First, I can't possibly do any better than Ian Wilson in refuting the notion that the Mandylion was "only a facial image." His work in that regard was stellar, though to my knowledge it has not been peer-reviewed.
By "later-rulers" of Edessa, I assume you mean those rulers who existed after the image was re-discovered. You certainly coudn't have been referring to Abgar's immediate successors, because according to the legend, the image was hidden a short time after his death. By the time of the re-discover, there was indeed a cloth image, and the "tile" was eventually sent to the city of Hierapolis as a gift.
The idea that the "blood" preceded the image is a product of the casual observation of a single fibril by one of the researchers in the case (I can't recall who, but the entire scenario is outlined by Heller in his book on the shroud). It was an offhand observation, that has become perpetuated over the years by people who should know better--the same people who are the first to crow over the "scientific" backing for the shroud as a relic, but who revert to theories based on faith and casual observation when the science doesn't support their beliefs.
If there were a hard prototype upon which the cloth image was based, that prototype was probably a form of sculpture in stone. Sculpture in stone does not "fly in the face" of any artistic tradition or style. I've heard this type of rationale used in answer to those who postulate a medieval origin for the cloth, and in that regard, I would find it a valid form of argumentation--but only as it regards a process, and not an artistic style.
As to the knowledge of crucifixion techniques and Jewish customs, they would have been instantly accessible to anyone working in the time period I postulate, i.e., the first or second centuries A.D. However, I have seen nothing in the corpus of shroud knowledge to suggest that the portions of the shroud upon which those ideas are based (techniques and customs) are anything other than what is recognized as "blood." I'm convinced, at least until someone can prove otherwise, that the "blood" was added after the fact by someone who needed the image to state more than it was stating. And the "blood flows" are very illogical and unconvincing--as much as they would be if you tried to paint them onto the surface of a two-dimensional photograph.
I believe it was Jackson who first came up with the idea of ionizing radiation having been responsible for the image on the cloth--a short burst of high-energy radiation, or something along those lines. He dismissed the idea (as do others) on the grounds that an event of that type would have destroyed the cloth. I think he's right. But what I'm suggesting isn't a short burst of high-energy radiation, but an extended exposure to low-energy radiation; the exact opposite of what Jackson postulated. Radiation is probably key to the solution of how the image was formed. It gives you exactly what you need to explain the properties of the image. In that regard, I'm certain that the scenario I'm presenting is wrong on many of its details--perhaps all of them. But until I see something infinitely better, I'll remain convinced that long-term ionizing radiation is the key we're looking for. In fact, I think I can state that it's not the scenario I'm hawking, but the principle behind it.
Finally, I'm not poking fun at the concept of peer-review. As Dickens once said, it was not religion that he satirized, but the cant of religion. Similarly, it is very easy to tell that the big names in Shroud research have bought into the notion of the shroud as a relic, and remain content to use science to advance that idea, so long as the science upholds their belief. If you think any evidence of this is wanting, simply examine the work over the past sixteen years, following the Carbon-14 revelations. Logic would have dictated that the best form of rebuttal to those findings would have been the provenance of the specimens, but that's not how it was done.
Let's consider some of Ray Rogers own words. The last sentence says it all:
The primary effect of all kinds of radiation is to heat the material it hits. This statement includes electromagnetic radiation (visible, ultraviolet, and infrared radiation); ionizing particles such as protons, electrons, and alpha particles; and non-ionizing particles such as neutrons. You can feel the heat when you hold a lump of plutonium, a flask of tritium, or a recently irradiated accelerator target. Intense irradiation can cause enough heat to explode explosives and burn metals (think of laser effects).
Cellulose molecules are folded back and forth in a fairly regular arrangement, and they show the properties of crystallinity. This is called a "fibrillar structure." When you rotate the stage of a petrographic microscope with crossed polarizers while looking at a linen fiber, straight lengths change from black through colored to black again every 90?. The fiber is birefringent and has an ordered structure.
When cellulose fibers are heated enough to color them, whether by conduction, convection, or radiation of any kind, water is eliminated from the structure (the cellulose is "dehydrated"). When water is eliminated, C-OH chemical bonds are broken. The C? free radicals formed are extremely reactive, and they will combine with any material in their vicinity. In cellulose, other parts of the cellulose chains may be the closest reactants. The chains crosslink. Crosslinking changes the crystal structure of the cellulose, and you can see the effect with a polarizing microscope.
When cellulose starts to scorch (dehydrate and crosslink), its characteristic crystal structure becomes progressively more chaotic. Its birefringence changes, and not all parts of a straight fiber go through clear transitions from dark to light at the same angle. Zones of order get smaller and smaller. It finally takes on the appearance of a pseudomorph and just scatters light. A significantly scorched fiber does not change color as the stage is rotated between crossed polarizers.
Proton-irradiated fibers by Rinaudo. Little, white, straight lines cutting across the fiber are the paths of the protons.
