My IQ has been increasing year by year.

1999, October.

Winter came suddenly in the south.

The day before yesterday was a bright and sunny day when people were running around in just a light shirt, but after a night of northerly winds, the whole city was shrouded in a layer of damp, cold, gray fog.

The classroom of Class 3, Grade 4 of Yuhong Primary School is located on the third floor of the teaching building.

For seven-year-old Chen Zhuo, climbing up to the third floor every morning with a schoolbag that was almost half his body was the first battle of the day.

There was no heating in the classroom.

More than forty children, around ten years old, huddled together, their breath condensing into a thick layer of mist on the glass window.

The air was filled with a unique aroma that blended the scents of damp umbrellas, scallion pancakes, and ink.

Chen Zhuo sat in the middle of the first row.

This was a special seat arranged by the homeroom teacher, right below the podium, right under the teacher's nose.

This spot is usually reserved for the naughtiest kid in the class, so the teacher can throw chalk at him whenever he wants.

But now, it belongs to the youngest student in the entire school—seven-year-old Chen Zhuo.

"Attend class!"

"stand up!"

"Hello, teacher!"

At the class monitor's command, the entire class stood up in a flurry.

Chen Zhuo also stood up.

But even when he stood up, he wasn't as tall as the students sitting in the back row.

This height difference makes him look like a dwarf who has wandered into a land of giants.

This is already the second month since Chen Zhuo skipped a grade.

After the initial novelty wore off, he faced a deeper isolation than he had in his first year.

It wasn't bullying; no one was bullying him.

Although a ten-year-old child is mischievous, he is not so bad as to bully a seven-year-old, especially someone like him who is given special attention by the teachers.

On the contrary, they were very curious about him, even looking at him with the eyes of someone looking at a rare animal.

But this kind of "goodness" is a kind of alienation akin to species isolation.

As soon as the bell rang, the boys would gather together to talk about "Digimon," whether the motors of their mini 4WD cars were "Golden Superpower" or "Audi Double Diamond," which girl in the next class was pretty, and about the end of the world and the King of Horrors.

The girls huddled together folding lucky stars and chatting about the little secrets written on scented stationery.

Chen Zhuo sat in his seat, looking at a junior high school textbook, "Biology," with a slightly torn cover.

He couldn't fit in.

He couldn't force himself to get excited about a non-existent "chosen child," nor could he understand why writing someone's name on a paper star would grant a wish.

His soul was too old, as old as a dried-up stone.

His body was so small, as small as a newly sprouted bean.

"Hey, prodigy."

A hand from the back seat poked Chen Zhuo in the back.

That was Zhang Qiang, the class's sports representative. He had already grown to 1.5 meters tall and was going through puberty, his voice sounding like a male duck.

Chen Zhuo turned around and pushed up the non-prescription glasses on his nose, which he wore just to look good.

"What is it?"

"Let me copy this problem."

Zhang Qiang handed over a crumpled math workbook, a slightly embarrassed yet self-righteous smile on his face.

"I stayed up late watching TV last night and forgot to write."

This is a word problem about distance, speed, and time.

This is a difficult point that fourth-grade children are just learning.

Chen Zhuo glanced at the question but didn't even pick up a pen.

"Car A travels at 60 km/h, and Car B travels at 45 km/h. They will meet in 3 hours."

"Holy crap, you didn't even need to calculate?" Zhang Qiang exclaimed in surprise.

"Mental arithmetic."

Chen Zhuo turned around and continued drawing his circle.

"Wow, that's incredible..." Zhang Qiang muttered to his deskmate as he scribbled furiously, "How does this kid's brain work? Can such a small head even hold all that?"

Chen Zhuo heard this muttering.

He wasn't angry; he just smiled bitterly to himself.

Can it fit?

It's definitely almost full.

Recently, he has felt an unprecedented fatigue.

As he gained more and more knowledge, he discovered that the seven-year-old body was beginning to sound the alarm.

It's like an overclocked CPU that can't keep up with the heat dissipation and has unstable voltage.

Whenever he engages in intense thinking for more than an hour, he feels a throbbing sensation in his temples, his vision blurs, and he may even experience nosebleeds.

That's the pain of hardware not being able to keep up with software.

This pain was amplified during the third physical education class.

While mental fatigue can be overcome with willpower, the gap in physical strength is an insurmountable chasm.

The wind was strong that day, and the cinder track on the playground was blown into a cloud of dust.

The PE teacher was a burly man in a dark blue tracksuit with a whistle around his neck. He looked at the group of children in brightly colored sweaters in front of him with a furrowed brow.

"Today's test is the standing long jump!"

The PE teacher's booming voice echoed in the cold wind, "The passing mark for boys is 1.5 meters, and for girls, 1.3 meters! Anyone who fails, run three laps around the track!"

