My IQ has been increasing year by year.

Lunar New Year's eve.

The snow in Zeyang City fell at a leisurely pace.

The hallway was a bit dimly lit. On the first floor, outside Grandma Wang's door, there were several uneaten cabbages piled up. On the second floor, Uncle Li's door frame had just been decorated with a new couplet, the paste still wet. Chen Zhuo went up the stairs to the fourth floor.

"Mom, I'm home."

Chen Zhuo changed into slippers and casually took off his down jacket and hung it on the coat rack behind the door.

Liu Xiuying, wearing a floral apron and holding a spatula, peeked halfway out of the kitchen.

"Where have you been all day? Your hands are all red from the cold. There's a freshly filled hot water bottle on the sofa. Go and warm them up quickly."

As Liu Xiuying spoke, she flipped the ribbonfish in the pot over.

"Our phone has been ringing off the hook since you weren't home this afternoon."

Chen Zhuo walked into the living room, picked up the hot water bottle covered with an old woolen cover from the sofa, and hugged it to his chest.

"Who hit him?"

Liu Xiuying pointed at the coffee table with a spatula.

"I wrote down all the numbers on the back of the calendar. There were several. Judging from their voices, they were all teenagers. There was a man who spoke like a machine gun, rattling off a string of words that gave me a headache. There was another man who spoke very formally, like a senior leader in our factory giving a report."

Liu Xiuying turned the fire down a bit and continued muttering.

"Oh right, there was also a little girl. Her voice sounded so cold. She asked if I was there, and when I said I was out, she just said 'thank you, Auntie,' and hung up immediately." Chen Zhuo listened to his mother's description and instantly recognized the person in the picture.

He walked to the coffee table, picked up the torn old calendar page, and on the back were several phone numbers scrawled in crooked handwriting with a ballpoint pen, some even with area codes. "Okay, I'll call them back in a bit."

"Don't make the call yet."

Liu Xiuying came out carrying a plate of freshly fried ribbonfish and placed it on the dining table.

"Let me check on you. The postman delivered a letter to you at noon. It's Chinese New Year, I wonder who would write a letter then."

Chen Zhuo responded and turned to go into the bedroom.

An envelope lay quietly on the table.

The envelope was the cheapest kind, made of thin paper, and the edges were already a bit frayed from the mailing process.

There was an 80-cent stamp affixed to the upper right corner, with the area code of Guanlong City printed on the postcard.

Chen Zhuo sat down in the chair and turned on the light.

The words on the envelope were written so forcefully that they almost tore through the paper.

It was sent by He Gui.

He picked up the small paper cutter from the drawer, carefully cut open the envelope, and pulled out a piece of paper.

Chen Zhuo unfolded the letter.

"team leader.

I'm doing well at the senior high school in this city, so don't worry about me.

It's gotten colder recently, and it's a bit windy in the dorm, but I laid out two layers of mats, so it's not cold.

The school waived tuition and accommodation fees for three years and gave me an extra 150 yuan in meal tickets every month. I didn't touch a penny of the prize money from the junior high school competition; I sent it all back to my dad. In his letter, he said that he had finally paid off the loan he owed to the town's credit union for my sister's medical treatment two years ago.

My dad said he didn't feel so stressed during the New Year.

I'm eating very well here; the cafeteria even has free braised pork every Wednesday.

My teachers at school have been very kind to me, allowing me to join the training team for the Physics Olympiad. This year, I'm going to compete with senior students from grades 11 and 12 to aim for the provincial first prize. Lately, I've been studying university-level "General Physics," but I encountered a past exam question from the Russian Physics Olympiad. It's an extremum problem involving multiple pulley systems with a spring oscillator in a non-inertial frame.

The teacher in charge of the group wrote two blackboards with calculus, but the result still contained very complicated approximations.

I always felt it shouldn't be this complicated. I thought about it for several days, drawing more than a dozen sheets of draft paper for force analysis, but I still couldn't find a simpler approach. I copied the problem on the back. If you're not too busy studying, could you take a look for me? If you don't have time, that's fine, it's no trouble at all." Chen Zhuo turned the letter over.

