Hidden Library: How Science Is Virtually Unwrapping the Charred Scrolls of Herculaneum

University of Kentucky/Brent Seales
University of Kentucky/Brent Seales

Brent Seales called them Fat Bastard and Banana Boy. They were two charred, highly fragile relics that had survived the Mount Vesuvius volcanic eruption of 79 CE, which doused residents of Pompeii and neighboring Herculaneum in a searing blast of destructive gas and volcanic matter. Herculaneum was buried under 80 feet of ash that eventually became solid rock.

Entombed for centuries, the city was rediscovered in the mid-1700s. Incredibly, the library of Herculaneum (known as the Villa dei Papiri) was still filled with over 1800 scrolls, solidified into dark husks. The words inside—religious text, scientific observation, poetry—could provide unprecedented insight into human history. Yet unraveling them has proved difficult. The papyri are so damaged and rigid from lack of moisture that they suffer from a kind of archaeological rigor mortis. And unlike the paralysis that seizes the body upon death, this condition is permanent. Delicate attempts to open the scrolls by hand have been destructive. For a long time, it seemed as if the secrets of the texts would remain locked away for good.

But as Seales stared at the two hardened masses in front of him in 2009, he didn’t share that pessimism. A professor of computer science at the University of Kentucky, he believed that the manual unwrapping that had long failed could be replaced by virtual unwrapping—the digital opening of the texts using computer tomography (CT) scanning and software to penetrate inside the rolled-up scrolls, revealing layers once thought invisible to the eye.

“It’s the only library from antiquity that we have,” Seales tells Mental Floss. “All the knowledge that seems lost, your imagination can run wild.”

 
 

Seales first grew curious about the role of digital manipulation in 1995, when he was invited to assist the British Library in London in scanning and preserving Beowulf. Its 1000-year-old pages had been damaged by fire and warped by the passage of time, imperfections that 2D scans left intact. The use of special software and a 3D visualization, Seales realized, could make it possible to actually flatten the pages and restore smeared copy.

The idea of capturing and manipulating visual data came from Seales's experience in medical imaging, where CT scans can peer inside the body in a noninvasive manner. What if, Seales wondered, the same principle could be applied to the study of fragile documents? What if a relic could be examined in the way a radiologist can visualize, say, the lungs? "That was the eureka moment," he says.

A digital CT scan of a damaged scroll that is being reconstructed
A CT scan of a damaged scroll, with layers visible (L). The red outline is digitally reconstructed in a process called "segmentation" (R).

Seales believed he could use these diagnostic tools to virtually rebuild manuscripts, and returned to the British Library in 2000 to examine other warped documents. After taking images using a prototype of a machine that achieved 3D scans without physical contact, he wrote software that smoothed out the buckled and bunched pages. He likens it to a computer mimicking the tug of gravity, or reversing the direction of a billowing flag. The technique worked—he was able to achieve realistic, flat versions of centuries-old damaged pages.

But Seales believed he could set his ambitions higher: to not only virtually repair a damaged page, but peer inside the Herculaneum scrolls without the risk of causing additional harm. Like many scholars before him, the allure of Herculaneum's vast repository of knowledge had captured his curiosity.

However, the idea of subjecting the scrolls to even minimal handling was something few would consider. Only the Institut de France—one of four major holders of the scrolls—would entertain the idea, and it took four long years to convince them of the possibilities. In 2009, they finally granted permission to Seales's team to scan two Herculaneum scrolls they had in their possession. Officially, the scrolls were categorized as P.Herc.Paris 3 and P.Herc.Paris 4. Seales nicknamed them Fat Bastard and Banana Boy.

The easiest way to imagine the first part of his process is to visualize a sheet of dough that is covered with small red letters and then rolled up. Seen from its edges, the wrap displays its layers and colored pieces, though no observer could possibly identify sentences from that perspective. By slicing the roll into cross-sections as small as 14 microns thick (human hairs are around 75 microns) in a process known as volumetric scanning, Seales can then use geometric "mesh" to reassemble them into a readable surface, depicting the paper so it appears to be as flat as the day it was first written on.

In 2009, the technique allowed Seales to peer inside a closed Herculaneum scroll for the first time, revealing a fibrous labyrinth of data that initially looked like coiled string.

