Contact - Carl Sagan [150]
"What are you saying? They changed the geometry of space?"
"Yes. We're saying that space is topologically non-simply connected. It's like-I know Abonnema doesn't like this analogy-it's like a flat two-dimensional surface, the smart surface, connected by some maze of tubing with some other flat two-dimensional surface, the dumb surface. The only way you can get from the smart surface to the dumb surface in a reasonable time is through the tubes. Now imagine that the people on the smart surface lower a tube with a nozzle on it. They will make a tunnel between the two surfaces, provided the dumb ones cooperate by making a little pucker on their surface, so the nozzle can attach itself."
"So the smart guys send a radio message and tell the dumb ones how to make a pucker. But if they're truly two-dimensional beings, how could they make a pucker on their surface?"
"By accumulating a great deal of mass in one place." Vaygay said this tentatively. "But that's not what we did."
"I know. I know. Somehow the benzels did it."
"You see," Eda explained softly, "if the tunnels are black holes, there are real contradictions implied. There is an interior tunnel in the exact Kerr solution of the Einstein Field Equations, but it's unstable. The slightest perturbation would seal it off and convert the tunnel into a physical singularity through which nothing can pass. I have tried to imagine a superior civilization that would control the internal structure of a collapsing star to keep the interior tunnel stable. This is very difficult. The civilization would have to monitor and stabilize the tunnel forever. It would be especially difficult with something as large as the dodecahedron falling through."
"Even if Abonnema can discover how to keep the tunnel open, there are many other problems," Vaygay said. "Too many. Black holes collect problems faster than they collect matter. There are the tidal forces. We should have been torn apart in the black hole's gravitational field. We should have been stretched like people in the paintings of El Greco or the sculptures of that Italian…" He turned to Ellie to fill in the blank.
"Giacometti," she suggested. "He was Swiss."
"Yes, like Giacometti. Then other problems: As measured from Earth it takes an infinite amount of time for us to pass through a black hole, and we could never, never return to Earth. Maybe this is what happened. Maybe we will never go home. Then, there should be an inferno of radiation near the singularity. This is a quantum-mechanical instability…"
"Ana finally," Eda continued, "a Kerr-type tunnel can lead to grotesque causality violations. With a modest change of trajectory inside the tunnel, one could emerge from the other end as early in the history of the universe as `you might like-a picosecond after the Big Bang, for example. That would be a very disorderly universe."
"Look, fellas," she said, "I'm no expert in General Relativity. But didn't we see black holes? Didn't we fall into them? Didn't we emerge out of them? Isn't a gram of observation worth a ton of theory?"
"I know, I know," Vaygay said in mild agony. "It has to be something else. Our understanding of physics can't be so far off. Can it?"
He addressed this last question, a little plaintively, to Eda, who only replied, "A naturally occurring black hole can't be a tunnel; they have impassable singularities at their centers."
With a jerry-rigged sextant and their wristwatches, they timed the angular motion of the setting Sun. It was 360 degrees in twenty-four hours. Earth standard. Before the Sun got too low on the horizon, they disassembled Ellie's camera and used the lens to start a fire. She kept the frond by her side, fearful that someone would carelessly throw it on the flames after dark. Xi proved to be an expert fire maker. He positioned them upwind and kept the fire low.
Gradually the stars came out. They were all there, the familiar