The back features a perfectly drawn diagram of pulleys and springs using a pencil and ruler.

Beside him were densely packed Newtonian mechanics equations, many marked with eraser marks, clearly written and erased repeatedly. Chen Zhuo stared at the intricate force analysis vector arrows.

He untied the pen and pulled a clean sheet of paper from the drawer.

He didn't follow He Gui's line of thought to write any calculus, nor did he draw those complex friction and centripetal forces.

There were no dizzying equations or lengthy treatises.

In the first line, he wrote a state function.

In the second line, he substituted the kinetic and potential energy of the system in the problem and wrote a clean and concise equation.

In the third line, he drew a small diagram of the energy conversion critical point next to it with a pen.

Then, a short comment was left below:

"Don't get bogged down in calculating forces. Use the Lagrange equations to treat the whole system as a whole and find the critical point of energy conservation. Basic Newtonian mechanics can easily lead you astray in non-inertial frames of reference. Take a step further and look at analytical forces." Chen Zhuo blew on the ink on the paper, folded the letter into thirds, put it in a new envelope, wrote the address, and affixed a stamp.

I had just placed the envelope on the corner of the table when the phone in the living room suddenly rang.

"Ring ring ring one"

The old-fashioned landline phone was very loud.

"Chen Zhuo, go answer the phone!" Liu Xiuying shouted from the kitchen.

Chen Zhuo walked out of the bedroom and picked up the receiver.

"Feed".

It was a bit noisy on the other end of the phone.

The faint sounds of classical symphony could be heard, mixed with the clinking of wine glasses and the polite toasts exchanged between elders. "Captain."

A gentle, clear voice, exuding a well-mannered and composed air, came from the room.

Chen Zhuo stood next to the landline phone.

"Shi'an, it's the Lunar New Year, it must be quite lively where you are."

"Don't even mention it."

Miao Shi'an sighed softly on the other end of the phone, his voice sounding as if he were covering the mouthpiece.

"I was surrounded by elders, toasting them one by one, my face was stiff from smiling so much. I finally found an excuse to hide in the sun and call you." Chen Zhuo heard the sound of a lighter being lit on the other end, followed by Miao Shi'an's low cough.

"You've already smoked it?"

I secretly tried a sip, and it was very choking.

Miao Shi'an smiled, his tone carrying a hint of casual laziness.

"Captain, my dad sent me to an international school."

Chen Zhuo didn't speak, but listened quietly.

"Now I'm facing textbooks in English every day, learning how to deal with foreign interviewers, how to make a nice resume and prepare for the TOEFL. The physics classes in school are as simple as junior high school common sense, and they don't even bother to go into force analysis." There was a pause on the other end of the phone, and then the sound of wine glasses clinking rang out again.

"Sometimes I miss the days in the summer training camp when Professor Wang forced us to build alarms out of scrap metal. Back then, physics was something you could actually touch." Chen Zhuo twirled the telephone wire with his fingers and smiled.

"International schools' labs must be pretty advanced. If you're feeling bored, why don't you dismantle and reconnect your school's fire alarm system? I think that would be quite interesting," Miao Shi'an chuckled on the other end of the phone.

"Forget it, if I do that, my dad will cancel my card tomorrow. Okay, I'm not talking to you anymore, my uncle is coming to see me. Happy New Year, Captain! I'll treat you to dinner when I get the offer." "Happy New Year."

The phone hangs up.

Chen Zhuo put down the receiver and glanced at the piece of paper with the number written on it on the coffee table.

He dialed back the number marked with two or three asterisks.

The phone rang twice and was answered instantly, as if someone had been standing right next to it the whole time.

"Hey, who is this? Is this Chen Zhuo?"

A series of rapid-fire sounds burst out of the receiver.

Chen Zhuo moved the receiver ten centimeters away.

"I'm a man of few words."

"Oh my god! Brother Zhuo! You finally called back!"

Wang, who rarely speaks, was shouting and yelling over there.

"I called you three times this afternoon, and your auntie got annoyed with me. Where did you go? You're not home watching TV during the New Year holiday, are you out having fun?" "Yeah." Chen Zhuo didn't deny it, "I went out with friends."

