This Fucking Works Too?

When Jiang Yang returned to the large office with Zheng Hua, more than an hour had already passed.

By then, a circle of teachers had gathered around Li Dong's desk.

Even teachers from the neighboring Chinese and English departments had come over to watch.

"This kid writes so fast. He doesn't even stop."

"Did he actually get them right?"

"Who knows? It looks pretty convincing."

When they saw Zheng Hua arrive, the teachers quickly made way for him.

"Group Leader Zheng is here!"

Ignoring their greetings, Zheng Hua walked straight behind Li Dong.

He first sized up the student.

He wore an ordinary school uniform, had slightly long hair, and looked rather delicate.

Li Dong had just turned to the second page and begun the fill-in-the-blank questions.

Zheng Hua's gaze fell on the test paper.

After just one glance, he quietly drew in a breath.

Li Dong had finished every multiple-choice question at the front.

And...

Zheng Hua quickly scanned several difficult questions he remembered clearly.

The first question—correct.

The fifth question, the equivalent resistance of that complicated circuit—B. Correct!

The twelfth question, the cutoff voltage for that photoelectric-effect problem—D. Also correct!

"This..."

Zheng Hua could no longer stay calm.

That speed, that accuracy... even last year's provincial first-prize contestants probably had not been much better.

What astonished him even more was Li Dong's approach to solving the questions.

Unlike ordinary students, Li Dong did not stubbornly grind through every single problem.

When he came across an optics fill-in-the-blank question about a "Fresnel Lens," he paused for only two seconds before decisively skipping it.

He had already judged that the problem would involve a long and tedious derivation using aspherical geometric approximations.

The next question concerned the time-dilation effect in Special Relativity.

Scribble, scribble, scribble!

Li Dong did not even glance at his scratch paper.

His brain ran like a high-speed computer, completing the Lorentz Transformation in an instant.

He directly wrote down the time interval in the observation frame, even mentally mapping the typical coefficient of v = 0.8c.

"This kid..." Zheng Hua understood.

Li Dong was not merely answering questions. He was performing a selective "operation."

Any problem involving mechanics, electromagnetism, or the core concepts of modern physics, he solved at lightning speed, like a scalpel cutting into tissue—clean and precise.

But when faced with pure computational drudgery, he chose to strategically avoid it.

That showed his knowledge system was extraordinarily clear. He knew what constituted "physical essence" and what was merely "mathematical complexity."

In truth, Zheng Hua had still underestimated Li Dong.

Li Dong was not afraid of calculations. He simply had not yet encountered that particular knowledge point. In unfamiliar territory, he would never waste even a second blindly trying things out.

At that moment, the class bell rang again.

It was already the third period.

Li Dong instinctively stopped writing and looked up at Old Yang.

"Teacher Yang, class is starting..."

"Keep going. Don't worry about anything else."

Old Yang was acting unusually.

"This period is mine. I'm giving you a pass."

Although Old Yang did not teach physics, his level was probably the highest among everyone present.

The prestige of Kyoto Normal University was not something just anyone could compare themselves to. And if not for certain unpleasant matters, Old Yang would have long since become the kind of person people called a scientist.

Naturally, he could understand these questions. Li Dong was doing very well, and he also wanted to see what score Li Dong would ultimately get.

Li Dong froze for a moment, then nodded at Old Yang and lowered his head again.

By then, a thin layer of sweat had seeped across Li Dong's forehead.

He was exhausted.

The latter half of the test involved an astonishing amount of calculation.

Yet the more he worked, the more excited he became.

It felt like a contest with the person who had written the test, fought across empty space.

The test setter laid trap after trap, maze after maze.

And Li Dong wielded the swords bestowed by Newton, Joule, and Einstein, cutting through every obstacle in his path.

Jiang Yang could not help leaning close to Zheng Hua's ear.

"Group Leader Zheng, is... is there something wrong with this?"

Zheng Hua could not be bothered to answer him.

Something wrong?

There was a huge problem!

This kid's solution methods were even more outrageous than the standard answers!

At last, Li Dong turned to the final page.

Question 26.

This was the final boss of the entire paper, the legendary question that made people give up.

[As shown in the figure, an insulated cylinder is divided into sections A and B by an insulated piston. Section A contains 1 mol of ideal gas, while section B is a vacuum. A light spring with spring constant k connects the piston to the bottom of the cylinder. Initially, the system is in equilibrium. The gas in A is then slowly heated by an electric heating wire. Find the relationship between the gas entropy change ΔS and the piston displacement x.]

The difficulty of this problem was that it combined the first law of thermodynamics, the definition of entropy, and mechanical equilibrium.

It also involved an enormous amount of calculation, making mistakes during integration very easy.

For the first time since he had begun the test, Li Dong stopped writing.

"Is he stuck?"

Zheng Hua's heart skipped a beat. Yet for some reason, seeing Li Dong stop actually made him feel relieved.

This question involved entropy change, which was university-level thermodynamics. High school students found it difficult to understand that integration process. If Li Dong could solve it without hesitation too, Zheng Hua would suspect that Li Dong had seen this problem before.

Yet just as he was beginning to doubt everything.

Li Dong suddenly smiled.

There was a trace of... smugness in that smile?

"So that's how it is..."

He murmured inwardly.

Good thing I have a habit of lurking in group chats. Otherwise, this really would've been hard to handle.

Isn't this exactly what Joule mentioned in the group that day—the perfect combination of the mechanical equivalent of heat and state functions?

There's no need to grind through that damned heating path at all!

Since it's a state function, all I need to do is construct a mapping between the initial and final states!

Li Dong picked up his pen and wrote a formula on his scratch paper:

dS = (dU + PdV)/T

Using the spring-force equilibrium relation P = kx/A together with the ideal-gas equation of state, he forcibly substituted for temperature T. What had originally been a complicated process requiring path integration instantly simplified under his pen into the algebraic sum of several logarithmic terms.

Standing behind him, Zheng Hua looked at the unbelievably concise derivation on the scratch paper and felt as if his brain were about to grow.

He could not stop himself from swearing.

"Holy shit! This fucking works too?"

Only after saying it did he realize he had lost his composure.

All the watching teachers turned to look at him in unison.

In their impressions, Group Leader Zheng was usually refined and gentle. Even when dealing with the most troublesome students, he would at most furrow his brow.

Who could have imagined that this teacher, always so composed, would curse aloud while watching a student solve problems?

"What... happened to Group Leader Zheng?" Teacher Xiao Lin from the neighboring department asked in a low voice.

"I don't know. How well is this student actually doing?"

Zheng Hua had no mind to spare for their whispers.

All his attention was fixed on Li Dong's scratch paper.

That concise line of reasoning was like a heavy hammer, mercilessly smashing against everything he thought he knew about physics.

At that moment, Li Dong slowly wrote the final answer on the test paper:

ΔS = (2C_V + R) ln (x_final/x_initial)

Then he gently set down his pen, rubbed his aching wrist, and let out a long breath.

"Teacher, I'm done."