One early clue that something was
wrong came from Alan Adler, a professor of
chemistry at Western Connecticut State University. He found significant levels of aluminum in
yarn segments from the radiocarbon sample area, up to 2%, by
energy-dispersive x-ray analysis. Why Aluminum?
Raymond Rogers, a chemist from the
Los Alamos National Laboratory would later answer that question in his
seminal paper disproving the carbon 14 dating. The aluminum was in the
form of hydrous aluminum oxide or alum, a common mordant used
with dyes. Spliced-in new threads used to repair the shroud had been
dyed to match older age-yellowed thread.
Adler had examined a fragment
of the carbon 14 sample and compared it to fibers from elsewhere on the
shroud. He used both Courier Transform Infrared
Microspectrophotometry and a Scanning Electron Microscope. "The results
clearly indicated differences in chemical composition," he wrote. The
samples were clearly not representative.
In 1988, Edward Hall,
then director of the Oxford University Radiocarbon Laboratory, had found
cotton fibers that might be from mending.
So did P. H. Smith, a consultant to the
Oxford lab. He later wrote an article for Textile Horizons
called "Rogue Fibers Found in Shroud," Smith suggested that those cotton
fibers were suspicious and might have been part of repairs.
Giovanni Riggi, the
person who cut the carbon 14 sample from the Shroud stated: "I was
authorized to cut approximately 8 square centimetres of cloth from the
Shroud. . . . This was then reduced to about 7 cm because fibres of
other origins had become mixed up with the original fabric . . . "
(emphasis added)
Giorgio Tessiore, who
documented the sampling, wrote: “. . . 1 cm of the new sample had to be
discarded because of the presence of different color threads.”(emphasis added)
The Arizona
lab made eight measurements with dates that varied widely. The clearly
suggested that the sample was not homogeneous. Rather than deal with the
problem, the British Museum asked Arizona to discard the four outside
measurements and use only those that were most similar. It was the only
way they could calculate a satisfactory error distribution.
Ultraviolet and x-ray photographs, taken in 1978
before the carbon 14 dating samples were taken, showed that there were
chemical differences between the sample area and surrounding areas of
the cloth.
No all of these clues, but just a few, were enough
to cast reasonable doubt on the radiocarbon dating of the Shroud of
Turin. But this information was held back when the results were made
public.
