Through Li Yang's three-in-one detection system and the observation of the Hubble-2 telescope, it was found that the fleet of the Trisolarans sailed 0.22 light-years, only 4 light-years away from the blue star.

Because the Trimaran Fleet can only leave an observable wake when it passes through interstellar dust clouds, geoastronomers have observed the absorption of background starlight and have identified five dust clouds in the space that the Trimaran Fleet will traverse during its four-century voyage, and these dust clouds are now called "snow fields", which means that the snow can leave traces of traversers.

If the trimaran fleet has been accelerating steadily for five years, today it will be time to cross the second "snowfield".

Fitzrow arrived early at the Hubble-2 space telescope control center, and Ringer laughed when he saw him.

"General, why do you look like a kid who just after Christmas wants a present?"

"You said you were going to cross the 'snow' today."

"Yes, but the Trimaran Fleet has only been sailing 0.22 light-years so far, and we are still 4 light-years away, reflecting that it will take four years for its rays to pass through the 'snow' to reach Earth."

"Oh, I'm sorry, I forgot that." Fitzrow shook his head awkwardly, I wanted to see them again, and it was important to be able to measure their velocity and acceleration as they crossed. ”

"No way, we're outside the light cone."

"What?"

"The propagation of light is cone-shaped along the time axis, which physicists call the light cone, and it is impossible for people outside the light cone to understand the events that occur inside the light cone. Think about it now, who knows how many major events in the universe are coming at us at the speed of light, some may have been flying for hundreds of millions of years, but we are still outside the cone of light of these events. ”

"Within the cone of light is destiny."

Lin Ge thought for a moment and nodded appreciatively at Fitzroy, "General, this analogy is very good!" ”

"But Tomoko can see what's going on inside the cone of light."

"So Tomoko changed his fate, that is, he changed the fate of the Trisolarans, and he also changed the fate of our human race." Fitzro said with emotion, looking at an image processing terminal. Five years ago, a young engineer was working there, and he cried when he saw the "brush", but then he suffered from severe depression and almost became a waste, so he was dismissed by the center, and now he doesn't know where he is.

Fortunately, there are not many people like him.

During this time, the weather quickly cooled down and began to snow, the surrounding green gradually faded, the lake was covered with a thin layer of ice, and nature faded its bright colors like a photograph that turned from color to black and white. Here, the warm climate is originally very short-lived, but in Luo Ji's feeling, this Garden of Eden seems to have lost its aura due to the loss of his lover and child.

That's right, winter is the season of thinking, and it is also the season of unexpected gains.

……

After experiencing the hibernation of his wife and children, the threat of PDC, and the suicide of Taylor under Li Yang's advice, Luo Ji began to use his brain to think.

When Luo Ji began to think, he was surprised to find that his thoughts were halfway through. In fact, from the moment he became a wall-facing person, he began to think, and never stopped, but the whole process was subconscious, and he didn't feel it.

Luo Ji quickly repeated the first few steps of the thought that had already been completed.

Now it is certain that all of this originated from the chance meeting with Ye Wenjie nine years ago. After the meeting, Luo Ji never talked to anyone about this meeting, for fear of causing unnecessary trouble to himself.

Now, Ye Wenjie is no longer alive, and this meeting has become a secret that only he and the Three-Body World know (Luo Ji doesn't know and Li Yang also knows). During that time, there were only two Zhizi who arrived on Earth, but it was certain that in front of Yang Dong's tomb at dusk, they were suspended beside them, listening to their every word, and the fluctuations of the quantum array instantly crossed the space of four light years, and the three-body world was also listening.

But what did Ye Wenjie say?

Say is wrong about one thing, the sociological research of the universe that Luo Jina has not started is very important, and it is likely to be the direct reason why the Three-Body World wants to kill him. Unbeknownst to Say, of course, that the research had been conducted at the suggestion of Ye Wenjie, although Luo Ji himself had just seen an excellent opportunity for academic entertainment—an opportunity he had been looking for.

