The reason why so many people came to the first class was that most of the students were out of frustration.

By the time of Cheng Nuo's time, there were only three public universities in the country, including Peking University, and the resources of higher education were very scarce, and it was not until 1921 that the situation improved, that is, it expanded to six.

There has always been a saying among Peking University students: "Peking University is old, Normal University is poor, and only Tsinghua University can be accommodating." ”

First of all, Peking University is old, which refers to its old history, old students, and old professors.

The history is easy to understand, it is the only product left after the failure of the Wuxu Reform Law, and it is also the earliest national university in the country. For example, in 1913, when Chen Hanzhang graduated from the Chinese history major with the first grade, he was already 50 years old, which was very rare in later generations. As for the elder professor, it also means that the teacher is generally older.

Besides, the teacher is poor, that is, "poor" in the literal sense, but it is not the school that is poor, but the students who are poor.

The predecessor was under the control of the government as the Normal Hall of Beijing Normal University, and the poor will definitely not be poor, and the teaching funds are guaranteed. However, because it is a normal school, according to the regulations, students are exempted from tuition and accommodation fees, which can save more than 100 yuan a year, and only need to pay a certain deposit for admission, so many poor children choose it as the first choice for studying.

Finally, let's talk about Qinghua's accommodation, as a school built by Gengzi indemnity, of course, it is very rich.

At this time, it was not strictly a university, but more of a "preparatory place for studying in the United States", and students did not graduate from universities after completing higher academic courses, but inserted into American universities, and from the fact that it was not under the jurisdiction of the Ministry of Education but under the jurisdiction of the Ministry of Foreign Affairs, its connotation can be understood. The vast majority of the school's teachers are foreigners, who pride themselves on being superior to others, and have irreconcilable contradictions with the students. Fortunately, preparations for the establishment of a complete university began last year, but unfortunately it took eight years after the approval to fully establish the university department.

But from another point of view, Qinghua has the best school spirit and the strictest discipline among these colleges. To what extent, everyone's hand towels and washbasins must be marked and placed, and if they are dirty, they will be punished. You must eat on time every day, and there is a school number sign on the dinner table, and you will be punished for absence. Students are only allowed to carry a small amount of pocket money, and every cent and every corner must be booked, and at the end of the month, the school has a special agency to verify the account book.

Every detail is required to be clear, but if one is violated, it will be criticized at the least, and the demerit or even expelled at the worst. Pan Guangdan, one of the four philosophers of Qinghua, was deducted once because he was afraid to walk at night and was convenient outside the dormitory.

After so much chatter, in fact, there is only one core idea, that is, there is a shortage of teachers, especially the scarce and high-quality Chinese teachers.

Whether it is out of curiosity or sincere study, Cheng Nuo treats these students equally, gives lectures in simple terms, and deliberately leaves ten minutes as a question and answer time before the end of class.

When everyone was still hesitating, a student took the lead in raising his hand, and after getting permission, he stood up and bowed: "Hello Professor Cheng, I am Gao Zhiwei from Qinghua School, thank you for teaching us the most cutting-edge mathematical knowledge, the content is vivid and interesting, but aside from professional knowledge, I have always had a question, that is, what is mathematics and what can it bring to our troubled country?" ”

Cheng Nuo smiled, asked the student to sit down first, and after a short thought, wrote a line on the blackboard, "What is mathematics?" ”

After a slight pause, he continued to write a few lines, and when he was done, he turned around and introduced to the students:

"I take the derivation of mathematical formulas as an example, all sciences - content = science, mathematics + some kind of content = some kind of science, so mathematics is the foundation of all sciences, that is, the mother of all sciences. In terms of natural sciences, it can be applied to astronomy, physics, chemistry, geology, etc., in social sciences, economics, insurance, accounting, etc., mathematics, and other disciplines such as Chinese painting, learning perspective, music and rhythm are also indispensable for his participation......"

"From this, the second question is easy to explain, the sharpness of the combat tools of modern times, and the novelty of construction projects, all of which are the driving force behind the advancement of this subject."

