Wandering Spaceship in Deep Space Chapter 418: A new era (end of volume 7)
Lin Xuanxuan was silent for a while after listening to Zhang Yuan’s description, and suddenly said: "The feelings between you boys are often purer. If I were you, I would have cried a lot..."
A star drifted from the light cluster behind, drew a complicated curve, and transferred to the light cluster in front. This is because the spacecraft 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 dorm will be smashed. Everyone forms. The respective small groups, I don’t know how complicated it is."
"I haven't heard you talk about it before."
Lin Xuanxuan said: "In fact, it's nothing, everything is over...Finally, near graduation, everyone ate a meal and then dispersed. The old and new hatreds disappeared. There was 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 you think. 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 my mother's appearance."
"I can't remember what my father looked like... I can only recall it by looking at the photos." Zhang Yuan sighed.
The two were silent for a while.
Lin Xuanxuan asked again: "...If I die suddenly, will you cry?"
"Why are you crying?" Zhang Yuan smiled and said: "Death is a new beginning. This cycle is over, and a new life will start again. It doesn't make much sense to miss the past."
"I can only wish you happiness in the new world and live your next life!"
Lin Xuanxuan was surprised at first, and then smiled: "I wish you also, in the future world, a bright future!"
……
In the last few years, Zhang Yuan has been working at the observatory, mainly in charge of teaching elementary and junior high school students how to use astronomical telescopes and how to distinguish planets in the universe, including the direction of the sun and the direction of Gliese 581 , These are the places where human beings were born, or developed here.
"If one day, you become captains, it will be terrible if you can't find a way home!"
This job is very easy, there is not much workload, and I am full and happy every day.
A clever little girl asked: "Grandpa Zhang, 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 spacecraft?"
"Even airplanes on the planet need to be navigated. How can a spacecraft navigate? Long-distance navigation must be accurate enough!"
Faced with this problem, Zhang Yuan thought for a while and took another sip of water: "It's very simple, there are 3 good ways in total."
" First, use accelerometers and gyroscopes, that is, inertial navigation systems. By measuring the acceleration and angular velocity at each moment, you can use integrals 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 surrounding stars, and sets up simultaneous equations. But as you said, everything is in motion, and the distance measured by the spectrum changes constantly. It’s difficult to measure very accurately."
" Method three, navigating through a fixed radio signal source, is also the method we use now. There are a large number of pulsars naturally in the universe that emit electromagnetic pulses periodically. Just observe multiple pulsars to form a pulsar The timing array is a natural deep-space network, also known as the “Galaxy Positioning System”."
"If you feel that the pulsars inside the galaxy are moving, causing a certain degree of error, you can even observe pulsars outside the galaxy, 100 million light-years away!"
"Such a distant planet, we can directly think of it as static."
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.
This girl asked again: "If we go out of the Milky Way and sail across the river system, how should we position it?"
Zhang Yuan replied: "There is a phenomenon called rapid radio bursts. These high-energy millisecond flashes, it is speculated that the signal source is very large, may come from outside the Milky Way. Maybe someday in the future, they will Become a beacon for human travel across galaxies. 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 human travel across rivers."
"Across the river system?!"
Thinking of there are so many natural lighthouses in the universe, all the students are yearning for them, and they can’t help looking out the window one by one.
It’s too far to cross the river system!
"Grandpa Zhang, there is another question, why are there as many integers as even numbers?"
After a while, a little fat guy 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’s astronomy, geography, mathematics, chemistry, or almost everything.
All children worship power. Knowledge is power. In their eyes, Zhang Yuan can be regarded as the person with the most extensive knowledge. He is also an old captain and has a gentle temper. He can basically 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 laughed loudly. It is still too difficult to talk about "infinity" with a child of this age.
pondered for a while, and he said: "Do you think there are more points on the 1 cm line segment or the 2 cm line segment?"
"Of course... there are more dots on the 2 cm line segment! 2 cm is longer than 1 cm, shouldn't there be more dots on top!" The little fat man looked nervous, this is not a very simple question...
It's embarrassing if you answer the wrong question.
The students around me also deeply agree, and there are a few more clever, tilted their heads and didn't speak.
Zhang Yuan smiled and said: "Have you learned functions once?"
"Of course I have learned it."
"Then, 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 is the same as the point on the diagonal line. Isn’t there a one-to-one correspondence? From (0, 0) to (1, √3), it is exactly 2 cm. Each x-axis coordinate can correspond to one of them."
"You have more points on the 2cm line segment. Where are the extra points?"
"If we can't find it, we can only think that there are as many points on the 1 cm line segment as there are as many points on the 2 cm line segment, right?."
The little fat man looked for those missing dots with a look of dissatisfaction, but he couldn't find it...
Finally, they launched a mass offensive and caused misconceptions such as "whether the 0.9 cycle is equal to 1" came out, but in the end they were very unwilling to lose.
"Can't find it, haha!"
