The rejuvenation of a great nation: from educated youth to national treasure scientist

Chapter 123 World-class Problems Easily Solved

Seeing this, Zhang Hongbing smiled and said to Wang Haoran: "Comrade Haoran, look, the classmates are very welcoming to you!"

Wang Haoran waved his hand and said, "This makes me feel a little panicked."

Accompanied by Zhang Hongbing, Wang Haoran walked into the auditorium.

At this time, the auditorium was already full of people.

At the front of the auditorium was a stage, with a long table covered with a red tablecloth placed against the edge of the stage.

There is also a blackboard on the back wall.

When Wang Haoran walked into the auditorium, he felt something was wrong.

Because the auditorium was surprisingly quiet.

The students sitting in the front row looked at him in a strange way.

Zhang Hongbing frowned, because there should be applause at this time.

However, students from prestigious schools are somewhat unruly.

As the principal, Zhang Hongbing was also a little helpless.

"Comrade Haoran, please!" Zhang Hongbing smiled and invited Wang Haoran to the stage.

Wang Haoran smiled and said, "Principal Zhang, please go first."

Zhang Hongbing smiled, took Wang Haoran's arm and walked onto the stage together.

At this time, a man's voice sounded, which seemed particularly abrupt in the quiet auditorium: "Wang Haoran, I wrote two partial differential equations on the blackboard and wanted to ask you for help. I wonder if you can give me some pointers!"

Wang Haoran looked at the man who was speaking. The man was tall and thin, wearing thick glass glasses and had a serious expression on his face.

Are you trying to show me off?
I said the atmosphere was so weird when I came in.

Wang Haoran smiled faintly and turned to look at the blackboard.

There are two partial differential equation problems on the blackboard.

However, for Wang Haoran, who has the blessing of a biochip memory capsule, these two questions are too simple.

Zhang Hongbing glared fiercely at the student who gave Wang Haoran a difficult question.

The student was from the Department of Mathematics, his name was Gao Xiangyang, and he was indeed very talented in mathematics.

But his personality is a bit weird.

Wang Haoran saw that Zhang Hongbing seemed to be about to scold Gao Xiangyang.

He quickly whispered, "Principal Zhang, it's okay, just two questions."

"If I want to convince the students of your school, I have to show some ability."

Zhang Hongbing coughed lightly and said apologetically, "Comrade Haoran, I'm sorry. I didn't expect this to happen."

Wang Haoran smiled and said, "We are all young people. We should encourage those who have the courage to challenge authority."

"If no one dares to challenge authority, how can academic research develop?"

After saying this, Wang Haoran glanced at Gao Xiangyang with a smile and said, "Classmate, thank you for asking me about math problems."

"I've already looked at the questions. These two questions are just very simple partial differential equations!"

"In fact, sometimes, as long as we open our minds, it is easy to solve the problem."

"Let me give it a try!"

Wang Haoran said this and walked to the blackboard.

Someone has already placed chalk on the edge of the blackboard.

Wang Haoran picked up the chalk and walked to the first question.

Everyone in the auditorium focused their attention on Wang Haoran.

Partial differential equations are a relatively difficult branch of mathematics, and it is not easy to learn well.

In the eyes of these Tsinghua students, Wang Haoran was just a freshman and it was impossible for him to have studied advanced mathematics.

No matter how smart you are, it is probably impossible to solve two difficult partial differential problems.

Before solving the problem, Wang Haoran said, "This problem is a partial differential equation with an initial value problem. I've thought about it for a while, so I'll try to solve it first..."

After saying that, he began to write on the blackboard.

This problem does not require too many calculation steps.

Wang Haoran was writing on the blackboard while talking about his solution to the problem.

Zhang Hongbing pulled the microphone over and placed it not far from Wang Haoran's mouth.

Therefore, Wang Haoran's voice was loud enough to spread throughout the auditorium so that all the students could hear it clearly.

"For this problem, let's assume z(s)=u(x+bs,t+s)..."

Wang Haoran finished his speech and wrote down the final answer.

All the students in the hall were stunned.

Actually, the knowledge level of Tsinghua students at that time was still relatively low. After all, most of them were recommended by workers, peasants and soldiers.

Most of the students in the auditorium didn’t even know what Wang Haoran wrote on the blackboard.

However, in this era, there are indeed some outstanding geniuses in the famous universities of Dragon Country.

These people all understood Wang Haoran’s problem-solving process.

The process of solving this problem is simply unbelievable.

A partial differential equation that was originally so difficult was solved in just a dozen steps?

The students who understood it were quite surprised.

