It is unhelpful and unconstructive to judge the TS as a choice between authentic or non-authentic. It’s like deciding whether a stuffed swan one is about to see in a natural history museum is black or white – it could be either.
The rational and constructive way of viewing it is to ask whether the TS is a contact or non-contact scorch.
If it’s a contact scorch, then it’s fairly certain the image is man-made, using a heated template to imprint the image (which will of course be a negative, explaining what might otherwise seem peculiar at least from an artistic standpoint, being much more photogenic centuries later when Secondo Pia-era photography and light/dark reversal became practicable).
If it’s a non-contact scorch, then all options are open, pro-authenticity ones included, radiocarbon dating notwithstanding.
But while there are groups who promote their own preferred non-contact scenarios (laser beams, corona discharges, sugar-seeking putrefaction vapours, earthquake-releases of radioactive emissions etc) few if any of them are willing to generalize and say it’s a non-contact process that is being proposed, and that the image characteristics are consistent with, and can be modelled in the laboratory as a non-contact process with a qualitatively-different outcome from the simple, uncomplicated man-made contact one I favour.
In short, we see systematic evasion of the scientific essentials, the latter based on model-testing and evaluation. Not a pretty sight.
Some folk’s thinking might be described as pre-Renaissance. Indeed, there may well be a hankering for pre-Renaissance certainties, when everyone, the unwashed, uneducated classes especially, knew their place and did not dare to question their social and intellectual superiors.
So, is Colin redefining the word scorch to mean anything that “resulted in oxidation, dehydration and conjugation of the polysaccharide structure of the microfibrils of the linen itself* (or perhaps of an impurity coating on the microfibrils)? Is that fair? Samuel Johnson did define the word as also meaning, “to be dried up.”
Are we to assume then, when Colin says all options are open for non-contact scorches, he means to allow, in addition to all-natural chemical processes, scorches produced from the imagined energetic or sub-atomic particle byproducts of miraculous events? Is that fair?
Does ‘all options are open’ extend to the appearance of a scorch that might have miraculously appeared on the cloth without any chemical process taking place? By without process I mean something that was not at some time partly formed or forming as we might imagine water changing into wine in steps. By without process I mean without heat or chemical reaction. By without process I mean without the passage of time, as if a changed visual state could have been photographed by an unimaginably fast camera in only two frames, visually not there and then visually there.
If we are thus open to miraculous images that seem to be non-contact scorches and might not have involved a formation process, must we not also be open to miraculous images that seem to be contact scorches and might not have involved a formation process?
Frankly, if we allow for miracles, we are beyond the limits of science. I don’t see any difference between contact and non-contact in this context.
It would be fair to argue that I threw miracles into the mix and that was never Colin’s intent. Fair enough. But that doesn’t solve anything, does it? Are not the investigators of UV, for instance, contemplating miraculous causation in some way or other? Is there a philosopher in the house? David Hume, where are you?
While I was writing this, Colin clarified his position of contact vs. non-contact. It is helpful, so here it is:
I use “contact scorch” to indicate there is no imaging except where template is in direct physical atom-to-atom contact with hot metal, ceramic, whatever. If there’s the slightest air gap, then there’s essentially no scorching, though a slight yellowing might just be possible from hot convected gases.
There are those who maintain that the TS image includes parts of the subject that could not have been in contact with linen. They have yet to convince this sceptic. All the important parts, i.e. raised relief, could or would be accessible, especially if linen were draped over template (whether bas relief or fully 3D) and then manually and forcibly impressed in and around important contours. The places most likely to get ‘missed’ are precisely those that appear as pale poorly or non-imaged areas on the TS (eye sockets, around the crossed hands, the gaps or even curvature between fingers etc.).
I use bas relief to imply something like the head on a coin with a little raised relief but much less in relative terms than the real live or dead subject, or a fully 3D representation of the latter (statue, bust etc). The wiki definition is OK seems OK for starters:
“Bas-relief is a type of sculpture that has less depth to the faces and figures than they actually have, when measured proportionately (to scale). This technique retains the natural contours of the figures, and allows the work to be viewed from many angles without distortion of the figures themselves.”
I believe the face (at least) of the TS image was imprinted from a bas relief (as incidentally did Prof Luigi Garlaschelli). The sharpish break in image continuity between cheek and hair on both sides is the give-away, suggesting there to have been a groove or trough in the template such that no imaging was possible in that gap. The idea that the break is just a banding effect in the linen, that the ‘missing’ image is retrievable with the right ‘enhancement’ with computer software etc, simply does not stand up to close critical scrutiny. That knob-twiddling-solves-all view is an example of what is known technically in boring old mainstream science as “pure tosh”.