Zhang Yuan gloatly said: "Actually, according to our theory, one-to-one correspondence is a very important method. There are as many points on a one-centimeter line as there are two-centimeter points; according to one kind of The method, one centimeter of points, and a piece of paper, that is, there are as many points on the plane.
" There are even a centimeter point, and the point on a large surface like the Kunlun Mountain spacecraft, or even the point in the entire cosmic space...even any point in the high-dimensional space, there are as many, and some methods can be used. One-to-one correspondence."
"That is, there are as many points on a one-centimeter line as there are points in the entire universe!"
"Huh?" Not only this little fat man, but also a lot of students behind him exclaimed.
How can they not think that such a small section can be compared with the entire universe, is this incredible?
let these children show a surprised expression, lamenting the mystery of the universe, which has become a great pleasure for Zhang Yuan.
Zhang Yuan smiled and said: "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 formed by real numbers, is called Aleph 1."
"...All possible mathematical functions: the number of continuous functions and discontinuous functions, call it Alef 2."
"I see, there are Alef 3, Alef 4, Alef 5!" The little fat man yelled, as if he had discovered something full of power.
Students at this age are always so second, gaining a little knowledge, and being able to show off in front of their peers.
Zhang Yuan smiled and said: "Yes, it can extend upwards infinitely... However, it is difficult for you to find a higher dimensional infinity, and its concrete meaning in reality, it can only become a string of symbols on paper. 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 can never be proven or denied. It is left there alone, and it has existed for nearly four thousand years, and it has not been resolved until now. "
"Why?" Wang Tiantian asked again, this world is too strange.
One problem has not been solved for four thousand years. He is a little bit ready to move in his heart
Zhang Yuan laughed again: "That's... another story, called Gödel's incompleteness theorem! The history of mathematics is another magnificent journey, a problem that cannot be solved in the world. There are so many!"
……
Time goes by day by day, as the aging continues, the body is getting worse every day.
Even on the journey to the observatory, he would feel very tired, but he still insisted on working and answering questions for the children. This can be said to be the greatest pleasure after the withering of friends one by one.
On this day, the doctor who checked his body showed a very regretful look. She said very carefully: "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 up to the standard. At the end of this month, if you wish..."
"Is this... really living long enough." Zhang Yuan nodded and sighed: "There is nothing unwilling, let me say goodbye to this era."
On August 29, 5812, the first captain of the Kunlun Mountain Fleet, Zhang Yuan, was about to leave the world.
The salute lit up briefly in this starry sky, and then disappeared silently.
At present, 90% of the population is in hibernation and there is no need to wake up specifically. The remaining 10% of the sober population are all performing this farewell ceremony spontaneously.
Many production activities in Kunlun Mountains have also stopped, and the school has a day off, and Zhang Yuan also deserves such an honor.
"Do you have anything else to say?" the doctor said.
Countless descendants who saw him off are looking at him, expecting something from him, or encouragement, or something else. There are also some old people who are wiping their tears. This time, he is not the last to leave.
"No, everyone is fine, go ahead." Zhang Yuan smiled and said: "The future still depends on you."
Several staff members helped him out of the wheelchair and lay down.
The hibernation warehouse is like a soft Simmons, lying very comfortable, Zhang Yuan turned his head and looked at the surroundings.
A former friend and colleague is saying goodbye to him.
seems to be few.
This feeling is 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, the moment he understood what death was all about, he squatted on the corner of the wall and cried.
"Can I not die?" Zhang Yuan asked with tears in his eyes.
"What does not mean to die?" His father Zhang Qiming replied.
"It's... to be alive all the time."
"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 can't live forever. "
The young Zhang Yuan couldn't receive this answer for a while, although many of his father's answers were inexplicable.
Zhang Qiming said: "I think you may think that the time period of immortality is too short to imagine. Immortality means infinity, one hundred years, ten thousand years, one hundred million years, or even ten billion years~IndoMTL .com~Compared with infinity, it is no different from zero."
"In the eyes of the real immortal, the universe may be heat dead within a second, that is, you feel all the happiness on the earth, only for a very short time. The next is the long , The time of lonely existence in the vast and empty universe. There is no matter and no company."
"Until waiting for that little cosmic big bang in the quantum sea, restarting a new era. But how much time will it take?"
"Humans may not be able to tolerate this kind of loneliness, or they may change their minds to another species, or they may stop thinking... I think, stop thinking and choose death." Zhang Qiming looked at the blue sky. Touching Zhang Yuan's head, he said solemnly.
Even though, Zhang Yuan, who was young, didn’t understand what his father was saying...
I don’t know why, before Zhang Yuan left this world, he remembered this conversation.
Maybe, a dead hero is a good hero.
just...how lonely...
Among the blooming clusters, Zhang Yuan vaguely heard bursts of crying. I don't know who is crying again.
confused, he quickly lost consciousness.
……
One era is over, and another era begins soon after.
Human beings will not stop their steps because of this. This great journey is still going on...
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