High-tech scanner cracks ancient letter secrets

Cuneiform script, invented around 3,000 years before Christ, was deciphered in the mid-19th century. Since then, the texts have been readable, and now even artificial intelligence systems are being trained to read cuneiform texts.

A research team from Hamburg now wants to go one layer deeper. Scientists from the Cluster of Excellence »Understanding Written Artefacts« at the Centre for the Study of Manuscript Cultures (CSMC) at the University of Hamburg and the German Electron Synchrotron (DESY) have developed a portable high-resolution X-ray tomograph that they can use to examine the clay tablets for inclusions such as plant seeds or fossils. Clay tablets from the Hilprecht Collection at the University of Jena are currently being examined in Jena.

Making millennia-old messages readable

The clay tablets are not readily sent on journeys, so it made sense to design a portable device. »The challenge was to develop a system that was as light as possible and had a high resolution,« says Andreas Schropp, a scientist at DESY. The result is called »ENCI«, which stands for »Extracting Non-destructively Cuneiform Inscriptions«—and Enki is also the name of a Sumerian deity, the god of wisdom and magic.

»ENCI« can be assembled like a kit from eight individual parts and weighs a total of approximately 420 kilograms. It delivers data sets of about 50 gigabytes each, which can be displayed in three dimensions after tomographic data evaluation. The measured data sets are approximately 100 times larger and the resolution achieved is ten times finer than in a typical medical CT scan. At the same time, the system is largely self-sufficient, requiring only a conventional power outlet for operation.

ENCI and the team from the University of Hamburg and DESY have already been deployed in Turkey, in Ankara and Kayseri, as well as at the Louvre in Paris last year. In the Hilprecht Collection at Friedrich Schiller University, clay tablets selected by Johannes Groß are being examined, among other things. The doctoral student of Assyriology at the CSMC is researching practical texts, such as feed lists from animal husbandry or inventory lists. »Perhaps the X-ray results will show whether the tablets came from a workshop or can be attributed to a particular scribe,« says Groß.

Attempts at deception were cleverly prevented

ENCI was originally developed with the aim of making previously hidden texts visible again, says Jonas Klöker, research assistant at the Department of Ancient Oriental Studies at the University of Jena. Similar to a letter envelope, the writers of that time sealed some of the clay tablets with a cover that was also made of clay. In the case of legal texts, this envelope usually bore the same text as the tablet it contained, while letters included the sender and recipient.

This envelope also indicated that the contents had remained unchanged, which prevented attempts at deception, says Jonas Klöker. This was particularly important in the case of contracts. Many of the envelopes are still intact today, and the letters or contracts have survived the millennia unopened. Since they are difficult to remove without destroying the valuable artefacts, the specific contents of the tablets have remained hidden until now. Thanks to ENCI, that is about to change.