Here is the story from Zenit News Service, yesterday.
Dan
Date: 2002-08-20
Scientists Find Errors in Dating of Shroud of Turin
Believe That Medieval-Era Mending Skewed Results
ROME, AUG. 20, 2002 (Zenit.org).- New studies reveal that the 1988 carbon-14 dating analysis of the Shroud of Turin did not take into consideration the mending done to the cloth in the Middle Ages.
"The mending was medieval, not the shroud," wrote Orazio Petrosillo in the Roman newspaper Il Messaggero. Petrosillo is the author of several books on the cloth widely believed to be the burial linen of Jesus.
Petrosillo explained that during the Middle Ages it was very common to use a type of sewing -- invisible to the naked eye -- to reinforce fabrics of artistic or historical value.
According to Petrosillo, whose thesis is based on studies by U.S. scientists Sue Benford and Joseph Marino, researchers from laboratories at Oxford, England; Tucson, Arizona; and Zurich, Switzerland, examined the shroud in 1988 without realizing it was mended with linen in the 16th century. That study concluded the shroud was made sometime between 1260 and 1390.
The new thesis was articulated after scientists presented fabric experts with a series of photographs of one of the small pieces of cloth of the shroud taken in 1988 for carbon-14 dating, as well as a section which was not used. The three experts agreed that there are different weaves in the sections analyzed.
According to Beta Analytic, a radiocarbon-dating service, a mixture of 60% of 16th-century material with 40% of first-century material could lead to a dating of the 13th century. The calculation of percentages is based on the observations of the three fabric experts.
Petrosillo also quotes the study of chemist Ray Rogers, who was part of the Sturp group of U.S. scientists that examined the shroud in 1978.
Rogers had linen fibers of both the area of the cloth taken to carry out the carbon-14 analysis (cut out by the Belgian fabrics expert Gilbert Raes in 1973) as well as other parts of the shroud.
Both in the section extracted by Raes as well as that used in 1988, the fibers are impregnated by a dark yellow substance, whose color varies in density from one fiber to another.
However, the fibers of the rest of the shroud do not have this substance. According to the experts, it is a type of yellow vegetable glue, often used in the past.
Rogers has verified that there is an invisible mend in the piece taken out by Raes, like those made in the 16th century.
In fact, a thread of Raes' section was dated with the carbon-14 method at the California Institute of Technology.
Half the thread turned out to be covered by starch. The thread was divided into two equal parts: the part without starch turned out to be of the third century, while the part with starch was dated in the 13th century.
Petrosillo concluded that the shroud continues to raise scientific questions calling for new and more adequate study.
I had heard rumors of an unauthorized C14 test of one of the Raes threads... this is the first I have seen it in print.
I suspect that the thread was interwoven / intertwined new and old material and BOTH halfs were still mixtures to a degree... one with more new fibers and one with more old fibers. Sure would be interesting to know how much of the starchy thread was included in the thread that reported 3rd Century dating.