They thought to themselves, there is no false reputation under such a great name!
Wang Haoran is too awesome.

Wang Haoran looked at Gao Xiangyang and said, "My friend, do you think my answer is correct?"

A hint of embarrassment appeared on Gao Xiangyang's originally defiant face.

The two questions he wrote on the blackboard were, in his opinion, more difficult ones in partial differential equations.

In the whole Tsinghua University, except for a few old professors in the Department of Mathematics, few people can do it.

But Wang Haoran, who was a few years younger than him and had never studied mathematics systematically, solved it so easily.

Gao Xiangyang blushed and said, "The answer is completely correct. Your solution is simpler than I could have thought of."

Wang Haoran nodded and said with a smile: "As long as the answer is right."

"I'll try to solve the second problem next."

This second question requires you to prove that Laplace's equation is rotationally invariant.

Partial differential equations are a very common mathematical tool, mainly used to describe the relationship between variables in multivariate function problems that vary with time and space. It has a wide range of applications in many fields, including physics, engineering, biology, economics, and computer science.

Wang Haoran explained again and solved the second question on the blackboard.

Zhang Hongbing was originally worried that Wang Haoran would make a fool of himself.

Seeing this, he sighed inwardly: What a peerless genius!

Wang Haoran put down the chalk, turned his head and wanted to talk to Gao Xiangyang.

However, at this time, there was a warm applause in the auditorium.

The applause was so loud and lasted for a long time.

Wang Haoran nodded with a smile. He knew that after he solved two partial differential equations, the students of Tsinghua University finally began to admire him a little.

When the applause died down, Wang Haoran looked at Gao Xiangyang again, nodded and said, "Classmate, are you satisfied with my answer?"

"If there is anything you don't understand, I can explain it to you."

Gao Xiangyang was already a little too ashamed to raise his head.

He felt that he was really too superficial.

He originally just wanted to give Wang Haoran a warning.

Unexpectedly, he himself has now become a clown.

"Cough cough!" Gao Xiangyang used coughing to cover up his embarrassment.

"Teacher Wang, you explained it very well. I understand."

Well! Gao Xiangyang even changed his address now.

Wang Haoran smiled and nodded. He suddenly thought of a famous problem of partial differential equations.

That is: the problem of the existence of global solutions to quasi-linear hyperbolic equations.

This is a problem about the isentropic aerodynamic equations, which involves proving the existence of global discontinuous solutions.

This problem was later solved by a Chinese scientist.

The person who solved this difficult problem was called Chen Guiqiang.

This person graduated from the Department of Mathematics at Fudan University and is a rare mathematical genius.

After being trained as a doctor by Longguo, he was poached by the United States.

In fact, a large number of talents emerging in Longguo have been poached by Lao Mei since the 80s.

Wang Haoran feels very sad about this phenomenon.

Looking back to the past, when our motherland was just established and there was nothing to be done, there was still a lot of talent who resolutely returned to China after completing their studies and contributed their lifelong efforts to the development and construction of our motherland.

What went wrong?

Wang Haoran felt a little heavy.

He said to Gao Xiangyang: "Classmate, I also have a question here, let's see if you can solve it."

Gao Xiangyang suddenly became a little nervous.

He thought to himself, oh no, the other party is starting to fight back.

He nodded and said, "I can give it a try."

Wang Haoran turned around and prepared to wipe the blackboard.

Unexpectedly, Zhang Hongbing had already wiped the blackboard.

Zhang Hongbing was very happy: Finally someone taught these students who thought they were geniuses a lesson.

"Thank you, Principal Zhang." Wang Haoran nodded in thanks, and then he began to write the problem of the existence of the overall solution to the quasi-linear hyperbolic system of equations on the blackboard.

After the question was finished, all the students in the auditorium stared at the blackboard with wide eyes.

Especially students from the Department of Mathematics, they read it more seriously.

But most of them couldn't even understand the question on the blackboard.

Gao Xiangyang understood the question, but his mind was racing and he had no idea where to start and had no idea of ​​how to solve it.

Wang Haoran turned his head with the chalk in his hand and scanned the entire audience. He found that everyone had a confused look on their faces.

Wang Haoran then said to Gao Xiangyang: "Classmate, take a look, do you have any ideas for solving this problem?"

Gao Xiangyang was ashamed and shook his head, saying, "I can't think of a solution for now."

"I'm afraid I'll have to think about it carefully before I can do it."

At this time, a professor sitting in the front row said: "This is one of the seven great problems in the world of partial differential equations!"

"For decades, mathematicians around the world have been struggling to find the answer."

“But no one has the answer yet.”

