Click click click.
The wheels rolled, raising clouds of smoke.
Xu Fenglei in the carriage looked at the young scholar in front of him with curiosity.
"Are you Li Chunfeng?"
He said with great interest,
"The one in charge of Qintian Prison?"
This trip was on Li Shimin's order to visit the palace.
Unexpectedly, there was someone along the way, and this person was Li Chunfeng, whom Xu Fenglei had always been interested in.
According to legend, this person is a 'Heavenly Official' who appears only once every five hundred years. Seriously speaking, he can be regarded as the ancestor of his former numerologist!
"The lower official is Li Chunfeng."
Li Chunfeng looked a little reserved, bowed his hands and said,
"I have met Grand Master Xu Gong."
"It is true that the lower official also serves as the Qintian Supervisor, but he mainly works in the Taishi Bureau as a general."
Xu Fenglei nodded slightly.
"Oh yes, it's the Taishi Bureau."
He smiled and said,
"The Taishi Bureau is in charge of astronomy, geography, calendar making, and history compilation. You have to be a genius to be able to do it."
"Brother Chunfeng is a great talent that is rare to see in a hundred years!"
When Li Chunfeng heard these words of praise, he waved his hands repeatedly.
"How dare you, how dare you... the grand master is so complimentary."
He said hurriedly,
"This official is just doing his job well. He is not a genius."
"People like Mr. Xu are the true pride of heaven..."
He was a little flattered by this sudden compliment.
"Hahaha, it's hard to say that I'm just lucky. I'm actually pretty good at it."
Xu Fenglei laughed loudly, waved his hands and said,
"Let's not be so polite. You and I are similar in age, so we can call each other brothers! I hate this honorific and that honorific the most. It just adds to the distance."
"I heard that you have an in-depth study of Yili and are also very good at mathematics. You are the number one mathematician in the world."
"It's boring all the way, why don't we discuss it?"
Li Chunfeng's eyes lit up.
He is not good at interpersonal communication, so he is a little impatient, but when it comes to academic discussions, he is not sleepy!
"I have long heard that Mr. Xu is the master of Yishu. We have been friends with Chunfeng for a long time."
Li Chunfeng continued,
"I don't dare to talk nonsense, but I still ask Mr. Xu for advice."
He no longer calls himself a lower official, but still uses the honorific title for Xu Fenglei.
After all, the two of them have just met. If someone is being polite to you, you can't take it seriously. Do you really want to call him Brother Feng Lei?
He is not good at interpersonal communication, but he is not stupid.
"well……"
Xu Fenglei nodded and asked,
"I heard that you are good at observing the sky to understand the world. I don't understand the relationship between astronomy and Yili, and I have never observed the sky."
"This is a blind spot in my knowledge. Can you tell me about it? If it involves confidentiality, forget it."
Although it was Li Chunfeng who 'asked' him, in fact, it was he who was asking Li Chunfeng for advice.
Just kidding, I am a heavenly official who appears only once in five hundred years!
I am just a little guy in the field of numerology. At most, I can rely on the prophetic advantage of the time traveler to be able to tell the truth, which is far worse than others!
Now that I have the opportunity, I naturally want to ask for advice!
"There is nothing secret or not. If Mr. Xu wants to know, Chunfeng knows everything and will tell you."
Li Chunfeng said with a smile,
"Did Mr. Xu ever hear that Fuxi observed the sky and the earth and deduced the innate gossip?"
"On this basis, King Wen wrote the Book of Changes. At the same time, there were also works on the Book of Changes such as Lianshan and Guizang."
Xu Fenglei nodded.
Of course he knows these basic common sense,
"Therefore, celestial phenomena are the foundation of Yi Xue, and can even be said to be the origin."
Li Chunfeng said in a deep voice,
"But with the passage of time, since Zhou Dynasty, more and more works about Yi Shu have appeared, and they have become more and more complicated."
"The origin is becoming more and more blurred."
"Therefore, compared to the methods of divination, prediction, and inference derived from various sources, I prefer observing the sky. Because it is closer to the origin and naturally more accurate."
Xu Fenglei suddenly realized.
“That’s it, be taught, be taught.”
He hurriedly asked for advice,
"How do you view the celestial phenomena? How do you connect the celestial phenomena with human affairs?"
Now he looks like a poor student who is receiving extra lessons...
"Personal affairs are small matters and have few changes, so ordinary judgment methods can be used to deduce them; state affairs are extremely complex and involve many things, so it is necessary to use celestial phenomena judgment methods."
Li Chunfeng patiently explained,
"Of course, some important figures came into being, and their fates will naturally be linked to the celestial phenomena."
