Torah scrolls [illustrative].
(photo credit: Courtesy)
Computer science and humanities departments have
joined forces at Ben-Gurion University in Beersheba to decipher
historical Hebrew documents, a large number of which have been
overwritten with Arabic stories.
The texts include fragments of Jewish prayer books from the Land of Israel.
The unique algorithm being used to determine the wording was
developed by BGU
computer scientists. The documents are searched
electronically, letter by letter, for similarities in handwriting which
help determine the date and author of the texts.
The documents being deciphered at BGU are degraded texts from
sources such as the Cairo Geniza, the Al-Aksa manuscript library in
Jerusalem, and the Al-Azar manuscript library in Cairo.
All together, the base consists of "100,000 medieval
Hebrew codices and their fragments [that] represent the book production
output of only the last six centuries of the Middle Ages," BGU computer
science professor Klara Kedem said this week.
Kedem has presented the new algorithm to other universities and research centers so a large number of texts can be deciphered.
The purpose of the project is to classify the handwritten documents and determine their authorship.
One problem is that many of the original Hebrew texts which were
found in the Cairo Geniza have been scratched off, and the parchment
used to write an Arabic text.
Ehrlich, head of the Prayer Research Project at BGU, explained,
"There was one book, found in the Geniza and which is now in Italy, but
which was originally used as a Hebrew prayer book."
However, the book had been rewritten as an Arabic text. "Our
aim was to read the first book and not the second book. So we needed to
find out how the Arab book could disappear and would leave only the
Hebrew letters of the original book. This is why the computer sciences
and humanities departments at BGU decided to collaborate," Ehrlich
"Although the texts are in Hebrew, the task of deciphering what
is written is difficult because the historical documents have degraded
over time," Kedem said. "Now, the foreground and background lettering
are hard to separate and there are smudges on the ink of much of the
text which intensifies the background coloring. Furthermore, ink from
the alternate side of the document adds blotches to the lettering."
To solve the problem, the algorithm is used to cover the text
in a dark grey color, which then highlights lighter colored pixels as
background space and identifies the darker pixels as outlining the
original Hebrew lettering.
There are two separate academic disciplines interested in
driving this project forward. First, linguistic specialists seek to
gain a deeper appreciation of the origins of the Hebrew language.
Second, Jewish philosophers are interested in studying ancient forms of
prayer that are thought to be contained in the texts.
Ehrlich is particularly interested in deciphering the texts
which are thought to include ancient prayers, so that the translations
can be added to BGU's The Prayer in Rabbinic Literature Database
Most of the fragments which contain prayers were found in the
Cairo Geniza. However, few documents remain fully intact, and "we are
trying to piece them together like a big puzzle," Ehrlich said.
It is unsurprising that prayers were found in the Cairo Geniza,
because it was there that Jews buried their sacred material when they
had no further use for it. Many of the fragments originate from Jewish
communities in the Land of Israel between the 9th and 11th centuries.
The texts arrived in Cairo because there were two big Jewish
communities in that city. One synagogue followed the Babylonian Jewish
traditions and prayers, and the other followed the Land of Israel
traditions and liturgy.
"It is very difficult to estimate the value of these fragments, but they would be very expensive," said Ehrlich.
Most fragments which have been discovered at the Cairo Geniza
are now in museums at Cambridge and Oxford universities, The British
Museum and in Israel and Paris. Until now the documents have not been
With the new algorithm, researchers hope to create a catalogue
of all the texts and piece together the ancient prayers and other
documents, including those citing Jewish law.