Labs Find Turin Shroud Dates to Middle Ages, Scientist Hints

A well-informed American scientist said Tuesday that all three laboratories that age-tested pieces from the Shroud of Turin have dated the revered relic within a span of 200 years, and he hinted that published news leaks in London were correct that the shroud was made in the Middle Ages.

However, the scientist, chemist Robert Dinegar of Los Alamos, N.M., would not say directly whether the tests showed that the cloth was as old as the 1st Century--and therefore possibly the burial cloth of Jesus--or a fabric dating from medieval times, and thus a fake.

The shroud has been the object of devotion for many believers because it bears the faint image of a bloodied, bearded man, suggestive of Jesus’ crucifixion.

Radiocarbon dating tests were conducted at Oxford, Zurich and the University of Arizona. The Sunday London Times, citing unnamed sources, said this week that the tests revealed a date between 1100 and 1500.

Another British newspaper said in late August that tests showed the shroud was made about 1350, the oldest certain period of references to the shroud, which was owned then by a French knight. But Prof. Luigi Gonella, scientific liaison for the archbishop of Turin, Italy, said last month that results of the three labs had not been compared.

The church-approved announcement of results is expected in the next few weeks.

Dinegar was not involved in the radiocarbon tests, but he spearheaded the decade-long effort by a team of U.S. scientists to persuade Catholic Church officials to permit the analysis. The team had conducted an array of tests on the shroud in Turin in 1978 that left it intact.

Reached by telephone, Dinegar said he was told the date of the shroud by an authoritative source but said he could not reveal it.

Yet, asked to comment on newspaper reports in London of a medieval origin for the shroud, Dinegar said, “I am ticked off with Oxford. These leaks always come out (of Oxford) and they are always correct.”

Pressed on whether the most recent account from London could be true, Dinegar would say only that he “saw no point” in anybody giving out false information.

Dinegar, who is both an Episcopal priest and a chemistry professor at the University of New Mexico’s Los Alamos campus, disclosed in the interview that all three laboratories got about the same date; that is, all three were within a 200-year range, the predetermined criterion for a valid finding. “I assumed we would get three out of three because they are excellent scientists,” Dinegar added.

Dinegar and the U.S.-based Shroud of Turin Research Project had recommended that six laboratories perform tests, but church authorities reduced the number to three.

A spokeswoman for University of Arizona scientists Paul E. Damon and Douglas J. Donahue said Tuesday that the two have repeatedly declined to say anything about their results or comment on news reports.

Each laboratory was provided a postage-stamp-sized sample from the shroud and two other known-age samples, none of them identified for the researchers. Tandem accelerator mass spectrometers were used to measure the radioactive decay of Carbon 14. This isotope of carbon acts as a natural clock to calculate the age of once-living things, including, in this case, the flax that was used to weave the cloth.

Dinegar said the new test data will not contradict the earlier findings of his team’s project. He said that none of its members had taken a position on the “date or place of origin of the cloth.” From the 1978 experiments, the team concluded that the image on the cloth was not produced by applied materials such as paint “but was rather due to an oxidation of the cellulose molecules that make up the flax.”

Just how that oxidation took place to form front and back images on the 14-foot-long cloth is undetermined, Dinegar said. In hopes of getting approval for more testing, Dinegar said that the American team will meet Oct. 22 in New Mexico with Gonella, the adviser to Cardinal Anastasio Balestrero, archbishop of Turin and keeper of the shroud.

Even if the cloth is only as old as the Middle Ages, Dinegar said the scientists are interested in more tests to determine how the image got onto the cloth, and church officials are interested in preservation techniques.