Walter Miller's post-apocalyptic novel A Canticle for Leibowitz begins with the discovery by monks of a precious and holy relic; a piece of paper with a message from the Blessed St. Leibowitz. The relic is brought back to the monastery, where it is ensconced in a reliquary and becomes the object of great devotion. Furthermore, the writing on the paper is analyzed, discussed, and prayed over, because surely any message from the Blessed Saint must have some deep meaning.
The message, in its entirety, was: "Pound pastrami, can kraut, six bagels -- bring home for Emma."
Humans have a tendency to confuse the words "mysterious" and "deep." If we don't understand something, especially something to which we have attached an aura of religion, intrigue, or romance, we seem to conclude automatically that it has great significance. While some texts that have yet to be deciphered are likely to contain interesting information, just by the law of averages we'd expect that some of them... don't.
My sense is that the Voynich Manuscript is one of the latter. It is a bound volume, allegedly from the 15th century, with colored drawings of plants, astronomical objects, mythical animals, and a host of other fanciful items. (You can see images of it, and read more about it, here.) The writing is in a set of characters that has yet to be deciphered, and has been the source of much speculation, from the ridiculous (that it is an alchemical manual whose contents contain magical knowledge of such power that it had to be hidden) to the pragmatic (it's a hoax).
The manuscript itself was named for Wilfred Voynich, who owned it in the early 20th century. After his widow's death in 1960, it was donated to Yale University, where it currently resides.
Recently, scientists were allowed to snip tiny pieces off of four different pages in the manuscript, and it was conclusively carbon-14 dated to between 1400 and 1438. Note that this only tells us the age of the parchment, not the age of the writing. The antiquity of the parchment has reawakened interest in the manuscript, both by legitimate scholars and by woo-woos who think that they'll be the one to translate it -- and acquire its secret knowledge.
Of the many hypotheses of its origins, the one that seems to be the likeliest is that it was produced by Edward Kelley. Kelley was a self-styled alchemist during the reign of Elizabeth I, who became friends with the famous alchemist and mystic John Dee. Dee was apparently duped by Kelley's fantastic claims, which included a purported ability to transmute copper into gold using a powder he'd obtained by grave-robbing a Welsh bishop's tomb. Apparently finding this scientifically plausible, Dee invited Kelley to accompany him to Prague, and Kelley became Dee's "scryer" -- Kelley would stare into a "shewstone" (the Elizabethan ancestor of the crystal ball) and have conversations with angels. The angels spoke a language that Kelley called "Enochian," but Kelley translated what they said, and Dee dutifully wrote it all down. Many scholars suspect that Kelley, in order to make his story more convincing (and probably to make money by selling the manuscript), turned out the Voynich Manuscript in "Enochian" to make his story more plausible.
But how do we know it isn't a cipher, or an actual language? There are a few features of the Voynich Manuscript that seem to indicate that it's nonsense. The first is that the best cryptographers in the world have been unable to crack it, even using computer algorithms designed for the purpose. Writing in ciphers was a common practice in medieval and Renaissance times, especially among the alchemists, and all of these passages have quickly fallen to cipher-breaking techniques. Given the length of the Voynich Manuscript (240 pages), it's extremely unlikely that these techniques wouldn't have cracked the code -- if there was anything sensible there in the first place.
Second, there are some very "un-language-like" features of the text in the Voynich Manuscript. There are a number of places where words are repeated two or even three times in a row -- something that is not at all common in written language. The distribution of word lengths is also suspect -- most of the words are between five and eight characters long, and there are very few extremely short words. This, again, is unlike virtually every written language currently in existence. Given the success of linguists in decoding written languages for which they had no spoken referent (e.g. Linear B in Crete), I'd say they're pretty good at recognizing what a real language looks like -- and, by extension, what a non-language would look like.
Most damning is a statistical study done in 2003 by Gordon Rugg, followed up by a 2007 study by Andreas Schinner, which showed that the frequency and patterns of syllables in the Voynich Manuscript was consistent with gibberish -- i.e., they were random. Schinner used a computerized analysis of the text from the Voynich Manuscript and showed that it could have been produced by a completely stochastic method -- one in which syllables were chosen in a non-meaningful manner, to give the appearance of language.
Of course, none of this will stop the woo-woos from claiming that the Voynich Manuscript contains the Secrets of the Ancients. As Casaubon found out in Umberto Eco's amazing novel Foucault's Pendulum, the more you deny that there is any meaning in something, the more the true believers become convinced that there must be -- otherwise, why would you be so desperate to deny it? It's hard for us to accept the possibility that there is no meaning in something as fanciful, and stirring to the imagination, as the Voynich Manuscript. Given that Miller's monks tried to find meaning in "Pound pastrami, can kraut, six bagels -- bring home to Emma," we shouldn't be surprised if the controversy over the Voynich Manuscript is not over any time soon.