Scientists re-created the Herculaneum scrolls. They found a clue to decoding hidden text

Charred to a crisp during Mount Vesuvius’ eruption in AD 79, hundreds of papyrus scrolls lie tucked away unread in Italy’s National Library of Naples.

The majority of these carbonized artifacts, known as the Herculaneum scrolls , are so fragile that they can’t be physically unrolled. Now, researchers and citizen scientists alike are using X-ray technology and advanced artificial intelligence to unlock the writings of ancient authors hidden within.

A new study, published September 16 in the scientific journal PLOS One , may offer another clue toward this daunting goal. By re-creating the papyri with inks containing varying amounts of lead, the researchers found that X-ray imaging could more easily detect ink with lead — present in some of the ancient scrolls — than nonmetallic ink.

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So far, only a few of the real scrolls have been virtually unrolled. The study’s findings could help identify which Herculaneum scrolls are the next best candidates to noninvasively unroll and decipher, the authors suggest.

“The scrolls are really just like a brick of charcoal that you buy for your barbecue. There’s not a lot of difference,” said lead author Douglas Seiler, a research volunteer with the University of California, Berkeley . “It’s just carbon, and that’s what the problem has been in reading these things. The ink is made from soot.”

AI has difficulty picking up the ink in scrolls that have no metal, as it is essentially “dark carbon on dark carbon,” Seiler said. But when lead is introduced, the ink lights up in the X-ray scans, allowing AI to better detect the text.

The next step after re-creating the scrolls, Seiler added, is to test the real Herculaneum ones to determine what percentage contain lead. “If they took these scrolls one by one to a facility, they could find out in a matter of minutes whether or not they had lead in them,” he said. “A lead signal is very strong.”

To date, one entire scroll and passages from others have been deciphered, largely thanks to the Vesuvius Challenge , a project launched in 2023 that encourages researchers to decode scrolls for cash prizes.

For the most part, the scrolls studied are the ones in the best shape, “the nice ones that look like toilet paper or a roll of a paper towel — symmetrical,” Seiler said. But there are more than 600 unopened scrolls, and many in the Naples library are crushed and in fragments. For these scrolls, the best method for virtually unrolling and deciphering text would be to scan for lead first, according to Seiler.

A philosopher’s words emerge from charred, ancient scrolls

Computer scientist Brent Seales, cocreator of the Vesuvius Challenge, first uncovered the metallic ink in Herculaneum scrolls in 2009 while studying one of them at the University of Kentucky in Lexington. Later, a 2016 study identified lead in two other fragmented scrolls, suggesting that the metal was intentionally added into the ancient ink.

To find out whether the lead could be useful in decoding the scrolls, Seiler and a team of researchers re-created multiple scrolls using Egyptian papyrus and carbon ink similar to that used in Pompeii. After writing their own passages — including material from the Bible, scripts from Alfred Hitchcock movies and the television show “The Outer Limits” — the researchers rolled up these scrolls and charred them in a low-oxygen, high-temperature furnace to carbonize them, mimicking the conditions that preserved the original scrolls during the eruption of Mount Vesuvius.

Courtesy Douglas Seiler

The team sent the replica scrolls to researchers at the National Institute of Standards and Technology in Gaithersburg, Maryland, to decipher. Using X-ray tomography and virtual unrolling techniques, the researchers were able to reconstruct the scrolls and identify readable text at each lead concentration level.

“In fact, they picked up the images much, much better than we thought,” Seiler added.

The results provide a “new opportunity to finally read some of the more complex Herculaneum scrolls,” according to a news release from the journal. Furthermore, the team’s method of re-creating the Herculaneum scrolls could allow for more training of AI and potentially improve the algorithm’s success at reading ancient texts, the study authors wrote.

Seales, professor of computer science at the University of Kentucky, said that those studying the Herculaneum scrolls have seen “wide variability” in the ink formulations, and there are scrolls with higher concentrations of metal. But the variation and overall low concentrations point to the metal being an accidental addition rather than a standard ingredient at the time, he added.

Paolo Verzone/National Geographic

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“Scrolls with metal in the ink are somewhat easier to read using virtual unwrapping. But that doesn’t mean that the scrolls without metal cannot be read,” Seales said in an email. “The Vesuvius Challenge has applied the power of analytical artificial intelligence to every phase of the problem, showing that even the most stubborn of scrolls can yield evidence of ink.”

Seales, who not involved with the new study, said he admired the team’s “enthusiasm and tenacity.”

“Somehow the scrolls found a way to survive, and we have found a way to redeem them,” he added. “If their revelation is helped by accidental chemistry like lead that found its way into the ink, we can add another miracle to a string of them needed to bring those words back from the brink.”

Taylor Nicioli is a freelance journalist based in New York.

