[Above: Dr. John Jackson (left foreground) about to begin STURP's five-day examination of the Shroud, 8-13 October, 1978: Wilson, I. & Miller, V., "The Evidence of the Shroud," Guild Publishing: London, 1986, p.46a]
"Cloth Collapse theory" to explain the origin of the Shroud's image is, in my opinion, one of the most important things ever written about the Shroud of Turin. This is because it claims to, and I agree that it does, "explain all image characteristics found on the shroud image." Yet, it has never been published online and can only be found in a comparatively obscure, out-of-print book: Berard, A., ed., 1991, "History, Science, Theology and the Shroud," Symposium Proceedings, St. Louis Missouri, June 22-23, 1991, The Man in the Shroud Committee of Amarillo, Texas: Amarillo TX. However, you can see Dr. Jackson's presentation of his theory at the St. Louis Symposium in the video, "What is Missing? "
I am publishing Dr. Jackson's paper here on my The Shroud of Turin blog , with the kind permission of Dr Jackson and his wife Rebecca's Turin Shroud Center of Colorado. The book's page numbers are in square brackets. Dr. Jackson has requested that I mention: 1) The paper represents his theological thinking as of 1991. Since the conference in St. Louis, he has completed advanced Biblical and Catechetical studies; and 2) The copyright belongs to Dr. John P. Jackson.
By John P. Jackson
*© Copyright, 1991. All rights reserved by the author
With the permission of Turin Shroud Center of Colorado
DISCUSSION OF THE SHROUD IMAGE
In this paper, I would like to begin by discussing certain characteristics of the Shroud image that may shed light on its image formation mechanism. These characteristics are so distinctive that the genesis of the image likely involves a mechanism that is heretofore unknown to modern science.
A. Characteristics of Bloodmarks
First, let us begin with those characteristics that allow us to conclude, with reasonable certainty, that the Shroud covered a real human when the body and blood images were formed. To demonstrate that the Shroud enveloped a crucified body, Lavoiel has brilliantly interpreted a certain blood feature, labeled A in Figure la, which cannot reasonably be attributed to artistic handiwork. He associates this with blood flowing down and under the forearm at the elbow where it pooled and dripped off the body. The arm must have been approximately in a crucifixion-like position in order for gravity to migrate the blood along such a path. Of course, this presents no problem since the Man of the Shroud appears to be a crucifixion victim. The elbow blood feature is then explained by asserting that the Shroud wrapped around the arm and received a clot imprint by direct contact.
Another indication that the Shroud enfolded a human body was described to me by Bulst.2 He pointed out a connection between the blood trickle off the dorsal foot, labeled G1 in Figure la, and a blood mark of similar size and shape next to the foot region of the frontal image, labeled G-2. In our experiments where a volunteer subject was enfolded in a full-scale model of the Shroud with an image drawn upon it, we found, as Bulst indicated, that Features G-1 and G-2 align directly over one another. This cannot be a coincidence nor the result of a supersophisticated artist who anticipated such a detail. This congruence strongly suggests that the Shroud was folded lengthwise over the head of a body and that the feet  were wrapped so as to bring the dorsal bloodstain into contact with the frontal end of the cloth where blood residue was transferred.
There are, in addition, other aspects of the Shroud which indicate that the cloth enveloped a real body. This is demonstrated by the numerous bloodstains, labeled B-F in Figure la, which correspond to distinctly  different flow directions, consistent with a vertical crucifixion first, followed by a horizontal burial of a real corpse. Several examples that illustrate flows in the vertical position are the wound in the side (Feature B), trickles along the forearms (Feature D), puncture wounds on the head (Feature E) and the wrist wound (Feature C). Conversely, the bloodstain across the small of the back (Feature F) and the trickle at the dorsal foot (Feature G-1) correspond to a body oriented in the horizontal position. The latter set of bloodstains depict liquid and, therefore, presumably late time post-mortem flows. In contrast, the vertical bloodstain set corresponds to clot transfers and, hence, earlier flows that had dried to some extent. Thus, the bloodstains are consistent with crucifixion followed by burial.
