Earth.
After several months, the Starship had traveled between various galaxies, successfully destroying all known supernova cannons and averting the imminent threat.
However, despite the Starship's speed, its return to Earth was not as urgent.
The base appeared near Earth. Lei, on a whim, decided to admire the beautiful Earth up close. To his surprise, as he looked up, he saw a fleet of warships docked near the moon.
"What are they doing? Are they going to war with someone?" Lei craned his neck, looking like a curious child.
With a thought, Gong Yiding retrieved the cause and effect from the internal network: "Oh, this is mainly about reusing old assets, selling decommissioned old ships to other civilizations."
What was initially a very ordinary response was met with Lei's eyes widening abruptly, and he asked in an extremely astonished tone, "You can sell old ones too?"
Gong Yiding was startled by his strong reaction: "Yes, we can. What's wrong?"
Lei glanced at Gong Yiding, then back at the ships outside, his eyes filled with disbelief: "This is commerce?"
Now it was Gong Yiding's turn to be speechless. Although they were a pair of mechanical prosthetic eyes, they conveyed an异常 glance: "Sir, do you have some misunderstanding about commerce?"
After a long while, he managed to reply, "This is just one aspect of commerce."
"Can you explain it to me in detail?" Lei asked enthusiastically.
"This is a long story," Gong Yiding immediately organized his thoughts. "Do you know what general equivalent is?"
"What equivalent?"
"It's money, it's gold, or other similar things!" Gong Yiding tried his best to explain.
Having a researcher of his level teach such basic knowledge felt like using a cannon to swat a fly.
Lei suddenly understood. After he grasped the meaning of money, Gong Yiding further explained what commercial behavior was. Simply put, as long as there was profit in a transaction, even negative profit, it could be classified as commercial behavior.
Selling warships was undoubtedly highly profitable, but the profits were all reinvested in the manufacturing of new ships, visible but intangible.
To enhance his persuasiveness, Gong Yiding bought and sold on the spot, searching for business war cases from the network to tell Lei, which made the latter exclaim repeatedly, praising it as amazing.
However, Lei's expression suddenly changed, and he stopped smiling: "But I think your warships are definitely sold too cheaply. You know, within a radius of several hundred light-years, this area has the richest heavy elements..."
Lei expounded at length on the scarcity of heavy elements, especially how rare planets like Earth, which possessed all natural heavy elements, were, ultimately concluding that humanity's act of selling warships cheaply was extremely unreliable.
Finally, Lei offered a suggestion, believing that humanity could completely get rich by selling its abundant reserves of heavy elements.
After finishing, he still didn't stop, his chest heaving rapidly for a while before slowly calming down.
Gong Yiding stared blankly for a moment, then a thought suddenly popped into his mind: After such a long monologue, how much resentment did the Prophet have towards heavy elements?
He couldn't help but ask it aloud. Lei's already troubled expression suddenly turned melancholic, and he instantly fell into distant memories: "Heavy elements, that's a hurdle all civilizations must face. The vast majority of civilizations, even before they had the chance to cross it, vanished for various reasons... Do you know how we felt when we first found Earth?"
Gong Yiding quickly grasped the key point: "You mean, Earth wasn't chosen randomly? Didn't you flee to Earth to escape the Black Yu people?"
"Yes and no," Lei continued his recollection. "Escaping the Black Yu people is true, but Earth was not chosen randomly. Without heavy elements, even if the seeds of civilization were sown here, there would be no chance to develop into a true interstellar civilization."
He hesitated noticeably at this point: "Have you ever thought about why there are so many civilizations here? Don't you think there are too many civilizations in the universe?"
Gong Yiding's cheek twitched, and his voice trembled: "Are they all seeds you left behind?"
"Yes!" Lei smiled happily. "We really want to know how intelligent life develops in an environment lacking heavy elements, and what kind of structure it would have if it had the opportunity to become an interstellar civilization."
Gong Yiding instantly felt extreme curiosity: "Did you get your answer?"
"Not the complete answer," Lei said.
If it were someone else, they might not have understood the meaning of his words, but Gong Yiding instantly understood.
The situation should be like this: the Prophet focused on cultivating Earth's civilization, but also observed the situations of other civilizations.
Those seeds sown by the Prophets took root and sprouted. Some grew strong, but more still quietly perished in the long river of history.
For those that had perished, Lei had already seen the outcome. For those that had grown strong, he had not yet seen it.
Speaking of this, Gong Yiding suddenly had a question: "If it were purely natural evolution, without external interference, how many civilizations should there be in this star region?"
Lei thought for a moment and said, "Half of the Orion Arm, absolutely no more than ten... I mean interstellar civilizations!"
Only ten?
Gong Yiding immediately felt dizzy.
Don't think ten is a lot. The Orion Arm is over ten thousand light-years long, over three thousand light-years wide, and over two thousand light-years thick. In terms of sheer size, it's abstract, but its actual volume is extremely vast.
Let alone a mere ten civilizations, even a thousand interstellar civilizations thrown in would not make much of a splash.
This was even considering the influence of heavy elements on native civilizations.
Gong Yiding immediately had another question: "What about non-interstellar civilizations? How many are there?"
"Thirty to fifty times that," Lei said.
"Five hundred?"
"Fewer rather than more," Lei added.
Gong Yiding sighed softly: "So, life... no, civilization is still a minority existence in this universe, right?"
"Of course," Lei agreed with a nod. "Planets with primitive ecosystems are common, but habitable planets with complex ecosystems are extremely rare. Civilizations only appear on a very small number of habitable planets. In your words, this is called the right time, the right place, and the right people. But among many civilizations, less than one percent have the chance to leave their home planet."
Gong Yiding suddenly interrupted Lei's eloquent discourse: "What about civilizations like ours?"
Lei's voice came to an abrupt halt, as if his throat had been choked.
"Are there many?" Gong Yiding asked again.
This time, Lei remained silent for a long time before answering softly: "I can only say, more than imagined, at least more than native interstellar civilizations."
"May I ask why?"
"Because native civilizations are all terrestrial species, naturally suited only to staying on the surface of planets. Artificial species have longer lifespans, better adaptability, and are more suited for long-term survival outside of celestial bodies."
Gong Yiding quietly sighed: We always thought we understood this universe well enough, but in reality, it was just a glimpse through a crack in the door. The true cosmic sea is far more complex than what we have already seen!