Cixin Liu - Death's End

“We’re home!”

“Can you believe it?”

“I’ll get to see my kids again.”

“We can have kids!”

When Bronze Age left the Solar System, the law had dictated that no one could be born on the ship unless someone died.

“She said she’d wait for me.”

“If you’ll have her! You’re now a hero of the human race; you’ll have a flock of pretty girls after you.”

“Oh, I haven’t seen flocks of birds in ages !”

“Doesn’t everything we’ve been through seem like a dream?”

“I feel like I’m dreaming now.”

“I’m utterly terrified of space.”

“Me too. I’m retiring as soon as we get back. I’m going to buy a farm and spend the rest of my life on solid ground.”

It had been fourteen years since the complete destruction of the Earth’s combined fleet. The survivors, after engaging in separate internecine battles of darkness, cut off all contact with the home planet. However, for a year and a half thereafter, Bronze Age continued to receive transmissions from Earth, most of which were surface radio communications, but which also included some transmissions intended for space.

And then, at the beginning of November in Year 208 of the Crisis Era, all radio transmissions from Earth ceased. Every frequency fell silent, as though the Earth was a lamp that had been suddenly shut off.

When humanity finally learned that the universe was a dark forest in which everyone hunted everyone else, the child who had once cried out for contact by the bright campfire put out the fire and shivered in the darkness. Even a spark terrified him.

During the first few days, even mobile phone use was forbidden, and antennas around the world were forcibly shut down. Such a move, which would have once caused riots in the streets, was widely supported by the populace.

Gradually, as reason was restored, so were the mobile networks, but severe restrictions regarding electromagnetic radiation were put in place. All radio communications had to operate at minimum power, and any violators risked being tried for crimes against humanity.

Most people surely understood that these reactions were excessive and meaningless. The peak of the Earth’s projection of electromagnetic signals into space had occurred during the age of analog signals, when television and radio transmission towers operated at high power levels. But as digital communication became prevalent, most information was transmitted via wires and optical cables, and even radio transmissions for digital signals required far less power than analog signals. The amount of electromagnetic radiation spilling into space from the Earth had fallen so much that some pre-Crisis scholars had fretted that the Earth would become impossible to discover by friendly aliens.

Electromagnetic waves are, moreover, the most primitive and least power-efficient method of transmitting information in the universe. Radio waves attenuate and degrade rapidly in the vastness of space, and most electromagnetic signals spilling from the Earth could not be received beyond two light-years. Only something like the transmission by Ye Wenjie, which relied on the power of the sun as an antenna, could be intercepted by listeners among the stars.

As humanity’s technology advanced, two far more efficient methods of signaling became available: neutrinos and gravitational waves. The latter was the main method of deterrence that humanity later deployed against Trisolaris.

The dark forest theory had a profound impact on human civilization. That child sitting by the ashes of the campfire turned from optimism to isolation and paranoia, a loner in the universe.

Most of the crew aboard Bronze Age attributed the sudden cessation of all signals from the Earth to the complete conquest of the Solar System by Trisolaris. Bronze Age accelerated and headed for a star with terrestrial planets twenty-six light-years away.

But ten days later, Bronze Age received a radio transmission from Fleet Command. The transmission had been sent simultaneously to Bronze Age and Blue Space, which was at the other end of the Solar System. The transmission gave a brief account of what had happened on Earth and notified them of the successful creation of a deterrence system to defend against Trisolaris. The two ships were ordered to return to Earth immediately. Moreover, Earth had taken great risks to send out this message to the lost ships; it would not be repeated.

At first, Bronze Age dared not trust this message—wasn’t it possible that it was a trap set by those who had conquered the Solar System? The warship stopped accelerating and repeatedly queried Earth for confirmation. No reply ever came, as Earth maintained radio silence.

Just as Bronze Age was about to begin accelerating away from home again, the unimaginable happened: A sophon unfolded into low dimensions on the ship, establishing a quantum communication channel with Earth. Finally, the crew received confirmation of all that had occurred.

The crew found that, as some of the only survivors of the holocaust suffered by the combined space forces of Earth, they were now heroes of the human race. The whole world awaited their return with bated breath. Fleet Command awarded all members of the crew with the highest military honors.

Bronze Age began its return voyage. It was currently in outer space, about twenty-three hundred AU from the Earth, far beyond the Kuiper Belt but still some distance from the Oort Cloud. As it was cruising near maximum speed, deceleration consumed most of its fusion fuel. Its journey toward the Earth had to be conducted at a low cruising speed, and took eleven years.

As they finally neared Earth, a small white dot appeared ahead of them and quickly grew. It was Gravity, the warship that had been dispatched to welcome Bronze Age .

Gravity was the first stellar-class warship built after the Doomsday Battle. Deterrence-Era spaceships were no longer constructed along fixed body plans. Rather, most large spaceships were constructed out of multiple modules that could be assembled into various configurations. But Gravity was an exception. It was a white cylinder, so regular that it seemed unreal, like a basic shape dropped into space by mathematical modeling software, a platonic ideal rather than reality.

If the crew of Bronze Age had seen the gravitational wave antennas on the Earth, they would have recognized Gravity as an almost perfect replica of them. Indeed, the entire hull of Gravity was a large gravitational wave antenna. Like its twins on the Earth’s surface, the ship was capable of broadcasting gravitational wave messages toward all corners of the universe at a moment’s notice. These gravitational wave antennas on Earth and in space comprised humanity’s dark forest deterrence system against Trisolaris.

After another day of coasting, Bronze Age, escorted by Gravity, entered geosynchronous orbit and slowly sailed into the orbital spaceport. Bronze Age ’s crew could see dense crowds filling the broad expanse of the habitat sector of the spaceport like the opening ceremony of the Olympics or the Hajj in Mecca. The warship drifted through a colorful snowstorm of bouquets. The crew looked through the crowd for their loved ones. Everyone seemed to have tears in their eyes, crying out in joy.

With a final tremor, Bronze Age came to a complete stop. The captain gave a status report to Fleet Command and declared his intent to leave a skeleton crew behind on the ship. Fleet Command replied that the priority was to quickly reunite all members of the crew with their loved ones. There was no need to leave anyone behind on the ship. Another captain from the fleet boarded the ship with a small duty team who greeted everyone they encountered with tearful embraces.