The wrist bloodstain (Feature C) is particularly interesting because it provides an independent confirmation that the flow-path was in the direction of gravity. Ultraviolet fluorescence photography of the wrist clot shows a clear halo emanating into the cloth. This can be explained as a gravitational separation of serum from blood. If the two streams of this blood feature are then positioned so as to be in the downward direction of gravity, the accompanying hand and forearm assume a crucifixion position.
We should not overlook the fact that it was only through ultraviolet fluorescence photography that the "scourge" marks were observed to contain many finely spaced lines or scratches, consistent with what would be expected from a flogging of real skin. In addition, on the dorsal foot imprint, the 1970 examination discovered an abundance of microscopic dust or dirt, atypical of the rest of the image. This, of course, was likely transferred to the Shroud from the feet of a barefoot man. These subliminal details cannot reasonably be ascribed to a hypothetical artist because (1) he himself could not see them and (2) there was no reason to put them there since no one else could see them either. Therefore, these particular details, including the blood features, are consistent with the concept that the Shroud enfolded a wounded and dirty corpse, as opposed to a statue, who had been scourged and crucified.
The above interpretations of the bloodstains assume, of course, that they are indeed blood as opposed to a reddish iron oxide pigment, such as has been proposed by McCrone. In this regard, we are fortunate to have the published work of Heller and Adler3 which conclusively refutes the McCrone interpretation and shows, by a large number of independent  microchemical tests on samples taken from the Shroud in 1978, that the bloodstains are in fact blood. We should note that their work was presented before the Canadian Forensic Society in 1981 and subsequently published in the journal of that society after appropriate peer review. Heller and Adler's work has also been referenced in other refereed scientific journals. Unfortunately, the McCrone studies never were subjected to peer review and appeared only in a periodical published by the McCrone Institute, of which McCrone is the founder and head.
B. Characteristics of the Body Image
As a final demonstration that the Shroud covered a human body, I would like to refer to my own studies of the body image. These studies show that the intensities of the frontal Shroud image can be calculated using a single mathematical relationship of intensity versus distance between two surfaces. These surfaces correspond geometrically to an anatomically reasonable body shape and a cloth draping naturally over that shape.
What is significant about the ability to characterize the Shroud image in this way is that; (1) two complex surfaces can be related to the complex intensity structure of the Shroud image by a single and simple mathematical equation and (2) that the two surfaces correspond to realistic body and enveloping cloth. Figure 2 shows how the image intensity on the Shroud can be converted to a three-dimensional plot of cloth-body distance by a single mathematical function. Although this three-dimensional plot should be strictly plotted from a draping cloth surface to produce the originating body surface, the sense of an anatomically reasonable human form is, nevertheless, apparent. This effect cannot be an accident nor the clever handiwork of an artist; it is further confirmation that the Shroud covered a body shape at the time of image formation. Thus, I believe we are on solid ground to conclude that the Shroud covered a body when the body and blood images were formed.
C. Physical Significance of Image Structure on the Shroud
Once it is recognized that the Shroud image was generated from a real human body, a particular set of questions may be asked which otherwise would not be posed if one were to assume that this image was produced in an artist's studio. Immediately, we recognize that the image must have been generated by some principle whereby body structure became encoded into varying shades of intensity on the cloth. The three  dimensional brightness surface of Figure 2 makes this point most graphically. If such a mechanism were not operative that could, in effect, convert cloth-body distance to corresponding shades of image intensity, then the computer generated brightness surface would not appear as a physiologically reasonable body shape.
Obviously, this has occurred to produce the Shroud image, but this conclusion brings forth certain problems. First, how could a physical mechanism act through the space between a body and cloth without blurring anatomical structures that are smaller than the projection distance, e. g., in the region of the lips? In a set of experiments I showed that images formed by direct contact exhibit high resolution, but lack gradation of intensity. On the other hand, images formed by diffusion or attenuated radiation from a body surface to an enveloping cloth contain shading gradations that correlate more or less with cloth-body distance, but suffer significantly in resolution. Yet, the Shroud image displays  simultaneously both a shading correlation with cloth-body distance and reasonably sharp focus.
