MTL - The Science Fiction World of Xueba-Chapter 484 Sirius
Life inside the spaceship is boring and warm.
In addition to completing the daily observation tasks of Samsung Centaur through the telescope, Pang Xuelin spent the rest of the time, besides engaging in Riemann's conjecture research, growing plants in the plant cabin with Mu Qingqing.
Because of the long hibernation of the crew, the plant cabin of the spacecraft will only start when the crew wakes up.
Pang Xuelin and Mu Qingqing planted potatoes, cucumbers, eggplants, tomatoes, corn, rice and other crops in the plant cabin, and also raised many bread bugs as a source of animal protein.
This kind of life reminds Pang Xuelin of the days in the Martian rescue world.
But there is no doubt that life on the spaceship is much more interesting than life on Mars.
Not only because of the diversity of food, but more importantly, there are also beautiful women.
The only thing that made Pang Xuelin a bit of a headache was that in the process of studying Riemann's conjecture, he still could not find any clues.
But this is not surprising.
From the twenty-three questions of Hilbert in 1900, to the seven major problems of world mathematics proposed by the Clay Institute in 2000.
Over a century, Riemann's conjecture still stands on the top of the world's mathematics.
The reason is of course not only because of the difficulty of the Riemann conjecture, but also because of the importance of the Riemann conjecture itself.
The primary reason is that it is inextricably linked to other mathematical propositions.
According to statistics, there are more than one thousand mathematical propositions in today's mathematical literature based on the premise of the establishment of Riemann's conjecture (or its generalized form).
This shows that once the Riemann conjecture and its generalized form are proved, the impact on mathematics will be very great, and all the more than a thousand mathematical propositions can be promoted to the theorem.
Conversely, if Riemann ’s conjecture is overturned, the more than 1,000 mathematical propositions will almost inevitably become burials.
A mathematical conjecture is closely related to so many mathematical propositions, which is unique in the history of mathematics.
Second, the Riemann conjecture is closely related to the distribution of prime numbers in number theory.
Number theory is an extremely important traditional branch of mathematics, which is called "the queen of mathematics" by the German mathematician Gauss.
The distribution of prime numbers is also an extremely important traditional subject in number theory, which has always attracted the interest of many mathematicians.
This kind of "noble lineage" deeply rooted in the tradition has also increased the status and importance of the Riemann conjecture in the hearts of mathematicians to a certain extent.
Furthermore, there is another measure of the importance of a mathematical conjecture, that is, whether it can produce some results that contribute to other aspects of mathematics during the study of the conjecture.
To measure by this standard, the Riemann conjecture is also extremely important.
In fact, one of the early results achieved by mathematicians in the process of studying Riemann's conjecture directly led to the proof of the prime number theorem, an important proposition about the distribution of prime numbers.
Before being proved, the prime number theorem is an important conjecture with a history of more than 100 years.
Finally, Riemann's conjecture has exceeded the scope of mathematics in a certain sense.
In the early 1970s, people discovered that certain research related to Riemann's conjecture was actually significantly related to some very complicated physical phenomena.
The reason for this connection is still a mystery to this day.
But its existence itself undoubtedly further increased the importance of Riemann's conjecture.
Because of this, the Riemann conjecture has attracted countless mathematicians to climb for more than 100 years since its birth.
Although these efforts have not been completely successful so far, they have achieved some stage results in the process.
The first of these results came in 1896, thirty-seven years after the Riemann Conjecture.
The nontrivial zeros of the Riemann zeta function are easy to prove that there is only one result, that is, they are all distributed in a banded area.
The French mathematician Hadama and the Belgian mathematician Poussin eliminated the boundary of the banded region by independent means.
In other words, the non-trivial zeros of the Riemann ζ function are distributed only inside that banded region, not including the boundary.
This result may seem insignificant. The boundary of a banded area is actually zero in area compared to its interior.
But it is only a small step for studying the Riemann conjecture, but it is a huge leap for studying another mathematical conjecture, because it directly leads to the latter's proof.
That mathematical conjecture is now called the prime number theorem, which describes the large-scale distribution of prime numbers.
