Deep Space Planet Leader

After listening to Zhang Yuan’s recount, Lin Xuanxuan was silent for a while, and suddenly said: "The feelings between you boys are often purer. If I were you, I would have been crying rustling sound a long time ago. ......"

A star drifted from the light cluster behind, drew a complicated curve, and transferred to the light cluster in front. This is because spaceship is sailing at high speed.

"The relationship in our dormitory is not very harmonious. You know, there are always such and other small frictions between girls. If there is a girl’s private life in chaos, then the whole dormitory will be utterly utterly smeared. . Everyone formed their own small groups. I don’t know how complicated it is."

"I haven't heard you talk about it."

Lin Xuanxuan said: "In fact, nothing, everything. It's all over...Finally close to graduation, everyone had a farewell dinner party and then they dispersed. The old and new hatreds are all disappeared. There will be no chance to meet again."

Zhang Yuan said: "It's nothing to be a pity. In fact, the connection between people is not as close as imagined. Sometimes when you go to a party, you don't bother to go. In a lifetime, one or two friends are enough."

Lin Xuanxuan thought for a while, "Hey, yes, I can't remember their names anymore! What's more, I can't even remember what my mother looked like."

"I can't remember what father looked like...you can only remember by looking at the photos." Zhang Yuan sighed.

The two remained silent for a while.

Lin Xuanxuan asked again: "...If I die suddenly, would you cry?"

"What are you crying?" Zhang Yuan smiled and said: "Death is new Begin. This cycle is over, and the new life will start again. It doesn’t make much sense to miss the past."

"I can only wish you a happy life in the new world. In the next life!"

Lin Xuanxuan was surprised at first, and then smiled: "I wish you a bright future in the future world!"

......

In the last few years, Zhang Yuan has been working in the observatory, mainly in charge of teaching elementary and junior high school students how to use the astronomical Telescope and how to distinguish planets in the universe, including the direction of the sun and Gliese In the direction of 581, these all are the former home planet, where human beings were born, or where they developed here.

"If one day you become a captain, it will be terrible if you can't find a way back home!"

This job is very easy, not much The workload, and everyday all is very fulfilling and happy.

A smart little girl asked: "Zhang grandfather, how should navigation in the universe be positioned? The galaxy is in motion and everything is in motion. How should we determine the position of our spaceship?"

"Even the planet needs to be navigated on an airplane, how does spaceship navigate? Long-distance navigation must be accurate enough!"

Faced with this problem, Zhang Yuan was pondering After a while, I took another sip of water: "It's very simple, there are three good ways."

"First, use the accelerometer and gyroscope, which is the inertial navigation system. By measuring every moment The acceleration and angular velocity can be used to calculate the speed and displacement of the aircraft. However, the shortcomings of inertial navigation are also obvious: the longer the time, the greater the error, so it is only suitable for shorter voyages and assisted positioning."

"The second method uses the relative positions of known celestial bodies to locate, observes the surrounding stars, and establishes Simultaneous Equations. But as you said, everything is in motion, and the distance measured by the spectrum is constantly changing. It is also difficult to measure very accurately."

"Method 3, navigating through a fixed radio signal source is also the method we use now. There are naturally a large number of pulsars in the universe, which are emitted periodically. Electromagnetic pulse. As long as you observe multiple pulsars to form a pulsar timing array, it is a natural deep-space network, also known as the so-called'galactic positioning system'."

"If you think of the pulses inside the galaxy Stars are moving, leading to a certain degree of error, and it is even possible to observe pulsars outside the Milky Way galaxy, 100 million light years away!"

"Such a distant planet, we can directly consider it to be stationary."

Zhang Yuan played several images of pulsars on the screen. These pulsars are equivalent to artificial satellites that constantly send signals to the outside world.

These students, faced with the real complex knowledge, looked at them all in a daze.

The girl asked again: "If we go out of the Milky Way and sail across the river system, how should we locate it?"

Zhang Yuan replied: "There is a rapid radio burst. Phenomenon. These high-energy millisecond flashes, it is speculated that the signal source is very huge, may come from outside the Milky Way. Maybe someday in the future, they will become a beacon for humans to travel across galaxies. These high-energy millisecond flashes, it is speculated that , Its signal source is very huge, it may come from outside the Milky Way. Maybe someday in the future, they will become a beacon for humans to travel across the river system."