A second problem concerns the directional relationship between points on the body to their corresponding image location on the Shroud. For example, a point on the side of the nose might conceivably be mapped perpendicular to the local body surface, or the local cloth surface where point is imaged, or vertically upwards from the nose point onto the Shroud. After careful study, I have concluded that body points are imaged essentially in the vertical upwards direction for the entire frontal image. This conclusion is further reinforced by noting that there are no side images about the frontal image and particularly in the space between the frontal and dorsal heads. If the image formation mechanism discolored the Shroud according to a principle that projected perpendicular to either the body or cloth surfaces, image shading should have occurred along the sides of the body and at the top of the head. On the other hand, a vertical mapping logically precludes shading in these regions where, in fact, no shading is observed.
We cannot, however, argue that the cloth was held away from the sides of the body as an attempt to explain the lack of side images, or that intervening material, such as burial spices, blocked image formation. Lavoie has shown that the blood feature off the elbow in Figure 1 could only have occurred by direct contact of the cloth with the side of the arm. Thus, the Shroud must have been in intimate contact with the body at that location and, yet, no image discolorations were formed there.
A similar argument follows from a consideration of the space between the frontal and dorsal heads. Geometrically, the Shroud must have been in intimate contact with the top of the head, as we have shown by enfolding a human body in a cloth model of the Shroud. Again, no image discolorations can be seen there. A hypothetical chin band may explain part of the void, but it is likely not to have covered the entire head and at the same time tuck neatly under the jaw.
A third problem arises in the comparison of the shading structures of the frontal and dorsal images. There are certain similarities between these images, for example, in color; however, there are noteworthy dissimilarities as well. The frontal image, appears as a blended, continuous shading structure that, as we have seen, contains a correlation with presumed cloth-body distance. The dorsal image, on the other hand, is discontinuous  in shading and has a mosaic-like appearance; see Figure l b. We see, in particular, that the shoulder region is bounded by a sharp, discontinuous change in intensity. However, running through this boundary, is a pattern of scourge marks. Since these marks contain dried blood material, they could only have been placed onto the cloth by direct contact. Accordingly, if the body image was correlated with cloth-body distance over the same several centimeter range deduced for the frontal image, the sharp discontinuity would not have occurred. Rather, we would have observed, at most, a blended intensity variation from the base of the shoulders to a several percent lower intensity in the small of the back. Instead, we see a complete and abrupt dropout of intensity at the base of the shoulders into the lower back region. Thus, the dorsal image has an intensity structure more like a direct contact image than one that is correlated with cloth-body distances over centimeter range as for the frontal image.
Still another significant characteristic of the Shroud image is the observation that the image discolorations penetrate only a few fibrils deep into the thickness of the threads comprising the Shroud cloth. Microscopic direct observations show that there exist yellow fibrils next to white fibrils. Thus, it appears as though the gross or microscopic shading structure that we see as the body image on the Shroud is determined by the ratio of yellow to white fibrils in a given area. In addition, the fibrils that possess the yellow color are, in fact, individually colored and there is no evidence of cementation or gluing between adjacent yellow fibrils such as would be expected if a paint pigment were applied to make the image. Direct chemical tests of the yellow fibrils have shown that the cause of the color is due to a dehydration phenomenon, as it is called, similar to the way linen is discolored, when scorched, say, by a hot iron. That is not to say that the body image was, in fact, set onto the cloth by heat, but only that the chemistry of the fibrils comprising the Shroud image appears to be similar to that caused by scorching. In fact, the scorching process, typically causes discoloration all the way through the thickness of the cloth such as was the case for the 1532 fire. In contrast, the depth of penetration of the Shroud image into the bulk of the cloth is completely superficial. Such an effect must be explained by any successful theory of image formation.
From the above discussion and the array of various facts about the Shroud, several conclusions seem warranted. First, the general arrangement of blood patterns on the Shroud and the intensity structure of the  body image are entirely consistent with the hypothesis that the Shroud image was formed from a cloth-covered human body shape. Because the blood stains tested positive for human blood and, because certain effects like serum separation are observed, we conclude that the body shape must have been that of a real human body that had been wounded and subsequently wrapped in the cloth at the time of image formation. As such, it is apparent that the image on the Shroud is not and cannot be the handiwork of an artist or craftsman.