"For example, Your Majesty, for example, Mr. Xu, are all important figures in the Tang Dynasty, and there must be corresponding stars. These are called emperor stars, Xiang stars, general stars, etc."
Xu Fenglei raised his eyebrows.
"I also have corresponding stars?"
He suddenly became interested and asked.
This is interesting. He is a time traveler. Normally speaking, he should not belong to this time and space.
If there is a corresponding star, that means...it is inevitable that he will come to Datang?
Thinking of this, Xu Fenglei felt a chill in his heart for no reason, making him shiver.
"Of course there is."
Li Chunfeng smiled and said,
"Xu Gong's sudden rise and his momentum are like a rainbow, which should be a great help to the country and the country."
Xu Fenglei raised his eyes and glanced at Li Chunfeng. Seeing his deep gaze, he suddenly felt uncomfortable as if his underwear had been seen through. He quickly changed the subject and said:
"Haha, I'll lend you some good words, I'll lend you some good words."
"Brother Chunfeng, please tell me the specific steps of this celestial phenomenon judgment method? I'm quite interested!"
Li Chunfeng withdrew his gaze and nodded.
"good."
He said in a deep voice,
"To tell the truth, we must first start with the fundamentals of Yi. There are three fundamentals."
"It's not easy, it's easy, it's easy." Xu Fenglei blurted out.
These are all the foundations of foundations.
"right."
Li Chunfeng nodded and said,
"The so-called difficulty is that the sun, moon and stars rotate around the sky and remain unchanged forever. The sky seen by the ancients thousands of years ago and Fuxi thousands of years ago is the same sky we see now. God, this is not easy."
Xu Fenglei nodded repeatedly.
"Today's people don't know the moon in ancient times. Today's moon once illuminated the ancients."
He read,
"The sun, moon and stars have never changed."
Li Chunfeng raised his eyebrows.
"Good poem, good sentence."
He praised,
"Xu Gong is also a great writer and poet."
Xu Fenglei smiled.
Literary man? Just a poetry thief.
To tell you the truth, I also know when the moon on the river shines on people for the first time, and who on the bank of the river sees the moon for the first time. Life is endless from generation to generation, and Jiang Yue looks the same every year. They all have similar meanings, but I am embarrassed to show them off again.
"The sun, moon and stars are not easy, but they will change."
Li Chunfeng said again,
"The moon waxes and wanes, the stars wax and wane, and the stars wax and wane. These are their changes."
"The frame is not easy, but the inside of the frame is easy. This is why there are elephants. Just like within a picture frame, you can draw cats, tigers, dragons, and snakes. The celestial phenomena are like cats, tigers, and dragons in the picture frame. . Like a snake, changing at any time, these are all elephants."
"And with the elephant, you can infer from the elephant, which is easy..."
"..."
Xu Fenglei heard it as if he was enlightened, and he was intoxicated.
This Li Chunfeng really didn't hide his secrets at all and directly expressed the most fundamental essence!
In just half an hour, Xu Fenglei felt that he had made rapid progress!
"Brother Chunfeng, please take a rest first. I have to find a notebook to write down my thoughts..."
Xu Fenglei took out a small notebook from his arms, found a pen from the carriage, and said with concentration,
"Wait for me for a while, and then continue to tell me..."
Swish, swish, swish.
At this moment, he was so full of thoughts that he felt like writing down his thoughts in a book. It was even more refreshing than taking a shower!
"Okay, Mr. Xu, just take your time."
Li Chunfeng smiled lightly and said,
"Please lend me a piece of paper. It's a long journey, and I just happen to be studying the next problem that has been bothering me for a long time."
Crack.
"Take it!" Xu Fenglei tore off two pieces of paper and handed them over together with a pen.
"Thank you Mr. Xu."
Li Chunfeng took the pen and paper, sat opposite Xu Fenglei, and after making a few random strokes, he fell into deep thought.
The carriage was bumpy, but the two of them felt nothing. They were both immersed in their own world...
After a while.
"call--"
Xu Fenglei put down his pen and said with a happy face,
"Listening to you today is better than ten years of studying!"
"The celestial phenomena are indeed mysterious. I have just gotten a glimpse of them!"
"Hahaha……"
He looked at the experience in his hand and laughed heartily.
Turning around, I saw Li Chunfeng biting the end of his pen, frowning, as if he was deep in thought.
This scene made Xu Fenglei a little surprised.
Even a genius like Li Chunfeng would have something he couldn't figure out?
He stood up, moved to Li Chunfeng's side, and looked at his piece of paper.
On the paper, a cylinder and half a round cover were clearly drawn, and on the far right, a ball was roughly drawn.
"Brother Chunfeng, what are you busy with?"
