After I partially quoted a comment by Hugh Farey in the previous posting, he commented thus: “The rest of my comment is a gripping read too….”
Gripping? Well . . . Thanks for the laugh. But the comment, in its entirety, is completely worth reading if you missed it the first time around.
And so we ask again, what is right or wrong with Item 2.0 from page 9 of The Shroud: A Critical Summary of Observations, Data and Hypotheses, by Robert W. Siefker and Daniel S. Spicer?
Here is the gripping answer:
Article I.2.0.A. The normal tones are reversed. The normal tones of what? Of body parts? I’m not light on the nose and dark in the cheeks.
Article I.2.0.B.The parts of the body closest to the cloth left the darkest marks. Sorry, but from a critical viewpoint you can’t just assume that a body was present to make the marks.
Parts of the body which would have been closest to the cloth if the image was made by a cloth lying over a body? Sorry, can’t allow that either, as the cloth could have been horizontal or draped or wrapped.Parts of the body lying closest to a theoretical horizontal plane level with the tip of the nose? Sorry, but you need also to specify if the body was also horizontal. Were the knees, for example, higher off the floor than the nose or not?
Parts of the body which would have been closest to a horizontal plane level with the tips of the knees assuming that the body was lying in a slightly knees-up position with the head also slightly raised? Er, no, as the head and particularly the nose is generally assumed to be the darkest area, and the knees would be much more prominent than the hands, for example.
Parts of the body which would have been closest to the cloth if the cloth had been draped over the body? Back of the head? Sides of the hair? Sorry.Parts of the body which would have been closest to the cloth if the image was made by a cloth lying over a body which draped naturally from head to toe but not at all from side to side? Rather like unrolling a carpet or Venetian blind over the body? I think we may be getting there…
Article I.2.0.C. The image has the characteristics of a photographic negative. Of a monochrome photograph of a person taken full face with a light source directly in front and a black background. Although we are often told that real photographs of people under just those conditions do not look like the shroud, as the 3D image derived from them is unconvincing. If this is true, the shroud does not have all the characteristics of a photographic negative. I concede that it does have some; rather general and rather subjective.
Article I.2.0.D. The contrasting photographs. The negative is clearly not the negative of the positive, but a different photo altogether. It is also printed at a different size. A “true” negative would have the famous “epsilon” blood stain pointing a different way.
For a scientific paper claiming to be :A Critical Summary …”, I’d have to agree with Hugh that Sieker and Spicer have been fairly careless and uncritical in their write-up, but maybe Hugh is just being a little too scientifically pedantic, even precious, in his criticism. It would seem that the two scientists have endeavoured to generalize conclusions resulting from the work of John Jackson and Eric Jumper which began around 1968. Ian Wilson first mentions this work in his 1978 book at Chapter XXII. Doubtless there are now more detailed and better write-ups available on this work, probably on the Shroud.com site.
Jackson and Jumper recruited another Air-Force colleague who seemed to match the TSM’s physique and draped a cloth over the subject. They measured the body-cloth distance and correlated their results with readings from a densitometer on a Shroud negative, obtaining a perfect match. Their further investigations with the VP-8 image analyzer followed, leading to the various 3-D images so familiar to us now.
How objective generalized scientific conclusions resulting from.that work may be written up is a matter of skill in accurate report writing. I’ll confine my conclusions merely to saying that the Shroud clearly contains 3-D encoding of the subject, a property first noticed by Paul Vignon following the development of Secondo Pia’s photographic negatives. The work of Jackson & Jumper quantified this property. This 3-D property cannot be denied!
Precious… good word… however, I wonder if you could be a little more specific here. I have seen photos of the cloth, carefully marked out with various coordinates, draped over the body, and seen how well the bloodstains fit and so on. But remind me, having draped a cloth over a body, how was the cloth-body distance measured? And in how many places? In the photos, the cloth is draped quite neatly around the back of the head, the sides of the shoulders and the legs, and yet, although the cloth-body distance is these places is clearly zero, no equivalent dark image image appears on the shroud.
Hugh can easily do what I just did, Go to the Shroud.com site and search on “Jackson and Jumper” – there’s 10 articles listed on each of 7 pages which he can access. URL came up as:
http://www.sitelevel.com/query?crid=5b7907994c2a69a2&query=Jumper+and+Jackson&B1=Search
Sorry, I’m not doing your leg work – it’s your party, But the two papers on page 1: BSTS Newsletter No. 9 – Part 6 and BSTS Newsletter No. 13 – Part 5 are probably both worth checking out. Or you can just go the Shroud.com site and search on anything else you want!
Tsk, tsk, you know me better than that. I have the 26 page “Correlation of image intensity on the Turin Shroud with the 3-D structure of a human body shape” before me, specifically the graph labelled Figure 2. For those not familiar with Jumper and Jackson’s remarkably inventive technique, this is what they did. They photographed the head of a man lying on the ground from the side, with and without a cloth draped over it. By superimposing the two photographs, the vertical distance between the two outlines could be measured. As it is difficult to identify most of the body parts with sufficient specificity, data from 13 places on the real head was compared with intensity data from 13 equivalent places on the shroud. Figure 2 shows the relationship. Being good scientists, they find that although the null hypothesis (that there is no correlation between image intensity and cloth-body distance) can be rejected, very little can be confidently asserted about what the relationship is. (The perfect match” quoted by daveb has, like so many derivations from original papers, become part of shroud dogma, but is in fact wholly fictitious.) They might have refined their calculations by omitting three, closely-spaced results which appear to me to be outliers, but, being good scientists, they didn’t.
These 13 cloth-body measurements, of 13 points on the head, provide the whole rationale for every subsequent attempt to read three-dimensional information from the shroud. And it works astonishingly well. Jumper and Jackson’s further investigations take the correlation as read, and devote the rest of their time to deforming the whole body image derived from it (which they find very unconvincing as is) until it matches the observed profile of a prone volunteer, thus establishing a theoretical cloth shape which looks entirely convincing. Other investigations using the same idea demonstrate that the cloth is more flexible along the warp than the weft, rather like, as I mentioned in an earlier comment, unrolling a carpet or a Venetian blind over a body.
The most important point about all this is that the cloth-body measurements that work so well were all made vertically (indeed, how could they not be, from a face?), not perpendicularly to either body or cloth, which fact has interesting ramifications for ideas about gas diffusion and minimum distance, among others.
Thanks for the detailed explanation Hugh. However, Wilson does write that they draped the cloth over the whole body, (not just the head) and provides diagrams of the arrangement, with a graph showing full body length medial section relative opacity. I should think it has some factual basis in what J & J actually carried out.
Comments in your last para above are intriguing. In Dan’s subsequent posting on this topic, Gabriel hints that there must be implications about the image-forming process. One might hypothesize for instance that if it has a chemical basis, then perhaps the gas(?) molecules emitted by the body are inherently unstable, and in the finite time that they take to arrive at the cloth are partly converted to a stable form, resulting in different concentrations at the cloth, giving the correlation between luminance (conversely opacity) and cloth-body distance. However I suppose other hypotheses could of course also be suggested. But from the correlation,it seems remarkable that random variations don’t seem to be as significant as one might reasonably expect in such a process.