I Don’t Want to Win Lying Down

It's really not difficult,

If Xu Mang was forced to find it difficult, and expanded a simple question into such a complicated one, it was so difficult to read that he almost fainted. Who the hell made this problem?

I really want to kill him.

As soon as the voice fell,

Tong Min and Lu Bo looked at Xu Mang in surprise. He just said it was not difficult?

Xiao Xu?

Are you sure it's not difficult? Tong Min asked with surprise on his face: If you take a closer look, maybe you may have misread it. This topic is not as simple as you imagined. From frequency movement to volume expansion, this calculation The amount is very large, are you sure it's not difficult?

Yeah?

I think it's okay. Xu Mang said with a smile, Do you have any paper and pen?

Yes, yes, yes!

Lu Bo hurriedly took out a black pen and handed it to Xu Mang. By the way, he passed over a writing board with some manuscript paper sandwiched on it.

After getting paper and pen,

Xu Mang started his own performance, but this time he planned to write slowly, pointing out where these people made mistakes while making calculations.

Look

According to the photon, when v reaches dv, the volume expands to v(t), so the calculation process is like this. Xu Mang wrote a very complicated calculation process, but as he continued to simplify, this complicated formula gradually became more complicated. easy.

If t(t)=r(t)t(t)/r(t), the distribution form of the black body spectrum can still be obtained. Xu Mang wrote the calculation formula on the white paper lightly, but at this moment, the scene The atmosphere condensed to freezing point.

Tong Min, Lu Bo, Liu Yan, and Zhao Pengpeng couldn't imagine what happened before them. The problem that had stumped them for more than half an hour turned out to be so simple in the hands of this stranger.

Is this in a fantasy world?

A world of dreams?

Otherwise, how could it be possible!

From an extremely complicated calculation process,

With the continuous simplification, the fog was gradually cleared away, revealing its current appearance. At this moment, the four people present felt that they were about to suffocate, especially Liu Yan, a graduate student from the Department of Mathematics.

Although,

It's all about the calculation process of physics, but Liu Yan couldn't believe his eyes because of the process of his every step from complicated to simple. Are you sure this guy is studying physics? Instead of majoring in mathematics?

this math ability

It seems to be almost the same as my own professor.

While the four of them were still in shock, Xu Mang had already completed his proof of the heat balance distribution and the time relationship with temperature dependence. The whole process was as smooth as flowing clouds and water, without any hesitation.

finished

Xu Mang asked with a smile, Is there anything you don't understand?

The four of them remained silent, shocked by Xu Mang's powerful strength.

Xiao Xu?

Who are you? Tong Min raised his head and looked at Xu Mang seriously: Are you really a Fu student? Are you et?

Have you ever seen such a handsome et? Xu Mang said angrily, You are allowed to have opinions on me, but please don't question my appearance. Shengshi Meiyan is not a joke. I have a nickname in Fuda ——Arsonist with a heart, do you know what it means?

The man who set fire to a woman's heart. Xu Mang sighed, glanced at Yang Xiaoman, and said helplessly, I don't want to bear such a title, but it's fate, and I can't change it.

???

???

???

so narcissistic,

I owe you a beating!

Could this guy be a lunatic?

Ahem!

I mean handsome guy Xu? Zhao Pengpeng said with a wry smile: Mr. Fangxin Arsonist, can you solve the third problem? If the above gas is replaced by a non-interacting but mass particle gas, and start When it is in thermal equilibrium, under the influence of the expansion of the universe, is it in thermal equilibrium?

words fall,

Four eyes shone on Xu Mang, and the four looked forward to Xu Mang's answer.

Faced with this question, I don't know what kind of explanation this mysterious Xiao Xu will give. Like the previous two questions, he got the answer in an instant, or the myth ended here.

Xu Mang didn't look at the topic. The third question and the second question were related to each other. Now that the second question was solved, the third question was as simple as finding something out of a bag.

talk

Have you been tricked? Xu Mang asked curiously: These questions should not be solved by graduate students like you. It involves many concepts. The second and third questions are based on heat death. That is, the cosmological deduction of the second law of thermodynamics starts from this core.

you

What's the name of the professor who provides this kind of topic? Xu Mang asked.

Hearing Xu Mang's words, Tong Min and Lu Bo's expressions were filled with the word calm. Tong Min said, Professor Simpdy is an expert in astrophysics and is an alternate member of the Princeton Astrophysics Association.

Xu Mang:? ? ?

What?

Alternate member?

reserve?

It was the first time Xu Mang heard that his research organization still had so-called reserve players.

Is this guy discriminating against Hua Guo? Xu Mang asked curiously: From your point of view, I feel the malice from the question maker. This is intentional to make things difficult for you. Given your limited level, it is impossible. Solving such complex cosmological problems.