The question becomes: what process was involved in creating the image of a human body onto the Shroud? This question is not straightforward, because most types of physical mechanisms can be excluded on the basis of certain characteristics we find on the Shroud image. For example, the idea that the frontal image on the Shroud was the result of a direct contact mechanism, i. e., where image discolorations were imprinted onto the cloth only where it touched the body is refuted by the gradations of image intensity that correlate with expected cloth-body distances. In other words, it seems as though the image formation mechanism acted through space, between the body and the cloth, such as for diffusion or radiation. However, these mechanisms must be excluded, because, although they can discolor the cloth at a distance, they cannot form a high resolution; sharp image, such as what we find on the Shroud. Thus, it appears as though the explanation of the Shroud image must be quite different from those that are based on direct contact, radiation, or diffusion.
There is, however, one particular observation that definitively places the Shroud image in a unique category. Consider Figure 3 which shows a view of the hands. If we examine this image region carefully, we can see, as recently pointed out by Carter,4 that the finger bones are visible well into the palm of the hands, extending right up to the base of the wrist. These cannot be interpreted as tendons, because tendons and ligaments are much too narrow. Rather, we see that the thickness of the fingers are individually preserved well into the palm of the hand. It thus seems as though we are looking at the internal skeletal structure of the hand imaged through the intervening flesh tissues onto the Shroud cloth.
In addition, at the base of the top hand, we see a diffuse discoloration with a color the same as the body image. In transmitted light, this feature is transparent like the rest of the body image, implying that it, too, must reside only on the surface fibrils of the cloth. Its intensity falls within the range of intensities found in the Shroud body image. Thus, it appears  that this discoloration, whatever it is, must be part of the body image.
But, if so, what does this feature represent? An important clue is evident from the fact that are no thumbs visible in the hand image. Now, given the apparent fact that internal finger bones of the hand are imaged onto the Shroud, it is a small step to propose that this particular discoloration is, in fact, the thumb folded into the palm of the hand and likewise imaged through the hand onto the Shroud, in a manner similar to the finger bones found in the palm. If this interpretation is correct, then it follows that whatever mechanism produced the image of the body onto the cloth, it must be a radically different mechanism, than any physical mechanisms that have been considered to date. For what process is  capable of rendering internal body structure into the image patterns that we see on the Shroud?
A HYPOTHESIS OF IMAGE FORMATION5
Keeping in mind these varied and surprising characteristics found in the Shroud image, let us now turn our attention to the problem of how the image was produced. To be sure, finding a satisfactory mechanism for the origin of the Shroud image has shown itself to be a complex and difficult problem. Perhaps the reason why a satisfactory hypothesis has not been found is not so much due to a lack of image characterization but to an overcharacterization. That is, we seem to have a situation where the set of observables is so restrictive that all hypotheses posed thus far must be excluded, or at least be considered highly questionable, often on the basis of multiple objections.
Therefore, perhaps the time has come to ask if we ought to start thinking about the Shroud image in categories quite different from those that have been considered in the past. In particular, perhaps we need to be more flexible in our scientific approach and consider hypotheses that might not be found readily in conventional modern science; for it is conceivable that the Shroud image represents, if you will, some type of "new physics" that ultimately requires an extension or even revision of current concepts.
Some time ago, I decided to pursue such an approach to see where it might lead, having first spent many years trying to understand the Shroud image strictly in terms of conventional science. But given the apparent failure, or difficulty, of conventional transfer mechanisms to explain all characteristics of the image, I wondered if I could conceive of a principle by which the image might have been formed, even if such a principle contradicted current concepts of science. The result was a simple theory that I think accounts for the entire set of diverse image characteristics described above and, further, makes certain new predictions which could be tested during a future examination of the Shroud. As will be seen, this theory clearly contains certain aspects which do not fall within categories of modern science, but nevertheless is scientifically well-posed and internally consistent. Finally, because we are dealing here strictly with image formation; the conclusions contained herein are independent of the recent radiocarbon date and it is to be further noted that there is no attempt here to presuppose anything concerning the identity of the "Man of the Shroud." The hypothesis will be developed and argued strictly  from considerations of image properties and no support will be derived from extraneous speculations.
Let us now develop the hypothesis. It is useful to begin with three basic inferences concerning the image formation process which I think can be deduced from observations made directly from the Shroud image. These inferences, when considered collectively, lead naturally, if not compellingly, to the hypothesis proposed in this paper. This hypothesis can then be tested against all image properties as per the Scientific Method.
