The Herculaneum papyri were discovered in the ruins of the town of Herculaneum, near Naples, Italy, and they represent one of the most extraordinary archives of ancient thought ever found. When Vesuvius erupted in 79 CE, the scrolls were covered by an estimated 65 to 70 feet of rock and ash. The extreme heat of the eruption carbonized the papyrus, transforming the delicate rolls into brittle, blackened cylinders that crumble at the slightest touch. While scholars have succeeded in opening and reading some of the scrolls, revealing previously unknown writings by Epicurus and other ancient thinkers, many more have proved simply too fragile to study by physical means. For centuries, the unopened scrolls have sat in collections as tantalizing, inaccessible objects.

In recent years, however, technology has begun to change the calculus. Artificial intelligence and X-ray tomography have allowed researchers to virtually unroll some of the scrolls and recover portions of their text without ever physically touching them. The technique involves scanning a scroll with X-rays in three dimensions and then using software to reconstruct and read the hidden writing layer by layer. Yet the method faces a fundamental physical obstacle: both the ink and the papyrus are made largely of the same material, carbon. Because the writing surface and the writing itself are chemically so similar, X-rays often have great difficulty distinguishing the letters from the background, and entire passages can remain effectively invisible even in the highest-resolution scans.

The turning point described in the new study comes from an unexpected discovery about the chemistry of the ancient ink itself. Some of the letters in fragments of the Herculaneum scrolls have been found to contain lead. Lead is a heavy metal that stands out vividly in X-ray imaging, and since X-rays can far more easily distinguish lead from papyrus than carbon from carbon, the presence of even small amounts of the metal could make text legible. The authors of the new paper therefore suggest a triage strategy: scan the surviving scrolls for lead first, and then attempt virtual unrolling on those scrolls that contain it, prioritizing the ones most likely to yield readable text.

Testing such an idea on the genuine Herculaneum scrolls themselves was not possible, since the irreplaceable artifacts cannot be subjected to experimental risks. Instead, the team did something remarkable: they recreated carbonized scrolls in the laboratory. The researchers wrote on new papyrus using ink prepared with various concentrations of lead, then heated the finished scrolls in a high temperature furnace until they carbonized. The result was a set of model scrolls that mimicked the tight packing of layers and the waviness of the ancient charred artifacts, replicating the very conditions that make unrolling algorithms struggle with the real thing.

The experiments delivered encouraging results on two fronts. First, X-ray fluorescence, a technique that maps the elemental composition of a sample, was able to detect lead in the recreated scrolls at each of the lead concentration levels the team tested. This means that even relatively modest amounts of lead in the ink should be detectable in a survey scan, validating the idea that lead detection could serve as a practical screening tool for the museum and library collections of unopened Herculaneum scrolls. A scroll that lights up with a lead signature would be flagged as a promising candidate for more intensive imaging.

Second, the team demonstrated that the text itself could be recovered. Using X-ray tomography combined with a custom software program, the researchers were able to re-read some of the words they had written on the carbonized model scrolls before charring them. In effect, the full pipeline from carbonization to detection to virtual unrolling to machine-assisted reading was exercised end to end. The reconstructed letters emerged from scans of a scroll that, to the naked eye, looked like an unremarkable blackened rod, precisely the form that has defeated conservators since the eighteenth century.

Beyond the immediate promise of reading more of the surviving scrolls, the laboratory-made artifacts serve a second, equally important purpose. Because the researchers know exactly what is written inside their recreated carbonized scrolls, they can use them as ground-truth training data for the algorithms that attempt to decipher real scrolls. Virtual unrolling depends on software that must infer the geometry of tightly packed, warped, and fused layers of papyrus, and that task becomes dramatically harder when the internal structure is unknown, as it is with the ancient originals. The model scrolls offer a rare test case in which the correct answer is already known, allowing developers to measure how well an algorithm performs and to refine it systematically. Success on the recreated scrolls, the team argues, could translate into improved success rates when the same algorithms are turned loose on the ancient texts.

The implications reach well beyond a single library. The Herculaneum papyri are the only intact library known to have survived from antiquity, and scholars believe many of the unopened scrolls may contain works by Epicurean philosophers, and possibly texts otherwise lost to history entirely. Every previously unknown book recovered from the collection has reshaped understanding of ancient philosophy, literature, and science. A reliable way to identify which scrolls are most likely to yield readable text could transform the pace of discovery, focusing expensive and time-consuming imaging campaigns on the artifacts with the highest probability of success. Douglas Seiler captured the spirit of the achievement in a characteristically understated remark: “It’s amazing what you can get electrons to do.”

The work, conducted with support from the Department of Commerce Radiation Physics Division and the Center for Neutron Research at NIST, demonstrates how physics, chemistry, and machine learning can converge on one of archaeology’s oldest unsolved problems. The recreated scrolls are published openly in PLOS One, and the freely available article provides full technical detail for other laboratories to build upon. For the curators who guard the carbonized library and for the scholars who have spent lifetimes waiting to read it, the message of the new study is straightforward: the combination of lead-sensitive X-ray fluorescence screening, tomographic imaging, and increasingly capable unrolling algorithms offers a realistic path into the interiors of scrolls that have kept their secrets since the afternoon the volcano buried them. The long-lost words of Herculaneum may not remain lost for much longer.

Subject of Research: Experimental recreation of carbonized Herculaneum papyrus scrolls to test lead-based X-ray imaging and virtual unrolling

Article Title: We may soon be able to read long-lost ancient scrolls damaged by eruption of Mt. Vesuvius

Article References: We may soon be able to read long-lost ancient scrolls damaged by eruption of Mt. Vesuvius. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Herculaneum papyri, Mt. Vesuvius, carbonized scrolls, X-ray tomography, X-ray fluorescence, lead ink, virtual unrolling, machine learning, papyrus, PLOS One, ancient texts, Pompeii eruption