Accompanied by this classmate, Xu Mang went to a classroom in the physics department building. He discovered a problem. This guy didn't bring any books. There were about sixty people in the classroom, and about ten of them didn't have books.

What's going on?

Does this major accept bad students?

"brother?"

"Why didn't these people bring books?" Xu Mang asked curiously.

"Attendant." The little brother said calmly: "Absolutely the same as you."

""

"What about you?" Xu Mang asked with a dark look on his face.

"I?"

"Of course I am also a spectator." The little brother smiled: "But I am better than them, including you, in astrophysics and physics."

Damn it!

I met a pretender!

Good guy, how dare you show off in front of me, Xu Mang?

Xu Mang was so angry. He had always tricked others by himself, but today he was tricked by others. The problem was that he was tricked by a graduate student. This was the biggest stain in his history of tricking.

"well!"

"Do your family members know that you are so awesome?" Xu Mang asked helplessly: "Good guy, you are obviously a spectator like me, how do you pretend that you are an astrophysics major?"

""

"You can't say that." The brother smiled bitterly: "I might be a little better than you, of course I mean maybe."

"Dare you ask me, brother, who is this person?" Xu Mang asked.

"Du Yuan."

"Oh" Xu Mang nodded and said silently: "Do you know who I am?"

Du Yuan was stunned for a moment and said calmly: "Who you are has nothing to do with me. It's just a chance meeting between you. Maybe after tomorrow, we won't have any intersection, so it's okay not to know the name. It will be less caring and more persistent."

read."

Xu Mang:(°ー°〃)

Damn it!

Encountered a well-matched opponent.

I feel like he is crazy.

soon,

A rather dignified professor came in and started the class directly without calling his name.

"Today we will mainly explain the physical properties of neutron stars." Although this professor is impatient, he has a wealth of knowledge. You can infer from his hairstyle and hair volume that he is extremely smart after all.

“When a massive star reaches an advanced stage of evolution, it will accumulate a huge iron core through nuclear combustion. When this iron core reaches a certain mass, it will collapse due to excessive pressure, resulting in violent gamma ray bursts and supernova explosions.

A neutron star was born."

"Actually, a neutron star is an ultra-dense star composed of neutron matter. How high is the density of a neutron star? I will give you five minutes to estimate the density of the neutron star. First of all, the mass of the neutron star is about the same as that of the sun, and its radius is ten kilometers."

"The radius of the sun is 700,000 kilometers, and the density is (1.4g/m^3)."

The words fell,

The professor said seriously: "Let's start counting, the time is five minutes."

Soon everyone started to count, and of course there were about ten auditors who were free of charge, sitting silently in their seats, waiting for the answers to be announced.

Xu Mang watched the students present making intense calculations, and couldn't help but feel a little confused. He asked curiously: "Well, this is a freshman, right?"

"How do you know?" Du Yuan said in surprise: "He is indeed a freshman."

""

"You don't even know the quick conversion of two stars with the same mass. What do you mean if they are not reborn?" Xu Mang said helplessly: "When two stars with the same mass, their density is inversely proportional to the cube of their radius.

.”

Du Yuan was stunned for a moment and said with doubt: "Are you sure?"

""

"Are you doing research in the astrophysics group?" Xu Mang asked: "Don't tell me that you are purely responsible for calculations?"

Du Yuan nodded awkwardly: "Then do you know this density?"

"Do you have a pen and paper?"

"have!"

Du Yuan didn't know where he took out the pen and paper and handed them to Xu Mang.

In less than ten seconds,

Xu Mang completed the calculation of the neutron star density, pns=(r/rns)^3xp≈(700000/10)^3x1.4≈10^14(gm^-3)

"Give!"

After Du Yuan got the answer, he looked at Xu Mang in horror and asked cautiously: "Brother, right?"

"You give it a try." Xu Mang shrugged and said calmly.

The reason why Xu Mang gave up the answer was because he no longer wanted to bear the title of Autism Maker. He wanted to give this title to Du Yuan.

Du Yuan thought for a moment, then hurriedly raised his hand and shouted to the professor: "Professor, I'm done!"

As soon as the words fell,

Caused an uproar.

"Who are you"

"Auditing student?" The professor saw Du Yuan and saw that there was no textbook on his desk, so he understood that this person was here to audit.

"Yeah!" Du Yuan nodded.

immediately,

The professor came to Du Yuan, took a look at his answer, and couldn't help but praise: "Which department are you in?"

"Department of Mathematics"

"I am a graduate student, and I happen to be in the astrophysics research group, responsible for calculation programs." Du Yuan said seriously: "In order to strengthen my business capabilities, I came to listen to the class. I have been listening to your class. Some of the knowledge points you taught me, I

Keep them all in mind.”

Xu Mang:(￣△￣；)

Talent!

No,

This is a wolf kill.

"good!"

"It's good to be motivated, keep working hard." The astrophysics professor nodded repeatedly.

Immediately afterwards,

The professor returned to the podium and began to continue teaching.

""

""

Xu Mang looked at Du Yuan, and Du Yuan looked at Xu Mang. Neither of them spoke.

"brother!"

"You are so awesome!" Du Yuan said to Xu Mang with a look of admiration: "I won't say anything anymore. I'll treat you to lunch."

Xu Mang smiled bitterly and said, "How did you get into Nanjing University?"

"I'm pretty good at math, but I don't know anything about astronomy." Du Yuan sighed: "If it wasn't for the sake of finishing a paper, what kind of astrophysics would I study?"

""

"Thanks for your hard work."

at this time,

The professor threw another difficult question.

"Pulsars are high-speed rotating neutron stars. The rotation speed of pulsars is very fast, and some can even reach more than a thousand revolutions per second. Such rapid rotation, coupled with magnetic fields and extreme conditions, will cause the poles of the pulsar to be aligned.

Sexual electromagnetic radiation.”

"Here's a question for you. Who can use digital calculations to prove that pulsars are neutron stars?" the professor asked, "think about it."
To be continued...