Chapter 60: Young Man, You

Hearing someone speak to him, Xu Qingzhou looked up and realized the girl with glasses was gone; a small card had been left on his left side.

【Senior, thank you for explaining the problem, I have something urgent and must leave.】

The one who just spoke was the old professor on his right.

“Of course, I’d be grateful if you could take a look.” Xu Qingzhou smiled and handed over the paper draft.

The reputation of Peking University professors is decent.

He had little wariness toward the math department professors—they’d been professors for decades, and their published papers likely outnumbered the math textbooks he’d read; they had no reason to covet the paper of an undergraduate.

Only certain inferior teachers would compete with students for first authorship.

Professor Gu Zhizhong took the paper, put on his glasses again, and only now noticed the student beside him—extremely serious, with draft papers laid out on the desk. When he saw the title, “On the Application of Euler’s Formula in Wave Function Representation,” his interest immediately sparked.

“Are you a student of that old man Zheng Shi Yi? Hmm, he’s hit the jackpot.”

Read! {

Is this guy really a freshman?!

He nodded in satisfaction, his gaze quickly shifting to the next two questions.

He rummaged through his desk and quickly pulled out a sheet of paper. “Derive this.”

Huh~ In the library, many students turned to look.

Xu Qingzhou wasn’t in a hurry; he waited quietly beside him.

Xu Qingzhou knew the professor was testing his ability. Deriving Euler’s formula required deep understanding of fundamentals like complex numbers, trigonometric functions, and series—perfect for assessing a student’s foundation.

He added at the end: “Actually, besides math, I’m quite skilled in physics.”

“The former covers a broad range of mathematics—from pure to applied—and leads to the latest frontiers; the latter often publishes articles involving mathematical or physical phenomena. Choose one yourself—I won’t give advice.”

Xu Qingzhou spoke fluently, explaining how he conceived the topic and how he integrated mathematical tools with physics.

Xu Qingzhou’s paper not only demonstrated solid mathematical knowledge but also revealed a very strong foundation in physics.

“Huh?” Gu Zhizhong’s expression changed; he blurted out: “You’re a freshman?!”

There are many ways to derive Euler’s formula: Taylor series proof, composite function proof, integral proof, and so on.

“I read your paper—the derivation is flawless, even perfect. Everything else is mostly fine too. If you weren’t just admitted, I’d want you to join my research team right away.”

“No need to be modest—I can see your level.” Gu Zhizhong sipped his tea, then asked: “I noticed you translating papers. Which journal are you planning to submit to?”

Xu Qingzhou.

“Alright.” Xu Qingzhou nodded and packed up.

The clock on the wall slowly neared 11. Gu Zhizhong finally finished reviewing the last step of the derivation, removed his glasses, and looked both astonished and pleased. “The younger generation is formidable. You wrote this well—I’ve had graduate students with less ability.”

These were problems he’d prepared for his two newly admitted graduate students.

He picked up his laptop and followed behind, turned a corner, and entered an office with Gu Zhizhong.

“Just solve the first sub-question.”

Seeing the other still needed time, Xu Qingzhou didn’t wait—he focused on translating.

“In high school we encountered Euler’s formula, but only its basic form: e^(ix)=cos(x)+isin(x), and how it connects exponential and trigonometric forms of complex numbers.”

Zheng Shi Yi, though in the math department, had considerable expertise in physics.

Fifty minutes passed.

Gu Zhizhong thought for a moment and said: “Domestic math journals vary in quality. I recommend submitting abroad—‘Advances in Mathematics’ and ‘Inventiones Mathematicae.’ Both lean toward theoretical mathematics.”

Curious what this freshman had done to shock the usually composed Professor Gu, Gu Zhizhong glanced skeptically at Xu Qingzhou, then looked at the draft. Xu Qingzhou had used de Moivre’s formula—linking complex multiplication with angle addition to derive Euler’s formula.

“I’ll study it after I get back.”

Seeing Gu Zhizhong’s misunderstanding, Xu Qingzhou sighed helplessly and explained with a smile: “Professor, I’m a freshman.”

Xu Qingzhou took the paper—it clearly showed a problem on Euler’s formula, including derivation, geometric interpretation, improvement or extension, and generalization to higher-dimensional space.

The calculation was concise and flawless.

Xu Qingzhou wasn’t nervous at all; he sat down casually and placed his laptop and draft papers aside.

!.

He immediately picked up his pen and began writing on the desk.

“Student Xu Qingzhou, could you briefly explain your motivation for writing this paper?”

The paper was written so well that he couldn’t believe it—or rather, refused to believe—that it was written by a freshman.

Gu Zhizhong: “.”

“Since you were busy, I just solved the remaining two questions too.” Xu Qingzhou replied shyly.

Quite fast. Gu Zhizhong was surprised—his graduate students typically needed over forty minutes for this derivation; some even took one or two hours.

After a while, Gu Zhizhong removed his glasses, returned the paper to Xu Qingzhou, and looked at him with admiration: “This paper is fascinating. Using Euler’s formula to represent wave functions as complex exponential functions greatly simplifies their computation and physical interpretation.”

Taking the paper, he noticed: “Why so many pages?”

Gu Zhizhong smiled. Indeed, still young—too full of vigor. Even at his age, he wouldn’t dare claim mastery over any field. But it was normal—if he’d written a paper like this as a student, he might have been even more arrogant.

“Afterward, I looked up some books myself. By chance, I discovered Euler’s formula could serve as a tool to simplify the computation and understanding of wave functions in quantum mechanics.”

“Professor, done.” Xu Qingzhou handed the paper to Gu Zhizhong.

Looking at his campus card, Gu Zhizhong’s expression turned odd; he realized he’d lost composure, returned the card, and said: “Student Xu Qingzhou, the library isn’t suitable for conversation. If you’re willing, come to my office to talk.”

“Alright.”

“Sit anywhere, don’t be formal.” Gu Zhizhong gestured to the chair.

“Do you have any recommendations, Professor?” Xu Qingzhou wasn’t familiar with math journals.

Professor Gu Zhizhong stared at Xu Qingzhou with sharp eyes, his pupils gleaming with unmistakable surprise behind thick reading glasses.

Seeing Xu Qingzhou immediately pick up his pen, Gu Zhizhong wasn’t in a hurry—he pulled out unfinished data to verify.

Xu Qingzhou remained humble: “You flatter me—I still have much to learn.”

“You’re not modest at all.”

Xu Qingzhou nodded and pulled out his campus card.

So Gu Zhizhong had assumed Xu Qingzhou was his old friend’s newly admitted graduate student.

Xu Qingzhou had seen these two—they were both SCI journals, matching his expectations.

Gu Zhizhong nodded with a smile, glanced at the clock, and said: “Alright, I’ve taken up too much of your time. Go back. When you finish translating, if you’d like, bring it to me—I’ll take a look.”

“Thank you, Professor. I’ll come again next time.” Xu Qingzhou was deeply grateful—having an experienced professor advise him would significantly raise the paper’s acceptance rate.

After bidding farewell to Gu Zhizhong, Xu Qingzhou didn’t return to the library—it was nearly 11, and the library would close soon. He headed toward the dormitory.

(End of Chapter)