The Dead Sea Scrolls, discovered some seventy years ago, are famous for containing the oldest manuscripts of the Hebrew Bible (Old Testament) and many hitherto unknown ancient Jewish texts. However, the scientists did not know who was behind the scrolls because the scribes were anonymous. Now, combining the sciences and the humanities, researchers at the University of Groningen have cracked the code that allows them to discover the scribes behind the scrolls.
The scribes who created the scrolls did not sign their work. The researchers suggested that some manuscripts should be attributed to a single scribe based on handwriting. They were trying to find a clue in the writing, for example, a very specific feature in a letter that would identify a scribe , explains Mladen Popović, professor of Hebrew Bible and Ancient Judaism at the Faculty of Theology and Religious Studies at the University of Groningen. He is also director of the university's Qumran Institute, dedicated to the study of the Dead Sea Scrolls. However, these identifications are somewhat subjective and often hotly contested.
That is why Popović, in his project The hands that wrote the Bible , funded by the European Research Council, teamed up with his colleague Lambert Schomaker, Professor of Computer Science and Artificial Intelligence in the College of Science and Engineering. Schomaker has long been working on techniques that allow computers to read handwriting, often from historical materials. He has also conducted studies to investigate how biomechanical traits, such as the way someone holds a pen or stylus, would affect writing.
In this study, along with doctoral candidate Maruf Dhali, they focused on one scroll in particular:the famous Great Isaiah Scroll (1QIsaa) from Cave 1 at Qumran. The writing on this scroll appears almost uniform, although it has been suggested that it was done by two scribes who shared a similar writing style. How can this be decided? According to Schomaker:This scroll contains the letter aleph, or “a”, at least five thousand times. It is impossible to compare them all with the naked eye . Computers are well suited to analyzing large data sets, such as 5,000 handwritten “a's”. The digital image makes possible all kinds of computer calculations, at the micro level of the characters, such as the measurement of curvature (called textural), as well as of the complete characters (called allographic).
The human eye is amazing and is supposed to take these levels into account as well. This allows the experts to “see” the hands of the different authors, but that decision is often not reached through a transparent process , says Popović. In addition, it is virtually impossible for these experts to process the vast amounts of data provided by the scrolls. That is why their results are usually inconclusive.
The first hurdle was training an algorithm to separate the text (the ink) from its background (the leather or the papyrus). For this separation, or binarization , Dhali developed a state-of-the-art artificial neural network that can be trained using deep learning. This neural network keeps the original ink strokes made by the scribe more than 2,000 years ago intact, just as they appear in digital images. This is important because the ancient ink strokes relate directly to a person's muscle movement and are specific to each person , explains Schomaker.
Dhali performed the first analytical test of this study. His analysis of textural and allographic features showed that the 54 columns of text in the Great Isaiah Scroll fell into two different groups that were not randomly distributed on the scroll, but rather clustered, with a transition around the middle. /P> 
Observing that there might be more than one writer, Dhali turned the data over to Schomaker, who recalculated the similarities between the columns, now using the patterns of the letter fragments. This second analytical step confirmed the presence of two different ones. Various additional checks and controls were performed. According to Schomaker:When we added additional noise to the data, the result did not change. We also managed to show that the second scribe shows more variation within his script than the first, even though his script is very similar. .
In the third step, Popović, Dhali and Schomaker have developed a visual analysis. They created heat maps that incorporate all variants of a character on the entire scroll. They then produced an averaged version of this character for the first 27 columns and the last 27 columns. When comparing these two average letters by eye, it is observed that they are different. This links computational and statistical analysis with approximate human interpretation of the data, as heat maps are not dependent on or produced from primary and secondary analyses.
Certain aspects of the parchment and the placement of the text had led some scholars to suggest that after column 27 a new scribe had begun, but this was not generally accepted. According to Popović:We can now confirm this with a quantitative analysis of the handwriting, as well as robust statistical analyses. Instead of basing judgment on more or less impressionistic evidence, with the clever help of the computer, we can show that the separation is statistically significant.
In addition to transforming the paleography of the scrolls—and potentially other ancient manuscript corpora—this study of the Great Isaiah Scroll opens up an entirely new avenue for analyzing the Qumran texts from their physical characteristics. Now researchers can access the micro level of individual scribes and carefully observe how they worked on these manuscripts.
According to Popović:This is very exciting, because it opens a new window on the ancient world that can reveal much more intricate connections between the scribes who produced the scrolls. In this study, we find evidence of a very similar writing style shared by the two scribes of the Great Isaiah Scroll, suggesting a common background or origin. Our next step is to investigate other scrolls, where we may find different origins or training of the scribes .
In this way, it will be possible to learn more about the communities that produced the Dead Sea Scrolls. Now we can identify different scribes , concludes Popović. We will never know their names. But after seventy years of study, it's as if we can finally shake hands with them through their writing .