Chapter 278 Lobbyists come to visit, a big deal from Peking University
1976.
The Bald Eagle's "Washington Post" reported a mathematical news on the front page and recorded a story in the article.
In the mid-1970s, on the campuses of prestigious Bald Eagle universities, people seemed to be going crazy, playing a mathematical game without sleep or food.
This game is very simple. Write a natural number N arbitrarily and transform it according to the following rules:
If the number is odd, multiply it by 3 and add 1.
If the number is even, divide it by 2.
Once this game was launched, students, researchers, professors, etc. within the school attracted many to join.
The reason why this game has such great appeal is because people find that no matter how familiar N is, there is no way to escape back to rock bottom 1. To be precise, there is no way to escape. The cycle of 16-8-4-2-1 that fell to the bottom will never escape this fate.
And this is the famous ‘hail conjecture’.
The greatest charm of this conjecture lies in its unpredictability. After the bald eagle caused a stir in academic inquiry, it naturally spread to the world.
After all, the bald eagle at this time is still a beacon to the world and the pure land of heaven in the hearts of countless people.
Regarding this conjecture, John Hutton, a professor at Cambridge University who never sets on the sun, made a new discovery and found a natural number 27.
27 does not seem to be a surprising number. , but if the calculation is performed according to the above method, then its floating and sinking are extremely violent, and it needs to go through 77 steps. The transformation reaches the peak value 9232, and then reaches the bottom value 1 after 32 steps.
The entire transformation process requires 111 steps, and its peak value is 9232, which is 342 times the original number 27. If To compare with a waterfall-like straight fall, the number N with the same distance would reach 2 to the 111th power.
In addition, in the range of 1 to 100, there are no violent fluctuations like 27.
Of course, this is not the only proof and attempt made by scholars around the world for the hail conjecture.
However, the entire academic community has not made much progress in proving the hail conjecture.
Even now, no one has actually proved this mathematical problem.
Wang Donglai chose to prove this mathematical problem just on a whim.
There are so many difficult problems in mathematics. The reason why he chose this difficult problem was because he suddenly remembered that when he was at Princeton, he had exposed a student from Asan who proved this mathematical difficult problem.
It is for this reason that he chose this difficult problem.
Seven days proved the hail conjecture.
That is, Wang Dong is here.
If it were anyone else, Han Hua would not believe anything he said, even a math master like Qiu Chengtong, he might not believe it.
However, Hanhua was willing to believe Wang Donglai.
Choose the mathematical problem of hail conjecture, and Wang Donglai began to go all out.
On the one hand, it is experiments and breakthroughs in battery technology, and on the other hand, it is necessary to prove mathematical problems.
Fortunately, other than that, Wang Donglai didn't have many things that he had to deal with personally.
There are only two open classes a week, and Wang Donglai can arrange the rest of the time at will.
one day!
Two days!
Three days!
The office assigned by the school is already covered with scratch paper.
In the past three days, Wang Donglai's proof of the hail conjecture has also advanced to a very advanced level.
To people outside of math majors, this is just a math game.
However, for people in academic circles, this is a number theory problem, or a classic problem in additive number theory, but in the final analysis, it is just a complex analysis problem.
The current academic method for proving this difficult problem is the arithmetic sequence verification method, which is a verification method established entirely based on the verification rules of the Hailstone Conjecture.
The method is very simple. It is to use an infinite arithmetic sequence to compare infinite natural numbers. The first term is an even number and the common difference is an even number. Then all the natural numbers in the sequence are even numbers. The entire sequence is divided by 2. If the first term is an odd number and the tolerance is an even number, then all the natural numbers in the sequence are odd numbers. Multiply all the natural numbers by 3 and add 1.
If the tolerance is an odd number and the first term is also an odd number, then the odd-numbered terms must all be odd, so multiply by 3 and add 1, and the even-numbered terms must all be even, so divide by 2.
If the tolerance is an odd number and the first term is an odd number, then the odd-numbered terms must be odd, so multiply by 3 and add 1, and the even-numbered terms must be even, so divide by 2.
If the tolerance is an odd number and the first term is an even number, then the odd-numbered terms must all be even numbers, then divided by 2, the even-numbered terms must be odd numbers, so multiply by 3 and add 1.
If you calculate according to such calculation rules, you will encounter many problems.
