Cixin Liu - The Dark Forest

“Master Ding, if you’ve got something to say, then just say it. You really have our highest respect.”

Ding Yi slowly nodded. Then he pointed upward. “If this spaceship has to go to maximum acceleration, everyone here will need to… be immersed in a liquid.”

“That’s right. Deep-sea state.”

“Yes, right. The deep-sea state.” Ding Yi hesitated again, and ruminated for a moment before resolving to go on. “When we go out for our examination, could this ship, ah, Quantum, be put into a deep-sea state?”

The officers looked at each other in surprise, and the captain said, “Why?”

Ding Yi’s hands began fluttering again. His hair glowed white under the fleet’s light. Like someone had noticed when he first came aboard, he looked quite a bit like Einstein. “Um… well, at any rate there’s no harm in doing it, right? You know, I don’t have a good feeling.”

After saying this, he remained silent, his eyes locked onto the infinite distance. At last he reached out, plucked the pipe out of the air, and put it into his pocket. Without saying good-bye, he awkwardly worked his superconductor belt to float toward the door as the officers watched him.

When he was halfway out, he slowly turned back around. “Children, do you know what I’ve been doing all these years? Teaching physics at a university and advising doctoral students.” As he looked out at the galaxy, an inscrutable smile played on his face—tinted with, the officers noticed, a hint of sadness. “Children, a man from two centuries ago is still able to teach university physics today.” With that, he turned and left.

The captain wanted to say something to him, but now that he was gone, the words didn’t come out. He remained deep in thought. Some of the officers looked at the droplet, but more of them turned their attention to the captain.

“Captain, you’re not going to take him seriously, are you?” one lieutenant asked.

“He’s a wise scientist, but he’s still an ancient man. Their thoughts about modern things are always…” someone else added.

“But in his field, humanity hasn’t made any progress. It’s still stuck at his era’s level.”

“He spoke of intuition. I think his intuition may have discovered something,” an officer said, in a voice full of awe.

“Also…” Xizi blurted out. But looking at the surrounding officers who outranked her, she swallowed the rest of her words.

“Major, please continue,” the captain said.

“Also, like he said, there’s no harm in doing it,” she said.

“Think about it this way,” a vice-captain said. “According to present battle plans, if the capture fails and the droplet unexpectedly escapes, then the fleet can only deploy fighters as a tracking force. But long-range tracking needs to be stellar-class, so the fleet ought to have warships prepared. This is an oversight in the plan.”

“Make a report to the fleet,” the captain said.

The fleet’s approval was swift: When the examination team had set off, Quantum and the neighboring stellar-class warship Bronze Age would enter a deep-sea state.

To capture the droplet, the fleet’s formation maintained a distance of one thousand kilometers from the target, a figure decided after careful calculation. There were various hypotheses about the manner in which the droplet might self-destruct, but the maximum release of energy would come from self-destruction by antimatter annihilation. Since the droplet had a mass of less than ten tons, the largest energy burst that needed to be considered was that produced by the annihilation of five tons each of matter and antimatter. That annihilation, if it occurred on Earth, would be enough to destroy all life on the planet surface, but in space, the energy would be released entirely in the form of light radiation. For stellar-class warships, with their super anti-radiation capacity, one thousand kilometers was far enough to allow for a sufficient margin of safety.

The capture would be accomplished by Mantis, a small unmanned craft that had previously been used for collecting mineral specimens in the asteroid belt. Its key feature was an extra-long robotic arm.

At the start of the operation, Mantis crossed the five-hundred-kilometer line held by the previous monitoring craft and carefully approached the target, flying slowly and pausing for several minutes every fifty kilometers so that the dense omnidirectional surveillance system behind it could perform a complete scan of the target. Only after confirming that there were no abnormalities did it proceed.

At one thousand kilometers from the target, the combined fleet had matched speed with the droplet, and most of the warships had turned off their fusion engines to drift silently in the abyss of space, their giant metal hulls reflecting the weak sunlight. They were like abandoned space cities, the whole fleet array a silent, prehistoric Stonehenge. The 1.2 million people in the fleet held their breath as they watched Mantis on its brief voyage.

The images seen by the fleet traveled at the speed of light for three hours before reaching Earth, where they were transmitted to the eyes of three billion people similarly holding their breath. All activity in the human world had stopped. The flying cars had disappeared from among the giant trees, and a stillness had fallen over the underground metropolises. Even the global information network, busy since its birth three centuries before, emptied out. The majority of data transmissions were images from twenty AU away.

Mantis ’s stop-and-go advance took half an hour to cover a distance that was hardly even a step through space. Finally, it hung in place fifty meters from the target. Now the Mantis ’s distorted reflection could be clearly seen in the droplet’s mercury surface. The ship’s many instruments began a close-range scan of the target, first confirming prior observations: The droplet’s surface temperature was even lower than the surrounding space, close to absolute zero. Scientists had thought that there might be powerful cooling equipment inside the droplet, but Mantis ’s instruments were still unable to detect anything about the target’s internal structure.

Mantis extended its extra-long robot arm toward the target, starting and stopping over the fifty-meter distance. But the dense monitoring system did not pick up anything abnormal. The grueling process lasted half an hour before the tip of the arm finally reached the target’s position and touched it, an object that had come from four light-years away on a nearly two-century-long trek through space. When the robot arm’s six digits grasped hold of the droplet at last, a million hearts in the fleet beat as one, echoed three hours later by three billion hearts on Earth.

Holding the droplet, the mechanical arm waited motionless. When the target still showed no response or abnormality after ten minutes, it began to pull it back.

It was at this point that people noticed a strange contrast: The mechanical arm was obviously designed purely as a functional object, with a rugged steel frame and exposed hydraulics that felt complicatedly technological and crudely industrial. But the droplet was perfect in shape, a smoothly gleaming, solid drop of liquid whose exquisite beauty erased all functional and technical meaning and expressed the lightness and detachment of philosophy and art. The steel claw of the robot arm clutched the droplet like the hairy hand of Australopithecus clutching a pearl. The droplet looked so fragile, like a glass thermos liner in space, that everyone was afraid it would shatter in the claw. But that did not occur, and the robot arm began to retract.