A chorus of groans erupted from the ranks.

Chen Zhuo stood at the very end of the line, his neck hunched, his hands tucked into his sleeves.

He hates physical education class the most.

It wasn't because he was lazy, but because it was the only subject in which he couldn't cheat using logic.

In math class, he can use adult thinking to deliver a powerful and insightful lesson; in language arts class, he can imitate the writing style of adults to produce profound essays.

But in physical education class, gravity is fair.

Newton's second law does not apply here.

Because his muscle strength was too weak, and although his body weight was light, he lacked explosive power.

"Next up, Chen Zhuo!"

The PE teacher called his name.

Dozens of eyes turned to look at them.

That was a fourth-grade student watching a first-grade "little bean".

Chen Zhuo walked to the sandpit.

That sandpit was like a desert to him.

He took a deep breath and quickly calculated the trajectory of the parabola in his mind.

"A 45-degree takeoff angle is optimal... The arm swing should shift the center of gravity forward... The explosive power of the calf muscles should be utilized at the moment of push-off..."

The theory is perfect.

He had already mentally calculated a jump of two meters.

"Jump!" the teacher whistled.

Chen Zhuo suddenly pushed off the ground and swung his arms forcefully—

However, the reality is cruel.

His brain issued a "burst" command, but his calf muscles, thin as reeds, were simply unable to respond to such a command.

His body was suspended in the air... about ten centimeters.

Then, like a kite with a broken string, it fell straight down.

"Smack!"

He plopped down in the sandpit.

Distance from the starting line: 1.1 meters.

Failed.

They didn't even reach the passing grade for girls.

A burst of good-natured laughter erupted from the crowd.

"Hahaha, Chen Zhuo, are you a frog?"

"That was hilarious! He looked like he was flying, but then he just fell down!"

"Oh, she's still young. 1.1 meters is already pretty good!"

Zhang Qiang laughed the loudest from the side: "Prodigy, looks like your brain works well, but your legs don't!"

Chen Zhuo sat in the cold sandpit, patted the sand off his bottom, and stood up expressionlessly.

He felt no shame.

As an adult, he wouldn't feel ashamed for not being able to jump far enough in front of a group of children.

He felt a sense of helplessness.

This is the constraint that hardware imposes on software.

This is the law of physics.

No matter how powerful your soul is, you cannot defy the basic laws of biology.

Seven-year-old muscle fibers are simply unable to generate enough kinetic energy.

"Chen Zhuo, you..."

The physical education teacher was also a little perplexed looking at the child who was not even as tall as his waist.

"Fine, you don't need to run laps anymore. Go play over there."

privilege.

It's another privilege.

Chen Zhuo nodded and silently walked out of the group.

He walked to the parallel bars in the corner of the playground, struggled to climb up, sat on the cold iron bars, and looked at the energetic ten-year-olds running on the track in the distance.

They ran breathlessly, their faces flushed, and sweat poured down their cheeks in the sunlight.

That is vitality.

That was the recklessness and passion that Chen Zhuo lacked, the kind of impulsiveness and passion that belonged to his age.

He pulled out the well-worn junior high school physics book from his pocket.

Since the body can't fly, let the brain fly.

He opened the book, skipping the sections on acoustics and optics.

Those things were too simple for him; he could understand anything he could see or hear.

He turned to Chapter Six.

Ohm's Law.

This is the tough nut he's been gnawing on these past few days.

It's not that the formula is difficult.

The formula I = U / R is so simple that even a kindergarten child can memorize it.

The difficult part is imagining.

Chen Zhuo stared at the simple circuit diagram in the book: a battery, a switch, and a light bulb.

The book says, "Electric current is the directional movement of electric charge."

The book says, "Voltage is the cause of the directional movement of free charges, forming an electric current."

The book says, "The essence of nerve impulses is also a kind of bioelectrical conduction."

He recognized each word individually, but when put together, his mind went completely blank.

For a seven-year-old's brain, concrete thinking is an advantage, but abstract thinking is a weakness.

He cannot see electrons.

He couldn't visualize the "electric charge movement" in his mind.

Is it like flowing water?

Is it like the nerve impulses described in biology textbooks?

Or is it like the Yangtze and Yellow Rivers depicted in geography books?

What exactly is voltage?

Is it stress?

Or is it the height difference?

He attempted to force a model.

"Imagine the wires are a river... the battery is a water pump..."

hum-

That familiar, nauseating dizziness came back again.

The brain is overheating.

Chen Zhuo closed his eyes in pain, cold sweat beading on his forehead.

He realized he had hit a wall.

This is the first real wall he has encountered since his rebirth.