Before the emergence of the three-body crisis, the study of extraterrestrial civilizations was indeed a sensational project, which was easy to be looked at by the media. This research that has not started itself is not important, what matters is the hint that Ye Wenjie gave him, and Luo Ji's thinking is clogged here.

He recalled Ye Wenjie's words over and over again:

I had a suggestion: "Why don't you study the sociology of the universe?"

A term I casually use is to assume that there are a huge number of civilizations distributed in the universe, and their number is an order of magnitude with the number of stars that can be observed, and these civilizations constitute a general cosmic society, and cosmic sociology is the study of the form of this super-society.

I think this because by combining your two majors, cosmic sociology presents a clearer mathematical structure than human sociology.

You see, the stars are all dots, and the complex structure of various civilizations and societies in the universe, in which chaotic and random factors, are filtered out by such a huge distance, and those civilizations seem to us to be points with parameters, which is relatively easy to deal with mathematically.

So your final result is purely theoretical, just like Euclidean geometry, first set a few simple axioms that are not self-evident, and then deduce the whole theoretical system on the basis of these axioms.

First, survival is the first need of civilization; Second, civilization grows and expands, but the total amount of matter in the universe remains the same.

I've been thinking about it for most of my life, but it's the first time I've talked about it, and I really don't know why...... Oh, and to deduce the basic picture of cosmic sociology from these two axioms, there are two more important concepts: the chain of suspicion and the technological explosion.

I'm afraid I won't have a chance...... Or, you just say whatever it is, I did my duty. ”

Yes, Ye Wenjie, who has experienced a lot of suffering, told mankind the axiom of the universe before leaving, and she did her duty no matter what.

……

Luo Ji recalled these words countless times, analyzing every sentence from all angles and chewing on every word.

No matter what, Luo Ji couldn't extract that hint from these words, the hint that made him the only person to be eliminated in the Three-Body World.

The long thinking is carried out in an aimless walk, Luo Ji walks on the bleak lake, walks in the colder and colder wind, and often unconsciously has walked around the lake for a week.

On two occasions, he even walked to the foot of the snow-capped mountains, which looked like the surface of the moon and were covered with snow, connecting with the snow-capped mountains in front of him. Only then did his mind leave the track of thinking, and Zhuang Yan's eyes appeared on the boundless blank space in this natural painting. But he was always able to control this mood in time and continue to turn himself into a thinking machine.

Unconsciously, a month passed, and winter had completely arrived, but Luo Ji was still outside carrying out his long mental journey, and the cold sharpened his mind.

At this time, Luo Ji integrated all his thoughts into two sentences:

Survival is the first need of civilization.

Civilization grows and expands, but the total amount of matter in the universe remains the same.

Luo Ji locked these two sentences, although he didn't know the ultimate mystery yet, but the long thinking told him that the mystery was in these two sentences, in the axiom of cosmic civilization proposed by Ye Wenjie.

But this hint is too simple after all, two self-evident laws, what does Luo Ji think he and all mankind can get from it?

Don't underestimate simplicity, simplicity means solidity, and the whole edifice of mathematics is built on this axiom that is too simple to be simple, but logically solid as a rock.

Thinking of this, Luo Ji looked around, everything around him was huddled in the cold of winter, but at this time, most of the earth was still full of life. This world of life, which is full of sea, land and sky, is complex and vast, but in fact, it also runs under a simpler law than the axioms of cosmic civilization: survival of the fittest.

Now, Luo Ji sees his own difficulties: Darwin summed up this law through the vast world of life, and he already knew the law, but he wanted to restore the picture of cosmic civilization through it, which was the opposite path to Darwin, but it was more difficult.

So, Luo Ji began to sleep during the day and think at night, and whenever the hardships of this path of thought made him daunting, the starry sky above his head comforted him. As Ye Wenjie said, the long distance makes the stars hide the complex individual structure, and the starry sky is just a collection of points in space, showing a clear mathematical configuration. This is the paradise of the thinker, the paradise of logic, at least in the senses, the world that Luo Ji faces is clearer and more concise than Darwin's.

