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Genesis scroll before and after infared imaging. Courtesy of Dr. Bruce Zuckerman, West Semitic Research.
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.
Closer view of Genesis scroll before infared imaging.
Courtesy of Dr. Bruce Zuckerman, West Semitic Research.

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.
Closer view of Genesis scroll after infared imaging.
Courtesy of Dr. Bruce Zuckerman, West Semitic Research.

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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