The prime number theorem has been outstanding for more than 100 years since it was proposed. At that time, it was something that the mathematics community expected more than the Riemann conjecture.
Eighteen years after the above results, in 1914, the Danish mathematician Bohr and the German mathematician Landau achieved another staged result, which is to prove that the non-trivial zero point of the Riemann ζ function tends to "Around the critical line.
In mathematical language, this result is that no matter how narrow the banded region containing the critical line contains almost all non-trivial zeros of the Riemann ζ function.
However, "close solidarity" is attributed to "close solidarity". This result is not enough to prove that any zero point is exactly on the critical line, so it is still far from the requirements of the Riemann conjecture.
But in that same year, another staged result emerged: the British mathematician Hardy finally inserted the "red flag" on the critical line-he proved that the Riemann ζ function has an infinite number of non-trivial zeros on the critical line.
At first glance, this seems to be a non-trivial result, because the non-trivial zeros of the Riemann zeta function are infinite, and Hardy proved that there are infinitely many zeros on the critical line. Literally, the two are exactly the same Too.
It is a pity that "infinity" is a very delicate concept in mathematics, which is also infinity, but it is not necessarily the same thing with each other.
In 1921, Hardy collaborated with British mathematician Lettwood to make a specific estimate of the "infinity" in his result seven years ago.
According to their specific estimates, what percentage of the "infinitely many non-trivial zeros" that have been proven to be on the critical line compared with all non-trivial zeros?
The answer frustrated them: zero percent!
Mathematicians pushed this percentage to a number greater than zero in 1942, twenty-one years later.
That year, the Norwegian mathematician Zelberg finally proved that this percentage was greater than zero.
When Zelberg made this achievement, the smoke of the Second World War was spreading all over Europe. The University of Oslo, where he was located, became almost an island, and even mathematical journals could not be delivered.
Perhaps because of this, Zelberg can accomplish such an outstanding achievement.
However, although Zelberg proved that the percentage was greater than zero, he did not give a specific value in the paper.
After Zelberg, mathematicians began to study the specific value of this ratio, among which the results of the American mathematician Levinson are the most remarkable.
He proved that at least 34% of the zeros are on the critical line.
Levinson achieved this result in 1974, when he was over 60 years old, and was about to reach the end of his life (died in 1975), but still tenaciously engaged in mathematical research.
After Levinson, the progress in this area has become very slow, and several digitists have spent their utmost to make a fuss about the second digit of the percentage, including Chinese mathematicians Lou Shituo and Yao Qi (they proved in 1980 that at least 35% of the zeros are on the critical line).
It wasn't until 1989 that someone shook the first digit of the percentage: American mathematician Kang Rui proved that at least 40% of the zeros are on the critical line.
This is also one of the strongest results in the entire Riemann conjecture study. After that, the Riemann conjecture hardly made any progress in the mathematical world.
Two years passed unconsciously.
On this day, Pang Xuelin floated in front of the porthole of the command and control cabin, looking at the starry sky in the distance.
For two years, Pang Xuelin's research on Riemann's conjecture has been stagnant.
This made him a little helpless.
This is sometimes the case with mathematics. Even if you think agile no matter how, when faced with a problem, if you can't find a suitable breakthrough, it is basically a black eye.
Now Pang Xuelin entered this situation when facing Riemann's conjecture.
Pang Xuelin took a deep breath and turned his eyes to the upper right corner of the porthole.
On the side of the starry sky, a tennis ball-sized fireball has appeared, spraying a hot flame into the universe, which is Centauri αB.
On the other side, there is also a bright star whose brightness is many times higher than that of Venus, the brightest star seen on earth, which is αA Centauri.
Over the past two years of observation, Pang Xuelin has had a clearer understanding of the situation of Centauri alpha.
There is only one Earth-like planet in the Alpha Centauri system, which is about the size of Venus.
The planet orbits the A / B binary star in a figure eight shape, and its orbit is stable, but the planet is not in the habitable zone of two stars, and spectrum analysis and various band observations show that the planet is basically not There is an atmosphere, and the surface is densely packed with impact craters, which is basically meaningless to humans.
