George W. Bush tried to laugh off the bulge. "I don't know what that is," he said on "Good Morning America" on Wednesday, referring to the infamous protrusion beneath his jacket during the presidential debates. "I'm embarrassed to say it's a poorly tailored shirt."
Dr. Robert M. Nelson, however, was not laughing. He knew the president was not telling the truth. And Nelson is neither conspiracy theorist nor midnight blogger. He's a senior research scientist for NASA and for Caltech's Jet Propulsion Laboratory, and an international authority on image analysis. Currently he's engrossed in analyzing digital photos of Saturn's moon Titan, determining its shape, whether it contains craters or canyons.