Chen Yin still remembers the sphere volume formula, and calculus is often used when calculating excavated earthworks.

However, thinking that the old man also deliberately came up with a loss rate, which naturally meant accurate numbers, Chen Yin had to force the calculus formula to be erased, and lowered his head to recalculate the exact version of the paint volume......

Daddy McCarthy stroked his white beard, leaned over to Chen Yin and looked at his draft, and suddenly pointed to the calculus equation and asked:

"What does that mean?"

Calculus ...... Well, I can't tell you for a while. ”

V=f(r)=4πr^3/3

r＇=50

△r=0.03

△V≈dV=f＇(r＇)△r=f＇(50)*0.03

……

"It's kind of interesting...... Are you looking for an approximation? McCarthy asked with a slight look and a smile.

"Huh? Do you understand? Chen Yin was stunned.

"Hehehe, what is this?" McCarthy let out his trademark trilogy again.

"In this way, you don't have to count the rest, just solve this approximation for me." McCarthy suddenly changed his mind?

"Really?" Chen Yin was overjoyed.

"Of course."

Then Chen Yin thought about it a little and wrote down the answer.

McCarthy took Chen Yin's papyrus, looked at Chen Yin's solution steps carefully, and nodded slightly: "Yes, yes, it seems that you are better than I imagined." What do you think? Do you want to continue? ”

"Of course." Although he knew that the next questions would definitely be difficult, Chen Yin decided to give it a try, and if he passed this level, he would be able to enter the Tower of Knowledge.

"Then I'm out of the question?" McCarthy stroked his beard, "In three-dimensional space, given three particles, if there is only gravitational interaction between them, then under the condition of given initial position and velocity, find their trajectory. ”

“……”

As soon as this question came out, Chen Yin was stunned for a moment, although his calculus was not thrown, but it was only limited to calculating the volume and the like, now let him deal with such a complex physical problem, how could he possibly solve it?

"What? Can't answer? Hehehe...... Confused, huh? Don't know how to get started, do you? Hehehe......"

I don't know why, Chen Yin always felt that McCarthy's three-part laugh was a bit of schadenfreude.

"Huh??" When Chen Yin was writing and drawing on the paper, he suddenly looked at the three particles he marked on the paper and was stunned.

"Oh? Got a clue? McCarthy was shocked.

"I want to think about it...... I seem to have seen this question somewhere. Where? Chen Yin lowered his head and thought for a long time.

3 particles, 3 particles......

Isn't this the three-body problem?

Chen Yin learned about this physics problem because of Liu Cixin's book of the same name, and was deeply fascinated by it for a long time, it can be said that if there is any cutting-edge science that Chen Yin cares about, then in addition to virtual reality, it is the three-body problem.

The reason why the three-body problem has become a difficult problem is not because it cannot be solved, but because the accumulated error will soon destroy the entire operating system, to put it bluntly, the current human computing power is not enough to deal with such a complex problem.

Scientists have found that the equation of motion of the three-body problem is an eighteenth-order ordinary differential equation, and 18 integrals must be obtained to get a complete solution. However, only 16 points of the three-body problem can be obtained, so it is far from being able to solve the three-body problem.

But fortunately, what McCarthy asked was just a "solution", and Chen Yin happened to know that there were several "special solutions" to the three-body problem.

"Special solution" is also "solution"!

So after McCarthy asked this question, Chen Yin just flattered it a little, and then, without saying a word, made an equilateral triangle on the parchment, and marked the three vertices of the equilateral triangle.

"This is my solution. The three particles move in a circular motion along the horizontal line. ”

"Huh?" This time it was McCarthy's turn to be surprised, "Equilibrium triangulation solution? How do you know? Wrong! No, you change it, this solution doesn't count! ”

"Okay, just change it!" As he spoke, Chen Yin clicked a dot on the paper, drew a circle with this dot as the center of the circle, and then made a diameter to mark the dot that directly intersected the circle, "The middle point does not move, and the two surrounding dots rotate around the central particle at the same speed......"

"Shhh...... Star-stable equilibrium solution? You know this, too? McCarthy was stunned, "No, no, no!" This doesn't count! You can't use special solutions, you can't use all thirty-six classic special solutions! ”

36 special solutions!?

This time it was Chen Yin's turn to be shocked, the scientific community on the earth only found 16 special solutions to the three-body problem!!

How so?

The sense of superiority that had always been in place collapsed.

"How? You don't need to solve it, right? Seeing that you didn't study hard, hehehe......" Looking at Chen Yin's appearance in a daze, McCarthy touched his beard with satisfaction.

Seeing the angry appearance of this old man, Chen Yin couldn't help but get angry, took a pen and drew randomly on the paper, and after drawing for a long time, the whole parchment was about to turn into a black mess, and then he stopped writing......

"This is the thirty-seventh special solution." Chen Yin pointed to the messy mess on the paper, his face was not red, and his heart was not beating.

"You're scribbling!" McCarthy saw through it at a glance.

"Of course it's not scribbled, I don't believe you!"

"You're ......"

"Count ......"

“……”

"Congratulations, Chen Yin has obtained the qualification for research! Rejoice, students! This year's first admission quota has been born! ”

McCarthy was undisciplined.

"Bang Bang ......"

The sparse applause rang out, and the people who were still gathered here to watch the excitement after the exam slapped their hands with envy and jealousy, and then dispersed in twos and threes. Occasionally, there is a sour complaint or two drifting along the breeze.

"Well, because we don't have a priest here who can teach and study for the time being, you have two choices now, one is to transfer to the headquarters of the Holy Light Church, where there is a research course, and the other is to wait here for a qualified priest to come...... Which do you choose? ”

McCarthy's dad looks like he's businessman.

"I, I'm not going anywhere, I just want to get into the ...... of knowledge"

"Well, you just want to learn knowledge but don't want to leave, I know, you go down first." McCarthy directly interrupted Chen Yin's words, and winked at Chen Yin as he spoke, looking like you know.

I know your sister!

Chen Yin rolled his eyes, but nodded cooperatively: "Okay, I'll go." ”

"Let's go, let's go, let's go." McCarthy waved his hand vigorously, his old hand full of tendons and folds.

……

Chen Yin walked through the huge garden, thinking about the previous events as he walked.

But judging from McCarthy, it seems that the science on this planet is not lagging behind, especially the final three-body problem, McCarthy's words make Chen Yin think about it......

"Hey! Are you interested in joining my group? ”

Just as Chen Yin was distracted, several people suddenly blocked his way.