39: Chapter 39 The Pebbles on the Sole of the Shoe

Not long after Jiang Yao left, Zhang Xiufen had already tidied up the house and hurriedly began bustling about the preparations for visiting her mother's home to pay New Year's respects.

"Jiang Jianguo, did you tie that box of hairtail securely or not? Don't let it leak later and get fishy smells all over us—it's the New Year, and people will find it annoying."

Zhang Xiufen's voice came from the bedroom, carrying an unconcealable, high-spirited emotion.

"It's secure. Your husband has spent half a lifetime hauling seafood and dealing with foam boxes every day; can't even tie a single box well?"

Jiang Jianguo squatted on the floor, pulling a red plastic rope in his hands, forcefully tightening it across the diagonal corners of the foam box.

Zhang Xiufen walked out of the room.

Today, she had purposely changed into a dark red woolen overcoat, her hair was coiled up meticulously, and she had even applied light makeup for the first time ever, putting on a bit of lipstick that brightened her complexion.

Her entire person looked radiant, and even the fatigue accumulated at the corners of her eyes over the years was covered by a layer of strange luster.

This was hardly surprising.

Jiang Lin's score of first place in the city-wide mock exams this time was like forcefully injecting a shot of adrenaline into her weary half-life.

In this secular society that emphasized human relationships and mutual comparison, a child's success was the strongest backing for parents to stand straight.

Although she said to the neighbors with her mouth that it was just good luck and couldn't be taken seriously since the Gaokao hadn't happened yet, today her steps were countless times lighter than in previous years as she walked.

She walked to the doorway, looked at Jiang Lin who was changing his shoes, and casually helped her son tidy the collar of his down jacket.

The family of three carried large and small bags as they went downstairs.

When they reached the residential complex where her maternal grandmother's home was located, before even entering the stairwell, they could smell the aromas wafting out from the exhaust fans of various households.

Climbing to the second floor, Jiang Jianguo had just raised his hand to knock twice when the door was pulled open with a click.

"Oh my, Elder Sister, Brother-in-law, and nephew have arrived! Come in, come in quickly. You must be freezing outside, right?" The one opening the door was the aunt, wearing an apron and smiling all over her face.

In past years when opening the door, the aunt's pleasantries always carried a bit of polite detachment, but this year, there was a bit more genuine warmth in her smile.

"Hey, Linlin is here. Let Grandma take a look—our Jiangcheng city-wide top prodigy has arrived."

The grandmother was wearing a deep purple, front-buttoned cotton-padded jacket, her silver hair combed meticulously, and her spirit looked extremely robust.

The elderly woman was advanced in age and her eyesight wasn't very good. She had originally been sitting on the sofa listening to traditional opera, but upon hearing her daughter-in-law say that her daughter and son-in-law had arrived, she immediately supported herself on the sofa armrest to stand up, grinning from ear to ear and repeatedly waving at Jiang Lin who had just stepped through the door.

Jiang Lin placed the gifts on the table and smoothly sat down beside his grandmother: "Grandma, Happy New Year. What city-wide first place? It's just an ordinary mock exam, nothing to be taken seriously."

"What do you mean by just an exam?" Upon hearing these words, the grandmother immediately became displeased, deliberately putting on a stern face, gripping Jiang Lin's hand, and saying, "Being able to score first place in the entire city on an exam is also a heaven-sent capability. Going back three generations in our old Zhang family, there has never been a Star of Literature who is so good at studying."

Jiang Jianguo carried the heavy seafood foam box into the kitchen, walked out rubbing his hands, and smiled sheepishly yet proudly: "Mom, it's alright, it's alright. It's mainly that the kid is willing to study himself and has become enlightened."

"Linlin really saved face for our family this time. Xiufen, Jianguo, the bitter days your couple has endured for over a decade are finally over."

Inside the kitchen, the uncle walked out carrying a plate of freshly fried radish meatballs, his loud voice full of vital energy.

Jiang Jianguo was so happy that wrinkles formed around the corners of his eyes when he smiled, yet he still modestly said: "It was just a fluke performance; the Gaokao is still far away, and there's still more than half a year ahead. Thousands of troops crossing a single-log bridge—we wouldn't dare boast right now."

"How is that boasting? Can being first in the city just happen by fluke?"

The uncle heavily placed that steaming plate of radish meatballs on the coffee table, poked one with a toothpick, handed it to Jiang Lin, and then abruptly turned his head, gazing like a torch toward the other end of the sofa.

"Zhang Yu, look at your older cousin, and then look at you. Forty-two points on the Physics final exam, and you still have the face to huddle there every day holding a cell phone playing games?"

Cousin Zhang Yu, who was slouching and playing with his phone, shrank his neck and protested: "Dad, I'm not playing games."

