Previous studies have shown that both images appear like rectilinear orthogonal projections of an unknown nature coming from the body and oriented in two opposite directions onto both halves of the Shroud such as would have been possible if the source of the image had had only two dimensions and been suspended between the flattened planes of both halves of the Shroud. Such a situation, which is scientifically untenable but helps us better understand the geometrical proportionality of the images, has been labeled the vertical alignment of the image and strongly speaks in favor of a radiational acting-at-distance transfer mechanism.xxi
On the other hand, the high resolution of the images [at least as good as 0.5 cm (Refs. 11, 16) or even approaching 0.1 to 0.2 cm (Ref. 22)] suggests rather a contact mechanism of transfer. But in that case the way the Shroud must have been laid on the body seems to require the formation of lateral images on both sides and of an uninterrupted transition between the image of the face and that of the back of the head with all the distorsions they involve.
The so-called tridimensionality implies a reverse correlation between the intensity of the shading and the estimated distance from the body, which indicates that only the darkest parts of the image could have been in direct contact with the body whereas other parts were acted upon at a distance.
Finally, note that the image itself was produced by some agent that left on the Shroud a superficial brownish degradation of the cellulose by oxidation, dehydration, and conjugation of the polysaccharide structure of the topmost microfibrils of the linen, changes that can be obtained by sulfuric acid or heat but usually at the expense of superficiality.12
Such are the main elements of the problem that led STURP to the conclusion that the image is “an ongoing mystery”.
3. Misleading Presuppositions
The contradictions just described — between vertical alignment and wrapping, full contact, partial contact and action-at-distance, the uniformity of both images, the gravitational asymmetry of the frontal and dorsal sides of the body, etc. — are the logical result of a number of tacit presuppositions none of which has been questionned so far.
Three are particularly important.
Presupposition 1. The images were produced by some chemical or radiant agent originating inside the body.
Presupposition 2. The images were formed while the body lay in the tomb.
Presupposition 3. Both images, the frontal and the dorsal, were produced simultaneously.
None of these presuppositions is substantiated by anything except the involuntary association of these images with the subsequent resurrection of Jesus, as described in the Gospels. In our opinion, resurrection is not a matter for scientific investigation, and the only assumption we are entitled to as scientists is that the images could be either a natural accidental byproduct of the burial procedure itself, not of the mysterious disappearance of the body, or a forgery (but, as stated, the hypotheses based on the latter assumption must cope with new problems and reject an important part of the available evidence).
Once we eliminate Presupposition 1, we no longer need to look for sources of energy, radiation, evaporation or whatnot inside the corpse of a dead man or try to understand how their pluridirectional diffusion or emission could have produced on a complex surface an image the optic quality of which requires either a focalizing lens or at least a beam of strictly parallel rays and a flat surface.
Once we eliminate Presupposition 2, we immediately identify the nature of those parallel rays. On a spring afternoon in the Middle East the whole atmosphere vibrates under the burning rays of the Sun. They could not have sprung out of the body, but they could very well have been reflected by it.
Eliminating Presupposition 3, we have solved once and for all the problem of alleged gravitational asymmetry between the frontal and the dorsal images. The rays of the Sun could not have reached the body on both sides at once, but nothing prevented the body from being turned over alternatively from front to back. And if so, there would have been no asymmetry.
Certainly this does not solve the main problem, and it even creates new ones, e.g., why both sides of the body were exposed to the Sun, but it clears up many sources of confusion.
Hence we have the following hypothesis. Both images were created by solar rays when and because the Shroud containing the body was exposed to the Sun, first face up, then face down (or the other way around). The rays were transmitted through the linen, reflected by the body and projected onto the inner side of the Shroud.
Could this lead to the formation and transfer of an image of the body onto the cloth such as what we have? This is the optical aspect of the problem. And if yes, how was this image imprinted on the linen? This is the photochemical aspect of the problem. Finally, what combination of circumstances could have created the unusual photochemical and optic conditions required to produce and record the image? This is the historical or, rather, philological (exegetical) aspect of the problem.
We answer the first question exhaustively in Section 4 (although without discussing in detail the concrete local effects on the accuracy of the image), suggest with others the most likely answer to the second question in Section 5, and try to reconstruct in Section 6, on the basis of the Gospels, the most probable sequence of events, acts, and motives that accidently created the necessary and adequate conditions for the images to be produced and recorded on the linen.
Wasting time? Not at all. Your ideas may in the long run be right. Or they may get us – together even maybe – going down new unintended paths of exploration and thought.