PS: Ask for a monthly ticket, ask for an evaluation ticket, ask for a recommendation ticket, ask for a qiē ticket!

Just as Xu Hongzu was about to buy a boat and go west to travel the Li River, Mr. Basten and his friends arrived in Hue, and soon received an invitation from Li Shouhan to invite this group of guests from Europe to the mansion for a banquet.

"Are we really going to see the monarch of the East?"

While arranging his embroidered silk robe, Descartes was still hesitating, or rather holding a shelf.

According to Mr. Basten, he was not only a great and powerful monarch, but also an accomplished scientist and inventor and designer. A lot of what we see is made possible by him. ”

Frank was very relaxed, and was able to have a dinner party in his palace when he was invited by a local monarch just after arriving in the mysterious East, which was also a great asset when he bragged to others after returning to Europe.

"What about you?"

Monsieur Descartes turned his gaze to Mr. Galileo, our old gentleman was no longer the watch who had just escaped capture, his hair and beard were well groomed, and he even wore some perfume, and he looked more like one of the unscrupulous and unscrupulous merchants and playboys of Pisa.

Pisan people in Italy have always been known for their cunning and untrustworthy business, and as Galileo, who has lived in Pisa for many years, is naturally infected with some glitz and glitz in the city.

"This, of course, is going to go, after all, he is the ruler of this place, and he will be my protector."

The group was led by Mr. Van Basten. Follow the two deacons of the General's Mansion to the General's Mansion.

After looking at the scenery in the street markets along the way, especially after entering the general's palace, Descartes couldn't help but feel it, "It seems that these eastern monarchs, whether they are the chieftains of the Arabs, the governors of Turkey, or the monarchs of the Sultan, the Ming Kingdom." It's all the same. Pursue a life of luxury. ”

"Don't the princes, dukes, and counts of Europe pursue such a life?" Van Basten sneered.

"Of course, the aristocrats of Europe also wanted such a life, but their gold coins. It's all become these things. ”

Frank as a mathematician and publisher. He touched Mr. Basten with his arm. He motioned to see the soldiers on patrol in the palace.

The soldiers wore eight-petal hats and iron-tipped helmets on their heads, cuirass on their bodies, and desperate knives at their waists. The firecrackle on his back makes people feel a sense of déjà vu. They had seen these things in France and in the Netherlands.

"Come to think of it, their gold coins are now resting peacefully in your treasury."

"No, my gold coins have become goods, in his warehouse." Mr. Basten was half wry, half ostentatiously complaining to his three companions.

I bypassed the cloister and passed through a moon gate, and there was a clump of bamboo in front of me. Xiuzhu acts as a screen for the moon gate, and people walk by the bamboo forest, and the breeze blowing out of the small bamboo forest makes people forget the summer heat for a while.

At the edge of the pond, the two deacons stopped, "The lord is waiting for you in the pond pavilion in front, and you can go over by yourself." ”

Shouhan was learning the spirit of Jiang Taigong in the pavilion by the pond with a fishing rod in his hand, but he didn't think he had the skills of Taigong, so he still used a fishing rod with a hook and bait to fish.

However, even with these, he is afraid that he will not be able to catch fish today.

There was a small tail beside him, shaking him incessantly, making the fishing rod in his hand keep moving, which stupid fish would come to eat the bait?

"Daddy! Dad! It turned out to be Erya, and she kept shaking Shouhan's right hand and arm, "Tell me quickly, what should I do with this arithmetic problem?" Tomorrow Mr. will collect his homework! ”

As the eldest daughter of Shouhan, he deliberately did not let his baby daughter go to school at home, but sent her to a school in Hue City, "The stage of children going to school is also a process of socialization of children. It's also good for her to know what the outside world is like in the academy and make a few friends. This is what Shouhan said to Yan Mei'er and Erya's mother when he fulfilled Yan Mei'er's wish to have another child. Yan Mei'er doesn't understand what socialization is, but she understands what it's like to know what it's like outside and make a few friends.

As a result, Erya's homework fell in front of Shouhan.

Putting down the fishing rod in his hand, Shouhan smiled bitterly and picked up Erya's homework book. Luckily, it's just a few simple arithmetic problems. However, it is obvious that Erya is a mess.

"Erya, let me ask you, how do you memorize the multiplication formula?"

Erya pursed her mouth, "I'm carrying it well!" The whole class is what I memorized! If you don't believe it, Daddy, I'll recite it to you, one by one, one by two, and two by two...... Ninety-nine-eighty-one! ”

"Then look at this topic, how did it become forty-nine thirty-seven?"

While speaking, Shouhan took the pencil in his daughter's hand and listed a vertical type on the scratch paper, "Erya, you see, if you are afraid of making mistakes in your oral calculations, you can calculate it vertically, so that the multiplier and the multiplier will be clear at a glance, as long as there are no errors in your basic formulas and addition, there will be basically no mistakes." ”

The conversation between the father and daughter in the pavilion was whispered by the interpreter around Basten to the four people who came to the banquet, and Mr. Basten knew his nobleman's specialty, and he did not object to this, but the three, listening to the interpreter's translation, could not help but be a little surprised.

"Vertical calculations?"

For these three giants of the seventeenth century, who were almost at the forefront of mathematics, vertical calculations were not new enough to surprise them. However, to their surprise, a little girl who seemed to be only seven or eight years old, under the guidance of her father, was able to skillfully use vertical calculations and come up with answers.

"A ruler of the East, who was able to use mathematics skillfully, was able to tell his daughter about knowledge. I was amazed. ”

Galileo rubbed his old eyes and sighed.

