Chapter 141 The worlds most powerful numeracy team in the 11th century! (6.6k)
"Oh? Mr. Yang Huai?"
in the house.
I heard this name given by Mr. Xie.
Lao Jia, who was studying ink, suddenly put down the ink stick, raised his head, and asked Lao Su
"Brother Zirong, could Mr. Yang Huai be the Han Gonglian and Han Wenyi who calculated the wheel scales in Yuanyou's Armillary Sphere?"
"Yes, it is this person."
Lao Su nodded, confirming what he said.
At the same time, there was a hint of apology on his face, and he explained
"The lens matter is of great importance, so I shamelessly invited a few masters of calculation to come and help. I also ask Mr. Tongyu not to be offended."
Lao Jia waved his hands indifferently and said
"Brother Zirong, it's a trivial matter, why should you blame it?
It just so happens that Wen Yi and I haven't seen each other for several years, so wouldn't it be nice to get together with him at your house and save a few bucks for a meal with you?"
What Lao Jia said was quite calm, and it was obvious that he really didn't think there was anything wrong with Lao Su's actions.
After all, he was a former Zuoban official, and after being transferred to Daizhou, he also participated in several engineering designs organized by the state government.
So he knew very well...
In the face of some practical projects, a person's ability is quite limited, and the government will not just put eggs in one basket.
At most, the priority is given in terms of status. In fact, the final calculation result still has priority.
Although he still doesn't know what kind of big thing Lao Su or Xu Yun are going to use the lens principle to do this time.
But it is not difficult to judge just from the formulas Xu Yun wrote previously. This is undoubtedly a project that requires a lot of tools, people, and computing power.
Therefore, not only was he not disgusted with the arrival of Han Gonglian and others, he even welcomed them.
after awhile.
Under the leadership of Mr. Xie Duguan.
Six men of different heights, sizes, fatness, and ages walked in outside the house.
"Mr. Tongyu, come on, I will introduce you to you."
After six people entered the house, Lao Su pointed at a few people and said
"This is An Shisong, also known as Yingtong,&bsp&bsphe is currently Zuo Lang, a writer in the Ministry of Civil Affairs, and is also known as Mr. Dongping."
An Shisong is a little old man in his fifties, a little thinner than Lao Jia, and has a goatee.
But what attracts the most attention is not his beard, but the fact that he is wearing a black mandarin jacket even in summer.
After Lao Su finished his introduction, this person bowed to Lao Jia very respectfully.
"Junior An Shisong,&bsp&bspI have met Mr. Tongyu."
Although Lao Jia seems to have a bad temper, he is still relatively polite when facing his colleagues. After all, mathematicians these days are as rare as genuine readers in later generations. I saw him returning the same greeting.
"Mr. Dongping, you are polite."
Seeing this, Lao Su continued to introduce
"This is Xiong Huanzhi"
"This is Song Ke"
"This is Lin Huainan"
When he came to the fifth young man,&bsp&bspLao Su emphasized a few more words
"This is Liu Yi, &bsp&bsp the name is Leyi,&bsp&bspI have no ID for the time being,&bsp&bspI am the youngest arithmetic instructor in Jigu Academy, and I can look forward to the future."
I heard the name Liu Yi.
Lao Jia had no reaction,&bsp&bspXu Yun couldn't help but look at this person a few more times.
Liu Yi.
This is one of the mathematicians who was mentioned during the selection process and whose name has been slightly left in the history books.
However, there are not many records about Liu Yi in history books, and they only mention that he was a figure in the late Northern Song Dynasty.
About the third year of Yuanfeng, he completed a work "On Ancient Roots" and proposed a method for finding the roots of quadratic equations.
Judging from the fact that Yang Hui later included him in "Shortcut Methods for Multiplication and Division of Field Analogy", his ability should be a little stronger than that of ordinary mathematicians.
After all, the difference between Yang Hui and the Northern Song Dynasty is only more than a hundred years, which is equivalent to modern research on the characters during the Opium War. In theory, there won't be too many mistakes or omissions.
After introducing Liu Yi.
Lao Su pointed to the fat man on the far right who looked quite tall.
"Mr. Tongyu,&bsp&bspI don't need to introduce this person."
After hearing this, Lao Jia stepped forward, looked at this person slightly, and said with some emotion
"Wenyi, we haven't seen each other for twenty years, right?"
The fat man, Han Gonglian, happily raised his hand to him.
"It's been twenty-three years. I haven't seen you for many years, sir, but his style remains the same."
Lao Jia gave him a simple greeting, and then asked curiously
"Wenyi, when I first met you, it seemed like you didn't even have enough to eat, and you had to do small jobs to make ends meet after your break.
Why haven't I seen you in these years, but you have gained a lot of weight?
And let me take a look at these clothes, are they from Tianxinxuan?"
Tianxinxuan.
Just by hearing the name, you can tell that this store has an extraordinary background.
After all, in ancient China, it was easy to name people, but there were not many shops with the word "天" in their shop names.
Not to mention that under the feet of an emperor like Bianjing, the people behind such shops are at least ordinary relatives of the emperor.
Looking at the surprised old Jia, Han Gonglian still looked cheerful.