"Across the river system?!"

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When I think of so many natural lighthouses in the universe, all the students are yearning, and they can't help looking towards the window.

It is too far to cross the river system!

"Zhang grandfather, there is another question, why are there as many integers as even numbers?"

After a while, a Little Fatty who had just entered junior high school asked again.

His name is Wang Tiantian, and I don’t know where he heard about this knowledge, whether it is astronomy, geography, mathematics, chemistry, and almost everything.

Little children all worship power. Knowledge is power. In their eyes, Zhang Yuan can be regarded as the person with the most extensive knowledge, and he is also the old captain in the past, and his temper is very gentle. Basically be able to answer all the content. You can even play on the computer here, so there are always many children gathered at the observatory.

"This problem is too complicated!" Zhang Yuan haha ​​laughed. It is still too difficult to talk about "infinity" with a child of this age.

After pondering for a while, he said: "Do you think there are more points on the 1 cm line segment or the 2 cm line segment?"

"Of course it is... 2 cm There are too many dots on the line! 2cm is longer than 1cm, shouldn’t there be more dots on the top!" Little Fatty looked nervous, this is not a very simple question...

I got it wrong. But it's a shame.

The surrounding classmates also agreed, and there were a few clever ones who tilted their heads and didn't speak.

Zhang Yuan said with a smile: "Have you learned a function once?"

"Of course you did."

"Then, y= √3x image can be drawn, right?"

This image is very simple, it is a straight line with an angle of 60 degrees with the x-axis.

Zhang Yuan intercepted 1 cm on the x-axis of the abscissa, and the corresponding oblique section was exactly 2 cm. He smiled and said: "According to the image of this function, the point on the abscissa and the oblique Isn’t the point on the line corresponding to one after another, from (0, 0) to (1, √3), exactly 2 cm. Each x-axis coordinate can correspond to one after another."

"You have more points on the 2cm line segment. Where are the extra points?"

"If you can't find it, we can only consider the 1cm line segment There are as many points on the line as there are on the 2 cm line segment. Isn’t that true?"

Little Fatty looked unconvinced to find those points that disappeared, but he was also impossible to find them. Obtained...

Finally, the mass offensive was launched, which caused misconceptions such as "whether the 0.9 cycle is equal to 1" came out, but in the end I was very unwilling to lose.

"You can't find it, haha!"

Zhang Yuan taking pleasure in other people's misfortune said: "Actually, according to our theory, one after another corresponds to a kind of Very important means. There are as many points on a line of one centimeter as there are points on a 2 cm line; according to one method, there are as many points as one centimeter on a piece of paper, that is, as many points on a plane.

"Even a point of one centimeter is the same as a point on a large surface like the Kunlun Mountains spaceship, or even a point in the entire cosmic space...Even any point in a high-dimensional space is the same. These methods correspond to one after another. "

"That is, there are as many points on a one-centimeter line as there are points in the entire universe! "

"Huh? "Not just this Little Fatty, but a lot of students behind them also exclaimed.

They couldn’t think that such a small section could be compared with the entire universe, which is incredible. Huh?

Let these little children show frightened and flustered expressions and lament the profound mystery of the universe, which has become a great pleasure for Zhang Yuan.

Zhang Yuan said with a smile: "But infinity also has its size. The set of natural numbers is called Aleph 0 in mathematics, which is the smallest infinity. "

"The smallest infinity? "

"The number of points on the line segment, that is, the infinite set of real numbers, is called Aleph 1. "

"...All possible mathematical functions: the number of continuous functions and discontinuous functions, called Aleph 2. "

"I see, there are Alef 3, Alef 4, Alef 5! "This Little Fatty yelled loudly, and seemed to have discovered something full of power.

Students at this age are always so secondary, gain a little knowledge, and are able to show off in front of peers.