Xu Mang's words made the four of them feel a little unconvinced. In his eyes, graduate students from the Ivy League had become limited?

indeed

Xiao Xu is very powerful, but Ke Ke can't be so arrogant, right?

This is a matter of relativity and cosmology, and Xiao Xu is engaged in the theory of relativity. Although there are some differences, it is derived from the same system after all, and he understands it more or less.

right!

He has a famous saying that he would rather recruit white and black students than Asian students. Tong Min said: Lu Bo and I are exceptions. The grades are so good that we have to teach.

Xu Mang nodded, and said calmly, I'll help you solve the third problem first.

words fall,

Xu Mang started to solve this problem. In fact, this malicious professor still has a little conscience. In terms of the concept of difficulty, Xu Mang proposed a division of levels, namely normal, nightmare, hell and death. Difficulty level, but there is a difficulty that transcends cognitive concepts.

It's called Xu Mang class

As far as the current three questions are concerned, they have only reached the level of nightmares.

actually

For this problem, we must first calculate the number of particles whose momentum is between p and p+dp in thermal equilibrium under the ideal gas approximation. Xu Mang explained the calculation process lightly while writing.

The chemical potential of e can be made equal to zero. Since the expansion of particles is adiabatic, tvr-1=constant. Xu Mang raised his head, glanced at the four of them, and said, So the existing thermal balance will be destroyed.

this

This is the end?

Not even thirty seconds!

Little Xu?

Solved? Tong Min asked in surprise.

yes!

It's not a big problem in itself. Xu Mang said with a smile: There are some conceptual knowledge in it, and you don't understand the normal ones, but for me, it's a matter of hand, and it's done with the white of your eyes.

The four of them did not speak, and stared at Xu Mang silently. This guy became more and more mysterious. He looked very young. Although he was wearing glasses, the overall outline seemed familiar.

The last problem, I'm going to grill the skewers after I've solved it. Xu Mang shrugged and said lazily, Let me take a look first.

moment,

Xu Mang began to solve this last problem. It was still in a hypothetical universe, but this condition was even more extreme. The photon gas had no interaction with each other, and its mass was all zero, while the particle gas was composed of mass. At a certain moment, photons and Neutrinos are in thermal equilibrium.

Typical velocities and kinetic energies are then given in terms of neutrino masses.

not difficult!

But cheap!

When Xu Mang saw the last request, he almost died of anger, and the difficulty suddenly increased from the nightmare level to the death level.

The professor asked for a fairly precise value.

Are you crazy?

Xu Mang's original decadent state suddenly disappeared. At this moment, his face was full of seriousness.

Fuck!

ruthless!

It seems that this really won't be resolved for a while.

Just when Xu Mang was thinking about how to do it, Tong Min and Lu Bo's hearts were almost in their throats. The two saw that Xu Mang's expression had changed. He was no longer as calm as before, but became a little more serious. Son.

It's over!

Feel bad!

Sure enough, the problem of the finale is different.

The two glanced at each other, and they both saw a trace of worry in each other's eyes. The first three problems were solved perfectly, but they fell on the last problem.

well

it seems that

The miracle is over.

Xiao Xu?

No, even if we can solve the three problems, it's already very good, and I don't think the professor will make things difficult for us. Tong Min said seriously: For the last question, he told us that no matter if we ask anyone, As long as we are untied, let us graduate, one can imagine how difficult it is.

Xu Mang froze for a moment, then asked curiously, So rampant?

???

???

???

Hearing Xu Mang's words, the four of them were stunned.

What's the meaning?

It seems that you are more rampant than him!

Xiao Xu!

It doesn't mean whether it's rampant or not. How can I explain it to you? Tong Min said helplessly, It means that there is no solution. He didn't give us any chance at all. This last question is just a display, just take a look.

Xu Mang understood what he meant, that he was doing something bad on purpose.

but

This problem is not unsolvable, but it is more complicated to demonstrate, and there are great challenges in calculation.

indeed,

It is a bit more difficult for these two graduate students majoring in astrophysics to solve it. Unfortunately, when I met Ben Shengshimeiyan, I can only say sorry to the malicious professor. I am afraid that these two students will graduate early.

well?

Are you inheriting the family business after graduation, or are you planning to do academic research in astrophysics? Xu Mang asked curiously.

If I inherit the family business, I will go to business school. Tong Min said seriously: If I graduate next year, I plan to engage in research in astrophysics.

Same.

Engaged in academic research in astrophysics. Lu Bo said.

Xu Mang glanced at the two of them and fell into silence.

for a long time,

Xu Mang said apologetically, I'm sorry to disappoint you.