A. Inferences concerning image mechanism deduced from observational data
INFERENCE 1. The body and blood images were formed directly from a human body that was enveloped in the Shroud. As discussed above, this assumption certainly is implied by the fact that image intensity can be described consistently between two complex surfaces, one corresponding to an anatomically reasonable body shape and the other to a cloth draping over that shape, by a simple and global mathematical relationship. This is compelling evidence that a cloth-covered body was directly responsible for the image. This conclusion is further strengthened by various characteristics associated with the blood patterns, as pointed out above. In general, forensic opinion regards the blood patterns as representing authentic flows from a human corpse, owing to their flow characteristics and general appearance on the Shroud. Even at the microscopic level, there is no evidence of pigment that can be associated at any statistical significance with the macroscopic body image. Further, it has been shown that the alleged bloodstains are composed of blood or blood derived substances. It is difficult to see how these various image subtleties and characteristics could be the work of human craftsmanship. Hence, it is reasonable to conclude that the image on the Shroud was generated directly from a cloth-covered body by some process.
INFERENCE 2. Gravity was a significant factor in the production of the image. We noted above that if the Shroud drapes over a body lying in a horizontal or supine position, image features align more or less vertically above the corresponding body part. That this should occur is not immediately obvious because it is conceivable that image features could have been mapped, for example, perpendicular to either the body or cloth surfaces rather than strictly vertical. The significance of this result is that whatever mechanism was involved in producing the Shroud image, it must have had the property of transferring body surface information in the vertical-only direction. But how could such a thing have happened? It would appear that, somehow, the image formation process must "know" the vertical direction at each point on the body. It is reasonable to suspect that gravity, because it naturally manifests a vertical symmetry, was responsible for the observed near-vertical alignment of the image with respect to associated body features. Without further information, it is not clear how gravity could have achieved this, but I am proposing its involvement in the image formation process because: (1) it possesses the required symmetry to account for the vertical alignment observed in the Shroud image, and (2) gravity is a natural physical phenomenon that unarguably must have been present during the time of image formation.
INFERENCE 3. The Shroud was in two different draping configurations when the body images were formed. Consider the bloodstains that appear in the hair along either side of the face as seen in Figure la. If we ignore the body image for a moment and ask where these bloodstains came from, we would find, by a simple draping experiment of a cloth over a face, as first noted by Lavoie6 that these bloodstains must have originated from the sides of the face. However, the sides of the face are visible in the body image and appear several centimeters inside the pattern denoted by the bloodstains. That is, the bloodstains and the locations where, according to the body image, they must have come from by direct contact do not coincide spatially on the Shroud. Therefore, if the body image and bloodstains were produced from the same body shape, it follows that the Shroud must have been in two distinct draping configurations when the body image and bloodstains were generated. The initial draping configuration must have been the one by which the bloodstains were transferred (because an independent observation pertaining to halos around the blood indicates that blood preceded the body image discolorations onto the Shroud). As can be seen in Lavoie's experimental photographs and discussion, this draping configuration corresponds to the way in which a cloth would drape naturally over a human face. Subsequently, when the body image was generated, the Shroud apparently deformed, for some reason, to a somewhat flatter draping configuration, the result of which laterally positioned the images of the sides of the face several centimeters inside the bloodstain pattern. These bloodstains now happen to be coincident with the hair images due to the geometrically induced shift of the bloodstains relative to the body image (note that the hair has nothing to do with the argument other than being a convenient way to describe the position of the bloodstains in question). 
B. Paradox posed by Inferences
The foregoing three statements concerning the Shroud image are logical inferences from certain empirical observations of image structure and layout. To my mind, their significance is not what they represent individually, but rather what they imply collectively. For I think that a specific picture of the image formation process is indicated. The problem, as I see it, is now to construct an image formation hypothesis that unites these three inferences and then test that hypothesis against all specific observations pertaining to the Shroud image.