At this time, Pang Xuelin suddenly shrugged his nose, a fragrant wind came behind him.
Immediately afterwards, a warm body embraced Pang Xuelin from behind.
"what happened?"
Pang Xuelin felt Mu Qingqing's delicate body trembling slightly, and seemed to cry.
He quickly pulled the girl in front of him.
Mu Qingqing's eyes turned red, sobbing: "Alin, I just received news from Brother Shuiwa, Brother Liu Qi ... gone."
In the past two years, Pang Xuelin and Mu Qingqing received information from the solar system almost every week.
The information was sent by the Earth after it was estimated that Ark One arrived at Alpha Centauri.
Of course, it also includes messages sent by Liu Qi and Shuiwa.
Pang Xuelin froze for a while, his head a little dazed: "Old Liu, he ... passed away?"
Mu Qingqing nodded and said, "It should have been four years ago. Brother Liu's heart has not been very good, plus 80 years old, it is said that he suddenly walked while walking in the courtyard."
Pang Xuelin was in place.
In the past two years, receiving messages from Liu Qi and Shui Wa from time to time is the greatest comfort for Pang Xuelin.
The azure blue planet four light years away always has a hint of concern.
Now another person worth worrying about is gone.
Although Pang Xuelin was already mentally prepared, at this moment, his heart was still in a state of panic.
In the train carriage many years ago, the fat man who smiled cheaply seemed to be still in sight.
In a blink of an eye, the Sri Lankan is dead, and he is far from the horizon.
Pang Xuelin took a deep breath and said, "Qingqing, let's hibernate too."
Mu Qingqing looked up at Pang Xuelin, nodded and said, "Okay!"
...
Passing alpha Centauri, the next target of Ark One is Sirius.
Sirius, also known as the alpha star of Canis Majoris, is the brightest star in the world except the sun. Although it is darker than Venus and Jupiter, it is brighter than Mars most of the time.
Sirius is a binary system in which two white stars revolve around each other, about 20 astronomical units apart (probably the distance between the Sun and Uranus), but the revolution period is only more than 50 years.
The brighter star (Sirius A) is an A1V type main sequence star with an estimated surface temperature of 9,940K.
Its companion, Sirius B, has gone through the process of main sequence star and became a white dwarf star.
Although the spectrum of Sirius B is now 10,000 times darker than Sirius A, it was once the larger mass of the two stars.
The age of this binary system is estimated to be about 230 million years.
In its early life, people suspected that two blue and white stars would revolve around each other in an ellipse, with a period of 9.1 years.
Sirius A is so bright not only because of its high luminosity, but also because it is very close to the sun, about 8.6 light-years, and is one of the nearest stars.
The mass of Sirius A is about 2.1 times that of the Sun. Astronomers use an optical interferometer to measure its radius, and the estimated angular diameter is 5.936 ± 0.016mas. Its star rotates slowly, at 16 kilometers per second, so the star does not become oblate.
The celestial model pointed out that Sirius A was formed when a molecular cloud collapsed. By 10 million years, its energy production had been completely provided by nuclear fusion. Its core is the troposphere, and uses the carbon, nitrogen, and oxygen cycles to produce energy.
Astronomers predict that Sirius A will run out of hydrogen stored in the core within 1 billion years of its formation. uukanshu.com at this time it will go through the stage of red giant star, and then gently become a white dwarf star.
Sirius B is one of the largest known white dwarfs. Its mass is almost equal to that of the Sun (0.98M☉), which is twice the average mass of white dwarfs 0.5 ~ 0.6M☉, but so much matter is compressed into Earth-like mass.
The current surface temperature of Sirius B is 25,200K.
However, since there is no energy generated inside, the remaining heat will be radiated in the form of radiation, and Sirius B will eventually gradually cool down, which will take more than 2 billion years.
A star will only become a white dwarf after passing through the main sequence and red giant stages.
When Sirius B became a white dwarf, it was a little more than half its current age, about 120 million years ago.
When it was still a main sequence star, it was estimated that there were 5 solar masses and it was a B-type star.
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