“We saw this amazing structure,” Seales says. But that's where things went wrong.

Seales had believed that trace metals commonly found in the ink of the period could be isolated by the imaging, separating them from the page once the scroll was unraveled and rendering the script legible. But so little of the metals were present that it didn't allow him to identify letters. Nor could Seales distinguish the carbon in the papyrus from the carbon in the ink, which rendered them indistinguishable from one another. The software also wasn't prepared to process the terabytes of data from the scan. While he technically had been able to look inside the scrolls, there was no functional way to determine what he was seeing.

Over the next several years, “Seales Stymied” became something of a headline in academic circles. That ignored the larger point: Seales had proven it was possible to retrieve images from inside the Herculaneum scrolls. It was now a matter of how best to visualize and process it.

 
 

The Herculaneum scans pushed Seales and his team to renovate their software, an act made easier by Seales’s sabbatical work as a visiting scientist at Google’s Cultural Institute in 2012 and 2013. “The interns helped me with the algorithms,” he says, which was a major perk of working for one of the world’s most concentrated and talented assembly of programmers.

His software was vastly improved by the time Seales was approached in 2014 by Pnina Shor, the curator of the Dead Sea Scrolls Project at the Israel Antiquities Authority. Shor had heard of Seales’s work and wanted to know if he could take a look at some CT scan data she had gathered from a 3-inch stick of parchment found in En-Gedi, Israel, in 1970. There was probably ink, but it was obscured by the folds and twists of the parchment.

A CT scan of the En-Gedi scroll, along with a virtual example of how it might look unfolded
The En-Gedi scroll's layers are tightly wound (L). Special software is able to isolate one layer to look for text (R).

Seales looked at the scans and applied his process for virtual unwrapping. He used a step he called "texturing," which identifies density differences and other data on the paper that indicate where ink has been applied and assigns a value to that point. Logging the information on individual voxels—the 3D equivalent of pixels—he's able to reassemble them so they appear as a familiar letter shape. The data is then flattened so it resembles an unrolled sheet.

The En-Gedi scroll was made from animal skin, which Seales says is better for contrast against the ink than papyrus, and also benefited from resolution that was twice as good as what he used in 2009. He sent his findings to Shore in 2015; she wrote him back an email humming with excitement. Seales didn’t know what he had uncovered—he doesn’t read Hebrew—but Shor did: It was the first two chapters of the Book of Leviticus, the earliest example of Bible text after the Dead Sea Scrolls themselves.

“When we saw the results we almost fainted,” Shor told reporters. “We had been certain it was just a shot in the dark.”

The fully unwrapped En-Gedi scroll with writing visible
The fully unwrapped En-Gedi scroll revealed writing that had not been seen in centuries.

Shor’s willingness to embrace new technology helped reveal text locked away for centuries. Conservators are notoriously cautious when it comes to handling such delicate relics—even though Seales never touches one personally, since curators are responsible for getting scrolls in and out of CT scanners. Only recently has Seales been able have more productive conversations at the Officina dei Papiri at the National Library of Naples in Italy, where the bulk of the Herculaneum scrolls are kept, and the University of Oxford. (The Institut de France and the British Library also hold Herculaneum scrolls.)

He remains optimistic that the method used for the En-Gedi material will work for the Herculaneum collection. At a conference this past March, he and members of his team presented new findings showing success in determining the column structure of one text (17 characters per line), as well as reading specific letters—and even entire names. Part of the breakthrough comes from high-powered x-ray beams like the one housed at Diamond Light Source in the UK, which are proving potent enough to isolate the trace amounts of lead in the ink.

 
 

The progress can seem glacial, but Seales has nonetheless gone from imaging a wrapped papyrus to isolating a clearly defined letter. Next, he hopes, will come sentences, possibly isolated by artificial intelligence software he's currently writing.

But even with permission, Seales’s pursuit of a viewable Herculaneum fragment is still dependent on funding. “I sometimes cringe when I see people say, ‘Seales has been working on this for two decades, unable to figure out the problem,’” he says. “Funding comes and goes.” Commercial applications for his software and methodology—like bone scanning or even virtual colonoscopy—could one day underwrite the academic work.

With access, cooperation, and a little luck, he remains optimistic we’ll eventually be able to uncover the knowledge long buried by Mount Vesuvius—time capsules that are slowly revealing their secrets, one micron at a time.