公元 79 年维苏威火山爆发时，数百卷莎草纸卷轴被烧成焦炭，如今静静地躺在意大利那不勒斯国家图书馆里，无人问津。

这些被称为赫库兰尼姆卷轴的碳化文物大多极其脆弱，无法通过物理方式展开。如今，研究人员和民间科学家们正利用X射线技术和先进的人工智能，试图解读隐藏在其中的古代作者的文字。

9月16日发表在科学期刊《PLOS One》上的一项新研究或许能为实现这一艰巨目标提供新的线索。研究人员使用含铅量不同的墨水重新制作纸莎草纸，发现X射线成像技术能够比检测非金属墨水更容易地检测到含铅墨水（一些古代卷轴中含有铅）。

在2000年前的烧焦卷轴中，最早破译的词语之一是“厌恶”。

迄今为止，只有少数真正的赫库兰尼姆卷轴被虚拟展开。作者认为，这项研究的发现有助于确定哪些赫库兰尼姆卷轴是下一个最适合进行非侵入式展开和解读的候选对象。

“这些卷轴其实就像你买来烧烤用的木炭一样，没什么区别，”论文第一作者、加州大学伯克利分校的研究志愿者道格拉斯·塞勒说。“它们都是碳，而这正是解读这些东西的难点所在。墨水是用烟灰制成的。”

塞勒表示，人工智能很难识别不含金属的卷轴上的墨迹，因为卷轴本质上是“深色碳上的深色碳”。但如果加入铅，墨迹在X光扫描中就会显现出来，从而使人工智能能够更好地识别文字。

塞勒补充说，复制卷轴之后，下一步是对真正的赫库兰尼姆卷轴进行检测，以确定其中含铅量。“如果他们把这些卷轴逐一送到检测机构，几分钟之内就能查出它们是否含铅，”他说。“铅的信号非常强。”

迄今为止，已经破译了一整卷卷轴和其他一些卷轴的部分段落，这主要归功于维苏威挑战赛，这是一个于 2023 年启动的项目，旨在鼓励研究人员破译卷轴，并给予现金奖励。

塞勒说，目前研究的卷轴大多保存状况良好，“看起来像卫生纸或纸巾卷一样，对称美观”。但还有600多卷未开封的卷轴，那不勒斯图书馆里的许多卷轴已经破损不堪。塞勒认为，对于这些卷轴，最好的方法是先扫描铅含量，然后再进行虚拟展开和文本解读。

一位哲学家的话语从烧焦的古老卷轴中浮现出来。

计算机科学家布伦特·西尔斯是维苏威挑战赛的共同发起人，他于2009年在肯塔基大学列克星敦分校研究赫库兰尼姆卷轴时，首次发现了其中的金属墨水。后来，2016年的一项研究在另外两卷残缺的卷轴中发现了铅，这表明金属是被有意添加到古代墨水中的。

为了探究铅是否能用于解读卷轴，塞勒和他的研究团队使用埃及纸莎草和与庞贝古城所用类似的碳墨，重新制作了多卷卷轴。研究人员在卷轴上写下了自己的段落——包括《圣经》节选、希区柯克电影剧本以及电视剧《外星界限》的片段——然后将这些卷轴卷起，放入低氧高温炉中进行碳化处理，模拟维苏威火山爆发时保存原始卷轴的环境。

图片由道格拉斯·塞勒提供

研究团队将复制的卷轴送往位于马里兰州盖瑟斯堡的国家标准与技术研究院进行解读。研究人员利用X射线断层扫描和虚拟展开技术，重建了卷轴，并识别出每个铅浓度水平下可辨认的文字。

“事实上，他们捕捉到的图像比我们想象的要好得多，”塞勒补充道。

根据该期刊发布的新闻稿，研究结果为“最终解读一些更为复杂的赫库兰尼姆卷轴提供了新的契机”。此外，研究作者指出，该团队重建赫库兰尼姆卷轴的方法可以用于对人工智能进行更多训练，并有可能提高算法解读古代文本的成功率。

肯塔基大学计算机科学教授西尔斯表示，研究赫库兰尼姆卷轴的学者发现，卷轴上的墨水配方存在“很大的差异”，有些卷轴的金属含量较高。但他补充说，这种差异以及总体较低的金属含量表明，金属是偶然添加的，而非当时的标准成分。

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“使用虚拟展开技术解读墨迹中含有金属的卷轴相对容易一些。但这并不意味着不含金属的卷轴就无法解读，”西尔斯在一封电子邮件中写道。“维苏威挑战赛将分析型人工智能的强大功能应用于问题的各个阶段，结果表明，即使是最难辨认的卷轴也能从中找到墨迹的证据。”

西尔斯并未参与这项新研究，但他表示，他很欣赏该团队的“热情和毅力”。

“这些卷轴不知何故得以保存下来，而我们也找到了拯救它们的方法，”他补充道。“如果像铅混入墨水这样的偶然化学反应有助于揭示它们的真谛，那么我们就能为拯救这些文字免于消亡的一系列奇迹再添一笔。”

泰勒·尼乔利是一位居住在纽约的自由撰稿人。