In the middle of the curtain, a smiling old man appeared.
He was wearing very plain navy blue overalls, with a white wall behind him, it was sitting on the sofa, its smile was as simple and unpretentious as his clothes, and it was only friendly.
He didn't have a speech script, but his finished script was completely different from that of Vice President Zhang. He didn't seem to have planned what he was going to say, but he just said casually to the camera: "Students, I'm sorry for using this method. It was a bit of a distance meeting you, but I think that distance should make both of us feel at ease."
The old man was very sincere, and all the students in the auditorium looked up at his face and showed relaxed smiles.
He said: "Actually, I am a very shy person. If I have to speak in front of many people, I always have to do a long time of psychological construction, so the organizing committee proposed that I can convey my heart to you in the form of video, my The first reaction was, oh my god this is so good."
He was sincerely grateful that his exaggerated smile infected all the children in the audience. The children and older children all laughed, and the old man himself laughed too, with loving eyebrows and shining eyes.
After a while, he continued: "Just now, your other teachers should have said a lot about the meaning of this summer camp, the purpose of learning, and all the things that can and cannot be done, someone must have talked about it, thank you They save me from having to repeat these very tedious things. So what am I going to say, well, I'll tell you the truth, every time I do a speech like this, my first impulse is to tell you how much I love Mathematics, I will tell you unabashedly that I love her very much, she is so delicate, beautiful, and profound... But she is such an interesting thing, no matter how much time I spend and how complicated it is to describe it to you, it is far from perfect. enough."
The old man was radiant, and when he talked about mathematics, he smiled even brighter, like a fire in his chest, infecting everyone in the venue.
"Let's put it this way, when I was very young, my father told me a picture when he was coaxing me to sleep. Imagine that at the beginning of this world, there was darkness. The so-called beginning is very early. Long before the birth of human beings, long before the birth of dinosaurs, and long before the formation of the earth. The so-called black is not the black that can be painted by any kind of seasoning you have ever seen. It has no light. There was no light. And then something happened, an extremely small and tight point exploded, it flipped inside out, time spread out, space spread out, and the world we know and don't start from there For a split second, they stretched out, that was the stretch of time and space, and over countless years. Long after that, small clusters of gas gradually brightened, which we call galaxies, and later, the sun appeared, and the earth was formed , and then after countless years, someone opened his eyes on an extremely small planet."
The old man's voice gradually became quieter, he squinted his eyes slightly, and his voice was as cheerful as a piano keyboard: "That person is you, and the time is very deep in the night, you look up and see the whole wonderful starry sky, the stars are shining and magnificent, someone told You, that's called the universe."
On the curtain, the old man's smile was still shining brightly. But there was no sound in the entire auditorium, the surroundings were silent, and all the children looked up. They were looking at him and the world he brought, and the surroundings were as silent as the universe.
The silence of thinking lasted for a while, and the old man smiled: "When I was a child, the picture my father told me really made me feel very beautiful. It's really interesting that the real world I live in came from this way. But later, I went to high school, went to college, I gradually gained more knowledge, and then I realized that every word my father told me when I was a child, it may be truth or it may be false, it is the cause of our universe Some kind of conjecture is still being perfected, maybe one day it will be confirmed, or one day it will be overthrown, this is all possible. You see, in fact, every day we stand on the edge of the known and the unknown. If you look at it this way, the world is so big and we know so little that everything seems uncertain, which is very frustrating. But I will tell you that the unknown is the most beautiful thing."
When the old man said this, he sat up straight, he was closer to the camera, and his face was more lively.
"Human civilization has experienced a long dark night, and at a certain moment in the dark night, our thinking collided with sparks, and our ancestors created the number 1. Starting from 1, human abstract logical concepts were formed. If the world we saw before is so big ..." The old man smiled and put his thumb and index finger together in a very small gesture.
He smiled and said, "After that, we gradually realized that the world will always be bigger than we imagined. For thousands of years, countless sages have gone on to perfect this subject. It is no exaggeration to say that it is mathematics It is the tool that opens our eyes and gives us the opportunity to see the whole unknown world as it is; it is mathematics that bridges the gap between seeing and knowing."
"Mathematics is a tool as well as a language. You may feel hard work in the process of mastering this tool or language, but believe me, compared with the joy of discovering the unknown, these hard work and hard work are worthwhile. Once you realize Realizing that we are just tiny human beings on a tiny planet, but trying to master something that can understand the truth of the universe, you will suddenly realize that your learning process itself is already remarkable enough!"
The old man paused, he smiled and licked his lips, as if he felt a little shy because he had said too much at once.
Lin Zhaoxi looked around again.
Pei Zhi had already woken up, and he was looking up at the old man on the screen with his small face up. His eyes were still clear, but there was an expression that had never been seen before, the same as that of the old man. If from now on, you want to be his student and work hard for it for many years, it is also a very remarkable thing.
Lin Zhaoxi laughed from the bottom of her heart.
The last voice of the old man came from the speaker. He said: "If you encounter any problems in learning, you can ask your teacher, or you can send me an email. I sincerely hope that you can feel the joy of learning mathematics, and sincerely hope I wish you all the best of luck in this process."
A line of email addresses was displayed on the screen, and the screen faded to black. Some people had already started applauding, but most of the entire auditorium still fell into a deep silence.
But suddenly, the old man in the picture raised his head and laughed again. He faced the camera, patted his head and said with a smile: "I forgot to say, I prepared a small question for all of you. If any of you can solve it, you are welcome." Send me the answer through this email. But believe me, even if you solve this question, you will not be able to represent the competition immediately, let alone get any rewards. This is just a delicious dessert after your hard study every day. I hope You can have a little taste of it, it's interesting."
The old man's face finally disappeared, and a cross chessboard appeared on the screen.
Questions were also typed out at the same time—
According to the rules, how many moves are needed to clear all the pieces except the middle position? and list your steps.
Right in front of the auditorium, some staff members had already stood up and carried several unremarkable boxes. They took out small wooden boxes from inside and distributed them.
The children who received the wooden box were very excited. They did not expect to receive gifts during the meeting. Some shook the box vigorously, and some opened it directly, making surprise laughter.
The chess boxes were passed down one by one from the seat on the left side. Lin Zhaoxi took one box and handed the rest to Pei Zhi. She opened it and found that it was exactly the same cross chessboard as on the curtain.
There are 33 depressions in the cross chessboard, and 32 squares are placed on the depressions, only the middle one is empty.
There is a small piece of paper inside the chess box, which states the rules.
1. After all the chess pieces are filled, take out the central one.
2. Chess pieces can only jump over adjacent pieces horizontally and vertically (not obliquely) to the vacant space.
3. The pieces that are skipped are eaten.
4. Continue to move according to the previous method, until you can't go any further, and count how many pieces are left.
5. The fewer chess pieces left, the more powerful you are. If there is only one chess piece left, you are a genius.
Lin Zhaoxi looked up at the question on the screen again—according to the rules, how many moves is the minimum required to clear all the chess pieces except the middle position
She looked at the young boy next to her again, speechless for a long time.
Pei Zhi had already opened the wooden box and fiddled with it. The light was dim, and his white and immature face showed an unprecedented excitement.
Suddenly, Lin Zhaoxi recalled a moment in the future when the adult Pei Zhi stood under the steps and asked her two terms that she had never heard before.
"Fisher linear discriminant function?"
"Classification of complete solutions?"
At that moment, she stroked the warm wooden chess box in her hand, as if she realized something in the dark.
Kongming chess, optimal solution, traveling merchant problem... fisher linear discriminant function, classification of complete solutions, pnp problem...
Everything starts here.