"Mr. Tongyu, you don't know something. In the seventh year of Yuanyou, my junior Boju won 700 yuan, bought several acres of land, and harvested some grain in the autumn.
At the beginning of the new year, the Qingtang Dynasty regained control, and the price of food soared, making me rich all of a sudden."
Lao Jia ad Xu Yun
""
have to.
Another little mystery has been solved.
Anyone who knows the history of the Song Dynasty knows that the Song Dynasty was a period when the gambling industry was very, very developed.
The more common ones are throwing money and Guan Pu, and the more advanced ones are Cuju and horse racing.
What's even more outrageous is that you dare to bet on which concubine the emperor will favor today - sometimes the emperor is still the emperor in the background. Can you believe it?
Basically, except for the ownership of the throne, anything can be a subject of gambling.
So, a very magical thing happened
Before the year of the Northern Song Dynasty, the names of European emperors who won the big prize every year would be recorded.
The seventh year of Yuanyou, that is, the year AD.
This chapter is not over yet, please click on the next page to continue reading! There was a European emperor in Bianjing who won more than 700 coins, and his registered name was Han Gonglian.
Therefore, some people in the mathematical community of later generations firmly believe that Han Gonglian is the mathematician, and the two are the same person.
After all, the name Han Gonglian can be said to be quite rare, and the probability of coincidence is not high.
However, for other people, they denied it on the grounds that they did not have accurate information.
Although it was for the sake of so-called rigor, in fact, Xu Yun was more inclined to express the anger from non-chiefs.
His gaze returned to its original position.
After introducing each other, Xu Yun briefly repeated the content of the question.
After a while.
Several mathematicians, who were at the very end of the first-class ranks of the contemporary era, officially began their calculations.
Take a look at this configuration
There are three mathematicians recorded in history books: Jia Xian, Han Gonglian, and Liu Yi.
Although the remaining three people are not well-known, it is not difficult to tell from simple conversations that these people have quite good mathematical literacy.
You can even say this.
In this current era, in AD.
These six people are the strongest calculation team in the world!
True limited edition.
In fact, from the perspective of future generations.
The question raised by Xu Yun is actually not very difficult.
This is a threshold for Fresnel approximation. Strictly speaking, it is a type of geometric optics, and the solutions can be said to be diverse.
The simplest one is, of course, the geometric optical mapping method.
However, simplicity is simplicity, and the information that the drawing method can give is very limited. It can only give the imaging properties of a lens with a known focal length.
It cannot relate the focal length to the properties of the lens itself, and is the simplest method in mathematics.
Going further, you can use the basic principle of geometric optics, which is Fermat's principle.
Using Fermat's principle, we can give the influence of lens shape and material on imaging in the case of geometric optics approximation, which is mathematically more troublesome than the previous one.
The third stage is the Huygens-Fresnel principle, which is the scalar wave diffraction theory of light.
Using this theory to analyze imaging problems can also give more information - such as the impact of lens aperture, etc. This is why the larger the aperture of an astronomical telescope, the better.
The more rigorous one is naturally Maxwell's equations, which solve the wave equation under given boundary conditions.
But in the end this method was too troublesome.
Give the most intuitive example
Have you seen the blackboards in university lecture halls in later generations?
If you use the fourth method, you will need at least six such blackboards - and you may not be able to calculate the analytical solution.
So unless the previous approximation theory does not apply, generally no one does this.
Because of this, Xu Yun was planning to take the third approach.
Although the second method is much more complicated in theoretical mathematics, calculating a lens requires two double integrals.
But first of all, its practical effect is the best. When the theoretical system lags behind seriously, the importance of practical effect goes without saying.
Secondly
Lao Jia, he is the real inventor of Yang Hui Triangle.
Yang Hui's triangle is one of the most suitable ancient tools for solving integrals, so if Lao Jia wants to take that step, it actually has a lot of practicality in theory.
Of course.
Taking a step here does not refer to the invention of calculus, but a temporary application of ideas.
After all, it is impossible to tinker with calculus by just relying on Yang Hui's triangle. It requires a certain amount of mathematical accumulation. More importantly, this kind of mathematical accumulation does not refer to personal accumulation, but to the accumulation of the entire mathematical community.
His gaze returned to its original position.
After suddenly discovering a new field, Lao Jia, Han Gonglian and others showed great interest.
After all, this kind of team public relations is too rare these days.
I saw only a few people discussing ideas or directly taking data measurements.
For example, a very primitive tool appeared in Liu Yi's hands.
Curved ruler.
When talking about the curved ruler, we have to talk about another concept first.
angle.
In their long scientific and technological practice, the ancient Chinese actually formed the concept of abstract angle very early - the word "zao" here can even be traced back to three or four thousand years ago.
But unfortunately.
They did not develop based on this and establish corresponding precise measurement of angles - note, it is precise measurement.
This situation lasted until the Ming Dynasty, when the concept of perspective brought by missionary Matteo Ricci broke this situation.
"Elements of Geometry", which he co-translated with Xu Guangqi, gave a general definition of angles, described the classification and various situations of angles, how to express angles, and how to compare angles with angles.