The professor who spoke was Lei Zhengshu, a senior professor in the Department of Mathematics.

There was a commotion in the auditorium.

Some students began to discuss in low voices.

"Wow! Is this a world-class problem? I was wondering why I couldn't even understand the question."

"I'm impressed. I didn't expect Wang Haoran to be so good at math."

"I originally thought that Wang Haoran was just a fraud, but now it seems that he is indeed a world-class genius!"

"Shame on me! Compared to Wang Haoran, I feel like a piece of trash."

"How ridiculous! We are the only ones who still dream of making Wang Haoran look bad..."

Zhang Hongbing heard a lot of buzzing in the auditorium, and it was a bit chaotic.

He frowned and said, "Everyone, please be quiet!"

"You must respect Comrade Haoran who took the time out of his busy schedule to give you a lecture!"

"I fought so hard to get this lecture!"

All the teachers and students in the auditorium quickly fell silent.

Wang Haoran smiled and said, "Dear students, I have actually been thinking about this question for a while."

"Now, I will try to solve it. If I can solve it, it will be of great help to our country."

After Wang Haoran finished speaking, he began to answer questions.

The proof process of this difficult partial differential equation is quite complicated.

Wang Haoran was still solving the problem on the blackboard while writing down the steps to solve it.

It took him about an hour to solve the problem.

A large blackboard was filled with the steps to the solution.

Finally, he successfully proved the partial differential equation.

The solution to this problem will provide a theoretical basis for the calculation of shock waves in gas dynamics and hydraulics.

During Wang Haoran's proof, the entire auditorium fell into silence.

Everyone stared at the blackboard with wide eyes. At the same time, they pricked up their ears, trying to understand Wang Haoran's explanation.

But unfortunately, only a small number of people can understand and see it.

When Wang Haoran finished his proof, Lei Zhengshu, who was sitting in the first row, slammed the table and shouted, "Great!"

"Comrade Haoran's proof is clean and concise, without any hesitation, very good!"

"This proof will be of great help to our aerospace industry and even the manufacturing and development of ships and submarines!"

Lei Zhengshu is a famous mathematician in China. If he recognizes this, then others will naturally understand how important the partial differential equation problem proved by Wang Haoran is.

"Wow!"

There was thunderous applause throughout the auditorium.

The applause was so warm and lasted for a long time.

Zhang Hongbing was very excited. He did not expect that he had only invited Wang Haoran to give a simple lecture, but it actually inspired Wang Haoran to prove a world-class partial differential equation problem during the lecture.

"Comrade Haoran, you must write down all the steps to solve this problem. I also suggest you write a related paper. This is very important to our country and the whole world."

Wang Haoran smiled and pointed to his head and said, "Principal Zhang, it's okay. It's in my brain and I will never forget it."

Zhang Hongbing said: "A good memory is not as good as a bad pen, so let others copy it."

"If I remember correctly, this is probably the biggest research achievement in the field of mathematics in our country in the past two years, except for Comrade Chen Jingrun's proof of the Goldbach conjecture."

Chen Jingrun is one of the best mathematicians in Longguo at present.

In 1977, he proved that any sufficiently large even number can be expressed as the sum of a prime number and the product of at most two prime numbers, abbreviated as 1+2. This is a difficult mathematical problem that has troubled the world's mathematical community for 200 years.

Wang Haoran waved his hand and said, "I can't compare with Comrade Chen Jingrun. I still have to learn from him."

Zhang Hongbing smiled and said, "You are really too modest."

Zhang Hongbing instructed a young teaching assistant from the Department of Mathematics to copy down the proof that Wang Haoran wrote on the blackboard.

This process is quite time-consuming.

At this point, Wang Haoran’s first lecture at Tsinghua University was considered a great success.

But he certainly didn't want this lecture to be just about doing a few math problems.

He has important things to do.

Of course, this problem is not too serious now.

We must nip the problem in the bud!

You know, a thousand-mile dam is often destroyed by an ant hole!

Wang Haoran smiled and spoke into the microphone: "Dear teachers and students, today's lecture was originally intended to share some insights with you, but inexplicably it turned into a math class."

"Well! Now, let's get back to the topic!"

"I've noticed that there is a trend of worshipping foreign things in society."

"There are some people who think everything is good when talking about foreign countries, but turn up their noses when talking about their own country. They look down on this and that!"

"What I want to say is that this is a question of character and morality!"

"If a person despises his own mother and insists that whoever feeds him is his mother, then he is a despicable and shameless person..."

Wang Haoran made a scathing satire and criticism on the trend of worshipping foreign things and fawning on foreigners.