Speaking of this, Cheng Nuo smiled at the student who asked the question just now, and asked kindly: "Student Gao, you just said that you are from Qinghua School, can you say that you will go to study on the other side of the Pacific Ocean one day in the future?" ”

Gao Zhiwei hesitated for a moment and nodded: "Yes, I will go to the United States next year." ”

Cheng Shuo looked at him and smiled: "Very good, I wish you a bright future." As far as I know, the shooting teaching group set up by the US Army in the artillery department has a famous mathematician named Moulton in the teaching group, who improves the accuracy of artillery shooting by teaching mathematics, and even has a special textbook "Ballistic Methods", you can find it and read it if you have the opportunity. ”

Cheng Nuo slapped the end of the chalk in his hand and faced everyone: "And shooting is only a small part of the application of mathematics in warfare, and other things such as the production of guns, warships, and artillery are inseparable from mathematics, which is actually a war of science, and it can also be said to be a war of mathematics." If our military strength is strong enough, the waters of Lu Province will not allow German submarines to roam easily. ”

After the 128th Songhu Anti-Japanese War, some scholars deeply felt that the ordnance was inferior to the Japanese army, and at the same time, they also attributed part of the reason to the lack of shooting accuracy, believing that the distance between the landing site Zhabei and the Hongkou artillery position was not very far, but the artillery of the national army was not accurate, resulting in the easy landing of the Japanese army.

"Whether it is people's livelihood or military affairs, mathematics plays a role that cannot be ignored."

There are more and more questions from the students, even if many of them are beyond the scope of the course of class field theory, Cheng Nuo tries his best to answer them one by one.

There were a lot of people in the classroom, and a small window was deliberately left to open for ventilation, and then a sparrow flew in, tilting its neck to watch the teachers and students in the room discussing hotly, and from time to time it seemed that the little guy was also participating.

Ten minutes was obviously not enough to answer these students' questions, and in the end, Cheng Nuo had to raise his hand to signal to stop asking this question, announce the next class time, and say that he would continue to answer questions before he was squeezed out of the student pile.

As soon as he returned to the office, he saw Feng Xuxun and others from the mathematics door sitting and waiting for him, and applauded him as soon as he entered the door.

Out of concern for Cheng Nuo, not long after he went to class, Feng Zuxun, Qin Fen and others entered through the back door to observe, on the one hand, to suppress him, and on the other hand, to prevent him from having insufficient experience in teaching for the first time, so that he could remedy his mistakes in time.

Unexpectedly, after the initial nervousness, Cheng Nuo actually completed the lecture with ease, and even the students would rather drag the class to let him continue the lecture, which is a treatment that only belongs to some liberal arts masters.

Cheng Nuo only smiled modestly after understanding: "This is all the love of the students, and there are still many deficiencies after class, and I still need to work harder." ”

Qin Fen handed over a cup of tea: "Zhiyuan, I thought that I might not be as good as you in academics, and I might not be ahead of me in teaching, but I didn't expect you to be good at it, you have to teach me two tricks to take care of your house." ”

In private, everyone has a good relationship, and it doesn't hurt to make ordinary jokes, Feng Zuxun echoed: "You have to teach him, don't you know when Jing Yang first came, the students gave him the nickname 'Hypnosis Professor'." ”

Suddenly, there was a joyful atmosphere in the math door office.

The influence of this class does not stop there, some students go back and organize the lecture notes and class solutions and put them in their own school journal.

After a reporter saw it, he took a part of it and published it in the popular press, which sparked a public discussion on mathematics.

Opponents believe that the role of mathematics is exaggerated: "Mathematics is only the addition, subtraction, multiplication and division of numbers, and it is not as practical as industry to save the country and save the people. ”

Of course, there are only a small number of opponents, and more are in favor of it: "If the study of mathematics is designed for counting things, it is a big mistake, and it is the foundation of the total academic science of mathematics, and there are those who can be the extreme of all things, and it is regarded as a matter of single calculation. ”

In this discussion, Cheng Nuo's reputation became more and more famous, and there were more and more supporters, and the previous small classroom could not accommodate so many people, and finally changed to an auditorium.

Some people do it to hear about class field theory, while others do it to solve their own mathematical problems.

But more people are not only beneficial, because the increase in the number of female students attending classes is intolerable to the old stubborn who adheres to the ban on women, and they have begun to criticize Cheng Nuo's practice in some non-mainstream newspapers and magazines.

Even with Peking University and Cai Yuanpei, they have also received some criticism.