All images courtesy of University of Kentucky/Brent Seales.

10 Citizen Science Projects That Need Your Help

A citizen scientist takes a photo of scarlet mushrooms.
A citizen scientist takes a photo of scarlet mushrooms.
lovelypeace/iStock via Getty Images

Channel your inner Nikola Tesla or Marie Curie by participating in actual scientific research, either out and about or without even leaving your couch. These projects unleash the power of the public to be places that researchers can’t be and to spread the workload when data start piling up. They really can’t do it without you.

1. Catalog photos of Earth's cities at night.

Photo from space of a city at night
Identify cities from the photos taken from the International Space Station.
Chris Hadfield, NASA // Public Domain

Cities at Night—a study by Complutense University of Madrid—asks people to catalog images of the Earth at night taken from the International Space Station, part of the millions of images in the Gateway to Astronaut Photography of Earth database. The current project, Lost at Night, needs people to identify cities within images of 310-mile circles on Earth. Hundreds of volunteers have classified thousands of images already, but classification by multiple individuals ensures greater accuracy. In fact, the project will determine the optimum number of people needed. The primary goal is an open atlas of publicly available nighttime images. Just log on to the image database to help.

2. Follow fish using high-tech tags.

You’ll have to go fishing—an outdoor activity you can do by yourself!—for this assignment. Volunteer to tag fish for the American Littoral Society, whose citizen scientists have tagged more than 640,000 fish since the program began in 1965. You can tag the fish you catch and release, or report tagged fish to the organization. The data is sent to the National Marine Fisheries Service Laboratory in Woods Hole, Massachusetts, where it helps scientists track the populations and movements of coastal species like striped bass, flounder, and bluefish. To get started, become a member of the American Littoral Society, which comes with a packet of tagging gear and instructions.

3. Spy on penguins in Antarctica.

Penguins on an ice floe
Keeping tabs on penguins is one way a citizen scientist can lend a hand.
axily/iStock via Getty Images

Here's another project for those stuck indoors. Penguins are threatened by climate change, fisheries, and direct human disturbance, yet scientists have little data on the birds. To fill in the gaps, 50 cameras throughout the Southern Ocean and Antarctic Peninsula take images of colonies of gentoo, chinstrap, Adélie, and king penguins year-round. You can help the University of Oxford-based research team by sorting through thousands of images to identify and mark individual adult penguins, chicks, and eggs. You'll be pinpointing seasonal and geographic variations in populations that may represent changes to the Antarctic ecosystem. Marking other animals in the images helps researchers figure out which ones are hanging around penguin colonies. Discuss a specific image or the project with the science team and other volunteers in an online forum.

4. Battle an invasive marine species.

Like to dive or snorkel? Make it count by reporting lionfish sightings or captures to the Reef Environmental Education Foundation's Volunteer Reef Survey Project. Lionfish, which are native to the Indo-Pacific, were first sighted in the South Atlantic in 1985 and were likely released by private aquarium owners. Since then, they have spread throughout the Caribbean and Gulf of Mexico and caused native fish populations to decline by up to 80 percent. Scientists say this invasion may be one of the century’s greatest threats to warm temperate and tropical Atlantic reefs. You can also join a lionfish derby to catch and kill some of the tasty fish so scientists can analyze their biology.

5. Count birds from your backyard.

Bluebirds at a bird feeder
Bluebirds dine on mealworms at a bird feeder.
MelodyanneM/iStock via Getty Images

North American birds are in trouble. Recent studies predict dramatic declines in the populations of migratory birds due to climate change—and much of the data that went into these studies came from citizen scientists who monitored species without leaving home. The Cornell Lab of Ornithology and Birds Canada launches Project FeederWatch in the winter months; you simply put out a bird feeder and report the number and species of birds that visit it. Citizen scientists can also join the Cornell Lab's NestWatch—you find a nest, monitor it every three or four days, and report your data. And every February, the Audubon Society runs the Great Backyard Bird Count, in which participants submit data to produce a real-time snapshot of bird populations across North America. Any time of the year, birdwatchers can submit lists of the birds they see on eBird, a huge database of sightings that informs public policy, conservation efforts, and other initiatives.

