Look at p. 14 in our paper from St. Louis. We have a simple explanation.
That would be Electric Charge Separation as the Mechanism for Image Formation on the Shroud of Turin: A Natural Mechanism by D.S. Spicer and E .T. Toton (Revised 23 May 2015) as found at shroud.com.
Before turning to page 14, it might help to look at an extract of the abstract that amplifies the meaning of the title and nicely explains the mechanism:
We advance the hypothesis that a constant, or slowly varying electric field was present in the tomb and that the two stated facts provide the underlying mechanism for formation of an image with vertical displacement information: the revealed surface charges on the Shroud serve as collection sites for polar gas molecules or ions emanating from the body or from the aloe and myrrh that had been applied before entombment, substances that could serve as oxidizers or other active species for inducing visual surface alterations, and the extension of the electric field in the vicinity of the surface of the body out to distances away from the body would provide mapping of surface features of the body onto the non-conforming (tented) portions of the Shroud.
… and the conclusion from the paper, here quoted from a posting last December in this blog, A Gedankened Image Forming Process:
As should be clear, our hypothesis depends on a completely natural mechanism. It does not conflate the image formation mechanism with the Resurrection, nor should it. The image is not the recording of the Resurrection but it is an image capture of the body of a crucified man consistent with the historical records of the crucifixion of Jesus Christ. That no hitherto satisfying mechanism for image formation has been discovered is not proof that a supernatural explanation must be the only other choice, nor does the discovery of a credible mechanism of image formation impugn the belief in the reality of the Resurrection. If it were possible to take a photo of the Ascension-where is the miracle? Is it the Ascension or the photo of it? We believe that the Shroud Image is indeed the image of Jesus Christ’s lifeless body only and it strengthens the historical argument for His existence, death, and His Resurrection.
And now the simple explanation on page 14:
Observers of the ventral side of the Shroud often comment on the detail in the hands and how long the fingers appear to be. Our mechanism for image formation explains this in a very natural way. First of all, there had to be considerable trauma to the hands and arms as a result of the crucifixion. They were elevated considerably above the rest of the body throughout the crucifixion and the arms must have been severely traumatized by having to manage the full body weight. Circulation had to be compromised and it would certainly be the case that the hands and forearms would have been considerably dehydrated due to profuse sweating, which would lead to a desiccated state for both the hand and forearm tissues, which, as a result, would reveal the underlying bones. In addition, this would have been much more pronounced than anywhere else on the body, with the possible exception of the mouth and lips. As a result of the desiccation state of both the hand and forearm tissues, the bones making up the hands and forearms would form prominences so that the surface charge density would naturally be greater on these body features, leading to sharper and high contrast images.
Dan Spicer offers an alternative, one that to me seems more realistic than a cloth falling through a body as a function or accident of resurrection. Moreover, Colin Berry’s explanation in support of contact imprinting must also be considered. And we must consider O.K.’s argument that the appearance of metacarpals in the image is possibly perfectly natural. As O.K. writes in a comment:
The maximum range for imaging is in my opinion (based on analysis of distances of my facial features), as well as Vignon’s no more than 1-2 cm (Jackson & Jumper 3.7 cm is clearly untenable). Based on 3D plot we see that the metacarpal gaps have a greyscale intensity of ~ 90-100 (they are white), while metacarpals, and fingers are about 150-160 (green-yellow). This would indicate level difference of maybe ~5 mm. Quite possible, especially for dehydrated hands. No X-ray is needed here.
The authors of Critical Summary carefully use the word judgment. That’s appropriate. But we must realize that this is the judgment of a small team in Colorado, albeit a distinguished scientific team that understands the shroud. It is not the judgment of the wider community that studies, ponders and debates how the images on shroud were formed. I think that much, if not most, of the larger community disagrees with or is ambivalent towards the falling cloth hypothesis. The page 73 chart does little or nothing to change anything in this regard.
Anyway, that’s my opinion. What’s yours?
The paper is A Critical Summary of Observations, Data and Hypotheses by Bob Siefker, Keith Propp, Dave Fornof, Ares Koumis, Rebecca Jackson and John Jackson. It can be downloaded to your computer or any cloud space you use. You can extract a working copy of page 73 by changing your destination printer to PDF file and printing only one page of what is effectively page 75. In Windows 10, you can copy the page into a Notebook tab.