"Right, you aren't playing games; you switched to scrolling short videos instead. Anyway, you're unwilling to put your mind into studying." The uncle glared at his son, shook his head, and turned back into the kitchen to help.

The living room fell quiet for a split second.

Zhang Yu was two years younger than Jiang Lin and was currently in his first year of high school with mediocre grades.

In fact, a few months ago, he and this older cousin studying in the third year of No. 7 High School still belonged to a pair of struggling companions during family gatherings.

During festivals and holidays, both of them were objects of sighs from the elders. Although the two brothers didn't communicate much, behind the shield of poor grades, neither looked down on the other.

Yet who could have imagined that right before this New Year, the older cousin who was originally in the same camp as himself would suddenly strike it rich and make an unreasonable, sudden rise.

Today, the family members even talked about being first in the city left and right, pricking his ears numb, so he simply lowered his head to scroll through short videos to achieve out of sight, out of mind.

To cover up the various overt and covert nagging noises from the elders and to conceal his own embarrassment, Zhang Yu intentionally turned up the volume.

Those synthetic voiceovers in the short videos full of industrial saccharin, exaggerated canned laughter, and deafening rustic DJ dance music poured forth endlessly like cheap products on an assembly line.

Zhang Yu didn't take in the content at all; his thumb mechanically swiped, changing videos every few seconds.

Jiang Lin sat beside his grandmother, holding a cup of hot tea poured by his aunt, patiently listening to the elderly woman rambling on about the trivial matters of the past year.

Regarding the noise made by Zhang Yu's side, he hadn't cared about it at first.

Until a man's voice came out from the phone.

"If someone tells you that because you are looking, the electron decides which path to take, this person is lying to you, or he has fooled himself."

"What on earth..."

Zhang Yu watched a man wearing a gray sweater sitting in front of a whiteboard speaking on the screen with zero interest. Flexing his thumb, he was just about to swipe away mercilessly.

"Wait a moment."

Jiang Lin, who had been quietly listening to his grandmother talk, suddenly spoke up.

Zhang Yu's fingers stiffened, stopping at the edge of the screen, and he raised his head in some bewilderment to look at his older cousin.

Inside the video, that man's voice continued to clearly transmit out: "Observation in Quantum Mechanics has never referred to the gaze of human consciousness, much less idealistic magic. It refers to physical interaction—an irreversible physical coupling that occurs between macroscopic measuring equipment and microscopic measured objects."

Jiang Lin stood up, walked in a few steps to the other end of the sofa, and looked levelly at Zhang Yu: "Can you let me look at this video?"

"Older cousin, you watch this stuff too?" Zhang Yu was full of incomprehension, but intimidated by the indescribable aura on Jiang Lin's body at the moment, he obediently handed the phone over.

"Mn."

Jiang Lin, whose attention was currently focused on the sound in the video, replied offhandedly and took the phone.

On the screen, a man in his early thirties sat in an office, behind a whiteboard covered in formulas and symbols.

The footage was unpretentious, containing only a quiet narration.

The account name was in the lower-left corner: Quantum Mechanics Is Not That Profound.

The video title was strikingly: [How Many Times Has the Observer Effect Been Misunderstood? The Truth of the Double-Slit Experiment]

Inside the screen, the man spoke unhurriedly facing the camera, as if chatting face-to-face.

"Many people recount the double-slit experiment like a ghost story. They say that the electron originally didn't know which path it was going to take and scattered like a cloud, but as soon as the human eye looks at it, out of shyness, it instantly collapses into a particle, determining which slit to walk through."

The corners of the mouth of the man carried a helpless, bitter smile.

"This explanation has great viral potential and is fantastic for shooting sci-fi movies, but it also very easily leads people into misconceptions."

"Because the real problem doesn't lie in whether consciousness participated at all, but rather whether your question itself is a well-defined good question in Physics when you are asking a quantum system."

"You think you are asking which slit the electron took."

"But you should actually be asking whether taking a certain slit has any meaning when no measurement occurs."

Zhang Yu leaned against the sofa cushion, looking at his older cousin's side profile as he stared unmoving at the screen, with a bewildered expression.

He had completely no idea why Jiang Lin would suddenly become interested in such a dry popular science video that could put people to sleep.

"When no measurement occurs, does the matter of which slit it took have any meaning?"

This sentence seemed to stop inside Jiang Lin's mind.

He had gotten stuck on this problem in the Wasteland.

Not for a day, not for a month.

At that time, he could do some basic quantum problems, solve the Schrödinger equation for a one-dimensional infinite potential well, calculate the normalization constant of the wave function, and follow textbooks to handle a few simple momentum operators and position operators.

Yet that question in the double-slit experiment had always been like a small pebble jammed in the sole of his shoe.

