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Genesis scroll before and after infared imaging. Courtesy of Dr. Bruce Zuckerman, West Semitic Research.
Science of the Dead Sea Scrolls
By Jessica Holmes Chatigny
The Dead Sea Scrolls rank among the greatest
archeological treasures of all time, yet many elements
of their meaning and origins have long been shrouded
in mystery. One of the ways to discover more about the
scrolls is to study them through the lens of science.
When the scrolls were discovered in 1947 in caves near the Dead
Sea, science and technology were light years away from the tool
available to researchers today. New methods and technologies have
deepened our understanding of the scrolls by unlocking more and
more information. Yet, even as our ability to investigate improves, key
questions remain unanswered: Who wrote the scrolls? Where were
the scrolls written? Which fragments belong together? And, perhaps
most pressing, can we halt the scrolls' relentless decomposition?
Carbon-14 dating
As fortune would have it, a scientist named William Libby developed
the Carbon-14 dating method in 1947—the same year as the scrolls’
discovery. The Carbon-14 (C-14) dating method, also called
radiocarbon dating, can accurately date biological matter up to
60,000 years old. Libby received the Nobel Prize in Chemistry in
1960 for this discovery.
The element Carbon is the building block that makes life possible.
There are several types or isotopes of Carbon, depending on the
number of neutrons. Carbon-12 (C-12) is stable, but C-14 is
radioactive and decays slowly over time. C-14 has a half-life of about
5730 years, which means that half the C-14 atoms have decayed to
Nitrogen-14 in 5730 years. As long as an organism is alive and well,
its levels of C-12 and C-14 remain stable because “fresh,” undecayed
C-14 is constantly ingested. However, as soon as an organism
dies—for example, the goat whose skin was used to make
parchment for the Dead Sea Scrolls—the ratio of C-12 to C-14
begins to change at a constant rate.
By looking at the ratio of C-12 to C-14 in the sample and
comparing it to the ratio in a living organism, it is possible to
determine the age of a formerly living thing. This technique is also
used with other radioisotopes, including Potassium-40 (half-life of
1.3 billion years) and Uranium-235 (half-life of 704 million years).
Unfortunately, the first scholars using this technology had much
less sensitive machines than those in use today. Large amounts of
material were required to date items in 1947—several grams, in fact.
In order to date a scroll, scientists had to destroy it. Consequently,
scientists would also rely on another dating technique: paleography,
which is the study and analysis of ancient writing. By analyzing
and comparing the scrolls—letter to letter, brush stroke to brush
stroke—to other dated documents, researchers were able to
gauge dates accurately.
Closer view of Genesis scroll before infared imaging.
Courtesy of Dr. Bruce Zuckerman, West Semitic Research.
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Get your hands dirty
Determining who wrote the scrolls is a key question for scholars.
Scientists aid our understanding of the Dead Sea Scrolls’ authors
with soil analysis and DNA testing.
No two soils are alike. Even dirt separated by a few miles is
distinguishable. The clay used to make the scroll jars and other vessels
that held the scrolls can serve as a guide to the location where the
jars were made, and possibly point to where the scrolls were written.
Small samples of soil are exposed to a process of nuclear activation,
which measures different levels of radiation in the soil sample.
Nuclear activation outlines the soil’s chemical composition, resulting
in a “fingerprint” to which researchers may match a soil.
Scientists tested the soil composition from the jars against soil
samples in and around Jerusalem, Qumran (an archeological site near
where the scrolls were found) and several other locations. They
discovered that most of the jars were made locally in Qumran and
four other nearby sites.
More recently, soil research has figured prominently in the
discovery of a latrine outside of Qumran, which, according to the
researchers, may indicate that the community strictly followed
sanitary practices mentioned in Deuteronomy and in the scrolls.
The business of genes
The characters in CSI: Miami are not the only group to use DNA
analysis. DNA testing aids the study of the scrolls in several ways.
Most scrolls were written on parchment made from goat hide.
Each strand of a person’s (or plant’s or animal’s) DNA holds
exactly the same information, yet no two humans’ strands of
DNA are exactly alike. With DNA testing and matching available,
scientists can now use the DNA of the parchment (i.e., of the
goats) to assist in the challenging task of piecing together scrolls.
Recently, six of seven previously unidentified fragments were
found to belong to the Temple Scroll.
Another benefit of the advent of genetic testing is that studying
the parchment’s DNA may also help determine the location(s)
where the scrolls were written. Scientists might be able to match a
scroll’s DNA to the bones of a goat buried at Qumran or, as some
scholars assert, in Jerusalem.
Additional DNA study is being undertaken: researchers are breaking
down the genetic code in pollen on clothing found at Qumran. This
gives us clues as to which plants flourished at that time. Head lice
have also been found attached to ancient combs. If researchers can
extract human DNA from the blood in one louse, it could help
identify modern-day relatives of Dead Sea Scrolls' scribes. Imagine
the thrill of locating a scribe's direct descendants or family group.
Closer view of Genesis scroll after infared imaging.
Courtesy of Dr. Bruce Zuckerman, West Semitic Research.
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Seeing the scrolls in a new light
Some of the scrolls have deteriorated significantly over the past
2000 years. Layers of grime and disintegration (from environment
and poor handling) make some scrolls difficult to decipher. How
then, are the words of the most fragile scrolls to be read and analyzed?
Once again, modern technology assists researchers: researchers
now employ infrared light and photography in search of lost words.
Infrared waves, out of the visible spectrum, turn out be the perfect
wavelength: while the space around the text absorbs the light, the
text bounces back infrared light, allowing researchers to see and
photograph the words that have vanished over time.
While the scrolls will continue to deteriorate, every effort is being
made to preserve them. The scrolls have been digitally photographed,
and all the scrolls and fragments are protected from light and humidity
damage. As Dead Sea Scrolls research continues, scholars are finding
that technology's march forward is one of the greatest tools at their
disposal. In this way, modern techniques help us learn a great deal
more about the ancient world.
Dead Sea Scrolls is a joint production of the Israel Antiquities Authority,
Dead Sea Scrolls Foundation, and the San Diego Natural History Museum.
SAN DIEGO NATURAL HISTORY: FIELD NOTES, July-August 2007
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