Time continued to pass.
The sunlight had turned a deep orange.
The clamor of students getting out of class occasionally drifted in from the hallway, but it quickly faded away.
"Time’s up."
At the lecture stand.
Professor Wang set down his mug.
He hadn’t looked at a watch; his timing was impeccable.
"Pencils down."
"Hand in your scratch paper."
Wang Huashao let out a long breath and handed over the crumpled sheet of paper in his hand.
He Gui’s face was beet red as he lowered his head and submitted his half-finished work.
Miao Shian pushed up his glasses and placed his paper, which had a half-written energy equation, in front of him.
Zhou Kai released his grip on his fountain pen, a deep indentation visible on his knuckle.
He expressionlessly handed over the sheet filled with calculus equations.
Lin Yi’s and Chen Zhuo’s papers were sandwiched in the middle.
Six sheets of scratch paper.
They lay on the wooden lecture desk.
Professor Wang took a pair of reading glasses from his jacket pocket.
He put them on unhurriedly.
He didn’t sit down.
He simply stood before the lecture stand, in front of the six middle school students, and began to read their six papers.
The classroom was utterly silent.
The only sound was the rustling of paper.
Professor Wang picked up the first sheet.
After a single glance, he placed it directly on the left side of his desk.
"Wang Huashao."
His voice was level, devoid of any critical tone. He was simply stating facts.
"You applied Ohm’s law from beginning to end. In your subconscious, an electric motor is nothing but a dead resistor."
"When it’s stalled, it’s a pure resistor. When it’s spinning, it’s a non-pure resistor."
"You don’t understand the physical process. It doesn’t matter how well you can plug numbers into a formula."
He picked up the second sheet.
And placed it on the left.
"He Gui, your line of thought is muddled. Your force analysis is missing a critical tension. Your fundamentals aren’t solid enough."
He picked up the third and fourth sheets.
He looked at them for a little longer.
Then, he placed them side-by-side in the middle.
"Miao Shian."
Professor Wang glanced at the boy sitting in the second row.
"You realized where the energy was going and knew to use conservation of energy, but you ignored the most crucial step."
"While an electric motor generates mechanical energy, the coil inevitably produces heat. You left out the heat component, so your equation doesn’t hold."
"Zhou Kai."
Professor Wang’s gaze fell on the tall boy in the front row.
"Your mathematical foundation is excellent. Your calculation ability is rare for someone your age."
"You attempted to use the method of infinitesimals and the concept of limits to derive the velocity."
"But physics isn’t purely a mathematical game. The infinitesimal model you constructed is physically meaningless. The coupling relationship between electrical and mechanical parameters can’t be brute-forced with math."
Zhou Kai remained in his seat.
His back was still ramrod straight.
He looked at Professor Wang without refuting him.
He merely pressed his lips together lightly.
Finally.
Professor Wang picked up the last two sheets of paper.
One was mostly blank, its writing bold and unrestrained.
The other was densely packed, its logic rigorous.
Professor Wang spread these two papers out.
On the far right side of the desk.
He took off his reading glasses.
And held them in his hand.
His gaze swept over the six people below.
"Out of six people, only two arrived at the correct result."
"Lin Yi, Chen Zhuo."
Professor Wang gently tapped the desk with the arm of his glasses.
"The four of you, after class, come and look at their problem-solving processes."
"One of them skipped all the superfluous steps. He has a complete, true physical picture in his mind and got straight to the point."
"The other performed an old-school, ruthless, brute-force deconstruction, breaking down a complex system into its most fundamental physical laws, then reassembling it with an impeccable chain of logic, not overlooking a single, minuscule loss."
Professor Wang pocketed his reading glasses and picked up his chipped enamel mug again.
"I don’t care if you use intuition or brute-force derivation."
"What I want to see is that you can all, in this classroom, cast aside those idealized fairy tales."
"And face real physics."
"That’s all for today."
"There’s nothing scheduled for this evening. Go to the cafeteria for dinner, then rest in your dorms. I’ll see you back in this classroom at eight tomorrow morning."
Holding his mug, Professor Wang didn’t say another word.
He turned, pulled open the door, and walked out of the classroom.
The sound of his footsteps faded down the hallway.

Comments

Loading...