National Geographic : 2017 Mar
On this parchment (left), the naked eye sees only one text. But a multispectral image (right), shows two: the visible text, in red, and an earlier, erased document underneath, in blue. fresh surface. The old text isn’t entirely gone, though. It remains embedded in the page as a ghostly shadow, which can be resurrected with a technique called multispectral imaging, designed to peer into both visible and invisible wave- lengths of light. So far the imaging has revealed some 6,800 hidden pages in 74 of the monas- tery’s 163 recycled parchments, called palimpsests. “We have identified erased texts in 10 languages that date from the fifth to the 12th centuries,” says Michael Phelps, the director of the recovery ef- fort. In the example above, a text in Syriac overlays a ninth-century trans- lation of a page from a medical treatise by the ancient Greco-Roman physician known as Galen. With dozens of palimpsests yet to be scanned, Phelps believes there are still treasures to come: “It’s not unlikely that St. Catherine’s holds many more pages of previously unidentified and unstudied texts from antiquity.” Built in the sixth century at the foot of Mount Sinai in Egypt, St. Catherine’s Monastery is the world’s oldest such institution in continuous use. Its library preserves hundreds of manuscripts col- lected during medieval times—classical texts, scriptures, and other documents of interest to the monks. But it turns out that people recycled the pages of some of those manuscripts, erasing texts they no longer needed. Since 2011 the monastery has been working to recover some of those long-lost erasures using modern digital technology. About half of the library’s manu- scripts were written on parchment, the specially prepared skin of a calf, goat, or sheep. Parchment can be recycled by scraping off any ink and writing on the RECOVERING ERASED WISDOM By A. R. Williams | EXPLORE | TOOLS AND TECHNOLOGY PHOTOS: ST. CATHERINE’S MONASTERY, USED WITH PERMISSION HIGH-TECH TRAPPINGS A researcher at the University of Tokyo spent six years trying to transform electrical currents into the flavor of salt. The result? A fork that fools taste buds by transmitting the sensation of salt to the tongue without a pinch of sodium. An Israeli tech start-up is replacing bifocals with “omnifocals.” The autofocusing glasses have infrared sensors that detect the dis- tance between pupils and the object being viewed, refocusing in 300 milliseconds. Your cell phone knows you best. Scientists at the University of California San Diego swabbed 39 devices and were able to identi- fy their owners’ groom- ing products, medical conditions, recently visited locations, and favorite foods. Such a composite character sketch can be used in criminal profiling or medical monitoring. A scientist at the University of Central Florida developed a material to harvest and store the sun’s energy. Woven into clothing, the copper-ribbon fila- ment will turn a wearer into a self-charging solar battery that may someday power a phone from inside a pocket.