To Crack the Voynich Code

In 1912, Wilfrid Voynich, an antique book dealer from New York, sat sifting through a chest of books offered for sale by the Society of Jesus at the Jesuit’s Ghislieri College near Rome. He discovered a manuscript of about 240 parchment pages written in a mysterious script—unintelligible but clearly penned from left to right—and filled with illustrations that looked like everything from botanical and biological images to astronomical and zodiacal diagrams.

He dedicated the remaining 18 years of his life to solving the book’s hidden meanings. He died never having deciphered any of its secrets.

Today, this same text, which has come to be known as the Voynich Manuscript, is currently owned by the Beinecke Rare Book and Manuscript Library of Yale University. Researchers from many different fields have, over the years, attempted to decipher the book’s meaning. One possibility is that it is a known language disguised through the use of an invented alphabet, perhaps with letters and words scrambled by some complex algorithm. Why the disguise? Perhaps the ideas it contains were considered controversial or even dangerous. If it is some sort of code, it has defied decryption by generations of cryptanalysts. Other theories suggest the book is pure nonsense, the work of a deranged madman or perhaps a clever charlatan. Perhaps the book is the literary equivalent of snake oil – something that appears to promise great knowledge but is in fact meaningless gibberish. Authorship theories have ranged the medieval philosopher Roger Bacon to Leonardo da Vinci to even Voynich himself. Whatever it is, decades, perhaps centuries of careful scrutiny have yielded few insights into the manuscript’s meaning.

Pursuing an Answer

While of interest to the academic community for nearly a century, the Voynich Manuscript has only recently become known to the general public. In 2009, two Austrian documentary filmmakers discovered the manuscript on an inventory list of possessions of a 17th century king and tracked it to Yale University. As the filmmakers worked with Yale to develop a story about the manuscript, they realized that they had all they needed to answer at least one key question about the book right away: When was the book actually made?

The team contacted Greg Hodgins, Ph.D., a research scientist and assistant professor who holds a joint appointment in the University of Arizona’s departments of physics and anthropology. Hodgins and his team had the perfect toolset to date the book: the NSF Arizona Accelerator Mass Spectrometry Laboratory.

Cracking the Carbon Code

Because the parchment pages of the Voynich Manuscript were made from animal skin, they could be radiocarbon-dated.

Carbon-14, a rare radioisotope of carbon, occurs naturally in the Earth's environment. There is only one carbon-14 atom per trillion non-radioactive or "stable" carbon isotopes. When a plant or animal dies, the level of carbon-14 in its remains drops at a predictable rate, and so can be used to calculate the amount of time that has passed since death.

To obtain the sample from the manuscript’s parchment pages, Hodgins traveled to Yale.  There he collaborated with Voynich Manuscript expert Rene Zandbergen and Yale University Library Book and Manuscript Conservator Paula Zyats. Together, they selected which pages would be best to sample.

"Then, I sat down with the Voynich manuscript on a desk in front of me, and delicately dissected a piece of parchment from the edge of a page with a scalpel," Hodgins says.

He cut four samples from four pages, each measuring about 1 by 6 millimeters—about the size of a fingernail clipping—and brought them back to the laboratory in Tucson. Here, they were thoroughly cleaned, the carbon isolated from the other parchment elements, and the spectrum of carbon isotopes measured.  

"In radiocarbon dating, the process is fairly complex," he says. "It takes many skills to produce a date. From start to finish, it requires archaeological expertise, biochemical and chemical expertise. We also need physicists, engineers and statisticians. It's one of the joys of working in this place that we all work together toward this common goal."

Hodgins and his team have concluded that the book was made between 1404 and 1438. Their discovery immediately put to rest some of the previously held hypotheses about the Voynich Manuscript’s origins and history.  Even scholars who favored a Renaissance age for the book were surprised by a date nearly 100 years earlier they suspected.

As for the documentary that was the original motivation for the effort, it was completed and National Geographic Television released the English version in early 2011 under the title The Book That Can’t Be Read.

For the Love of Mystery

While Hodgins is quick to point out that anything beyond the dating aspect is outside his expertise, he admits he is just as fascinated with the book as everybody else who has tried to unveil its history and meaning. And Hodgins is no stranger to using science to unlock the secrets of history. He and the Mass Spectrometry Lab team have helped to work with other historic mysteries, as well, from the Shroud of Turin to the Dead Sea Scrolls.

In 2005, they worked on a crumbling papyrus book written in a rare Coptic language of unknown origin. Because it might have been stolen, it was unsellable and languished crumbling and untranslated in a bank vault. The National Geographic Society and the Maecenas Foundation for Ancient Art rescued the book now known as the Codex Tchacos, and scholars are unraveling its significance.

Hodgins and his colleagues dated the codex to 220-340 AD, and it is now believed to be the oldest written version of the Gospel of Judas. After conservation treatments and studies are complete, the Codex Tchacos will be given to the Coptic Museum in Cairo. 

As for the Voynich Manuscript, its meaning will remain a mystery, at least for now.

"Who knows what's being written about in this manuscript, but it appears to be dealing with a range of topics that might relate to alchemy,” says Hodgins. “Secrecy is sometimes associated with alchemy, and so it would be consistent with that tradition if the knowledge contained in the book was encoded. What we have are the drawings. Just look at those drawings: Are they botanical? Are they marine organisms? Are they astrological? Nobody knows."