This wall is not a matter of the difficulty of knowledge, but rather a matter of the dimension of cognition.

He was trapped in the body of a seven-year-old, trapped in a world where he could only understand what he could "see and touch".

"Damn it..."

Chen Zhu cursed under his breath and closed the book.

Eight o'clock in the evening, at the Chen family's residence.

Chen Jianguo was watching the news in the living room, while Liu Xiuying was washing dishes in the kitchen.

Chen Zhuo locked himself in his small study on the balcony.

This small balcony, which was originally used to store miscellaneous items, has now become his private territory.

The table was piled high with various books, and in the corner was a box of scrap parts that Chen Jianguo had brought back from the factory.

The table lamp emitted a dim, yellowish light.

Chen Zhuo sat at the table, staring intently at the pile of things in front of him.

A single size D battery (it was taken from a flashlight).

A thin copper wire (stripped from an old electrical wire).

A small light bulb (also found in flashlights).

If you can't figure it out with your brain, then use your hands.

This is the essence of "great skill appears clumsy".

When intellectual abilities fail to break through, one regresses to the most primal sensory experiences.

If you don't understand what "electricity" is, then touch it.

Chen Zhuo picked up the battery.

It was heavy and cold.

It is marked 1.5V.

The book says this is voltage.

He wrapped one end of the copper wire around the threads of the light bulb and pressed the other end to the negative terminal of the battery.

Then, he took the other end of the copper wire and carefully touched the positive terminal of the battery.

Snapped.

The light bulb turned on.

It was a faint, orange-yellow light.

Chen Zhuo stared at the ball of light.

This is electric current.

In this closed loop, countless electrons, invisible to the naked eye, rush out from the negative electrode like a thousand horses, gallop along the copper wire, squeeze through the thin tungsten filament in the light bulb, collide with atoms to emit light and heat, and finally return to the positive electrode.

The scene is beautiful.

But it's still just imagination.

He still couldn't feel the presence of "electricity".

For him, it was like a magic trick, with the process in between being a black box.

"I want to feel it."

Chen Zhuo put down the light bulb.

His gaze fell on a square battery to the side.

That's the battery in Chen Jianguo's multimeter, a stacked battery, 9 volts.

If you don't feel anything at 1.5 volts, what about 9 volts?

Reason told him that voltages below 36 volts were safe, and 9 volts wouldn't kill him; at most, it would cause a slight numbness.

But his body is only seven years old, and his nervous system is much more sensitive than that of an adult.

Chen Zhuo took a deep breath.

He picked up the 9-volt battery like an alchemist preparing to perform some kind of dark ritual.

There are two round contacts at the top of the battery.

One positive, one negative.

He stuck out his tongue.

This is the most sensitive and moist conductive part of the human body.

If you ask a madman, how do you understand physics?

He will tell you: hit it with your body.

Chen Zhuo slowly and firmly brought his tongue closer.

The instant the moist tip of the tongue touches the two metal contacts simultaneously—

Noisy!

An indescribable feeling exploded within me instantly.

That's not pain.

It was sour, numb, and astringent, mixed with a metallic, fishy smell.

It felt like countless tiny needles piercing the nerve endings along the tip of the tongue.

At that moment, his tongue felt as if it no longer belonged to him, but had become an electrified wire.

Chen Zhuo abruptly retracted his tongue, jumped up from his chair, covered his mouth, and tears instantly streamed down his face.

"hiss--"

It's so numb!

My entire mouth felt numb, and I was drooling profusely.

But this "electric shock" was like a bolt of lightning, cleaving through the fog in his mind.

He sensed it.

That's voltage!

That's potential energy!

In that instant, he clearly felt how eager that force was to pass through his tongue, flowing from the positive pole to the negative pole.

That feeling of being pushed back in your seat, that unstoppable momentum, that's voltage!

The resistance, heat, and numbness felt by the tongue are electrical resistance!

It turned out to be the case.

It turns out that those cold, hard formulas in the book are actually U for thrust, R for obstacle, and I for result.

This is not an abstract number.

This is real, tangible force.

Chen Zhuo wiped away the tears from the corners of his eyes, but a crazy smile spread across his lips.

Although his tongue was still numb, he felt his mind was clearer than ever before, and the abstract model that had been troubling him suddenly became concrete.

He hasn't had enough fun yet.

He picked up the thin copper wire again.

This time, he didn't catch the light bulb.

He directly attached the two ends of the copper wire to the positive and negative terminals of the large battery.

Short circuit.

This is a major taboo in physics experiments, but it is the most intuitive way to experience the "thermal effect of electric current".

one second.

two seconds.

Chen Zhuo's fingers gripped the copper wire tightly.

At first, I didn't feel anything. But soon, I felt a warmth on my fingertips.

