”
OK. I am waiting for your explanation.
But because of your continuous insults,I’ll answer on the other site (not only about the onion experiment).
Here’s the reply to the final part of your battery of questions (pity you had to raise inconsequential and irksome details with the first ones).
We are told that a contact scorch can never hope to reproduce the superficial nature of the Shroud image – supposedly 200-600nm thick (though that would seem to be little more than a guesstimate if based purely on those stripped ‘ghosts’).
Why? Had anyone tried producing superficial contact scorches from a hot template?
Apparently not since the ENEA people went straight to their uv excimer lasers.
Can anyone give me a theoretical reason as to why a contact scorch cannot be as superficial as one wishes, simply by metering down on the chief variables (temperature, contact time, contact pressure, presence of absence of a damp overlay or underlay)?
Personally I see no reason why a faint scorch that is only just visible should not be highly superficial, affecting just the first few hundreds of nanometres of the fibre, if that.
That expectation is supported by the botany and the chemistry. The PCW of a linen fibre is reckoned to be about 100nm thick, and comprises a lot of heat-sensitive hemicellulose (pyrolysis at 220- 315 degrees C according to Yang et al) The underlying SCW is predominantly crystalline cellulose, with a higher pyrolysis temperature range (315-400) with a mere 15% or so of hemicelluloses. So there is every reason to suppose that selective pyrolysis and browning of the PCW should be feasible to give a highly superficial coloration and image.
On to the practical. Paolo Di Lazzaro chose 230 degrees for his hot coin experiment, but held it against the linen for much too long, and did not try a series of imprints as the template cooled down.
In his own words: “We have heated a 5-cents euro coin at about 230 °C in contact with a linen cloth. Just 5 seconds after the coin reached the max temperature the whole cross section of threads in contact with the coin was colored. After 15 seconds all the thickness of the cloth was colored and the round shaped image of the coin appeared on the opposite side.”
So instead of concentrating on faint imprints, he trumpeted the fact that he saw scorching on the opposite side, and proceeded to make the bizarre claim that reverse side scorching is unavoidable. Ludicrous! Common sense alone should have told him that a scorch can be as superficial as one wishes, thermal energy being a continuous variable that can be metered.
Yes, I knew two years ago that Di Lazzaro’s claim was nonsense, having done serial scorching down to images that were barely visible, and seeing NO reverse side scorching. (There is a small caveat there with more intense scorches that I propose to address in my next posting, but it in no way negates anything said here).
Now for the rationale for the onion epidermis experiment.
While I can produce faint non-penetrating scorches, I have no way of measuring their thickness, and I’m not even sure that anyone has done so, such is the aversion in Shroud research to addressing any non-authenticity mechanism such as contact scorching from a bas relief etc. Was there perhaps another approach that might tell us how far a contact scorch will penetrate when encountering a primary cell wall and whatever lies underneath?
Yes, there is, or was. The onion epidermis is just one cell thick. When it is stripped off the inner surface of bulb scale leaves and dried, it loses its vacuolar cell sap and consequently its turgor, collapsing down to a double layer of PCWs, albeit with some scanty remnants of cell membrane, cytoplasm etc in between, rather like a deflated balloon. The dried epidermis is therefore a PCW (approx 100nm thick) with debris, and then another heat-sensitive PCW. So why not lay that epidermis on top of linen, and see how readily the PCW of the underlying linen scorches? If superficial scorching is impossible from a hot template, then we expect to see the underlying linen scorched in addition to the epidermis. In fact, I predicted that might happen, but hoped to see some worthwhile measure of protection.
But that did not happen. Certainly, the epidermis became highly scorched, but there was virtually no scorching of the underlying linen. That was a totally unexpected result, but in retrospect one I think can be explained. But first one has to address a likely objection. Maybe there was so much heat removed from the template to scorch the epidermis as to leave insufficient to heat to scorch the linen. I anticipated that objection in advance. After scorching the epidermis, I moved the template to a fresh area of linen for direct metal-linen contact, and was relieved to observe a definite scorching of the latter. (Am still at a loss as to why you make so much of that scorch being mainly from the edge of the template. So what? It’s still hot metal)
If scorching can be confined to a pair of PCWs and a little cytoplasmic debris, all easily pyrolysable, then why, when the hot template is applied directly to linen, should it not also be confined to linen’s own PCW, and possibly a little of the underlying SCW as well (given that has a little hemicellulose)?
I believe my onion experiment constitutes experimental proof that a contact scorch can be highly superficial, of the order of 100-200 nm, or, if one’s conservative, maybe as much as 500-600nm (but then the Shroud image is also said to be in the range 200-600nm).
How can a few hundreds of nanometres of primary cell wall protect underlying carbohydrates? The answer I believe lies in the endothermic nature of scorching under non-standard (thermodynamic) conditions, where water can escape as steam without re-condensing. (Under standard conditions at 15 degrees Celsius/298 degrees Kelvin it would return the large latent heat of vaporisation/condensation of H2O.) With so much heat being abstracted from the template to drive off steam, its temperature drops fairly rapidly, falling below the pyrolysis temperature for hemicelluloses. Heat conduction through singed material may also be impaired (it takes only the smallest air gap to prevent scorching by atom-to-atom conduction, so scorched epidermis may be a less efficient conductor than the undegraded material).
I gather you will not be posting any responses here, Thibault. OK, that’s you choice, but please be aware I have severed my connection with the site I now call Troll Central. I’m only in this for the science, more correctly, to wage war on pseudoscience which I heartily detest. Shroudology is just the tip of the iceberg.
I will be as rude as I like to anyone whom I consider is systematically deploying pseudoscience to promote an agenda. Their names should go on a science-offenders register. Engineers who posture as objective scientists are my current bugbear.
Thank you Colin for your detailed (and polite) answer.
I’ll read it carefully and will also consider the other topics (half-tone, fuzziness ..).
About fuzziness, I have seen the picture in “Why is the Shroud image so superficial ?” but it is very blurred.
Is it possible for you to post this picture with a higher resolution?
I’ve located the original imprint, Thibault, or one very similar, and re-photographed. The results have been placed under the one you mentioned. That’s probably the best I can do with my very basic camera for now, but may try again tomorrow in daylight.
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