Multispectral Imaging: "Da Vinci Code II?"

By Tom Hundley
Chicago Tribune
OXFORD, England - The scholars at Oxford University are not sure how it works or why; all they know is that it does.

A relatively new technology called multispectral imaging is turning a pile of ancient garbage into a gold mine of classical knowledge, bringing to light the lost texts of Sophocles and Euripides as well as some early Christian gospels that do not appear in the New Testament.

Originally developed by NASA scientists and used to map the surface of Mars, multispectral imaging was successfully applied to some badly charred Roman manuscripts that were buried during the eruption of Mount Vesuvius in A.D. 79. Examining those carbonized manuscripts under different wavelengths of light suddenly revealed writing that had been invisible to scholars for two centuries.

Now scientists are shining the multispectral light on the Oxyrhynchus Papyri, an enormous collection of texts unearthed from the rubbish heaps of the vanished city of Oxyrhynchus, about 100 miles south of Cairo.

First excavated by two Oxford archaeologists in the late 19th century, the hoard of papyrus from Oxyrhynchus has long been a source of fascination and frustration for scholars: fascination because it holds some of the lost masterpieces of classical literature, frustration because much of it is in such poor condition it’s impossible to read.

But the multispectral imaging has ``produced miraculous results,’’
according to Dirk Obbink, a lecturer in papyrology and Greek literature at Oxford who is directing the project.

No one knows exactly why it produces the results it does,'' Obbink said of the technology. But with texts that are difficult to read, it’s a night-and-day difference.’’

In the past few weeks alone, researchers have succeeded in deciphering a 70-line fragment from a lost tragedy by Sophocles and a 30-line fragment from Archilochos, a Greek soldier-poet who chronicled the Trojan Wars.

The Archilochos fragment confirms what scholars have long suspected: that the Greeks got lost on their way to invade Troy and mistakenly landed at place called Mysia. There they fought a battle, lost and had to regroup before heading off again for Troy.

The Archilochos fragment will be published this month. The newly discovered lines from Sophocles are scheduled for publication in August.

``To get a piece like that every 10 years, we think ourselves lucky, so I’d have to say that this is a very exciting development,’’ said professor Richard Janko, head of the classics department at the University of Michigan.

Multispectral imaging uses digital cameras equipped with a kind of revolving Lazy Susan of light filters that isolate the waveband at which the obscured ink contrasts most vividly with the dark background of the papyrus, the paper of the ancient Egyptians.

``Some parts (of the writing) respond well to infrared; other parts respond to something further along the spectrum,’’ Obbink said.
A sequence of images taken at all ranges of the light spectrum are then put together, and the result often is a document of startling clarity.

The technique for adapting NASA’s technology to the reading of ancient manuscripts was developed at Brigham Young University in Utah, which is assisting Oxford with the Oxyrhynchus project.

The Oxyrhynchus collection, housed at Oxford University’s Sackler Library, consists of more than half a million scraps of papyrus. Some of it is in excellent condition, but much of it is worm-eaten and darkened by time.

All of it was collected from the rubbish dumps of Oxyrhynchus, a city that flourished after the conquest of Egypt by Alexander the Great in 332 B.C. The city remained prominent in the Roman and Byzantine periods but declined after the Arab conquest in A.D. 641.

For a thousand years, the inhabitants dumped their trash in the desert. Over time the dump sites were covered by sand, and they remained covered until 1896 when Oxford archaeologists Bernard Grenfell and Arthur Hunt began excavating the area.

At first, Grenfell thought that what he and Hunt had found was ``nothing but rubbish mounds,’’ but they quickly came to appreciate that they had found a remarkable window into the literary and ordinary lives of the ancients.

There were plays by Sophocles and Euripides, poems of Pindar and Sappho, and some of the earliest documents recording Christianity’s spread to Egypt. The gospel of Thomas, for example, records the ``Sayings of Jesus’’ in a manner that some scholars of early Christianity believe is more authentic than the Gospels in the New Testament.

There also is an abundance of life’s everyday stuff and miscellanea - tax records, marriage contracts, horoscopes, erotic musings, advice on how to buy a donkey and advice on how to cast a decent magic spell.

``It’s as if you took a slice out of everybody’s hard drive, or every 10th page out of every 10th book in the library - what you have is a complete slice of life,’’ said Obbink, the project director.

The problem was sorting the wheat from the chaff and deciphering scripts that had been damaged or obscured.

Working steadily for more than a century, scholars at Oxford managed to decipher, interpret and publish about 5,000 text fragments, about 1 percent of the total collection, according to Nick Gonis, the collection’s curator. Multispectral imaging could help speed the process.

Meanwhile, the Oxford team is looking at another promising application of the technology. Scholars have long known that the elaborately painted cartonnage used to encase mummies was a kind of papier-mache made from papyrus. A lot of the papyrus has writing on it, but there didn’t seem to be a way of reading it without destroying the decorative cartonnage.

In one recent trial, the imaging process was able to read writing beneath the painted surface of a cartonnage fragment. Scholars were thrilled, even though it turned out to be just another government report.