SAN FRANCISCO – Previously hidden writings of the ancient Greek mathematician Archimedes are being uncovered with powerful X-ray beams nearly 800 years after a Christian monk scrubbed off the text and wrote over it with prayers. Over the past week, researchers at Stanford University's Linear Accelerator Center in Menlo Park have been using X-rays to decipher a fragile 10th century manuscript that contains the only copies of some of Archimedes' most important works. The X-rays, generated by a particle accelerator, cause tiny amounts of iron left by the original ink to glow without harming the delicate goatskin parchment. “We are...