For example, the general formula of even numbers is 2n. Since they are all even numbers, divided by 2, we get n, which is a natural number.
Just when Wang Donglai was trying to prove this mathematical problem in the office.
Xu Songyao and Academician Huang Yun of the Mathematical Society came to his office together.
However, as soon as he entered the office, Academician Huang Yun focused on the slightly messy draft paper in the office.
When I saw it, I was fascinated.
As the chairman of the Chinese Mathematical Society, Academician Huang Yun still has academic abilities in mathematics.
After watching for a while, I saw what Wang Donglai was doing.
And it was precisely because he saw it that Academician Huang Yun was shocked.
I was shocked, but also a little excited and complicated, and I quickly asked: "Professor Wang, can I ask how far you have come in proving Kakutani's conjecture?"
< br>I heard Academician Huang Yun ask, Wang Donglai Then he completely stopped what he was doing, thought about it seriously, and then said out loud: "It should be 70%, and it should be almost there in two days."
Wang Donglai said this answer as soon as he said it. , Xu Songyao and Huang Yun were both breathless.
It is worth mentioning that the Hail Conjecture is also called the Kakutani Conjecture in China. The reason is also very simple. It was a person named Kakutani from Sakura Country who spread it to China, so it was called this name.
"Okay! Okay! Okay!"
Xu Songyao said hello three times in a row, and his excitement was beyond words.
The same goes for Academician Huang Yun, his eyes were shining and he looked at Wang Donglai with great enthusiasm.
“I knew you would not disappoint Donglai. As expected, a hero comes from a young age. It has only been a few months since we proved Goldbach’s conjecture. I didn’t expect that your proof of the hail conjecture would have reached this stage. "
To be honest, Academician Huang Yun is really happy that Wang Donglai proved the hail conjecture.
After all, he is the chairman of the Chinese Mathematical Society, and Wang Donglai is a member.
The greater the results Wang Donglai achieves, the more benefits he will naturally reap as the chairman of the Mathematical Society. "By the way, are you using the arithmetic sequence verification method, or the verification method of ignoring even numbers and not recording them?"
Huang Yun thought for a while, but still could not suppress his curiosity, so he I asked tentatively.
Although he is the chairman, he is still an academic researcher at heart.
At this time, when I saw Wang Donglai proving a mathematical problem with my own eyes, and he was only a part away from success, my heart was already scratching my head with curiosity.
However, Huang Yun also understood that these things were top secret until the academic papers were published.
So after struggling for a while, Huang Yun asked a question that did not involve secrets, which could satisfy his curiosity to some extent.
Ignoring even numbers and not recording the verification method is actually very simple.
The first odd number that is verified may be an odd number that is divisible by 3, or it may be an odd number that is not divisible by 3, but the second odd number and the third odd number that are reached, Every odd number reached, encountered, and visited during the entire process must not be divisible by 3.
If we start from the odd numbers that can be divisible by 3 and verify, every odd number that we encounter, arrive at, and visit on the path must be no longer divisible by 3, and ultimately all can be attributed to 1, then we must traverse all the odd numbers. ;If you start the verification from odd numbers that are not divisible by 3, then every odd number that is encountered and reached on the path is summarized. It must no longer be divisible by 3, and ultimately all comes down to 1; so in the verification process of the forward hail conjecture, all odd numbers that can be divisible by 3 can be named as the odd number at the starting point, and 1 is the odd number at the ending point. , but in the reverse hail conjecture verification process, it is the opposite. 1 is the odd number at the starting point, and the odd number that is divisible by 3 is the odd number at the ending point.
In fact, during the verification process, odd numbers that are not divisible by 3 are all present in an infinite number of odd numbers from the previous step, accounting for 1/3 of the odd numbers that are not divisible by 3, accounting for 2/ The ratio of 3 is an odd number that is not divisible by 3. This phenomenon coincides surprisingly with the situation of natural numbers.
Huang Yun asked about the method of verifying the arithmetic sequence and the method of ignoring even numbers and not recording them, which was not considered a secret.
Wang Donglai didn't care about this, so he smiled and said: "Actually, the verification method does not matter, it is not that important."
"I used the binomial theorem and the elimination method After studying the possibility of the existence of main counterexamples and reverse thinking methods, we finally found an entry point, which should not be far from a complete proof. ”
Wang Donglai just introduced a few sentences briefly, and Huang Yun's mind seemed to be having a brainstorm, and he subconsciously verified it based on what Wang Donglai said.