Xu Fenglei said casually,
"Are you calculating?"
"Yes." Li Chunfeng took a breath, shook his head and sighed, "I am measuring the size of the ball. According to the method proposed by Zu Xun, I only need to find the size of the square cover, and then I can get the size of the ball, because the height is equal Two objects of the same height with the same cross-section must have the same size, but why..."
Xu Fenglei almost fainted.
"What about cross-sections at high altitudes? It's so confusing that I can't understand it."
He said,
"Isn't it just asking for the volume of the sphere? This is easy to do."
Li Chunfeng raised his head suddenly.
"Guild Xu's calculation?"
He continued,
"Please enlighten me!"
Xu Fenglei was a little confused by his sudden appearance, but when he saw the desire in the other person's eyes, he also reacted.
This Li Chunfeng is a master of Yi Studies and a mathematician who loves mathematics!
The essence of Yi learning is elephants and numbers. It is impossible for people who are proficient in Yi theory not to be interested in mathematics.
"Here, give me the pen."
Xu Fenglei took Li Chunfeng's pen and said,
"To calculate the volume of a sphere, there is actually a formula."
"This formula is - V=4/3πR cubed."
Li Chunfeng was stunned; "..."
"What is V? What is π? What is R? What are the symbols of 3 and 4?"
He was completely confused.
Xu Fenglei wrote so quickly that he couldn't understand a single word!
"Uh... these are all symbols of reference."
Xu Fenglei held his forehead. This time it was his turn to explain patiently.
"V means volume."
"3 and 4 are relatively simple numbers, representing three and four. The others are 0, 1, 2, 5, 6, 7, 8, and 9. I have taught these to the prince and them, and I will teach them to you now. , this number will be much simpler, otherwise it would be too troublesome and too abstract to use Chinese characters, which is not conducive to our mathematical research."
When Li Chunfeng saw this series of numbers, his eyes shone brightly.
"Using simple symbols to replace Hanzi one, two and three? This is indeed a pioneering work!"
He said in surprise,
"Did you invent this, Mr. Xu?"
"Uh... I also learned it. The people who invented it were Tianzhu people." Xu Fenglei scratched his head and did not shamelessly take the credit on himself. He smiled and said, "There are many religions in Tianzhu, including Buddhism and Tianzhu Sect. Various sects often debate scriptures among themselves. In order to overwhelm each other, they need to use huge numbers to show the power of their own gods, so...their number skills are also very developed."
Arabic numerals were invented by Indians...well, I remember correctly.
"I see."
Li Chunfeng clicked his tongue in surprise and said,
"It must be a magical country to be able to create such numbers."
"If you have the opportunity, you should communicate with the people of Tianzhu."
When Xu Fenglei heard this, he couldn't help but smile secretly.
A magical country? Then Ah San’s country must be magical!
It's just that there's nothing you can't think of that Third Brother can't do.
"What about this π?"
Li Chunfeng looked at the paper again, pointed at the symbol and said,
"What do you mean?"
"This is the meaning of pi, you must know it." Xu Fenglei said, "Liu Hui once used the circle cutting method to get the pi to 3.1416, and Zu Chongzhi based on Liu Hui's work, he got the pi to 3. 1415926! Leading the entire world!”
Li Chunfeng nodded repeatedly.
"I know this. It's recorded in "Nine Chapters".
He praised and sighed,
"Liu Hui and Zu Chongzhi are both extraordinary people! It's a pity...numerology has never been taken seriously."
"I have always felt that numeracy is actually very important. It is closely related to everything in this world. Well..."
Xu Fenglei raised his eyes slightly.
"Your feeling is right."
He said seriously,
"Mathematics is the foundation of all science and engineering."
"Only when mathematics develops, can other things develop with it, so I have plans to vigorously promote and develop mathematics in Datang!"
"In this way, the country can progress!"
When Li Chunfeng heard this, he immediately stood in awe.
"Xu Gong is far-sighted!"
He gave a thumbs up and said,
"If this can really happen, it will be a great blessing for the Tang Dynasty!"
Xu Fenglei grinned.
"When the time comes, I'll need your help."
He patted Li Chunfeng on the shoulder and said,
"My Chang'an Academy offers mathematics courses, and there is also a mathematics academy next to it."
"The choice of dean is decided by you! Brother Chunfeng."
Li Chunfeng: "?!"
"I...how can I be so virtuous and capable?" He looked shocked and was about to refuse, but his hand was held down by Xu Fenglei. "Datang, you are the only one who is a well-deserved mathematician!"
Xu Fenglei said seriously,
"The position of dean of mathematics belongs to you!"
"Just think of it as a favor, and stop refusing!"
(End of chapter)
