Authenticating the gospel
Some facets of the document did suggest authenticity. The most promising of these characteristics, Barabe said, was that the ink wasn't piled up in the warped papyrus, suggesting the document was written before the warping happened. Had someone tried to write on a pre-warped papyrus, the ink would have gathered in crevices and dips -- a sure sign someone had intentionally tried to make new papyrus look old. Instead, the Gospel seems to have been written on flat papyrus and aged naturally. National Geographic also commissioned other analyses of the Gospel, including radiocarbon dating, script analysis and linguistic style.
Barabe hit the books, looking for other studies on early Egyptian inks. The study of Egyptian marriage certificates and land documents from the Louvre proved to be the clincher.
That study found that contracts in Egypt in the mid-third century were written in lamp black ink, in the traditional Egyptian style. But they were officially registered in the traditional Greek style, using brown iron gall ink.
The Louvre study findings suggested to the teamthat the presence of both inks was consistent with an early date for the Gospel of Judas, Barabe said.
What's more, the Louvre study found that the metal-based inks from this time period contained little sulfur, just like the ink on the Gospel of Judas.
The discovery gave the researchers the confidence to declare the document consistent with a date of approximately A.D. 280. (Barabe and his colleagues caution that this finding doesn't prove beyond doubt that the document is authentic, but rather that there are no red flags proving it's a forgery.)
"There was definitely a point where, all of the sudden, I just kind of relaxed and said, 'This is probably just fine,'" Barabe said.
Barabe presented the behind-the-scenes story of the Gospel of Judas investigation today (April 8) at the annual meeting of the American Chemical Society in New Orleans. After the National Geographic investigation of the Gospel of Judas, the document was returned to the Coptic Museum in Cairo.
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