The Shroud of Turin, bearing the faint brownish image of a man and believed by many to be the burial cloth of Jesus, will undergo a variety of advanced scientific tests early October - but possibly not a crucial carbon 14 dating analysis.
The study by U.S. and European scientists and technicians will follow one of the relic's infrequent public displays in the Italian city's cathedral from Aug. 27 to Oct. 8.
An estimated half-million pilgrims will view the linen cloth, which is 14 feet, 3 inches in length and 3 feet, 7 inches in width. Full-length impressions of a man's front and back sides are seen on the cloth.
Skeptics generally have regarded it a hoax dating from theMiddle Ages, the period when the shroud first appears in the historical record.
But scientists who have taken an interest in the shroud in recent years have been unable to find paint pigments or other evidence for an artistic rendition of a bloodied, bearded man on the cloth.
A Zurich criminologist also claims to have found pollen samples on the cloth that would have placed the cloth in Palestine at one time.
Advanced color photography techniques plus X-ray fluorescence, infrared and ultraviolet analysed are among the scientific tests, possibly on Oct. 9, to be allowed by Archbishop Anastasio A. Balestrero of Turin and others charged with the shroud's care.
One of the biggest questions is the age of the cloth. But carbon 14 dating analysis proposed by an expert in the field, Walter C. McCrone of Chicago, has not recieved approval.
"At present, they haven't decided to ao ahead with that. They've neither approved nor rejected it," said the Rev. Adam J. Otterbein, CSSR, of Hampton, Va., president of the Holy Shroud Guild in America.
McCrone and other scientists on a U.S. committee had hoped to use one of two pieces removed earlier from the shroud for the dating test.
But Otterbein said officials have contended that if a carbon 14 test were done it should be done on a small piece cut espiacially for the testing in order to leave no doubt where it came from.
Instrumental in proposing an array of tests for the relic have ben two Air Force Academy physicists, John Jackson and Eric Jumper. The two, working with the Holy Shroud Guild, convened a two-day research conference in Alburquerque, N.M., in March 1977 that also drew scientists from Jet Propulsion Laboratory in Pasadena, Calif., and Los Alamos (N.M.) Laboratory.
Jumper told a recent New York conference that "we could get enough data in 24 hours of testing to keep us busy for 30 years after the information obtained has been reduced by computer."
The Air Force Academy scientists and Ray Rogers, a thermochemist at Los Alamos, have suggested that the human image on the shroud must have been formed by a quick burst of radiant energy.
Left unsaid or quietly downplayed in many of these discussions is the implication that the "scorching" of the cloth was made supernaturally at the momemt of Jesus' Resurrection, a basic tenet of Christian belief.