Immediately afterwards, the warmth turned into scalding.

That's the heat generated by the electrons colliding wildly between copper atoms.

A few seconds later, the copper wire started to get hot, so hot that it hurt my fingerprints.

"hiss--"

Chen Zhuo released his grip, and the copper wire fell onto the table.

He even saw a tiny wisp of blue smoke rising from the battery's two poles.

That's energy.

It instantly converts chemical energy into heat energy.

Chen Zhuo looked at his fingertips, which were red from the burn, and then licked his still numb tongue.

Pain, touch, taste.

The stimulation of the three senses completed a perfect physical model in his seven-year-old brain.

He reopened the junior high school physics textbook.

Then look at the sentence "Voltage is the cause of current".

He smiled.

It's no longer dry, boring text.

He could see the electrons dancing on the paper; he could feel the pressure of voltage and the friction of resistance.

He took the pen and wrote a line in the blank space of the book:

"Electricity is flowing fire, imprisoned thunder. It is invisible, but it bites painfully."

"Cough cough."

A cough suddenly came from behind me.

Chen Zhuo was startled and turned around abruptly.

Before anyone knew it, Chen Jianguo, the father, was already standing at the balcony door, holding a cup of hot milk in his hand.

Chen Zhuo instinctively wanted to hide the batteries and copper wires on the table, since playing with fire and short circuits were reasons to get a beating in his parents' eyes.

But Chen Jianguo was not angry.

He came over and put the milk on the table.

His gaze swept over the smoking battery on the table, then looked at Chen Zhuo's reddened fingertips, and finally landed on the open physics book.

As a veteran technician in a machinery factory, he certainly knew what had just happened.

Short circuit.

This kid is playing a short circuit.

Most other parents would probably have slapped him by now: "Why are you playing with electricity? Are you looking to die?"

But Chen Jianguo did not.

He looked at his son's eyes, which shone frighteningly bright in the dim light.

In those eyes, there was no fear of having caused trouble, only the excitement and fervor of having just glimpsed the truth.

Chen Jianguo was very familiar with that look in his eyes.

He had the same look in his eyes when he first spun a perfect thread at technical school.

"Does it feel numb?"

Chen Jianguo suddenly asked a question, pointing to Chen Zhuo's mouth.

Chen Zhuo paused for a moment, then subconsciously licked his lips: "Numb."

"Is it hot?" Chen Jianguo pointed to his hand again.

"hot."

"Do you understand?"

"Understood."

The father and son's conversation was so simple it was like they were exchanging secret codes.

Chen Jianguo smiled, reached out and touched Chen Zhuo's head; his palm was rough but warm.

"That's good enough."

He picked up the discarded battery from the table and weighed it in his hand.

"This lesson is ruined. Dad will bring you some new ones tomorrow. Also, next time you want to try, don't use your tongue, use a multimeter. Dad will teach you how."

As he spoke, he took out the 500-type analog multimeter he treasured from his pocket and placed it on Chen Zhuo's table.

"This is more accurate than the tongue."

Chen Zhuo looked at the black, heavy multimeter.

That's what my father uses to make a living; he's not allowed to touch it normally.

"Dad..." Chen Zhuo's throat felt a little choked up.

"Alright, drink your milk and go to sleep."

Chen Jianguo turned and walked out, but stopped at the door.

"By the way, that physics book... it's okay if you don't understand it. You're only seven. You'll understand some things when you grow up. Don't force yourself."

After Chen Jianguo finished speaking, he closed the door.

Chen Zhuo sat in a chair, holding a cup of hot milk.

The warmth from the cup flowed down my palm and into my body, dispelling the chill left over from the gym class.

He looked at the multimeter, then at the phrase "Ohm's Law" in the book.

He knew that his father had misunderstood.

His father thought he was putting on a brave face and that he was trying to force things to grow too fast.

But only Chen Zhuo himself knew that tonight, he had really broken down that wall.

Although it was done in the most basic way—licking with the tongue, touching with the hands, and enduring the pain with the body.

But this is precisely Chen Zhuo's way.

It's as clever as it is clumsy.

Since I don't have Einstein's genius imagination of "traveling on beams of light in my brain," I'll just be a sapper rolling around in the mud.

If you can't see it, touch it.

If you don't understand, just try it.

If you can't figure it out, then try to exhaustively search for all possibilities.

Using physical pain to gain a sudden enlightenment.

Chen Zhuo took a sip of milk; it was sweet.

The numbness on the tip of my tongue has subsided considerably, replaced by a sense of peace and security.

He picked up a pen and drew a circuit diagram on the draft paper.

This time, the lines are no longer rigid symbols.

In his mind, the circuit came to life.

The electric current flowed like a golden river across the paper.