How to achieve such a unification, however, is not immediately obvious, because, at first thought, Inferences 1-3 seem mutually contradictory. For example, according to the third inference, we apparently must require that the Shroud was flattened or straightened subsequent to the time when the bloodstains were formed. This flattening must have been significant in order to account for the several centimeter misregister between the locations of the bloodstains appearing in the hair image and those of the sides of the face where the bloodstains must have originated. Now, the second inference proposes that gravity was involved in the image formation process. Since obviously something must have caused the flattening or straightening of the Shroud, and gravity must apparently be incorporated into the image formation mechanism, it is logical to propose that the flattening was due to gravity. However, when considering the first inference that the formation of the body image involved an underlying, real human body, we encounter a logical difficulty in that the body structure would prevent the cloth from flattening under its own weight.
C. Proposed solution of Paradox and formulation of Hypothesis
Thus, it would appear as though the three inferences contain ideas that are not easy to reconcile. Yet, I think each one of them taken separately is a reasonable interpretation of certain documented characteristics of the Shroud image. If that is granted, the problem still remains as to what hypothesis of image formation is consistent simultaneously with all three inferences. It might be tempting to discard the concept of a cloth being flattened by gravity because of the apparent contradiction that the body prevents the collapse. Nevertheless, it seems to me that the collapse idea is a reasonable and natural synthesis of the two very different ideas contained in Inferences 2 and 3. If we retain the proposition of a  collapsing cloth, then it seems to me that we are left with only one alternative in order to unify all three inferences. We must assume that, according to Inference 1, the Shroud initially covered a body shape, but, for some reason, that body did not impede the collapse of the Shroud during the time of image formation.
Now, such a conclusion can be interpreted in two very different ways. On one hand, it might mean that the observational data or logic taken to arrive at this point are defective, for a violation of common sense appears to be required to reconcile the three inferences. On the other hand, it might mean that "common sense" or, more properly, currently accepted laws of physics, may be inadequate to explain the image on the Shroud.
In the remainder of this paper, I would like to develop the thesis that the second interpretation is correct; specifically, that in the case of the Shroud image, the cloth did collapse into and through the underlying body structure. As a physicist, I admit to having my own difficulties with this concept, but I also know that scientists must be ready to overturn even their most hallowed principles if observation warrants. The real test of any hypothesis is not so much the logic by which it was deduced, but its ability to explain observations, make predictions, and provide insight into how reality is constructed. And, let us keep in mind that, to date, no "conventional" hypothesis has been advanced, which successfully explains the Shroud image. To this end, I would like to ask the reader to put aside, for the moment, any reservations he or she might have concerning the "unconventional" nature of this concept and consider it merely as a hypothesis to be evaluated critically using the well established principles of the Scientific Method.
The concept of a cloth falling into the underlying body region and receiving an image, in essence, requires that two separate assumptions be made. First, we must assume that the body became mechanically "transparent" to its physical surroundings and, second, that a stimulus was generated that recorded the passage of the cloth through the body region onto the cloth as an image. With regard to the latter assumption, it is unclear in an a priori sense what to assume for the physical nature of the stimulus. However, we at least know that it was able to interact physically with cloth; otherwise, image discolorations would not have been formed. I propose that, as the Shroud collapsed through the underlying body, radiation emitted from all points within that body discolored the cloth so as to produce the observed image. As will be seen below, this assumption  explains the superficiality of the Shroud image and, perhaps, the differentiation in fibril coloring.
D. Image Characteristics explained by Hypothesis
Let us now show how this concept explains each of the image characteristics of the Shroud discussed at the beginning of this paper.
1. High Resolution. As various points on the Shroud intersect different topographical features on the body surface during the collapse process, radiation dose on the cloth begins to accumulate. If the radiation is assumed to be strongly absorbed in air, radiation effects on the cloth cannot begin until virtual intersection with the body surface occurs. Thus, a one-to-one mapping between a given point on the body to a unique point on the cloth is achieved for all points on the Shroud, which is equivalent to stating that the resulting image is well resolved.
2. Superficial Penetration of Image. Once the cloth enters the body region, radiation emitted from within the body volume interacts with each cloth fibril throughout the bulk of the cloth from all directions. However, fibrils on both surfaces of the cloth receive a greater dose than those inside because they are unobstructed by overlying fibril layers. These fibrils would probably be highly absorbing to the radiation because the air, which is less dense by nearly three orders of magnitude than cellulose, is assumed to be highly absorbing to account for image resolution. (See also discussion in Item 5 below pertaining to absorption in cellulose.) The net result is an exaggerated dose accumulation of the surface fibrils over those inside the cloth.
