Chapter 31: The Tomb of Seven Billion Humans

Words : 1552 Updated : Sep 12th, 2025

This was the final departure from the Sun, a departure with no return. As the fleet moved farther away, the Sun grew dimmer, and Xiao Yu’s mood became inexplicably heavy. The road ahead was long and arduous. Awaiting Xiao Yu was a journey of 10.5 light-years, a passage of 6,300 years of unbroken time. What strange occurrences might he encounter along the way? What dangers lay ahead? Xiao Yu did not know. Yet he had made up his mind to depart. Dominating the mind of a scientist was an insatiable thirst for exploration—a passion so fervent that even life could be sacrificed for it. Thus, Xiao Yu chose not to continue developing within the solar system. Upon achieving interstellar travel capability, he immediately decided to set out. To be precise, Xiao Yu’s current technology could only be considered capable of interplanetary travel. With the speed afforded by nuclear fusion propulsion, interstellar voyages spanning millennia would render such travel impossible for any lifeform with a lifespan under 10,000 years. However, having merged with a computer and abandoned his physical body, Xiao Yu’s spirit could potentially exist indefinitely. This near-cheating method granted him the ability to use interplanetary technology for interstellar travel. Humanity had once calculated that the minimum threshold for interstellar travel was reaching 5% of the speed of light—15,000 kilometers per second. At this speed, a journey from the solar system to the Proxima Centauri system would take approximately 200 years, a manageable timeframe compared to human lifespans at the time. However, without the development of a new generation of propulsion systems, the 15,000 kilometers per second threshold remained an unattainable luxury for Xiao Yu. After returning to Titan from Jupiter, Xiao Yu did not land on the moon’s surface. The two large photon computers had already been transferred to the Solar and the Voyager, leaving the base on Titan under the control of the outdated computer from his first small spaceship. Although this computer now seemed archaic and painfully slow to Xiao Yu, it was sufficient for the simple maintenance tasks required on Titan. Ninety-nine bases on the moon had ceased operations, with all machinery sealed. Only basic maintenance tasks remained, easily handled by the old computer. The low oxygen content and freezing temperatures of Titan’s atmosphere meant there was no concern about rust or mechanical deterioration. Xiao Yu hoped these machines and equipment would endure for thousands or even tens of thousands of years, remaining intact far into the future. Due to the significant atmospheric loss on Venus, the planet’s surface temperature had dropped. In the boundless future, intelligent life might eventually evolve there. Xiao Yu hoped that the remnants he left behind could guide any future intelligent life on Venus, serving as evidence of humanity’s former existence within the solar system. Gazing at the mist-covered Titan from space, Xiao Yu was overcome with emotion. “Twenty years have passed just like that,” Xiao Yu silently calculated. In the blink of an eye, twenty years had passed since he left Earth. During these two decades, so much had happened. The carefree days of life on Earth felt as if they had been just yesterday. Memories of the past streamed through Xiao Yu’s mind: the fear of leaving Earth for the first time during the Jupiter-Moon collision, the joy of his first sumptuous meal, the struggles on Titan, and the exhilaration of mastering controlled nuclear fusion—each event vivid and unforgettable. “Let’s go. Let’s go. While the solar system is safe and comfortable, no great achievement can be made without braving storms. Let’s go. Let’s go. The boundless universe is my ultimate destination,” Xiao Yu thought, casting his nostalgia aside. He steered his massive fleet toward Saturn. Within Saturn’s system, Xiao Yu conducted the final fuel replenishment. After half a month of frenzied resource gathering in Saturn’s atmosphere, he finally departed, his tanks filled to capacity. Taking one last, lingering look at Titan, Xiao Yu resolutely pressed onward, steering his fleet beyond the solar system. At this point, Xiao Yu had loaded half of his fleet, including the three “County-Class” ships—the Voyager, the Solar, and the Proxima—as well as nearly 500 “Village-Class” and “Town-Class” ships, with materials of every kind. Had it not been necessary to maintain some ships’ mobility for emergencies, Xiao Yu would have filled every last ship with supplies. During this period, Xiao Yu had come to a profound realization: in the vastness of space, regions filled with