Controversy Builds as Shroud Tests Near
Raloff, Janet, Science News
Controversy builds as shroud tests near
While the Catholic Church has agreed to let scientists attempt to date the Shroud of Turin, a linen relic that many believe once wrapped the crucified body of Christ, officials have not publicly announced when. However, people familiar with the radiocarbon-dating tests believe they will begin soon -- and midst considerable controversy.
The controversy erupted last year when Cardinal Ballestrero, the Archbishop of Turin and pontifical custodian of the shroud, announced the Church had chosen three labs to date the textile (SN: 11/7/87, p.302) -- half the number a scientific consortium had recommended one year earlier. The scientists' protocol (SN: 4/25/87, p.265) also would have employed two different types of carbon-14 test procedures--the conventional proportional-counting technique (which measures emissions from radioactive carbon) and tandem-accelerator mass spectrometry (which can directly measure carbon-14 without waiting for its decay). But since accelerators need only a third as large a sample as the counter tests, Ballestrero decided to limit testing to accelerators. He further limited participating labs to those routinely dating archaeological samples.
The process winnowed the field of researchers down to those at the University of Arizona in Tucson, the Federal Technical Institute in Zurich, Switzerland, and the University of Oxford in England. It also reduced by two-thirds -- to about 40 milligrams -- the quantity of shroud allowed to be sacrificed.
Some scientists express concern about the three-lab decision. Among them are Harry Gove of the University of Rochester (N.Y.) physics department -- whose lab developed the accelerator carbon-14 dating technique -- and Garman Harbottle of Brookhaven National Laboratory in Upton, N.Y. According to Harbottle, there "appears to be about a one in five chance for any given measurement" that the answer will be very wrong. …