hughfarey wrote:2) (Kurieou) Then at most we have a mystery, don't we, considering the image of the shroud can't be replicated.
We have a mystery, yes, and the image has not been replicated, yes. Whether it can be replicated or not is of course the crux of the authenticist/medievalist argument.
No, it's more the crux of the medievalist argument, not with those who believe it authentic which draw from many other arguments. I do think attempts to replicate are helpful to shedding light on different features of the shroud image itself and just how unique it is.
hughfarey wrote:3) And there are many fantasies on how the shroud was created, yet to date none have really come close upon careful consideration.
A fantasy is a idea plucked from the aether without any supporting evidence. Those who have thought of 'clever' ideas - such as photography, hot statues, Leonardo da Vinci and so on - have at least made some attempt to support their ideas by experimentation or research. If the results of this research have been found wanting, the ideas have been rejected. To class such hypotheses as fantasies is terminologically inexact. The idea that the threads of the shroud have been spliced together was plucked from the aether after Mechthilde Flury-Lemburg and John Jackson insisted that no repair was evident, but has never been tested in any way. It remains a fantasy, and can only be dignified by the term hypothesis if some attempt is made to substantiate it.
Why does the corner of the shroud that the 1988 sample was cut from fluoresce differently if it is same material? And the cotton... sorry, but I'm going with Rogers on this one, who was a materialist, skeptic and initially peeved that the C14 date was challenged by those he considered fanatical believers. On the other hand, while you are very much interested and knowledgeable with the shroud, I don't know much about your credentials or experience with the shroud. So, based upon authority alone, being non-authoritative myself, I ought to defer to a higher authority.
I do know Rogers had access to the shroud as Director of Chemical Research for the Shroud of Turin Research Project (STURP). So here, I rest with someone of authority who is in a better to know than myself, who is neutral and even was anti-authenticity immediately after the 1988 carbon dating. If you are granted access to the shroud to perform direct tests, then that may change.
hughfarey wrote:4) ironisation (when no iron particles are present on the shroud)
The Shroud is covered in iron oxide particles. There is no dispute about that. The nature and distribution of the particles is much discussed. Again, remember that McCrone looked in detail at whole tape-slides, whereas all Heller and Adler's tests were carried out on individual fibres from which extraneous matter (mostly the glue of the tape) had been carefully washed off.
If you added up all the iron oxide particles together that exist on the shroud, then you'd likely still need a microscope to see them. And then, oxide mainly exists in parts (water stained), not across the whole. The iron that is there, is consistent with natural effects. (more below)
hughfarey wrote:5) contain full saturation (i.e., bas relief where cloth makes full contact with surface covered in pigment) compared the the shroud which has 20% saturation and includes 3D information to within 4cm)
A series of meaningless ideas here, I'm afraid. There is no definition of "full saturation". If it is an attempt to quantify an image intensity derived from a contact, then it is generally thought that the hair and nose of the image represent contact, whether from pigment or from natural causes. "20% saturation" means nothing to me at all. The idea that the Shroud "contains 3D information" does not of itself say whether that 3D information derives from a body, a bas-relief, or a painting.
If you mean that a bas-relief covered in paint would only produce a binary "contact or no-contact" image, then experiment shows that this is incorrect. While it is true that no contact means no image, there is a wide variation in intensity in contact areas, because pressure plays a large part in determining it.
By "saturation" I meaning "saturation points" in 3D terms.
When you apply pigment direct to a surface direct (as is bas-relief), all the points which touch the surface are 100% saturation, and those points that don't come into contact are 0% saturation.
Looking at the shroud, we see the nose came into contact with the shroud causing it to be more light (when the negative is digitally processed) - 100% saturation. Further back are the cheeks and eye sockets which have less saturation. This saturation content is what enables a 3D image to be constructed from a 2D impression.
Pressure plays a large part in determining intensity, yet produce a 3D image from those bas-relief examples, and you only have dark spots (0% saturation) or very light spots (100% saturation). It's really "distance" encoded in a 2D image that provides true saturation information required for 3D ("contact pressure" is inadequate).
Furthermore, the image of the shroud isn't just on one side of the linen as far as I'm aware. Rather, we have the image on the cloth on both sides of the linen with nothing in-between
. In that first video of my previous post, he likens it to a sandwich. We have an image on one side, then blank, blank, blank in the middle of the linen, and then a very faint image found to be coming through on the other side. So then, the bas-relief and any attempt at replication, needs to do the same.
hughfarey wrote:6) paint substance seep too deep into cloth (the shroud image is rather superficial, scrape a couple of microscopic threads off the top and it'd vanish)
No. I keep being told that one or another experiment "would" result in this or that, entirely by people who have never carried out any experiments themselves. It is easy to paint a cloth such that the paint doesn't seep anywhere, especially with a cloth of very dense weave such as the Shroud.
No, it's not that I'm saying experiments would result in this or that, so much as specific conditions that all replications must meet in order to claim success. If bas-relief impressions are done intended to replicate the shroud image, then so long as it meets these specific unique features that pertain to the shroud, then fine. I doubt they will. They're inadequate to account for the features I'm aware to.
Re: the image of the shroud, the image is so superficial, it only exists to a microscopic depth. Scrape off a few fibres, 1/100th of a strand, and the image would vanish. The shroud is no doubt absorbent like any linen. The image layer is so thin that it has been said for a painted picture to have the same "thinness" would require someone painting pigment on with a camel hair. I doubt bas-relief could replicate this feature. Hence, we get into "powder"-based ideas.
hughfarey wrote:7) powder would evidently distort over time, wash, rendering powder theories invalid.
Would it? I don't know if you have access to iron oxide pigment. It is extraordinarily fine, and in my experience will not completely wash out even after repeated attempts to do so. I hope you will forgive me for getting a little fed up when these very old authenticists "would do"s are blithely trotted out year after year without anybody making any attempt to find out if they are true or not.
Again, while iron is found on the shroud, it is so minute that say egg yolk mixed with oxide particles would yield much more iron oxide than actually exists on the shroud, let alone what is in the shroud image itself. "Thus we find three types of iron on the Shroud:
a) a cellulose bound chelated form
b) heme bound forms
c) iron oxide (Fe2O3)
The predominant form is the cellulose bound form. We have been able to identify Fe2O3 primarily in the water stain margins and charred blood areas indicating that it only constitutes a very small percentage of the total iron forms found on the Shroud."
"Although iron in several forms is found over the whole cloth its distribution is shown to be accounted for by natural processes rather than as an added pigment."
"A prior investigator17-19 has published a microscopic evaluation of the samples from the Shroud. This study claims that the body image is due to an iron oxide First published in: Canadian Society of Forensic Sciences Journal, 14 (3), 1981. 36 earth pigment bound with an age yellowed animal binder that had been painted onto the cloth.17, 18 The blood marks are attributed to a mixture of iron oxide pigments and vermillion in this same binder.19 In light of our chemical findings we disagree with these conclusions."https://www.shroud.com/pdfs/ssi43part3.pdf
hughfarey wrote:8) photography wasn't invented in medieval times, yet even with such tests, it is a fully clear negative and not simply down to 4cm.
Photography is not essential for producing an image which will appear, after being photographed, to appear extraordinarily realistic. There are several such examples on the net, including one of mine. The accuracy and detail of the negative is largely created by the human mental tendency to recognise faces.
It's not essential, yet it (producing a photographic negative) was one test done, perhaps more for fun since medieval folk didn't have such. The detail was much too specific and clear. That's all I meant.Edited: to make more clear around 3 hours after posting.