Chapter 155

Zhang Yuan quickly built a mathematical model: "take the galaxy as a plane, namely R ^ 2. Consider one of the spaceships doing standard Brownian motion, or two spaceships doing independent standard Brownian motion.

"When the distance between two spaceships is less than a small constant, such as 0.01, it is regarded as meeting."

"Because the two-dimensional Brownian motion is recurrent in the neighborhood, as long as the time is long enough, the two spaceships will definitely meet."

"Consider two independent standard Brownian motions a (T), B (T). A (1) + B (1) and a (2) are identically distributed, because B (2) = B (1) + [b (2) - B (1)] is also the sum of two independent standard normals. This means that the distribution of the sum of two independent standard Brownian motions at time t is equal to the distribution of a standard Brownian motion at time 2T. "

Zhang Yuan frowned and said: "considering this simple model, the probability of a moving spacecraft observing alien civilization is twice that of a stationary one. That is to say, if we can observe a civilization that can travel to the stars once every 1300 years on average, it will take 2600 years for earth civilization to observe once. "

Lin Xuanxuan opened her mouth slightly, which was just some information from nothing!

She was a little proud, and sighed that she had a good eye.

Soon, Zhang Yuan shook his head, this is just a simple model, plus the sample is too small, the real situation and estimation must be very different.

"If interstellar civilization is not so rare, then the universe may be more wonderful than we imagined!"

Of course, Zhang Yuan is not the only smart person in the spaceship. With such a simple encounter, various ideas have emerged one after another.

First question: how big is this alien spaceship and where is it going?

According to astronomical observations, it's at least the size of mercury! And it is moving at 40% of the speed of light. The faint light spot is the light produced by the friction and collision between the super fast moving ship and the micro particles in the universe.

Because of the extremely high sailing speed, the observed image is a bit elongated like noodles.

The direction of its movement is about 123 degrees from the direction of the earth time. The destination is unknown. Anyway, it is definitely not the earth or glitzer 581.

See here, Zhang Yuan slightly down, anyway, and their destination has nothing to do, like..

The second question is, did the alien spacecraft discover the earth age?

Probably not. The earth age is still too small. In the dim universe, you can't see anything. If there is no external electromagnetic radiation, it's difficult to find an object 0.12 light-years away.

But the other side once sent a series of short signals, and I don't know whether it was directed or sent in groups in all directions.

Zhang Yuankai's series of signals have about 600 bytes, and many peaks and troughs are repeated, which shows that it is a logical electromagnetic signal.

Unfortunately, because the amount of data is too small, it is impossible for people to decipher these alien characters.

And then there is no next. Even if the other party has good intentions, human beings dare not boldly observe it, let alone write back or scan it with radar. Besides, the earth age radar can't scan anything 0.12 light years away.

Zhang Yuan felt a little sorry that there was never a lack of material in the universe, and the most precious thing was information. Human beings who have never communicated with the interstellar civilization have missed this time. Next time, they don't know how long it will take

There are many of the same views in the following posts.

[this civilized technology must be much better than us. 】

[are you sure you don't see a planetary spacecraft? There should be no way to accelerate this planet to 40% of the speed of light with nuclear fusion 】

[in my opinion, we use vacuum zero energy or black hole energy. Maybe it's an anti gravity propulsion device. We don't seem to see the plasma flame at the jet. 】

[if only there were more observation data 】

after all, I didn't feel the fear from the unknown. In recent posts, people's thoughts are more optimistic and open. Zhang Yuan is a little itchy to see all kinds of discussions, and also wants to express his own opinions.

"Watch it, confiscate it!" Lin Xuanxuan snatched his mobile phone. "That's all for today. The patient has to look like a patient. I don't care what happens when you leave the hospital. "

A week later, Zhang Yuan was officially discharged from hospital and began his normal work.

He is already a high-level manager. With the aging of the spacecraft, he no longer has a lot of his own time as before.

His work has become even busier. Basically every week, he organizes a team to maintain the whole ship.

Moreover, in addition to the alien spaceship he met by chance, Zhang Yuan also learned some other stories that have happened in the past few hundred years

It's not a good thing.First, the old captain left the ship he loved three years after his hibernation.

His successor is captain Lin of the Council of science.

This kind of feeling even after many times, even if ready, still not so comfortable.

As soon as you open and close your eyes, some people have disappeared

Second, unfortunately, since the death of Mr. aiding on earth, the spaceship has completely lost contact with the earth.

There is no great man of the same era.

What happened to the earth's civilization is a complete unknown.

Zhang Yuan sighed and threw himself into his work

……

One year passed quickly, seeing off one colleague after another, and then it was time to have dinner together and Hibernate again.

Lin Xuanxuan is the only one who can accompany him for a long time.

During the meal, Zhang Yuan suddenly felt that it was really nice to have someone who had been with him all the time Without this life partner, life would be worse.

“…… How old are you this year? " Asked Lin Xuanxuan.

"Me? I'm over 1300 years old. What's the matter? " Zhang Yuan is just eating.

"True age!"

“…… 30？” After careful calculation, Zhang Yuanzai suddenly found that he was already 30 years old. And it happens that today is my birthday. In this kind of environment, he really can't tell the passage of time clearly, and he never has the habit of having a birthday.

"Happy birthday, 30-year-old uncle!" Lin Xuanxuan took out a red apple and handed it to him.

"Thank you, beautiful little sister And your temperature! " Zhang Yuan joked. If you get used to fighting, you will always have an instinctive sense of randomness, just like real relatives.

(how come there are so many comments in the book review area, and one person still sends several? There's nothing to say...)

(what else needs to be fast paced and relaxed? This is not Xiaobai. My reading object is never Xiaobai, OK