EVER SINCE the Dead Sea Scrolls were discovered by Bedouin shepherds in the 1940s, debate has raged over their exact age. The scrolls, which contain the earliest surviving copies of books from the Hebrew Bible and other religious texts, mostly written in Aramaic and Hebrew, are thought to have been compiled sometime between 300BC and 200AD. Dating each of the 1,000-odd individual scrolls would help historians understand how literacy spread among ancient Jewish populations and the first Christians, and offer a valuable window into the genesis of the sacred texts. But scholars hoping to do so have had little but their own intuition to rely on.