The teleport in Carroll's asylum laboratory gave the physicist warning that they were coming through. He turned as they entered with an annoyed smile on his face. Before him was a long paper record of Lawson Radiation recordings that Carroll was studying through a magnifier.
Majors handed Carroll the photo, saying, "What do you make of this?"
"It's a bad blur—like a misfocused image," replied Carroll.
"Yes—but why?"
"You've heard of the Einstein Lens?"
"Vaguely, but thought it was just a dream—a probability that never happened."
Pollard shook his head. "I don't know about it at all," he admitted.
Carroll smiled tolerantly. "Light has energy and energy has mass," he said. "Ergo light has mass. Masses attract one another according to the Newtonian Law of Gravitation. Ergo light is bent by passing close to a mass."
"I see," said Pollard leaping to the right conclusion. "Then light radiated from a very distant galaxy may pass close enough to a dark mass—with Terra, the mass and the galaxy in line—to have the distant galaxy focus itself here?"
"Yes," replied Carroll. "The mass acts as a biconvex lens because it bends all tangential light toward the center as the beam passes."