There is a strange mystery in this simple world: on the nearest star to us, there is a higher intelligent civilization, but the entire galaxy is such an empty desert, and it is in this mystery that Luo Ji finds an entry point for thinking.

Gradually, the two mysterious concepts that Ye Wenjie did not explain became clear, and that was right: the chain of suspicion and the explosion of the skill wood.

……

It was colder than usual that night, Luo Ji stood by the lake, the cold seemed to make the starry sky more pure, and the silver dots in those black spaces solemnly displayed the clear mathematical structure again. Suddenly, Luo Ji entered a state that he had never felt before, in his senses, the entire universe was frozen, all movement had stopped, everything from stars to atoms was at rest, and the stars were just countless cold dots of no size, reflecting the cold light of the outside world...... Everything waited in stillness, waiting for his final awakening.

A dog barked in the distance, pulling Luo Ji back to reality, probably a military dog of the guard unit.

Luo Ji was excited, just now, he didn't see the last mystery, but he really felt its existence.

Luo Ji concentrated his thoughts and tried to enter the state just now again, but he didn't succeed. The starry sky was still there, but the world around him interfered with his thinking.

Although everything is hidden in the night, you can still distinguish the snow-capped mountains in the distance, the forest and meadow by the lake, and the villa behind you, and the dark red fire in the fireplace can be seen through the half-open door...... In contrast to the simplicity and clarity of the starry sky, everything in this vicinity symbolizes complexity and chaos that mathematics can never grasp, and Luo Ji tries to remove them from the senses.

He walked up to the frozen lake, and at first he was cautious, but when he found that the ice seemed to be very strong, he slid as he went, and went faster until the shore of the lake around him could not be seen clearly in the night. At this time, he was surrounded by smooth ice, far away from the complexity and chaos of the world.

He imagined that the plane of ice extended infinitely in all directions, and he got a simple flat world, a cold and flat platform for thought. The haunting was gone, and he was soon back in that state, feeling like everything was still and the stars were waiting for him again......

With a bang, the ice under Luo Ji's feet shattered, and his body fell straight into the water.

At the moment when the ice water flooded Luo Ji's head, he saw that the still starry sky shattered, and the sea of stars first rolled into a vortex, and then dispersed into a turbulent silver chaotic wave.

The biting cold was like a crystal lightning, instantly piercing the fog in his consciousness and illuminating everything. He continued to sink, the turbulent starry sky shrinking above his head into a blurred light from the ice breach, surrounded by only cold and inky darkness, Luo Ji felt that he was not sinking into the ice, but into the dark space.

It was in this dead silence that he saw the truth of the universe.

Luo Ji quickly floated, his head rushed out of the water, he spat out a mouthful of water, and wanted to climb up the ice on the edge of the breach, but his body was only halfway up, and the ice was crushed, and then climbed, and collapsed again, so he carved a way on the ice, but the progress was very slow, and his physical strength gradually became exhausted in the cold.

He didn't know if the guards would be able to spot anomalies in the lake before he drowned or froze to death. He took off his waterlogged down jacket so that the burden of movement was much less.

Then it immediately occurred to him that if he spread the down jacket on the ice and climbed up, it might be able to dissipate some pressure. He did so, and with only enough strength left to climb again, he tried his best to climb up the edge of the ice covered with his down jacket, and this time, the ice did not collapse, and he finally lay on the ice, and carefully crawled forward, until he was far from the breach, and then he mustered up the courage to stand up.

At this time, he saw a flashlight shaking on the shore and heard someone shouting.

Luo Ji stood on the ice, his teeth clucking in the cold, which did not seem to come from the lake and the cold wind, but directly from outer space.

Luo Ji didn't look up, he knew that from this moment on, the starry sky was already another look in his eyes, and he didn't dare to look up again.

Like Rediaz was afraid of the sun, Luo Ji has since suffered from a severe phobia of the stars.

With his head bowed, his teeth chattering in the shiver, he said to himself:

"Luo Ji, the wall-facer, I'm your wall-breaker."

……