Xueba's Sea of ​​Stars

Chapter 245 Talking
"There are still many important problems in high-energy physics that have not been resolved. There are also some wonderful mathematical structures in superstring theory. If you are interested in it, you might as well learn more about differential geometry and topology."

Talking with contemporary masters of theoretical physics, the topic will inevitably involve string theory, which is the most popular and most likely to become the grand unified theory of physics.

Although Mr. Yang is now 95 years old, he is still in high spirits when talking about the fields he is familiar with, and the few points he occasionally mentions make Wu Bin very educated.

"You seem very interested?" Elder Yang looked at Wu Bin and smiled slightly, as if he saw the flame of interest in his eyes.

"I'm interested in the unknown."

As an ordinary teacher, when encountering a person like Wu Bin who does research on everything, he usually sighs with regret, thinking that he can't come up with anything with a hammer here and a stick there.

But Yang Zhenning in front of him is different. He himself is the kind of person who has made great innovative contributions in multiple fields. How can he narrowly think that scholars should spend their entire lives in one specialized field?

So Yang Zhenning was very happy to hear Wu Bin's answer, and continued: "If you think this direction is right, then you may be disappointed in the future, because the idea of ​​superstrings has too little contact with actual physics."

"It seems more like a math problem now." Wu Bin said after thinking for a while.

"Yes, but in my academic career, I have seen too many theories that have little contact with actual physics and it is difficult to succeed in the end."

Taking a sip of hot tea, Yang Zhenning continued: "However, the digital structure of superstrings is very wonderful. If you can absorb the subtleties inside, it may be helpful for you to develop some kind of real problem-solving ideas in the future. From this standpoint If so, I suggest that you can make superstrings.”

Mr. Yang spoke unhurriedly, but his tone still revealed some disapproval of superstring theory.

"I'll try it." Wu Bin nodded seriously.

After listening, Yang Zhenning nodded slightly: "There are very few examples of insights that come from abstract mathematics that can be greatly successful in physics. I hope you can understand this before researching."

From Mr. Yang's words, Wu Bin read that he was afraid that he would be disappointed if he didn't get anything after studying superstrings, so he replied directly:

"Actually, I am not very entangled in the right or wrong results. What I pursue is the fun of participating in it."

"Hahaha."

There was a burst of rhythmic laughter, and the expression on Yang Zhenning's face revealed a little satisfaction.

After laughing, Yang Zhenning picked up a notebook on the coffee table, then took out the pen in his coat pocket and started writing on it.

[Mathematics (1)] - [Theoretical structure of physics (2)] - [Part of combining theory and experiment (3)] - [Experiment (4)]

Pushing the notebook in front of Wu Bin, Yang Zhenning continued: "This is the relationship between mathematics, theoretical physics and experiments, and the combination of 2 and 3 is theoretical physics. A theoretical pure structure is connected with experiments through the second part. "

Hearing this, Wu Bin couldn't help picking up the conversation, "But if the pure structure cannot be connected with the experiment for a long time, will it inevitably lose its place in physics..."

Yang Zhenning nodded with a smile after hearing this: "That's right, the value concept in physics still has to come from experiments in the end, and the reason why superstrings are so controversial is because they haven't been connected with experiments through the second part. "

Looking at Wu Bin's thoughtful expression, Yang Zhenning continued: "When I was in the United States, some students debated with me. They said that when I did gauge field theory in 1954, it was also a pure structure that had nothing to do with experiments?"

Changing his posture, Yang Zhenning went on to say: "It is true that it had little to do with the experiment at that time, but if they had read my article carefully, they would have found that it was already related to two theoretical structures that already had a solid experimental basis. Affinity is created, they are..."

"Isospin Conservation and Maxwell's Equations?" Wu Bin couldn't help answering a wave.

"Hahaha."

After listening to Wu Bin's "answer", Yang Zhenning burst into rhythmic laughter again, looked at Wu Bin happily and said: "I really wish you were sitting down when I talked about this topic in class last time."

After being praised, Wu Bin smiled shyly and said, "I also hope to have the honor to listen to your class once."

"Alas..." With a sigh, Yang Zhenning shook his head and said: "A few years ago, I was able to lead a group of students to class, but now I don't have the physical strength."

After finishing speaking, looking at Wu Bin who was about to speak, Yang Zhenning waved his hand: "Don't say any polite words that I look young, I can't understand my own body very well, tell me about you, I heard that you have already Have you finished learning all the contents of the four major mechanics in college?"

Wu Bin shook his head, and replied: "I can only say that I have a superficial understanding, and I dare not say that I have learned it."

"It's very modest." Yang Zhenning took a sip of tea, and then said: "In 71, when I went back to China many times, I found that the so-called "Four Mechanics" in the physics department overwhelmed the students. , Of course, I do not deny the importance of the four major mechanics, they are the backbone of physics, but only the backbone of physics is just a skeleton, and it must have flesh and blood to be a living physics."

"Then what is the flesh and blood of physics?" Wu Bin asked curiously.

"New things, living things, things that are closely related to phenomena, in plain language, pay more attention to the frontier of research, and in my eyes, now you are a physical person with flesh and blood."

Faced with this sudden high evaluation, Wu Bin was a little dazed.

Without giving Wu Bin a chance to reply, Yang Zhenning went on to say: "In your paper, I read that kind of innovative spirit that is not afraid of anything, you dare to make breakthroughs, and you are willing to make breakthroughs. I love that spirit."

Wu Bin: "I am very happy to be affirmed by you, Professor Yang."

"It's time to eat."

Hearing the voice from the kitchen, Yang Zhenning said to Wu Bin, "Let's eat first."

Wu Bin: "OK."

However, for the two people who were in the middle of a conversation, sitting at the dinner table was just a change of place to talk. After three hours passed, the topics they talked about had changed several times, but the rice in the bowl was hardly touched. .

It wasn't until Weng Fan brought the reheated pork rib soup to the table for the third time that Yang Zhenning looked at Wu Bin with a smile and said, "Let's eat first, the taste will really be wrong if you reheat it."

"Okay." After hearing this, Wu Bin immediately moved his chopsticks and started to sweep the table, not forgetting to say a few words towards Weng Fan: "Your craftsmanship is really good."

(End of this chapter)