A supercomputer on the campus of Tel Aviv University is set to revolutionize research on one of the world’s most important repositories of ancient documents – the Cairo Geniza, which came to light 117 years ago behind the wall of an ancient synagogue.

The computer, fed more than 300,000 images of fragments from the geniza collection, began work on May 16. Over five weeks, it will make 12 billion visual comparisons between pieces, suggesting possible matches.

By Sunday afternoon, at the time of a briefing for reporters, it had conducted 2.8 billion comparisons. The computer is set to complete its work on June 25, marking perhaps the most dramatic leap forward in geniza scholarship in a century.

The Cairo Geniza collection includes around 320,000 fragments of parchment and paper documents from a millennium of Jewish life in the Muslim metropolis, beginning in the 9th century C.E. They include religious texts, contracts, recipes, magic amulets, letters among businessmen involved in trade with India, and even papers written by the famed 12th-century philosopher Maimonides.

According to Jewish law, documents bearing the name of God cannot be thrown out. Instead, for centuries Cairo’s Jews simply stuffed such documents and others through a hole in the wall of the women’s section of the Ben Ezra synagogue in the Fustat district and into a small room – known as a geniza, from the Hebrew word “to store” — where they were kept, preserved by Egypt’s dry climate, until coming to the attention of European scholars in 1896.

Understanding the documents from the geniza requires matching together scattered pieces of the same document. But the fragments are now scattered among 67 libraries across the world, making that difficult. Only about 4,000 such matches have been made in more than a century of research.

The new computation effort was made possible by the efforts of the Friedberg Genizah Project, based in Jerusalem, which since 2006 has been scanning fragments from nearly all existing collections and uploading them to a website, www.genizah.org.

The Cairo Geniza collection contains around 320,000 fragments scattered among 67 libraries. Pictured: Pages from Maimonides' 12th-century philosophical work 'Guide for the Perplexed' (photo credit: Courtesy of the Cambridge University Library)

The Cairo Geniza collection contains around 320,000 fragments scattered among 67 libraries. Pictured: Pages from Maimonides’ 12th-century philosophical work ‘Guide for the Perplexed’ (photo credit: Courtesy of the Cambridge University Library)

“This is the first time the whole geniza has been available to researchers anytime, anywhere,” said Yaacov Choueka, the computer scientist in charge of the project. Choueka was born in Cairo and left when he was 20, amid the exodus of the city’s Jews because of persecution in the mid-20th century.

For the first time since 1896, he said, the entire collection was together again.

“We want to restore the geniza to the way it was at the beginning, and release researchers from the need to look for matches all over the world,” he said.

Choueka’s son, Roni, is one of the computer specialists behind the work of the supercomputer. The recognition software, he said, looks at characteristics like the number of lines, the density of text, and the average width of a line, helping the computer select probable matches from hundreds of thousands of possibilities.

The efficacy of the software was demonstrated earlier this year when one researcher, Stefan Reif of Cambridge, was looking for a match for a vellum fragment of an 11th-century Passover Haggada that had been brought to the British university in 1897.

The Israeli geniza project was putting the finishing touches on its computer program. Researchers ran the image through the new software and immediately found a match: A sister fragment from the same Haggada was in the library of the Jewish Theological Seminary in New York.


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