Sep 22, 2016

Dead Sea Scroll 'Virtually Unwrapped'

Shown is the completed virtual unwrapping for the En-Gedi scroll.
The En-Gedi scroll, a text that includes part of the Book of Leviticus in the Hebrew Bible that was ravaged by fire about 1,400 years ago, is now readable, thanks to a complex digital analysis called "virtual unwrapping."

Rather than physically unfurl the scroll, which would have destroyed the crumbling artifact, experts digitally scanned the document, and then virtually flattened the scanned results, allowing scholars to read its ancient text.

"We're reading a real scroll," lead study author Brent Seales, professor and chairman in the department of computer science at the University of Kentucky, said in a news conference yesterday (Sept. 20). "It hasn't been read for millennia. Many thought it was probably impossible to read."

Archaeologists found the scroll in 1970 in En-Gedi, where an ancient Jewish community thrived from about the late 700s B.C. until about A.D. 600, when a fire destroyed the site, the researchers said. Excavations of the synagogue's Holy Ark, a chest or cupboard that holds the Torah scrolls, revealed charred scrolls of parchment, or animal skin. But each scroll was "completely burned and crushed, had turned into chunks of charcoal that continued to disintegrate every time they were touched," the researchers wrote in the study.

The En-Gedi scroll is different than the original Dead Sea Scrolls, which a young shepherd discovered in caves near Qumran in the Judean Desert in 1947. However, Dead Sea Scroll has become an umbrella term for many ancient scrolls found in the area, and some researchers also call the En-Gedi artifact a Dead Sea Scroll.

The scorched En-Gedi scroll fragments sat in storage for more than 40 years until experts decided to give them another look, and try the newly developed "virtual unwrapping" method for the first time on the scroll.

Potential scroll fragments from En-Gedi that are severely burned.
The virtual journey began in Israel, where experts digitally scanned the rolled-up scroll with X-ray-based micro-computed tomography (micro-CT). At this point, they weren't sure whether the scroll had text within it, said study co-author Pnina Shor, curator and head of the Dead Sea Scrolls Projects at the Israel Antiquities Authority. So, they increased the spatial resolution of the scan, allowing them to capture whether or not each layer had detectable ink.

Their exhaustive attention to detail paid off: There was ink, and it likely contained metal, such as iron or lead, because it showed up on the micro-CT scan as a dense material, the researchers said.

However, the text was illegible. So Shor and her colleagues in Israel sent the digital scans to Seales in Kentucky so he and his team could try the new "virtual unwrapping" technique.

"It was certainly a shot in the dark," Shor said.

This new method marks the first time that experts have virtually unrolled and noninvasively studied a severely damaged scroll with ink text, Seales said.

The unwrapping took time and involved three steps: segmentation, texturing and flattening, he said.

With segmentation, they identified each segment, or layer, within the digital scroll, which had five complete revolutions of parchment in the scroll. Then, they created a virtual geometric mesh for each layer made of tiny, digital triangles. They were able to manipulate this mesh, which helped them "texture" the document, or make the text more visible.

"This is where we see letters and words for the first time on the recreated page," the researchers wrote in the study.

Finally, they digitally flattened the scroll, and merged the different layers together into one, flat 2D image that could easily be read.

The scroll holds the beginning of the Book of Leviticus, the third of the five books of Moses (known as the Pentateuch) that make up the Hebrew Bible, biblical scholars said. In fact, the En-Gedi scroll contains the earliest copy of a Pentateuchal book ever found in a Holy Ark, the researchers said.

The virtual unwrapping revealed two distinct columns of text that include, in total, 35 lines of Hebrew. Each line has 33 to 34 letters. However, there are only consonants, no vowels. This indicates that the text was written before the ninth century A.D., when Hebrew symbols for vowels were invented, said study co-author Emanuel Tov, a professor emeritus in the department of Bible at Hebrew University of Jerusalem.

Radiocarbon dating places the scroll in the third or fourth century A.D., but studies based on historical handwriting place it at either the first or second century A.D., the researchers said. Regardless, the data suggest that it was written within the first few centuries of the Common Era, they said.

Read more at Discovery News

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