Thursday, June 19, 2014

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

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

June 18, 2014 at 4:06 pm
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 :

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:

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.

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.

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