More than thirty years ago, I was in high school in the county, and in my sophomore arts and sciences, I chose science and transferred to another class.
I am a boarder in the junior high school in the countryside, and I say I am a boarder, but the bed is only for sleeping at night, and I study in the classroom most of the time. At that time, reading seemed to be the only way out. We didn't go back to the dormitory for lunch break at noon, ate lunch in the cafeteria, and immediately returned to the classroom to read books and do problems. When I am tired, I just lie on the table for a nap.
One day, at noon, I was lying on my desk, and I heard the creaking sound on the podium, as if a teacher was in class, and when I opened my eyes, it was really a teacher writing something on the blackboard. I concentrated, but strangely, there were only a few students in the class, all sleeping on their desks, and no one listened. I woke up, so I looked at the teacher and listened to the lesson. He was a short man, less than one meter six, with his face facing the blackboard and constantly writing. The blue on the back is indeed washed gray, and the collar is probably brushed frequently, and the folded part has also turned white. When he raised his hand, I could clearly see a large blue patch under the armpit of his sleeve. He only had a handful of hair on each side, and his half-bald brain moved left and right in front of the blackboard, which was very conspicuous. I looked closely at the blackboard, which was a series of physical formulas, and the handwriting on the board was greatly tilted from right to left, but the handwriting was beautiful and regular. When he turned around, I finally saw his face, a vicissitudes but neat little old man, with his eyes lowered, showing a kind of humility. He timidly glanced at the podium, and when he looked back, a scar on his forehead that fell from the left was squeezed together, like a brown centipede. He mouthed something and soon faced the blackboard again, writing non-stop, without saying a word.
My mind searched for the look of my high school physics teacher, who was by no means our high school teacher, and I had no impression of him.
Soon after the afternoon class time, one after another students entered the classroom, he hurriedly picked up the blackboard to wipe, and began to clear the blackboard handwriting. I clearly saw the content on the blackboard this time, which is the law of the difference between displacement and the same time in free fall: △h=gt2, but strangely, in the illustration and derivation on the blackboard, this formula becomes: △h=gt, which is actually the primary square of time t, and in fact the displacement difference is the quadratic of time t.
But it seems that this teacher's derivation is very rigorous. When I stopped thinking and looked at him, I met his gaze, and there seemed to be gratitude in his eyes, perhaps because I was looking at the blackboard seriously. He packed some information and a small bag into a shabby-looking black handbag of Shanghai brands, which was filled with chalk, which he had brought with him. He hurried out of the classroom, and I realized that he was barefoot, with his trouser legs high and low.
I was a student who had transferred to Class 6, and my classmates from Class 6 told me that he was a crazy person who would often attend classes in the class at noon. The classmate said that what this madman said was the wrong formula, and no one paid attention to him; The classmate also said that although he is a crazy person, he does not hit and scold people, does not speak in class, but only whispers, and never noisy students who take a nap...
This crazy teacher often came to our class at noon, and I gradually got acquainted with him, and sometimes I carefully looked at what he wrote on the blackboard, and the formula he solved the problem was completely different from the book, either less square or multiple parameters. He was intoxicated by his own physical world, and once a classmate shouted at him: "According to your formula, the acceleration unit becomes meters per second, what is the unit of speed?" After listening carefully, he turned back to the blackboard to derive the acceleration, a dense list, some of which were unseen formulas, in which a lowercase F symbol appeared many times, and the result of the derivation was that the acceleration was meters per second. Several classmates gave him a thumbs up, and he laughed happily without knowing that he was making fun of himself.
It was a Sunday, and I was carrying a bag of rice and a bottle of sauerkraut meat back down the alley. At noon, the alley was empty, and suddenly three punks with long hair and flared pants and shirts about the same age as me appeared, they surrounded me, one short man took out a dangling switchblade and pointed it at me, the other two fumbled in my pocket, and the wielding knife with the knife hit a big fork -
"Take it out!"
"The countryman has no money, rice for you."
"Hmph, the money was found to slaughter you!" A tall man said through vicious gritted teeth.
They searched me again, I had ten dollars hidden in my pants pocket, and I was anxious and scared when I suddenly heard a loud roar: "What for? Grab students' money!"
The punk was startled, and suddenly the birds and beasts scattered, and I looked back and was surprised to see that it was the crazy teacher, who was all muttering with his head down during class, and I had not heard his voice speak.
"Thank you, teacher!"
"You call me teacher?" He stayed for a long time, suddenly smirked, and said to himself, "I am the smelly old nine, I am the smelly old nine." ”
"When you go to class, you are the teacher."
He seemed to grin at me gratefully. He quickly took out a few crumpled bills from his pocket and handed them to me: "Here, here you go." ”
"No need, no robbery."
"Take it, take it."
"I have, I have." I was embarrassed and hurried away with the rice.
He took the money and whispered something to say, and the sun shone on his head, and the scar was very conspicuous.
He still used to come to our class at noon, clean the blackboard, and hurry away with his old worn-out Shanghai bag.
In the evening after the final exam of my third year of high school, I went back to the classroom to get my books, and the teaching building was empty. I heard the voice of the madman teacher, coming from class 5 next door, and I stood in the hallway and listened, it was the first time I heard him loudly in class.
"Light is light, what waves? to kill you again. ”
"De Broglie proved that light is a wave and a string of particles."
"When light particles hit metal, they create an electric current."
"The double-slit interference experiment is proof of this"
……
"Ah, you hit me."
"Damn, the stick is broken."
"Action and reaction, the stick hit my head with a force of 50 pounds, and it also bears the same 50 pounds of force."
……
Through the window, I saw the madman teacher covering the scar with his left hand, and his right hand writing on the blackboard, saying loudly parameters and words that I didn't understand.
From the beginning of the second semester of high school to the end of the college entrance examination, I never saw him again, and I heard that it affected the students' rest and was driven away by the school.
I haven't seen him again for decades, but the centipede-like scars on his half-bald head will always be in my memory...
In college class a year later, I learned that the symbol like f is calculus, and that wave-particle duality is the basis of quantum mechanics.
(Xie Chunwu, author's unit: Minxi Prison)