3. Correlation of Image Intensity with Cloth-Body Distance. The initial draping configuration of the Shroud over a body establishes the initial cloth-body distances. If, then, the Shroud overlying the body falls into the body region, different points on the cloth will intersect the body surface at different times depending upon how far that point was originally away from the body. Thus, each cloth point will receive a radiation dose in proportion to the time that it is inside the emitting body region. Since that time is inversely proportional to the initial cloth-body distance, it follows that the radiation dose, and hence image intensity, is likewise inversely proportional to the initial cloth-body distance. However, since the cloth on the dorsal side of the body does not move into the body, image discolorations are generated only at point of contact; hence, the  dorsal image appears as a direct contact image.
4. Absence of Side Images. As the cloth collapses into the body region, internal stresses within the cloth cause it to bulge away from the sides of the body and at the top of the head. Because the radiation is strongly absorbed in air, very little dose is accumulated in the side and upper head regions of the cloth and, hence, no image is visible there.
5. Chemical Nature of the Image. Electromagnetic radiation that is absorbed strongly in air consists of photons in the ultraviolet or soft x-ray region. It happens that these photons are also sufficiently energetic to photochemically modify cellulose. Such photons are strongly absorbed in cellulose over fibril-like distances. Experiments performed by the author have shown that subsequent aging in an oven of photosensitized (bleached) cloth by shortwave ultraviolet radiation produces a yellow-browned pattern like the Shroud body image composed of chemically altered cellulose. Thus, I posit that radiation from the body initially photosensitized the body image onto the Shroud. This pattern would have appeared, if the radiation was ultraviolet, as a white (bleached) image on a less white cloth. With time, natural aging would have reversed the relative shading of the image to its presently observed state where it appears darker than the surrounding cloth (which also aged or darkened with time, but not as fast). This mechanism is consistent with (1) the observed lack of pyrolytic products in microchemical studies of Shroud fibrils expected from high-temperature cellulose degradation (in this case image coloring occurs by natural aging at ambient temperatures over a long period of time) and (2) the absence of substances in the image areas that chemically colored the cloth (Note that image coloration is produced onto the cloth only by radiation and without any extraneous chemicals).
6. Blood on the Shroud. As the Shroud is initially draped over a body covered with blood, that blood is transferred naturally to the Shroud by direct contact.
7. Vertical Alignment of Image and Associated Body Features. As the Shroud collapses into the body region, each cloth point falls vertically downwards. Thus, relative to the initial draping configuration of the Shroud over the body, image features tend to align vertically over their corresponding body part. The only exception to this rule would be where stresses in the cloth are sufficient to perturb the otherwise vertical motion. Such stresses  would probably be significant mostly near the sides of the body image due to the flattening of the cloth and bulging away from the body as explained above.
8. Equivalence of Maximum Intensities of Frontal and Dorsal Images. Image intensity is determined solely by contact time of the cloth with the body region. Thus, assuming the radiation event is operative on a time scale less than the time for the upper part of the Shroud to fall completely through the body region, as discussed above, it follows that the interaction timed for cloth points, whether initially in contact with the frontal or dorsal surfaces of the body, are equal. Hence, the doses, or image intensities, at those initial contact points should be equal.
Thus, the hypothesis of the Shroud collapsing into a radiating body explains all the above characteristics of the Shroud image, something that other image formation hypotheses posed thus far fail to do.
E. Testable Predictions of Hypothesis
In addition, there are several other predictions of the theory which should be noted:
1. Possible Imaging of the Internal Body Structures. If the assumed radiation is homogeneously generated throughout the body region, then image intensity would be determined strictly by the length of time that a given part of the cloth is inside the body region. However, if the radiant emission varied with type of internal structure, such as tissue versus bone, then internal body structures, might be convoluted into the general image picture. However, the fact that the surface details of the body appear to dominate the image indicates that the assumed volumetric emission of radiation would have to have been nearly homogeneous. In the context of the collapse theory, the hand region might be an example where an internal body structure dominated the image which normally recorded body surface topography. In particular, the "elongated fingers" discussed above might actually be images of the internal bones of the hand extending into the palm region, which, as the cloth passed through the hand region, recorded a greater dose than the surrounding tissue.