meteor swarms are not the most dangerous places. The truly perilous zones are the empty expanses of the void. In those regions, the nearest celestial body is thousands of years of travel away. There is nothing—no resources to replenish. If something goes wrong, there is no possibility of rescue. The only outcome is to exhaust all energy and perish, becoming a frozen relic adrift in the endless void of time. Intergalactic travel would be even more terrifying than interstellar travel. In such a journey, obtaining a mere piece of scrap metal could require millions of years of light-speed travel. The greatest adversary in interstellar exploration is not the dangers of space but the passage of time itself. Xiao Yu’s thoughts wandered as he idly piloted the fleet, accelerating gradually. Back when he first left Earth, he had yearned to leave the solar system. But now, on the verge of departure, he found himself reluctant to let go. He thought of someone—a young, lively, and beautiful girl, full of energy and innocence. Back on Earth, she had been a researcher in Xiao Yu’s lab. The girl had admired Xiao Yu, but he had been wholly devoted to science, dismissive of romantic entanglements. He had even scolded her harshly for her feelings, causing her to leave the lab in dismay. Xiao Yu had never believed he was wrong. Yet, at this moment, a twinge of regret stirred in his heart. “She must be... gone now, right? Dead, along with the seven billion humans who perished. But now that I think about it, after she left the lab and up until Earth’s destruction, those seven years, I never heard any news of her. I don’t know what happened to her after that.” Lost in thought, Xiao Yu operated the Solar’s 3D color projection system, crafting a figure in the air. In the ship’s cabin, the projection slowly formed the image of a girl. “Hmm, no, her eyes should be bigger. Uh, fine, let’s make her waist slimmer, her nose sharper, her chest larger...” Adjusting the parameters bit by bit, Xiao Yu gradually created a smiling image of the girl. She stood there, gazing forward with gentle eyes as if she had many unspoken words. Xiao Yu generated a line of code. Upon execution, the projection spoke. “Director Xiao, how are you?” The voice was soft and shy, exactly the same as how she used to speak on Earth. Xiao Yu stared at the projection, murmuring, “Chen Mo, I’m fine. I’m still alive. And you?” “I’ve been dead for twenty years,” she replied with a faint smile. “Yes, you’re gone—dead for twenty years. Meanwhile, I’ve gained infinite life. But I no longer have a body,” Xiao Yu said bitterly. Separating his consciousness from his body had been an incredibly risky endeavor. Back on Earth, Xiao Yu had stumbled upon an unknown cosmic material. After years of study, he had risked everything to separate his spirit from his physical form. Until he fully understood this material’s properties, Xiao Yu dared not attempt such a fusion again. Even if a new body became available, Xiao Yu would not integrate with it. Doing so would subject him once more to the limitations of the body—birth, aging, illness, and death. “Chen Mo, wait for me. Once I’ve fully decoded the human genome, I’ll bring you back to life,” Xiao Yu murmured. When Xiao Yu had left Earth, he had brought a genetic library and a sperm bank. However, during the escape from the Jupiter-Moon Collision, these had been lost to an asteroid impact. “I’ll wait for you,” Chen Mo said softly, smiling. Then, in an instant, her projection dissolved into light and disappeared. “When you’re resurrected, I’ll accept your confession,” Xiao Yu whispered, staring blankly at the vanishing light. “Haah...” Xiao Yu sighed, pulling himself back from the torrent of emotions. Shaking off the distractions, he continued steering the massive fleet toward the outer reaches of the solar system. Months passed in a blur. Xiao Yu’s fleet had now reached the orbit of Uranus. “We’re nearing Uranus. Here, I’ll leave a tombstone for human civilization,” Xiao Yu thought. The orbit of Uranus lies approximately 2.7 billion kilometers from Earth. At this distance, the Sun appeared as little more than a bright point in the sky, indistinguishable from the other stars. Sighing deeply, Xiao Yu used his stored metal to craft a monument. Employing nuclear fusion technology, he created a battery capable of lasting millions of years to power an eternal light. This tombstone, with a 130-year orbital period around the Sun, would remain illuminated for up to a million years, shining upon a single inscription. “The Tomb of Seven Billion Humans! Erected by Xiao Yu, The Last of Humanity.”

Chapter 31: The Tomb of Seven Billion Humans

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