"I knew it!"

Wang was a man of few words, he just chuckled.

"You have no idea how bored I am here. Let me tell you, our high school is super strict! The dean of students patrols the playground every day and catches them dating all the time." Chen Zhuo held the receiver a little further away.

"You adapted quite quickly."

"What can I do if I can't adapt?"

He took a breath, then changed the subject and began to pour out his grievances.

"By the way, the school insisted on putting me into the Physics Olympiad training team, and we didn't get a break until the 29th of the Lunar New Year! That coach tortures me with past years' semi-final exam papers every day. I can calculate the critical points of those sliders with my eyes closed. I also have to stay up all night with those bookworm seniors. It's so annoying!"

Chen Zhuo switched the receiver to his other ear.

"Being able to calculate the critical point of a slider with your eyes closed, it seems you're doing quite well."

"It's nothing special, just a random first prize in the province for fun."

Wang's taciturn tone revealed an undisguised smugness.

"Hey, Zhuo-ge, do you know any pretty female seniors at USTC? Introduce me to some, I don't mind being older." "Not even a female mosquito flies into my area."

Chen Zhuo remained expressionless.

"That's bullshit."

Wang is a man of few words, and I don't believe him.

"By the way, Zhou Kai called you too, right?"

That kid's gone crazy right now. I heard he's been glued to Cheng Jiafu's "Mechanics" textbook every day, even drawing force analyses on scrap paper while getting food at the cafeteria. I think he just can't swallow the humiliation of being outdone by you back then, and he's determined to win first place in this year's Physics Olympiad to prove himself.

"Okay, I'll call him back in a bit."

"Okay, my mom's calling me for dinner. Happy New Year, Zhuo Ge! I'll come visit you during summer vacation!"

Chen Zhuo hung up the phone.

Chen Jianguo pushed open the door and came in, carrying two bottles of beer in his hand and radiating the chill of the outside air.

"Who are you calling?"

Chen Jianguo placed the beer on the table and rubbed his hands together.

"Friends from previous training camps."

As Chen Zhuo answered, he dialed a third number.

The phone rang for a long time before it was answered.

"Hello, who are you looking for?"

The voice was steady and measured.

"Zhou Kai," Chen Zhuo said.

There was a moment of silence on the other end of the phone, then Zhou Kai's voice became tense, as if he had suddenly straightened up.

"Chen Zhuo, you called back."

"Yes, I went out this afternoon. Happy New Year."

"Happy New Year." Zhou Kai's greeting was also very standard. "How's your progress at USTC?"

"good."

"I looked at some of the USTC's past final exam papers."

Zhou Kai's voice carried a competitive edge.

"The calculus and linear algebra parts have a huge logical gap; are you able to handle them?"

"It'll do."

"I will catch up with you."

Zhou Kai took a deep breath, his tone very serious.

"I'm currently a first-year high school student, and my school has approved my participation in this year's National Physics Olympiad, which is ahead of my grade level."

"Congratulations."

"My goal is to get first place in the national team, join the national training team, and get a direct admission spot to Tsinghua or Peking University."

Zhou Kai's tone conveyed a sense of calm planning.

"It's okay if I don't get into Tsinghua or Peking University through the guaranteed admission program. I checked the Ministry of Education's policy. This year, the country started piloting independent admissions. As long as I have a provincial first prize, I'm qualified to knock on the door of Tsinghua or Peking University." He had calculated every step of the rules and his backup plan clearly.

"Okay." Chen Zhuo smiled. "Don't just focus on studying policies and doing exercises, take care of your health."

"The same to you."

After Zhou Kai finished speaking, he hung up the phone decisively.

Chen Zhuo put down the receiver and looked at the last number on the calendar.

He pressed the number keys.

The phone was answered after only one ring.

But there was no sound of speaking.

It was very quiet in the receiver; I couldn't even hear the firecrackers or television sounds that should be in the background.

"Lin Yi?"

Chen Zhuo tentatively called out.

About three or four seconds passed.

"Um."

A single syllable, conveying a girl's unique coolness and decisiveness.

"Are you home?" Chen Zhuo asked.

