If Sotheby’s were a hospital, his department would be “the E.R. or a clinic.” One analysis is like an M.R.I., and another is like a CT scan. He described analyses as “noninvasive.” Mr. Martin tried to keep the discussion understandable to nonscientists, even comparing one device to a “Star Trek” phaser, but he also said things like: “Each one of the million pixels has its own spectrum.”