But there is something which was very amazing (at least for me) :
it is impossible to get an even faint discoloration of the heated side in the area that is just above the 3-4 mm depression of the heated plate : the linen remains white even if the temperature is high enough to give a strong brown discoloration of the surrounding areas in contact with the hot plate. In other words, the radiant energy of the heat is unable to color the linen even at a distance of 3-4 millimeters of the source.
This is very important. Why ?
Because it is absolutely impossible (in the context of the Shroud) to have a perfect contact everywhere, particularly in the face area. If one uses a statue or even a bas-relief, there will be necessarily some (even small) non contact areas, i.e. some non colored areas. A life-size bas relief has nothing to do with small coins.
I’ll try to provide soon my photographs and if possible the results of microscopy observations.
Well, you may find it amazing, Thibault, but I have been saying the same thing for months now, and quietly grinding my teeth when I continue to come across statements like “the intensity of the body image is inversely proportional to the body-cloth distance”, imputing some quantitative measurements have been recorded that somehow never get displayed.
No, there is NOT an inverse relationship, if it implies that a doubling of the air gap gives a halving of image intensity (or quarter if conforming to Newton’s inverse square relationship). That might (conveniently) fit a radiation model, but the most casual inspection of the Shroud image suggests there to be what could better be described as an “all-or-nothing” relationship, as Thibault has now discovered for himself.
Note the tenting effect (essentially no imaging immediately below the upper of the two hands where cloth loses contact with the lower hand)
Yes, cloth has to make direct and intimate contact for there to be imaging. The slightest air gap means essentially no imaging, because infrared radiation is largely reflected/scattered off white linen in the same way as visible light.
Where Thibault and I are likely to differ is in my interpretation of the all-or-nothing effect. It implies that the Shroud image was formed by direct and intimate contact between an INANIMATE object and linen. It has to be inanimate, because the first has to withstand being heated to a temperature that, when pressed against or into linen, leaves a scorch mark – one that is a “negative” of the contours of the inanimate object. My recent experiments suggest an initial temperature in the region of 250 degrees C is needed, more or less, depending on how much cooling time elapses between removal of the object from the oven and receipt of the scorch onto linen.
As for the “object”, I believe it to have been a replica of a real person, dead or alive, produced with standard Plaster of Paris technology. In other words, one first coats the subject, brave volunteer or more likely a recently deceased corpse, in wet plaster. One then lets it set hard to produce a shell, rather like a jelly mould, and then uses the latter to get a faithful bas-relief replica (using a second batch of Plaster of Paris). That would account for why the face of the Man in the Shroud looks so mask-like, with that roughly rectangular shape and the sharp cut off at the edges of both cheeks. (But the cut-off is not so sharp as to have been due to that “banding” in the linen that we hear so much about – too much in my view. Note the wavy boundary at the prominent cheek bone etc).
Mask-like face of the Man in the Shroud – as if produced by thermal imprinting from some kind of plaster cast or other heat-resistant replica.
And now for something completely different: beware playing tennis at Grand Slam level. It too can bring on a “mask-like” grimace:
Andy Murray – through to the final, Flushing Meadow NY Sept 8, 2012
PS to Thibault: I’ll discuss with you another time that “take-away message” re the “absolutely impossibility” of having perfect contact everywhere. For now, let me just say that your point is partly answered by the evidence that there is indeed imperfect contact, due to the tenting effect identified above and elsewhere in the Shroud image. On that there is no disagreement.
You also appear to be imagining that linen was placed on top of the figure, relying on gravity alone for contact. I dispensed with that model a long time ago, proposing that the heated template was pressed DOWN into linen with an underlay of something yielding (sand? snow? moist wool of fabric?) to get improved contact.
Note added Jan 2013: I have since qualified the above conclusion, pointing out that pressing a heated template into linen produces a range of hot gases and vapours that can produce secondary scorching at a distance. Heat transfer can occur by radiation, conduction and via CONVECTION. It is the last of those three one tends to overlook when debating the merits and.or demerits of radiation versus conduction. Convection and scorching by hot gases (superheated steam etc) might go some way to explaining the “fuzziness”, i.e soft focus character of the Shroud image. Scorching is not a blunt instrument – in the right hands, with the right template – it can produce subtle images with a wide spectrum of contrast.