Scorched by fire, ravaged by mold and further damaged by human forgeries, the 1,000-year-old goatskin manuscript isn’t pretty to look at. And it’s even harder to read. But because it’s the oldest, most authentic copy of Archimedes’s approaches to calculus and the question of infinity, physicists and scholars have joined forces to uncover the words and decipher the meaning of them.
First copied down in Greek by a 10th-century scribe, the manuscript was almost obliterated two centuries later by a monk in search of reusable writing paper. He doused the text with an acidic wash and then scrubbed it off the parchment pages with a pumice stone. By cutting the pages in half, rotating them 90 degrees and rebinding them, the monk created a new book where he could write medieval prayers. Overwriting one manuscript with another resulted in what’s known as a palimpsest.
Consigned for centuries to a monastery in the Judean desert, the palimpsest passed through occasionally shady hands, including one owner who painted Byzantine religious illustrations on several pages in the hope of increasing its value as a work of art. In 1906, Danish philologist Johan Heiburg discovered the manuscript in Constantinople, Turkey (now Istanbul). Using only a magnifying glass and natural light, he was able to read some faint lines of brown ink and determine it was a copy of the work of Archimedes, the 3rd-century Greek genius who had calculated the value of pi. The Archimedes palimpsest ultimately was bought for $2 million in 1998 by an anonymous collector who turned it over to the Walters Art Museum in Baltimore for restoration.
Teams of researchers from Johns Hopkins, Rochester Institute of Technology, Rutgers, RB Toth Associates and ConocoPhillips had recovered writings on some 80 percent of the 174 extant pages by the time Uwe Bergmann, a physicist at the Stanford Linear Accelerator Center, heard about the project in 2003. But while they use ultraviolet light and computer imaging to make the ancient Greek letters more visible, Bergmann turned to X-ray fluorescent spectroscopy to identify traces of iron in the original ink—and, like a dot-matrix printer, to map out individual letters, one by one. Between the two approaches, researchers hope, scholars will be able to study virtually the entire manuscript.
Last spring, researchers from the Walters museum traveled to Palo Alto with three pages of the Archimedes palimpsest as carry-on luggage, in a sealed container the size of a cigar box. For five days in May, Bergmann and his team painstakingly X-rayed the leaves. Working in cramped quarters behind the light blue door of hutch BL 62 at the Stanford Synchrotron Radiation Laboratory (SSRL), they were able to scan one half-page each day.
Stanford classicists and mathematicians are hopeful about the project, which will continue in January. “At this stage, it is too early to speak of the contents of the three pages for which we made the preliminary experiments at SLAC,” says Reviel Netz, professor of classics and a historian of premodern mathematics, who has been studying the palimpsest since 2001. “But one thing is clear—for the pages covered by [painted] forgeries, X-rays are going to provide a workable image, which would have been impossible with any other technique.”
Keith Hodgson, director of SSRL and, like Bergmann, a specialist in spectroscopy, is used to studying biomolecules, not inks on ancient parchments. But he clearly sees the excitement in the new experiment. “The ability to use the technology we have to study an antique object of great historical significance is really the ability to go back and look at something that was lost,” he says.
