Looming above all other issues is what physicist Paolo Di Lazzaro calls “the question of questions”: how the image was produced, regardless of its age.
The Shroud of Turin, as featured on the home page of National Geographic. Note, however, Nat Geo rotates principle articles so if you click on it you may not see this page as it is portrayed here.
The MUST READ article’s title is Why Shroud of Turin’s Secrets Continue to Elude Science.
The lead reads: “As the venerated relic goes on public exhibition, its origin remains a mystery wrapped in an enigma.”
The author, Frank Viviano, has written a fair and balanced story. A couple samples:
The sum result is a standoff, with researchers unable to dismiss the shroud entirely as a forgery, or prove that it is authentic. “It is unlikely science will provide a full solution to the many riddles posed by the shroud,” Italian physicist Paolo Di Lazzaro, a leading expert on the phenomenon, told National Geographic. “A leap of faith over questions without clear answers is necessary—either the ‘faith’ of skeptics, or the faith of believers.”
Looming above all other issues is what physicist Paolo Di Lazzaro calls “the question of questions”: how the image was produced, regardless of its age. Every scientific attempt to replicate it in a lab has failed. Its precise hue is highly unusual, and the color’s penetration into the fabric is extremely thin, less than 0.7 micrometers (0.000028 inches), one-thirtieth the diameter of an individual fiber in a single 200-fiber linen thread.
Di Lazzaro and his colleagues at Italy’s National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) conducted five years of experiments, using state-of-the-art excimer lasers to train short bursts of ultraviolet light on raw linen, in an effort to simulate the image’s coloration. The ENEA team, which published its findings in 2011, came tantalizingly close to approximating the image’s distinctive hue on a few square centimeters of fabric. But they were unable to match all the physical and chemical characteristics of the shroud image. Nor could they reproduce a whole human figure.