Every time he stepped forward, every time he tried to build a grander Physics picture, that pebble would pierce his nerves.

He knew the standard answer.

All the textbooks were telling him that he could not use the concept of trajectories in classical mechanics to ask which slit the electron actually took without measurement.

The wave function was not a probability table for a classical little ball secretly choosing a route; it was a probability amplitude, containing the phase information of interference.

He had accepted this standard answer because that was how problems were solved and formulas were calculated.

However, he was very clear that between accepting a premise and truly figuring it out intuitively lay a long and painful gulf.

The last thing he could do back then was to use his reason to forcibly press that pebble into the crevice of the shoe sole, enduring the discomfort and continuing to walk forward.

Because there were no teachers on the Wasteland and no one to discuss with, he didn't have the ability to take that pebble out and place it under the sunlight to see clearly what shape it actually was and where its boundaries lay.

And now, inside the screen, this Physics teacher named Professor Lu Zhixing used merely a single sentence to nimbly pick up that pebble he had pressed under his sole back then, placing it squarely on the desktop.

This teacher was not in a hurry to give a profound answer; he did something even more advanced—describing the question itself more accurately.

Zhang Yu watched Jiang Lin staring at the screen looping this segment over and over as if bewitched, and couldn't help asking in a low voice: "Older cousin, can this stuff be understood? How come I feel like I'm listening to heavenly scriptures?"

"Just taking a casual look."

Jiang Lin's voice was somewhat absent-minded as his slender fingers tapped lightly on the screen, opening the homepage of this blogger named Quantum Mechanics Is Not That Profound.

The account's avatar was extremely rustic—just a casually taken photo of an office whiteboard, with marker traces that hadn't been completely wiped clean still remaining on the whiteboard.

The personal profile was written extremely briefly, exuding the distinct competence of a science and engineering man: Professor Lu Zhixing, Department of Physics teacher. Quantum Mechanics is not profound, but it is indeed difficult.

There were 869 followers and a total of thirty-two published works, all of which were tens-of-minutes-long Physics popular science videos.

Jiang Lin didn't have a phone; he merely let his gaze linger on the three characters Professor Lu Zhixing for two seconds, memorizing this name along with the account name.

Seeing him look so focused, Zhang Yu's internal sense of imbalance from being suppressed bubbled up again, and unable to hold back, he asked: "Older cousin, you're already the top student ranked first in the entire city, how come even when watching Douyin during the holidays, you're watching these study things? Aren't you tired?"

The aunt, who was carrying a bowl of steaming braised pork to the table, happened to hear these words and immediately slammed the bowl down heavily onto the table: "Zhang Yu, listen to what you're saying! Do you think your older cousin's first place in the city dropped from the sky? Look at him—he studies even when watching Douyin. Look at you again—when you watch Douyin, it's either borderline female streamers or game commentaries. If you could have half of your older cousin's composure, I could laugh myself awake in my dreams."

Zhang Yu was rebutted into speechlessness, his face flushing crimson, and he immediately shut his mouth.

The New Year meal at noon was exceptionally lively.

The grandmother doted to the extreme on Jiang Lin, this grandson who had suddenly achieved success. While continuously putting food in his bowl for him, she said with a beaming smile: "Linlin, eat more. You scholars sit in front of desks all day using your brains; your brains spin fast, so your nutrition must keep up."

At the dining table, the uncle drank two cups of white liquor, his face glowing red, and started inquiring again: "Elder Sister, Linlin made such huge progress this time—did you couple go behind our backs and secretly enroll him in some closed-off score-boosting sprint class outside? If the cram school teachers are really that capable, send Zhang Yu over next semester too."

Zhang Xiufen was ladling soup for Jiang Jianguo. Hearing this, she immediately raised her head, her tone carrying unconcealable pride: "Big Brother, you know what kind of conditions our family has; where would we have that idle money to enroll in cram classes that cost one or two hundred yuan per class? Linlin studied all by himself, locking himself in his room and figuring it out on his own."

The aunt listened from the side and sighed with heartfelt emotion: "Oh my, that's truly the ancestors blessing us. This child's mind has completely become enlightened."

Jiang Lin, who had his head down eating, heard the word enlightened and did not offer any explanation.

Because he knew better than anyone else.

In this world, what instantaneous enlightenment was there from being touched on the crown of the head by immortals?

He simply possessed a little more time than others.

After the meal, the adults sat in the living room watching TV while continuing to chat about everyday family matters.

Zhang Yu used studying as an excuse, but actually bolted at top speed into his own room, locked the door, and started playing games.

Jiang Lin accompanied his grandmother for a while. Seeing that the elderly woman was getting a bit sleepy, he quietly sat to the side, reviewing that sentence from the video just now in his mind.