And before that.
There are generally only two rough ways of measuring angles in China.
The first one is very simple, it is divided only according to obtuse angles and acute angles, and the words used are arrogant and hook.
Arrogant means blunt, hook means sharp.
The middle moment of the hook is a right angle.
The second one is more complicated.
It is somewhat similar to measuring orientation
Using the twelve earthly branches of Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai, we add A, B, B, D, Geng, Xin, and Ren among the ten thousand.
, Gui and Qian, Kun, Gen and Xun in Bagua form twenty-four specific names to express angles.
In other words, each name is about fifteen degrees.
But it’s very strange that it can even be said to be an unsolved mystery.
The ancient Chinese sages actually knew this concept
When our ancestors conducted astronomical observations, they used a graduation system that divided the circumference of a celestial body into degrees. This is actually infinitely close to the degree method.
What a pity.
In other situations other than astronomy when measuring angles, our ancestors did not use this system at all.
therefore.
This indexing method cannot play any role in the establishment of Chinese angle measurement.
So in some marketing slogans you will see the statement "China is actually the first nation to define degrees", which uses the celestial body graduation system - unfortunately, the second half of the sentence is fine, but
The entire sentence is wrong.
Or if we give a modern example, we should be able to better understand where the blame lies.
This is probably similar to the century where a scientist correctly analyzed the concept of high-dimensional space, but he did not apply this concept to scientific research. Instead, he used it to create certain basic settings for novels and movies. But this set
The setting has been used in many movies, so almost everyone on the planet has heard of it.
This chapter is not finished yet, please click on the next page to continue reading the exciting content! But in the scientific research community, everyone seems to have ignored this setting and only delved into various inefficient judgments.
This is indeed a strange situation
Because the circumference of celestial bodies is also determined by the method of arranging circles, it is impossible for the ancestors to have thought of this with the wisdom of our ancestors.
Therefore, in some civil circles of later generations, some people put forward some nagging conjectures.
For example, the cognition of ancient ancestors has been blocked, the fragments of relevant angles have been removed, etc.
There are even some people who advocate this, which is quite bizarre.
The topic returns to its original place.
No matter which method the ancestors used to divide the angle, after dividing the angle, another step must be carried out
Measurement.
It is precisely because of this that the curved ruler appeared.
This is a right-angled ruler with one side long and one short, and there are also special arc-curved rulers.
In some places, this thing is also called a square, commonly known as a turning ruler.
I only see this moment.
Liu Yizheng is holding a ruler and measuring the angle of the lens
"The middle part of the clown is carved with the Wu corner, the bottom part is carved with the Hai corner, and the top part is carved with the Yin corner."
Carve up, carve down, carve in.
This should be a classification that Liu Yi came up with himself, which is another refinement compared to the angle division.
But even so.
It only achieves the accuracy of points, but the separation is a full five times worse.
There is only one way to correct the five-fold difference
By constantly adjusting the lens angle, a large amount of corresponding information is collected, and the most accurate answer is screened out step by step.
When Xu Yun saw this, a trace of unbearability flashed in his eyes.
To know.
This is the most basic link in the entire process.
Later generations only need three to five surveying and mapping data to lock a certain interval, but Lao Jia may need more than a hundred sets.
After all, there is a square root process, which means that the amount of calculation has increased many times.
Then Xu Yun opened his mouth, wanting to tell Liu Yi and Lao Jia about the concept of angles.
But after much hesitation, he gave up the idea.
After all, according to his original intention, he really couldn't participate too much in this convex lens derivation.
If I told Lao Jia the concept of angle.
What about the incidence angle and exit angle?
What about the waist radius?
What about screen function sampling?
What about the Fourier transform?
These are all connected concepts.
Although Xu Yun only spoke a few words, in order to break through these barriers, the sages (both Chinese and foreign) paid a huge price.
Therefore, no matter what, this hole must not be opened.
Just like women's clothing, there are only zero and countless openings.
You know, Xu Yun can only stay in this world for a short time, only more than a year.
True.
He can make some big news during this period of time, which will shock these ancient people.
But if only one person instills finished knowledge, without telling the deeper root causes, without establishing a system with self-thinking feedback.
Then after Xu Yun leaves, everything will only become a "black technology" that only knows the outside but doesn't know the inside.
The fate of this kind of rootless Ping was vividly reflected in the Chinese Jinyuan football in later generations.
When capital pours in, the capital introduces well-known foreign players and keeps the stars who have studied abroad or are expected to study abroad in China.
Overdrawing their youth and not cultivating new players, the league has been the same for a while, and they have achieved good results in the AFC Champions League and even the Club World Cup.
But when the gold dollar recedes.
Everything was returned to its original state, even worse than before.
Now the national football fans can look forward to losing to Myanmar.
This is what Xu Yun is worried about
Knowing it but not knowing why is a very dangerous situation.
Therefore, Xu Yun would rather move slower and bring less changes to the world.
I also hope to create a vibrant soil for them.
The first step in reclaiming land.
It fell on Lao Jia, Han Gonglian, Liu Yi and others.
Think of this.
Xu Yun couldn't help but take a deep breath and said to Xu Yun