6. Photograph plants for climate change research.

The Appalachian Mountain Club's Mountain Watch program asks hikers to document alpine and forest plants for ecological research. By taking photos of flowers and fruiting plants along woodland trails and uploading them to the iNaturalist app, participants provide data about the times and places that plants bloom. Scientists then compile the information in an online database and analyze it for trends that could indicate changing climates.

7. Comb through ships' logbooks for weather data.

Old handwritten letters
Practice your handwriting-deciphering skills on the Old Weather project.
scisettialfio/iStock via Getty Images

Ships’ logs from mid-19th century American sailing vessels contain detailed weather observations. Citizen scientists can help transcribe observations from whaling vessels for the Old Weather project; scientists will use the information to learn more about past environmental conditions and create better climate models for future projections. Historians will also use the data to track past ship movements and tell the stories of the people on board.

8. Make American history documents and science notes accessible to more people.

The Smithsonian Libraries are stuffed with original history and science documents that have lain in drawers for decades. Help open up "America's attic" to the public by organizing and transcribing digital versions of handwritten field notebooks, diaries, logbooks, specimen labels, photo albums, and other materials. You'll join thousands of other volunteers to investigate documents like the Sally K. Ride Papers, the collection of the Freedmen's Bureau (which helped former slaves following the Civil War), and field studies of insects by the Irish naturalist Arthur Stelfox.

9. Investigate historical crimes in Australia.

Drawing of a convict ship to Australia
A drawing of a 19th-century convict ship destined for Australia.
Photos.com/iStock via Getty Images

If you're obsessed with true crime, you'll love this project. Volunteer to investigate and transcribe criminal records from 19th- and 20th-century Australia, which was founded as a British penal colony. Alana Piper, a postdoctoral research fellow at the Australian Centre for Public History at the University of Technology Sydney, will use the transcriptions to construct the "life histories and offending patterns of Australian criminals" from the 1850s to the 1940s. More than 40,000 subjects have been completed so far.

10. Map the unique features of Mars's South Pole.

Travel to Mars—without the hassle of zero gravity or space-vegetable farming—through Planet Four, a citizen science project that is currently tasked with identifying features on Mars's dynamic South Pole. Volunteers examine photos from the HiRISE camera on NASA's Mars Reconaissance Orbiter and pick out "fans" or "blotches" in the landscape of seasonal carbon dioxide ice. Scientists believe these structures indicate wind speed and direction on the Martian surface and offers clues about the evolution of the Red Planet's climate.

Why Cats Like to Shove Their Butts in Your Face, According to an Animal Behavior Expert

This cat might be happier showing off its butt.
This cat might be happier showing off its butt.
Okssi68/iStock via Getty Images

Cats are full of eccentric behaviors. They hate getting wet. Their tongues sometimes get stuck midway out of their mouths, known as a “blep.” And they’re really happy hanging out in bodegas.

Some of these traits can be explained while others are more mysterious. Case in point: when they stick their rear end in your face for no apparent reason.

Are cats doing this just to humiliate their hapless caregivers? What would possess a cat to greet a person with its butt? Why subject the person who gives you food and shelter to such degradation?

To find out, Inverse spoke with Mikel Delgado, a postdoctoral fellow at the School of Veterinary Medicine at UC Davis. According to Delgado, cats don’t necessarily perceive their rectal flaunting as anything aggressive or domineering. In fact, it might be a cat’s way of saying hello.

“For cats, it’s normal for them to sniff each other’s butts as a way to say hello or confirm another cat’s identity,” Delgado said. “It’s hard for us to relate to, but for them, smell is much more important to cats and how they recognize each other than vision is. So cats may be ‘inviting’ us to check them out, or just giving us a friendly hello.”

For a cat, presenting or inspecting a butt is a kind of fingerprint scan. It’s a biological measure of security.

Other experts agree with this assessment, explaining that cats use their rear end to express friendliness or affection. Raising their tail so you can take a whiff is a sign of trust. If they keep their tail down, it’s possible they might be feeling a little shy.

If you think this situation is eased by the fact you rarely hear cats fart, we have bad news. They do. Because they don’t often gulp air while eating, they just don’t have enough air in their digestive tract to make an audible noise. Rest assured that, statistically speaking, there will be times a cat giving you a friendly greeting is also stealthily farting in your face.

[h/t Inverse]

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