Specific types of radiation cause specific types of defects in the crystals of flax fibers. For example, protons ionize the cellulose as they pass through the fiber. This warps the crystals, making the protons' paths birefringent. You can see where they went in the fiber by the straight lines of their paths (see the "Proton-irradiated" figure).
Neutron-irradiated fibers from the Lyma mummy wrapping by Moroni. Observe the small, white, vertical streaks made by recoil protons between the bright growth nodes. There is also a faint haze in the background that was made by an associated gamma flux from the re actor.
Not all kinds of radiation ionize the material they penetrate. Neutrons and neutrinos donot have any electrical charge. Neutrinos hardly interact with matter at all, the fact that made them so difficult to detect. They have practically no chance of being stopped as they shoot through the entire diameter of the earth. The effects of neutrons depend on their energy, but they normally interact with hydrogen-containing materials to produce "recoil protons." They knock a hydrogen nucleus out of the material, producing an ionizing proton. You can see the ionization streaks of these (usually lower energy) protons (see the "Neutron-irradiation" figure).
The crystal structure of the flax fibers of the Shroud shows the effects of aging, but it has never been heated enough to change the structure. It has never suffered chemically significant irradiation with either protons or neutrons. No type of radiation that could produce either color in the linen fibers or change the 14C content (radiocarbon age) could go unnoticed. All radiation has some kind of an effect on organic materials.
This proves that the image color could not have been produced by thermal or radiationinduced dehydration of the cellulose. Image formation proceeded at normal temperatures in the absence of energetic radiation of any kind.
Sorry, that is misinformation put out by skeptic organizations. The FACT that the image does not exist under the blood stains has been confirmed in other research, most recently during the 2002 "restoration" of the shroud... and it has been peer reviewed and the work duplicated. Heller reported on the first observation in his book published in 1983. Do you think that no other research has been done on the blood on the shroud since then? Other researchers set out to either prove or disprove the observation. It has been proved to be true.
Sculpture in stone does not "fly in the face" of any artistic tradition or style.
It does if the STYLE does not match the work done in that time and period. Extreme realism in sculpture, especially showing a naked form in an area where sculptures were very stylized, would "fly in the face" of what would be expected... especially mounted over a city gate.
Logic would have dictated that the best form of rebuttal to those findings would have been the provenance of the specimens, but that's not how it was done.
Actually, it was. Some, when presented with the results of the C14 tests, immediately began claiming fraud... and blaming various people for "substituting" bogus linen for the Shroud linen. One published article accused a curator from the British Museum because he was seeking "herringbone Twill linen of medieval provenance" from other museums. The author did not know about the need for a "control" sample... which they never found... and misconstrued the legitimate search for that control as a "conspiracy" to fake the C14 test by substituting 13th Century linen for the Shroud samples,
Others started looking for scientific reasons why, among a flood of evidence that the Shroud's provenance is much older than 1260 -1390AD, this ONE test claims that date. Challenges were immediately made about the last minute changes in protocols about the sampling location, the number of samples, and several of the STURP team even stated that the results would be questioned because the sample was taken from the ONE location that every member of the STURP team was in agreement should be avoided. The major problem was that they had been left out of the loop on the C14 tests... and their recommendations were ignored.
Some of those hypotheses why the C14 date was so out of step with all the other evidence were outlandish...or crackpot... or not based in science... and it was THESE researchers who negated everyone of those and finally found the key... a medieval patch that has now been conclusively proved to be the answer.
Read the papers... they are available at Shroud.com. You will find that the scientists set out to disprove most of these "theories" and succeeded. The "bio-plastic coating of microbe poop" theory was put forward by a pediatrician... it was shot down almost immediately in the SCIENCE... but the popular press you have been reading kept it alive far beyond the disproving. The altering of the C14/C12 ratios because of fire was ALSO shot down in Science... and again, the popular press kept that hypothesis alive.
The one hypothesis that was proposed was that of the patch... which survived the science.... was not disproved... and has now been proved to be true. The C14 labs did an excellent job of dating the sample they were given... a sample that WAS taken from the Shroud but that was contaminated with 16th Century linen and cotton.
I have just returned from a Shroud conference in which Barrie Schworz showed the micro-photographs of Rogers' findings. Rogers had in his possession the middle sample of the five cut from the Shroud for C14 (four were destroyed in testing) and the Raes sample taken in 1973 from the area just below the 1988 C14 sample. The photomicrographs of these samples CLEARLY show the change over from old material to new material... and the very skillful splices where 16th Century Linen/Cotton fiber was spliced into the original Shroud linen. In addition, it can be clearly seen that the "patch" was surface dyed in place to match the darker original shroud material. This can be seen where the dye did not color threads passing under others. This was GOOD science.
The protocols for the C14 test REQUIRED the chemical testing of the samples, All three labs ignored that protocol and later, when asked why, one spokesman replied "Why should we? We knew it was from the shroud!" That's BAD science.