2. Surface Discolorations on Both Sides of the Shroud for the Frontal Image. As noted above, the superficial nature of the image is explained by the theory. However, the above reasoning leads to one other prediction  concerning the superficiality of the image; the frontal image should reside on both sides of the Shroud, whereas the dorsal image should reside on only one side. The reason is that when the upper part of the Shroud falls into the body region, radiation from the body impinges upon both sides of the cloth. However, in the case of the dorsal image, radiation impinges from only one side because the cloth there never moves into the body. Unfortunately, there are no suitable data available to test this prediction because the reverse side of the Shroud has been covered since 1534 with a backing cloth. But if such a prediction could be confirmed by a future examination of the reverse side, then the theory proposed herein would be given considerable support. It is likely, however, that if a frontal image discoloration exists on the reverse surface of the Shroud, it would be somewhat less intense than the discoloration which is observed on the normal viewing side because that side presumably entered the body first. However, one complication might exist; depending upon how the body was actually wrapped in the Shroud, it is possible that the sides of the cloth were folded back onto the top of the body, making a double layer with the top part of the cloth. It is unclear how such a folding configuration might affect the generation of a possible frontal image on the reverse side of the Shroud.
3. Photochemical Modification of the Shroud Blood. Given that the assumed radiation stimulus induced a chemical change in the cellulose of the Shroud, which we refer to generically as the "body image," it is reasonable to ask if analogous chemical changes might also have been induced in the blood which remained attached to the Shroud during the hypothesized collapse. This possibility could be addressed by further direct chemical testing. In this context, I would like to note that the off-elbow bloodstain discussed above in Figure la is brown, whereas the blood flow to which it is connected on the forearm is red, suggesting a possible chemical difference between on-and off-image bloodstains. It is also possible that the collapse hypothesis might explain Barbet's "mirror image" effect of the bloodstains.7
F. Final Remarks
Thus, the hypothesis of a collapsing cloth into a radiating body appears to explain all known characteristics of the Shroud image and makes certain testable predictions, some of which have yet to be verified. I have endeavored to show that this hypothesis arises strictly from considerations of specific image characteristics. The major problem with the hypothesis  is, of course, to explain why a human body would behave in such a manner. It is beyond the scope of this paper to address this question and it is unclear how physics would have to be modified in order to accommodate the thesis presented here. But, in spite of the unconventional nature of the hypothesis, I think there exist sufficient reasons to seriously consider it per standard practices of the Scientific Method. I would hope, however, that it would not be rejected merely on the subjective grounds that it is "unconventional." As pointed out in the text, more studies and data are required in order to test the theory further.
It might be that a simple piece of cloth, known as the Shroud of Turin, represents a valid case for rethinking certain concepts of modern science. To this end, I would encourage my colleagues in science to realize that the image on the Shroud of Turin is far from being defined by one radiocarbon test, but could be one of history's greatest scientific puzzles.
1. G. Lavoie et al, "Blood on the Shroud of Turin: Part I," Shroud Spectrum International, June, 1983.
2. W. Bulst, "The Imprints of the Feet on the Shroud of Turin. A Complex Problem," private communication, 1987.
3. J. H. Heller and A. D. Adler, "A Chemical Investigation of the Shroud of Turin," Can. Soc. Foren. Sci. J., Vol. 14, No. 3, 1981.
4. G. Carter, "Formation of the Image on the Shroud of Turin by x-Rays: A New Hypothesis," ACS in Chemistry, No. 205, Archaeological Chemistry. -III, Joseph B. Lambert, ed., 1984.
5. J. P. Jackson, "Is the Image on the Shroud Due to a Process Heretofore Unknown to Modern Science?", Shroud Spectrum International, March, 1990.
6. G. R. Lavoie et al, "Blood on the Shroud of Turin: Part III," Shroud Spectrum International, Sept., 1987.
7. P. Barbet, A Doctor at Calvary, Garden City, NY: Image Books, 1963.
(Jackson, J.P., "An Unconventional Hypothesis to Explain all Image Characteristics Found on the Shroud Image," in Berard, A., ed., 1991, "History, Science, Theology and the Shroud," Symposium Proceedings, St. Louis Missouri, June 22-23, 1991, The Man in the Shroud Committee of Amarillo, Texas: Amarillo TX, pp.325-344).