Section 277

"Then let's return to the topic of prime numbers."

"There are infinite prime numbers. This is a result that can be obtained through rigorous proof. The earliest proof was given by Euclid in Proposition 20 of Volume 9 of "Elements of Geometry", which used a proof by contradiction. "

"Is there any classmate who can give this proof by contradiction?"

Xiao Yi asked.

Quite a few people raised their hands immediately off the court.

This itself is a very classic proof, so there are many students who know it, and there is no exception.

Xiao Yi quickly selected a student.

The student came to the podium and began to write the process smoothly on the blackboard.

"Using proof by contradiction, we must first assume that the prime numbers are finite. Then, we might as well assume that all prime numbers are p1, p2,..., pn."

"Then, we let N=p1*p2*...*pn+1."

"Obviously, N is not divisible by any of p1, p2,..., pn."

"Then, this means that either N itself is a larger prime number, which means that among the originally limited number of prime numbers, we have found a larger prime number, which contradicts the hypothesis; and if N is not a prime number If , it means that it can be divisible by a larger prime number, which means there is a new prime number, which also contradicts the hypothesis. "

"In this way, we can prove that there are infinitely many prime numbers."

Xiao Yi nodded with a smile and said, "Yes, it's written correctly."

Most of the students in the audience also nodded. Basically, students from the School of Mathematics can understand this proof.

Of course, it is inevitable that other majors will come to join in the fun, so some people also expressed doubts, such as why a limited number of prime numbers multiplied by one plus one cannot be divisible by these prime numbers, and why if N is not a prime number, Does that mean it is divisible by a larger prime number?

However, Xiao Yi did not explain much about this kind of question that high school students would probably understand.

"Very good, now that we have figured out the infinity of prime numbers, the next question becomes, how do we determine whether a number is a prime number?"

"Especially when you're dealing with a particularly large number."

"It's hard to tell whether it's prime."

"Then at this time, we can use the sieving method."

"The sieve method is a very important method in the study of number theory. It can help us quickly determine prime numbers, or the prime factors of a large number."

Xiao Yi wrote [Screening Method] on the blackboard again.

The study of number theory is inseparable from this knowledge.

Of course, there are many things involved in number theory, but for now, Xiao Yi plans to start with prime numbers and the sieve method.

After all, who in the world doesn't recognize him as the most powerful sifting master today?

The students in front of them also knew it, so, because of this, when they heard Xiao Yi talk about the sifting method, they became even more interested.

As a top mathematician, he can arouse the interest of these students, and interest is what Xiao Yi mainly wants to teach these undergraduates.

His graduate students have basically developed a great interest in their majors, so he can train them from a more professional perspective, but for undergraduates, it is important to keep them interested in mathematics. Most important.

Therefore, next, Xiao Yi will focus on guiding these students to learn number theory from the aspect of interest.

Among them are the twin prime conjecture or Goldbach's conjecture that he once proved.

Just saying "When I first proved the twin prime numbers/Goldbach's conjecture, I learned from this step..." is enough to mobilize all the interest and attention in learning something.

And don't forget that he is also known as the "most popular paper author" in the mathematics community. The papers he writes have always been very detailed in steps, so that many people in the mathematics community highly praise his papers.

And this fine tradition of his has naturally been brought to the classroom.

As long as students can maintain their attention, they can basically understand his explanation of concepts or methods.

In this way, time passed quietly.

The first class ended before many students could react, making them feel as if the class had just started.

The second class was in the same state. The 45-minute class passed by without even realizing it.

As the bell rang for the end of get out of class, Xiao Yi did not delay the class at all. He pointed at the two exercises left on the blackboard and said: "Then after we go back, everyone will try to solve these two sieve method exercises. Let’s review today’s course content, then we’ll see you next week.”

"get out of class is over."

After Xiao Yi finished speaking, he was ready to leave.

But what he didn't expect was that the students in the audience stood up in unison, bowed to him and shouted: "Thank you for your hard work, teacher!"

Xiao Yi had no choice but to come back, bowed, and said, "Thank you for your hard work, classmates."

Then he was able to leave.