"sky."

Lin Yi's voice came through the telephone line, without any inflection.

"It's too noisy inside."

"Is winter cold in Huizhou?"

Lin Yi suddenly asked a question.

It's a bit colder here than where I am.

Chen Zhuo glanced at the frost flowers that had formed on the windowpane.

"Is the gifted youth program fun?"

"It's alright." Chen Zhuo thought for a moment, "but it doesn't feel as interesting as when we participated in the physics training camp."

Silence fell again on the other end of the phone.

There was a faint sound of wind whistling through the gap in the microphone.

"Professor Wang called me a few days ago," Lin Yi said.

"What did you say?"

"They asked me if I was interested in going to the Physics Department at Nanjing University ahead of schedule."

"What did you say?"

"I said I'm not interested." Lin Yi's voice was calm. "The high school questions are too stupid, but I don't want to go to Nanjing University."

Chen Zhuo didn't ask her where she wanted to go; such a question was unnecessary for Lin Yi.

"Don't stay out in the wind for too long, or you'll catch a cold," Chen Zhuo said.

"understood."

Before hanging up, Lin Yi added something that was unusual for him.

Happy New Year, Chen Zhuo.

"Happy New Year."

The receiver was busy.

Chen Zhuo put the receiver back on the landline.

Four phone calls, one letter, five completely different life trajectories.

Expensive international schools, noisy Olympiad training camps, ruthless rule calculations, the cold wind in the sky, and that lined paper with Lagrange's equations written on it. These sounds were like invisible threads, pulling him back from those ethereal manifold boundaries and the singularity of physics at Princeton. He felt grounded.

"Chen Zhuo! Come and serve the dishes!"

Liu Xiuying called from the kitchen.

Chen Zhuo stood up and walked towards the kitchen.

"They're here."

The dining table was piled high with food.

In the very center is a large braised carp, symbolizing abundance year after year. Next to it lies a glistening roast chicken, a plate of freshly cooked and still steaming braised pork ribs, and a large bowl of crispy-on-the-outside and tender-on-the-inside deep-fried meatballs and lotus root slices.

Squeezed in a few cold dishes to go with the drinks: pig's ears in chili oil, cold seaweed salad, thinly sliced ​​braised beef, and a plate of crispy fried peanuts. Chen Jianguo used a bottle opener to pry open the beer bottle and poured two glasses.

He glanced at Chen Zhuo standing beside him.

"It's Chinese New Year, and you've grown a year older too. Want a drink?"

Liu Xiuying came out of the kitchen carrying a large bowl of dumplings and glared at Chen Jianguo.

"How old is he? You let him drink? If he ruins his brain, are you going to pay for it?"

"So what if I was eleven? When I was eleven, I was already working in the fields with my dad."

Although Chen Jianguo said that, he still moved his beer glass closer to himself.

Chen Zhuo pulled out a chair and sat down.

"I'll just drink some Jianlibao."

The television was on, broadcasting the Spring Festival Gala. Uncle Benshan and Gao Xiumin's skit had just begun. Chen Jianguo ate ribs while watching TV and laughing. Outside, the sound of firecrackers began to intensify, one wave louder than the next.

The windowpanes rattled and vibrated.

Chen Zhuo picked up a piece of pork rib and put it in the bowl; the meat was stewed until very tender.

After dinner, Liu Xiuying washed the dishes in the kitchen while Chen Jianguo leaned back on the sofa and ate sunflower seeds.

Chen Zhuo sat at the dining table, watching the gala on the TV screen, and took a sip of Jianlibao from the can.

The bubbles burst in my throat, a little cool, but very satisfying.

Nothing dramatic happened on New Year's Eve.

There were no overseas calls, no dean banging on the door.

In this remote southern town, Chen Zhuo was just an ordinary kid who had just finished helping a classmate solve a physics problem, wished a few friends a Happy New Year, and then sat at home eating a meal of braised pork ribs. As for the shock and sleepless nights on the other side of the ocean, they were all shut out from the quiet door of this home.

Tomorrow is the first day of the Lunar New Year.

I still have to mail that letter with the 80-cent stamp.