Attempt to ‘virtually unwrap’ ancient scrolls buried by Vesuvius

Scientists and scholars in the United Kingdom are trying to use technology to unlock some of the most notorious items in the “invisible library” – unreadable ancient manuscripts that may offer insights into life thousands of years ago.

The so-called Herculaneum papyri were buried during the eruption of Mount Vesuvius in 79 AD, with the hot ash and gases charring and carbonising the scrolls and turning many into impenetrable log-like cylinders.

The 1,800 works, excavated in 1752 from a villa believed to belong to Julius Caesar’s family in Herculaneum, Pompeii’s sister city, are considered the only surviving complete library from antiquity. 

Various attempts at deciphering the texts, believed to contain mostly Greek philosophy, or unrolling the delicate scrolls over the last 270 years have proved fraught – with many of the artefacts destroyed in the process. 

To date, none of the ancient Roman scrolls unearthed in the villa has been deciphered in its entirety. 

“Texts from the ancient world are rare and precious, and they simply cannot be revealed through any other known process,” said Professor Brent Seales, director of the Center for Visualization and Virtual Environments at the University of Kentucky, who is leading researchers in the most recent attempt to unlock the scripts. 

His team, working with scientists at Diamond Light Source, the UK’s national synchrotron facility, has used a unique technology to X-ray two complete scrolls that for generations were thought to be lost to history. 

“The idea is essentially like a CT scanner where you would take an image of a person, a three-dimensional image of a person and you can slice through it to see the different organs,” said Laurent Chapon, physical science director of Diamond Light Source.

The synchrotron is a particle accelerator in which beams travel around a closed-loop path to produce light many times brighter than the sun. 

“We… shine very intense light through [the scroll] and then detect on the other side a number of two-dimensional images. From that we reconstruct a three-dimensional volume of the object… to actually read the text in a non-destructive manner,” Chapon said.

‘Rare and precious’

But the digital scan, while using advanced technology, is only the first step in the decoding process. 

“The scan session promises to be a key moment in our quest for a reliable pathway to reading the invisible library,” said Seales.

However, the researchers “do not expect to immediately see the text from the upcoming scans, but they will provide the crucial building blocks for enabling that visualisation”, he said.

In 2015, Seales led a team that digitally accessed writings trapped inside five complete ancient Hebrew scrolls, hailed as the first time an artefact that could not be physically opened was digitally deciphered.

But the Herculaneum scrolls pose a more difficult challenge, as the script is written with carbon ink, which has a similar density to the papyrus it sits on, according to Seales.

Many ancient texts were written with metal-based inks that are more easily picked up by X-rays.

Because of this, the research team is now building a machine-learning algorithm that will go through the digital scan of the scrolls to detect “evidence of ink, even when it is invisible to the naked eye”, Seales said.

If all goes according to plan, the final product will be a complete recreation of the text, an important addition to the ancient Herculaneum library.