When the students in the audience saw Xiao Yi leaving, they immediately started talking.

"I feel that Xiao Shen's class is very good!"

"Yeah! I haven't felt that a 45-minute class can pass so quickly for a long time! The last time I felt this way, it seemed to be in junior high school."

"I feel the same way."

A bunch of students sighed.

Feeling that the class is too long is mainly because you can't listen and concentrate.

And the reason they feel that a class is over so quickly is because they are so interested in the class that they don't even notice the passage of time.

This is immersive learning, which naturally brings about the rapid absorption of knowledge.

They couldn't help but recall what Xiao Yi said at the beginning, that it was his first time to teach, so he couldn't guarantee whether the class was good or not.

Now it seems... it's really too modest!

Of course, not everyone has such an experience. Those students from other majors who came simply to join in the fun naturally felt uncomfortable. Considering Xiao Yi's opening words, they finally decided not to come to the next class. They couldn't grasp mathematics.

...

The news spread quickly, and Xiao Yi's class itself attracted a lot of attention, so there were also quite a few people who paid attention to the quality of his class.

As these news spread, and some students recorded the entire class process and shared it online, people couldn't help but sigh, how come some people are good at academics and teaching?

Is there no limit to genius?

As for the students who were persuaded to leave by Xiao Yi at the beginning, they all beat their feet and stamped their chests, they were fooled!

The lecture was so good, but he actually lied to them that it was the first time to teach. Is the class still a problem?

For a while, they all said that they must arrive early for Xiao Yi's next class.

However, Xiao Yi has communicated with the school about this matter, hoping to restrict these non-mathematics students. First of all, it must be ensured that all students in Hua Luogeng's class can enter the classroom and have seats, and secondly, it must be ensured that all the students who attend the class must be mathematics majors.

The school naturally agreed and will make a plan as soon as possible, and the School of Mathematics will of course actively cooperate.

Just kidding, Xiao Yi's class was just average, but now it is so good, of course they hope that students from the School of Mathematics will listen.

This is the resource of the school!

The School of Physics also shouted, Xiao Yi is also a professor in their School of Physics!

He should also take a physics class!

Of course, the School of Materials and the School of Chemistry also joined in the fun.

For a time, Xiao Yi's class caused a dispute in the school.

Xiao Yi had no choice but to agree to give these colleges a few open classes at that time.

As for how they quarreled later, Xiao Yi didn't care.

He had more important things to do.

EAST-S, the Super Eastern Super Ring, developed by the Institute of Plasma and the Science Island Laboratory, was officially launched.

That's right, the name was finally determined to be EAST-S.

After Xiao Yi left that day, the remaining three people couldn't think of a better name for this open plan, so in the end, they decided to use the name that Zhao Zhanyou said at the beginning.

When Xiao Yi learned about this, although he didn't say a word, Zhao Zhanyou and Li Jiangan always felt that Xiao Yi looked at them with contempt. As for Director Liu, he had already gone to Shangjing, so he avoided being ridiculed by Xiao Yi.

Of course, the name of the plan in secret, the creation of the sun, was unsurprisingly well received, and in order to cater to the four-character myths such as Kuafu chasing the sun and Houyi shooting the sun, the full name of the creation of the sun plan is called: Mortals create the sun, but usually it is simply called the creation of the sun.

In this way, this plan, which was only for the construction of a new tokamak experimental device, was launched.

The construction site of the sun-making device was placed in the northern suburbs of Luyang District.

Of course, if you look closely, you can find that this location is also very close to the nearest power plant.

Chapter 237 Feasibility Verification

In a conference room in the plasma institute.

"Okay, today is the first meeting of our EAST-S."

Director Liu sat in the first seat, representing the importance the country attaches to this plan, and also came here to announce some of the country's requirements for this plan.

However, as the name came out, everyone present couldn't help but look at the two seats next to Director Liu, where Li Jiangan and Zhao Zhanyou sat.

Obviously, everyone present basically knew that this somewhat unoriginal name was given by the two of them.

Although it was finally approved by the higher-ups, someone had to take the blame.

So the two people who were responsible for taking the blame became these two.