Xueba's Sea of ​​Stars

Chapter 87 Group Theory
Seeing a group of people sitting in a row in the dormitory and eating fruit, Wu Bin smiled and started talking.

"There used to be a high school student in a certain key point. When he was in the second year of high school, he felt that the college entrance examination course was a bit boring, so he took part in the physics competition."

"Okay, this is a big deal." Xu Bo nodded.

Wu Bin also nodded, and continued: "After participating in the physics competition for the first time, he was rejected in the semi-finals, but he slapped his head and thought the competition was very interesting, so he decided to continue it. .”

"But at that time, several of his teachers did not recommend him to participate in the physics competition, because the same problem, if the people in the competition class can solve it in an average of one hour, he would have to spend two to three hours, while the competition class It’s another race against time and rhythm.”

Although the people who are listening want to complain about the competition, isn’t it a competition of IQ, but now the boss is telling the story, so what he says is what he says.

"Then this high school student expressed dissatisfaction after listening to it. Why can't I do it? I just want to participate!"

"Seeing that he is so determined, those teachers stopped pouring cold water on him, and threw "Difficult Problems" to him, asking him to make a manuscript."

Speaking of this, Wu Bin took a few thick books from the bed and stacked them together, pointing to them and said, "About a year later, this high school student found the teacher with six file files thicker than this, and said He is confident that he can get the national one."

Looking at the book in Wu Bin's hand, which added up to more than 1500 pages, everyone in the dormitory raised their heads and made up six files thicker than this. How spectacular it is.

After showing the thickness around again, Wu Bin went on to say: "In those six files, he saved all his ideas for doing the questions, the experiment process diagram and the experiment report, etc., and he has written in the upper left corner of each page. Marking, for example, if the collection of difficult problems is the first book he reads, he will mark it as A, and then he will mark a certain question in the collection of difficult problems as page A-396, and refer to the relative motion problem of the same system, like this.”

"In the end, when he swiped to the sixth folder, the mark in the upper left corner had changed to AY, but AZ was not enough for him, so he continued to subscript from AA."

"Fuck... Are there so many books for him to read?" Xu Bo was surprised.

"Are you afraid that you don't have any books if you want to brush up the questions? You can ask Mr. Cai tomorrow. It is estimated that he can quote more than 1000 books for you."

"God, more than 1000 copies..."

"What happened later? Did he win the prize?" Xu Hao asked curiously.

"Well, he did take the National One, but he didn't enter the national team." Wu Bin picked up "The Collection of Difficulties" again, "At that time, the teacher told us that he just brushed this "Compilation of Difficulties" Five times, and every time there is something new."

"Can't be offended, can't be offended."

After finishing speaking, everyone returned to their beds and continued to read their books.

Looking at Gu Fan who quickly walked away, Wu Bin picked up a jelly and smashed it over and said, "I don't require you to brush the "Collection of Problems" five times. If you brush the chemistry book five times, you will be fine."

Gu Fan, who was hit, took off the jelly, peeled it off, ate it, and said, "I see, this is just watching."

……

As soon as the midterm exam was over, Wu Bin naturally entered the state of going all out to prepare for the competition.

In the evening self-study on Wednesday, Wu Bin returned to the small classroom after completing several experimental reports with Bi Wanqing in the laboratory.

"Let's save the experiment of measuring the refractive index until tomorrow or the day after tomorrow."

"Okay." Wu Bin nodded after sitting down.

"Well, let's continue with yesterday's discussion of those more unorthodox questions." After speaking, Wan Qing picked up the chalk and wrote on the blackboard while saying.

[Approximate solution of Lagrangian (star mass)>>Planet mass>>Satellite mass]

"When calculating the first two or three points, the center of mass can be approximated as a star, and when calculating the fourth and fifth points, the center of mass should be approximated as the center of mass of stars and planets. What should you pay attention to here?"

Bi Wanqing turned around and asked Wu Bin.

"You can't take it too early." Wu Bin replied immediately.

"Yes."

……

Wu Bin's progress is undoubtedly rapid, so now Bi Wanqing spends most of his time discussing and doing questions with Wu Bin. If he teaches occasionally, he also teaches some relatively partial knowledge. If he passes the test, he is considered a winner.

During this period of time with Bi Wanqing, Wu Bin did know the special situations that would happen in various exams.

For example, even if you know the method of some questions, it is almost impossible to get it right in the exam, such as the famous hand calculation of the sixth-order determinant.

In addition, there are some fresh knowledge that Wu Bin saw when he was flipping through various books. What Bi Wanqing told him is that it is better to master some knowledge when it is really needed.

For example, the Hilbert space is really needed when learning quantum mechanics.

Memorizing various Gaussian integrals is also when learning quantum mechanics.

In addition, when Bi Wanqing once told him that my country's quantum mechanics calculations are at the forefront of the world, he suddenly became very interested in this subject.

Another one is group theory.

After hearing this, Bi Wanqing told him that this is only used when he needs to do some strange Mathematical Olympiad problems, and group theory problems are rarely used in competitions.

But this is of course not to say that group theory is some fancy and useless technique, but that Wu Bin has not yet come to use it.

In truly cutting-edge scientific research, whether it is mathematics, physics or chemistry, group theory has a large number of applications.

Because there are many different physical structures under study, crystal structures as well as hydrogen atomic structures can be modeled using group theory methods.

On the podium, after explaining the approximation of Lagrange, Bi Wanqing patted the chalk dust on his hands, looked at Wu Bin and said, "The exam should be less than a month away, right?"

"Well, there are still more than 20 days." Wu Bin nodded.

"It can work!" Bi Wanqing slapped the podium, "I think you have a chance of winning the first place in the national team even if you go now. If I give you another 20 days, the national team will definitely not be a dream! I will definitely go to see Jing on site then. How did Bei rob you, hahahaha."

"Huh? Teacher, are you going to the scene?" Wu Bin asked in surprise.

"Of course I'm going! How can I not go when my students participate in the national competition? Even if I lose my job, I will go." Bi Wanqing said with a smile.

"If the teacher also goes, then I will definitely increase my confidence!"

"Hehe, it's not me who should give you confidence, but the knowledge in your head." After finishing speaking, Bi Wanqing took a sip of tea and continued: "Well, for the remaining 20 days or so, you should still rely on self-study. Lord, let me take a few nights for self-study during the period, and I will consolidate mechanics for you, although it is the most basic foundation of physics, it is also the most important thing."

"Okay!" Wu Bin nodded vigorously.

(End of this chapter)