Play Live Radio
Next Up:
Available On Air Stations

A Prayer Book's Secret: Archimedes Lies Beneath

Why would anyone pay $2 million for a tattered book of Christian prayers from 1200 A.D.? The anonymous philanthropist who coughed up the sum in 1998 wasn't lured by the holy writings. He was after the faint ink beneath -- mathematical theorems and diagrams from the Greek scholar Archimedes, who lived more than 2,000 years ago. It's the oldest known copy of his work, but the writings were barely legible. But now, a new restoration technique may make it possible to recover all of Archimedes' original text.

Bathtub Brilliance

As the legend goes, Archimedes discovered the principle of buoyancy in his bathtub, prompting him to shout "Eureka!" Regardless of whether this story is true, Archimedes was, without a doubt, a great mathematician. Little of his work has made it down through the ages, but what has survived is startling. He writes about infinity -- different levels of infinity, actually -- which is astounding for a scholar from the second century B.C.

Hidden Text

The prayer book is known as the "Archimedes Palimpsest" -- a palimpsest is a document with hidden writing -- and it resides at the Walters Art Museum in Baltimore.

"It’s the ugliest thing in the collection," says William Noel, curator of rare books at the Walters. "It is also by far the most important text manuscript in a palimpsest that the world knows."

Noel cannot reveal the owner's name; he'll say only that he has a big heart. And a big agenda. He wants every possible word of Archimedes extracted, even though some pages are at the point of crumbling into dust, and others have fallen victim to the ravages of bookworms.

A parchment shortage is to blame for the overwriting. The original text apparently sat in a library in Constantinople until 1229 A.D. Then a scribe erased it; he needed someplace to write a prayer book. Seven hundred years later, Archimedes expert John Ludwig Heiberg discovered the traces of Archimedes after reading a few lines transcribed by a scholar in 1899. Over the next few decades, the book had a mysterious life, disappearing and reappearing. Eventually, it was sold at auction.

Since then, scholars and scientists have used ultraviolet light to make letters stand out. But the method did not work on every page. Some were too damaged; others were covered with forgeries – paintings created in the 20th century and made to look older to drive up the value of the book.

Of Spinach and X-Rays

Popeye's favorite vegetable holds the key to uncovering the rest. Uwe Bergmann, a Stanford physicist, was attending a conference in Germany when he stumbled upon an article describing the Archimedes Palimpsest. At the Synchrotron Radiation Laboratory, a Department of Energy research facility in Stanford, Bergmann studies the physics of photosynthesis -- in particular, photosynthesis in spinach.

"I read that there is still some significant text missing, and that there are forgeries and that there's iron in the ink. When I read the word 'iron,' I said, 'Wait a minute, we are studying iron in spinach.' I thought we should be able to use the same method and just then do imaging with it."

Bergmann proposed his idea in an e-mail to William Noel, suggesting that the Stanford Linear Accelerator in California might be used to provide the necessary X-ray pulses through the document. Although at first concerned about potential harm to the document, Noel and the team conducted tests and decided the technique could be done safely. Bergmann’s idea worked. The first pictures emerged, line by line.

"I wished I could read ancient Greek. Very beautiful looking characters all over the place," Bergmann remembers.

The Man Who Erased History

The museum pressed ahead in its research and, just a few months ago, uncovered new diagrams and text in the original Greek -- as well as the signature of the scribe who erased the Archimedes text and wrote the prayers on top.

"It just popped up," says Noel. "A guy called Johannes Myronas."

Despite the damage done to the ancient text, Noel doesn’t blame Myronas for the present state of the book. In fact, Myronas was most likely responsible for the book's survival.

"What a gift he gave us," Noel points out. "The great advantage of having them wrapped up in a Christian prayer book is that they were treasured and looked after for centuries."

So it was a love of math that preserved Archimedes' work for the first thousand years -- and a love of God that carried it to the present.

Copyright 2023 NPR. To see more, visit

David Kestenbaum
David Kestenbaum is a correspondent for NPR, covering science, energy issues and, most recently, the global economy for NPR's multimedia project Planet Money. David has been a science correspondent for NPR since 1999. He came to journalism the usual way — by getting a Ph.D. in physics first.
Related Stories