Uwe Bergmann had a magic wand. That's how it seemed, anyway, to the folks who crowded into his small experimental workstation at the Stanford Synchrotron Radiation Laboratory (SSRL) in May 2005.
Bergmann, a staff scientist at SSRL, had learned about the Archimedes palimpsest while he was visiting his hometown of Karlsruhe, Germany. His mother had left a copy of GEO magazine next to his bed, and inside was an article about the trouble the palimpsest project's leaders were having imaging its most damaged folios.
Bergmann didn't know much about Archimedes. But he knew a lot about synchrotron radiation, the intensely bright X-rays emitted by particles circulating near the speed of light in Stanford's Positron Electron Accelerating Ring. Since SSRL's founding in the early 1970s, researchers have found all kinds of interesting uses for these powerful by-products of the atom-smashing process. Bergmann was using them to illuminate dilute solutions of pureed spinach, to understand how plant cells take up and split water molecules during photosynthesis.
As Bergmann pored over the article, one particular detail caught his eye: Byzantine scribes made their ink by mixing crushed oak galls with ferrous sulphate. The physicist wondered: if synchrotron radiation could detect trace amounts of iron in his spinach solutions, could it also be used to image the iron particles in the palimpsest's ink?
Efforts to read through the forgeries and grime with commercial X-ray imaging systems had proved agonizingly slow. So the Walters Art Museum staff authorized tests to make sure that the synchrotron's continuously moving X-ray beam, about the width of a human hair, wouldn't hurt the palimpsest's delicate parchment. When those proved satisfactory, a team from the museum flew to California with several folios carefully packed inside sealed boxes within their carry-on luggage.
Working with about a dozen enthusiastic SSRL scientists, Bergmann carefully prepared a cramped, lead-lined workstation for the team's arrival. Along the way, he improvised. To keep the parchment from curling in California's dry air, he modified a humidifier from Sears. “It didn't look like a professional setup,” Walters curator William Noel recalls in The Archimedes Codex. “Inside the hutch the guts of the machinery were scattered all over the place; outside the hutch looked like an electronics junk yard.”
Nevertheless, Noel recalls, “from the moment the scanning started, it was clear that something extraordinary was happening. The charred, stained and worm-eaten parchment in the hutch appeared on the screen as a dense lattice of Greek characters. I knew that we were seeing, pixel by pixel, line by line, here at the Stanford synchrotron, a map of the iron on the page.”
Walters staff were so pleased with the results that they came back to SSRL the following year with more damaged pages, including several that were unreadable because of mold and soot. By the end of last summer, Bergmann and his colleagues were capable of imaging a full page every 12 hours—hundreds of times faster than systems relying on commercial X-ray tubes. Among their magical revelations: a previously invisible Page 1 inscription written by the priest who created the palimpsest in 1229, Ioannes Myronas.
“Originally when I was starting this project, I said to myself, 'I hope that we can just read at least one word which has never been read before.' But now we have done more than that, and it's fantastic,” Bergmann says. “It would have been more exciting for me if I could read ancient Greek,” he adds, laughing. “But all in all, it was ecstatic.”