While Wang Haoran was speaking, the entire auditorium was silent.

Of course, there are also people who are obviously dissatisfied.

For example, Wang Weiying, a professor of mathematical economics sitting in the front row, suddenly raised his hand high after Wang Haoran had been speaking for about 20 minutes.

Wang Weiying was sent to a European country for a visiting scholar program at the beginning of this year.

After coming back, he changed a lot.

He told everyone he met how developed, advanced and civilized the Lizard Country was, and actively suggested that they should learn from the Lizard Country unconditionally. Only in this way could the Dragon Country become prosperous and strong.

When Zhang Hongbing saw Wang Weiying raising his hand, he frowned. He thought to himself, what is this troublemaker going to do next?
Wang Haoran naturally also saw Wang Weiying's raised hand. He thought to himself, it is really difficult to give a lecture in Tsinghua University!
I guess this is going to be a counter-argument again.

Wang Haoran stopped and glanced at Wang Weiying: "I wonder if this teacher has any questions?"

Wang Weiying stood up, walked to the bottom of the stage and handed Wang Haoran a note.

Then he returned to his seat.

Wang Haoran took a look at the contents of the note and frowned.

The note read: Comrade Haoran, I have been to several European countries. They have advanced technology and developed industries. They are very rich. The income of their civilians is dozens of times that of our country. I think there must be a reason why they are so advanced! We must learn from advanced countries, instead of being complacent, self-contained, and arrogant! Please don't label others as worshipping foreign things!
Zhang Hongbing had also finished reading the note. He sighed softly and said to Wang Haoran, "Comrade Haoran, what do you think of this issue?"

It seems that Zhang Hongbing also thinks that there is some truth in what is written on the note!

Wang Haoran said: "Then let me explain this matter."

He cleared his throat, glanced at Wang Weiying, and said, "Let me read the contents of this teacher's note first..."

He read again what Wang Weiying had written on the note.

Then he began to criticize point by point.

First of all, why are the Lizard countries so developed and rich? That is because they have been plundering the world for a long time in the past, which has accumulated huge capital; and in order to plunder and compete with each other, the Industrial Revolution was born!
The Lizard Kingdom is an industrially advanced country. To this day, they still control all advanced industrial technologies and use the industrial scissors gap to fleece the whole world!
This is the main reason why the Lizard Party is rich and powerful!

The second point is, why are we lagging behind? Because we had almost no industrial foundation before the founding of the country! If we want to develop industry, we must learn Western technology, but the lizard side has blocked us from all directions, so that our industrial development has never been modernized and upgraded! This is the main reason why Longguo lags behind in the industrial field!
The people of Longguo are broad-minded! The Chinese nation is very good at learning and has a strong ability to accept. As long as there is an opportunity, they will seize it to develop themselves! As long as we can continue to develop advanced industrial capabilities, we will surely be able to develop rapidly!
The third point is that yes, we should learn from Xifang, but what to learn is the key to the problem!

The Lizards don't want us to learn their advanced industrial technology. They hope that we will always lag behind!
Wang Haoran believes that the more the other party forbids us to do something, the more we must do it with all our strength!
When we learn from Xifang, we must learn their advanced technology and their advanced industrial capabilities!
We must never think that since the Lizard Country is developed and rich, then everything it does is right!
We must not be fooled by the Lizard Party and ignore the things we really need to learn, but instead learn the bad things from them!
Wang Haoran obviously regarded Wang Weiying as a target.

His words were sharp.

His reasoning is extremely logical and persuasive.

In the entire auditorium, all the audience obviously took Wang Haoran's words to heart.

Many people nodded as they listened, thinking that Wang Haoran was right.

Wang Weiying's face looked a little bad.

He didn't expect that a question he had carefully designed would be criticized to pieces by Wang Haoran.

Most importantly, Wang Haoran’s words directly and completely negated the economic system he had originally established and intended to promote in Longguo.

Wang Weiying wanted to refute Wang Haoran, but he couldn't think of any strong arguments to support his point of view.

Wang Haoran talked incessantly for more than half an hour about the issues on Wang Weiying's note.

He concluded: "Comrades! We must definitely build up strong national self-confidence!"

“If you feel the pain, think about the 25,000 Red Army soldiers. If you feel tired, think about the veteran revolutionaries!”

"Maybe we have encountered a little setback temporarily, but I must say this: as long as we seize the current development opportunities, we will definitely become an industrial power in ten years! We may even crush all the current developed countries on the Lizard Side!"

There was a commotion in the auditorium; it was obvious that many people did not believe it.

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(End of this chapter)