Zhang Yuan said with a smile: "Yes, it can be extended upwards infinitely... However, it is difficult for you to find a higher dimensional infinity. In reality, it can only become a paper A string of symbols on the. Moreover, the difficulty in mathematics is whether there is an infinite number larger than Alef 0 and smaller than Alef 1? This problem is called the continuum hypothesis. "

"Although the continuum hypothesis is a hypothesis, it is always impossible to be proved and impossible to be denied. It is left there alone, and it has existed for nearly four thousand years, and it has not been there until now. Was resolved. "

"Why? "Wang Tiantian asked again, this World is too strange.

A problem has not been solved for four thousand years. He has begun to stir in his heart.

Zhang Yuan Haha laughed again: "That's... another story, called Gödel's incompleteness theorem! The history of mathematics is another surging forward with great momentum. There are so many impossible problems in the world! "

...

Time goes by day by day, as the aging continues, the body is getting worse every day.

Even the journey to the observatory, He felt very tired, but he still insisted on working to answer questions for the children. This can be said to be the greatest pleasure after friends withered.

On this day, the doctor who specially checked his body, With a very regretful look, she said very cautiously: "Old Captain, your physical condition has reached the standard for entering the virtual world. "

"I will file a report for you, and your wife is already up to the standard. At the end of this month, if you want to..."

"Well...I really live long enough. "Zhang Yuan nodded, sighed: "There is nothing unwilling, let me say goodbye to this era." "

On August 29, 5812, Zhang Yuan, the first captain of the Kunlun Mountains Fleet, was about to leave this World.

The salute was briefly lit in this starry sky. It starts and disappears silently.

At present, 90% of the population is in hibernation and there is no need to wake up specially. The remaining 10% of the awake population are all spontaneously carrying out this farewell ceremony.

Many production activities in the Kunlun Mountains have also stopped, and the school has a day off, and Zhang Yuan deserves such an honor.

"What else can you say? Want to talk? "The doctor said.

Countless younger generations who saw him off are looking at him, expecting something from him, or encouragement, or something else. There are also some elderly people who are constantly wiping their tears. , This time, he is not the last person to leave.

"Nothing, everyone is fine, go ahead. "Zhang Yuan said with a smile: "The future still depends on you." "

Several staff helped him up from the wheelchair and lay down.

The hibernation warehouse is like a soft Simmons, it is very comfortable to lie down, Zhang Yuan turns Overlook and look around.

A former friend and colleague is saying goodbye to him.

It seems that there are not many.

It feels very subtle. Zhang Yuan is not a person who is afraid of death, but at this moment, there is still a feeling of breathlessness.

He suddenly remembered--

When he was very young, at the moment he understood what death was all about, he squatted in the corner and cried.

"Can I not die? "Zhang Yuan asked with tears.

"What does not mean to die?" "His father Zhang Qiming replied.

"It's...always alive. "

"Oh, you mean...you want to live forever. "Faced with this question, Zhang Qiming pondered for a long time, and said with a serious face: "I think it's better to die. People cannot live forever. "

The young Zhang Yuan was unable to receive this answer for a while, although many of the answers from father are unfathomable mystery.

Zhang Qiming said: "I think you are likely to live forever The period of time is imaginatively too short. Eternal life means infinity, one hundred years, ten thousand years, one hundred million years, or even ten billion years, which is no different from zero when it comes to infinite grand competition. "

"In the eyes of the true immortal, the universe may be heat dead within a second, that is, all the happiness you feel on Earth only exists for a very short time. The next is a long, lonely time in the vast empty universe. There is no material, no company. "

"Until waiting for that little Universe Great Explosion in the quantum sea, restart a new era. But how long does it take? "

"Humans may not be able to tolerate this kind of loneliness, or their thinking forms may change to another species, or they may stop thinking... I think it's better to stop thinking and choose death. "Zhang Qiming looked towards the blue sky, touched Zhang Yuan's head, and said solemnly.

Even though, the young Zhang Yuan didn't understand at all, what his father was talking about...

I don’t know why, Zhang Yuan remembered this conversation before leaving this World.

Perhaps, the dead hero is the good hero.

It’s just... How lonely...

Among the flowers, Zhang Yuan vaguely heard a burst of crying. I don’t know who is crying again.

He was confused and soon I lost consciousness.

...

One era is over, and another era begins.

Humans will not stop themselves because of this. Footsteps, this great journey is still going on......

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