However, Huang Yun reacted in just the next second.
With a wry smile on his face, he said aloud: "I used to always say that you need to be calm during big events, but now it seems that I am still far behind!"
"Okay, let's not mention the proof of the hail conjecture anymore. If I say it again, I'm afraid I won't be able to help but feel jealous."
Huang Yun did not hide his performance just now. Making fun of himself somewhat self-deprecatingly.
Faced with what Huang Yun said, Xu Songyao and Wang Donglai naturally couldn't say anything more and changed the subject.
"Xu Xiao, is there something wrong?" Wang Donglai asked aloud.
Xu Songyao said: "I don't have anything important to do with you. Academician Huang has something to do with you."
Hearing this, Wang Donglai turned his attention to Huang Yun.
Huang Yun did not say it immediately, but looked at Xu Songyao, then at Wang Donglai, hesitated for a moment, and then said aloud: "Actually, I am here this time because Academician Tian from Peking University asked me to I’m here to be a lobbyist.”
"Peking University hopes that Professor Wang will consider going to Peking University for academic research. The conditions given include but are not limited to 50 million academic research funding approval rights, director of the Theoretical Mathematics Research Center, and a teaching laboratory building and other conditions."
"Academician Tian came to me personally, and I couldn't refuse, so I had to come over for a quick trip."
When Huang Yun said this, Xu Songyao's face was already a little ugly, but He didn't explode, but held it back.
Wang Donglai's expression was extremely calm, and there was no big surprise.
After all, with his academic performance at this moment, colleges should have contacted him long ago and wanted to poach him.
In fact, many top foreign universities have sent invitations to make Wang Donglai a special professor.
If Wang Donglai had been more proactive, he might not have been able to gain academician status abroad earlier.
Huang Yun naturally noticed the change in Xu Songyao's expression. He was not surprised, but he did not expect Wang Donglai to be so calm.
You know, the conditions Peking University asked him to propose this time were extremely generous.
Academic research funding is one aspect. The Theoretical Mathematics Research Center was probably set up specifically for Wang Donglai. However, with the brand name of Peking University, Wang Donglai's identity naturally changed after he became the director again.
If this condition were placed on Huang Yun, he would have agreed to it.
In fact, as early as the beginning, I might have gone to Peking University.
Thinking about this, Huang Yun spoke again: "Of course, Academician Tian also said that he will respect Donglai's ideas, and this condition will always be maintained."
"Except In addition, Academician Tian also made a suggestion, that is, he would like to invite Donglai to Peking University for academic exchanges.”
“There is already a practice of academic exchanges among C9 universities. It is normal for academicians to make this suggestion.”
Just as Huang Yun finished saying this, Xu Songyao spoke.
"Leave this matter to Dong Laiqi to handle on his own. No matter what choice you make, I will still support you, and the school will be your strong backing."
" Whether it’s going abroad or going to Peking University, as long as it can help you gain something, that’s all!”
Xu Songyao’s words were not false, but a sincere thought.
He saw very clearly that Tangdu Jiaotong University was indeed inferior to Peking University in mathematics and inferior to top foreign universities. The gap was obvious.
Wang Donglai stayed here, and his growth rate was indeed not faster than when he went to these places.
If it was just for the sake of the mathematics major of Tangdu Jiaotong University and the academic status of Tangdu Jiaotong University, then Wang Donglai would definitely not be allowed to leave.
But Xu Songyao would not do this, because he understands a truth, which is to treat others with sincerity and reciprocate with sincerity.
Things were exactly as Xu Songyao thought. Wang Donglai did not hesitate at all and directly rejected the offer from Peking University.
“I would like to ask Academician Huang to thank Academician Tian for his kindness. I am nostalgic and will not leave Tangdu Jiaotong University.”
"However, there is no problem with academic exchanges. As long as the two schools communicate well, I have no problem."
Huang Yun also had a faint smile on his face and breathed a sigh of relief.
But I secretly made up my mind to never accept such a thing again.
“Okay, I will tell Academician Tian about this.”
“However, compared to this matter, I am more looking forward to your academic achievements. I have a hunch that our domestic mathematics The profession will usher in a huge take-off, and this is all due to you!”
Huang Yun said with emotion.
(End of this chapter)