"Mr. van Basten, I am now beginning to believe the relationship between logarithms and exponents that you have relayed to me about the ruler."

Descartes also whispered quietly in Mr. van Basten's ear.

The next thing made Li Shouhan feel like he was getting a big axe in front of Lu Ban, and the axe was still stolen from Lu Ban, this feeling was very cool!

First, he gave Galileo a pair of glasses, so that his dizzy old eyes could see the world again, of course. Glasses that have not undergone accurate refraction can only be said to be better than what they are looking at.

Here's what's next. It was to make Galileo's glasses almost shattered!

"Mr. Galileo, I have heard my friend Mr. Basten say that your theory, and frankly, I think your theory is a fallacy. But it's also a fallacy. ”

"Your theory is that the sun is the center of the universe. This shatters the fallacy of geocentrism. I have found a basis for many natural phenomena that can provide reasonable explanations, but I have to tell you. According to my research and findings, heliocentrism is also very wrong, and the sun is not the center of the universe, in fact, the universe has no center! ”

In a word, several people led by Galileo were all surprised!

The heliocentric theory is the most demonic theory of this era, and this monarch who doesn't know the depth actually says that the heliocentric theory is also insufficient, and the universe has no center?

In order to prove his statement, Shouhan whispered a few words in Erya's ear, and Erya immediately jumped away, "I asked my daughter to fetch my polished lenses for you, you can assemble them into binoculars according to your own habits, and you can observe them yourself at night." See if you can find the center of the universe. ”

When the second girl jumped and led two servants to the water pavilion with a telescope and several parts that could assemble the telescope: lenses, lenses, and lens barrels, they found that Descartes' glasses were also shattered.

"I've been thinking about a question over and over again: geometry is intuitive, while algebraic equations are more abstract, can we combine geometry with algebraic equations, that is, can we use geometric figures to represent equations? The key to this is how to hook the points that make up the geometry to each set of "numbers" that satisfy the equation. Because my fleet has been traveling to and from various places for maritime trade, if there is such a method, then the depiction of the nautical chart, the calculation of the voyage, the distance of the voyage, and the arrangement of the shipping schedule will be greatly affected. For this reason, I have been thinking of ways to connect the "point" such as the ship with the "number" such as the route. ”

Descartes didn't care about the exquisite dim sum on the table, he glanced at Van Basten who was tearing a piece of steamed pork ribs there with some disgust, and came back to his senses and asked Li Shouhan, "Have you found such a method?" ”

"That day, my builders repaired my house and invited me to see it. In a corner of the construction site that had been completed, a spider in the corner of the roof, pulling its silk, hung down and landed in the corner of the wall, where it was going to build its web, and although it was quickly destroyed by the carpenters of the construction plant, it soon fell down again. Thanks to this spider, if we think of the spider as a dot that can move up, down, left and right in the room, can we determine each position of the spider with a set of numbers? Moreover, it happened to fall in the corner of the wall in the room, where there are three lines where two walls intersect with the ground, if you take the corner of the wall on the ground as the starting point, and take the three lines handed over as the three number lines, then the position of any point in the space can be used to find the three numbers in order on these three number lines. Conversely, a set of three ordered numbers can be given in space to find a point P to correspond to, and in the same way, a set of numbers (x, y) can represent a point on a plane, and a point on a plane can be represented by a set of two ordered numbers. ”

On the one hand, Shouhan also used his right thumb, middle finger, and ring finger to demonstrate, and the three fingers represent three directions, so that different numbers jù point to the same point.

"Daddy."

When Erya was present with outsiders, she showed full education and politeness, put the high-powered telescope that her father had given her to bring in front of her father, and then nodded with a few guests very well, and stood behind her father.

"Daughter, I want to discuss my knowledge with these gentlemen, you go to your study!"

"In order to know any point of the axes. Distance from the origin. Suppose, we can characterize the values on the axes. Then, starting from the origin, in the direction of the axis, the value is depicted on the axis every other unit length. This value is the number of depictions, and it is also the positive integer distance from the origin; Similarly, with the direction of the axis pointing at the back, we can also characterize the negative integer distance from the origin. The value of the x-axis depiction is called the x-coordinate, also known as the abscissa. The value of the y-axis characterization is called the y-coordinate. Also known as ordinates. Although, here, both the coordinates are integers that correspond to the specific points of the axes. In proportion. We can generalize to every point of the real coordinates and their corresponding axes. These two coordinates are the Cartesian coordinates of the Cartesian coordinate system. ”

In our plane. 1637. Descartes published his magnum opus, Methodology. This book, which specializes in the study and discussion of Western approaches to scholarship, provides many correct insights and good ideas for later Western academic developments. There is a great contribution. In the appendix to the Methodology, he added another book, Geometry. The official announcement of the establishment of the Cartesian coordinate system in the field of historiography appears in the book Geometry. Descartes' study of coordinate systems, which combined algebra with Archimedes' geometry, was a key guiding force for his later contributions to analytic geometry, calculus, and cartography.

But, unfortunately, it was here that he met Li Shouhan.

"So, sir, has your theory found a verifiable basis?"

Descartes put away his arrogance, and he began to believe that the Orient was a mysterious place, that he was hundreds of years ahead of Europe, that his people were polite and cultured, that the streets were clean, that the army was strong, and that business dealings were faithful.

These legends in Europe have been gradually verified by Descartes along the way, but he is still very confident in his academic research, thinking that in this mysterious East, no one will understand the relationship between algebra and geometry better than himself.

However, this self-confidence was ruthlessly shattered.

"OMG!"

Galileo on the side fell pale on the chair, and the kind Mr. Basten hurriedly stepped forward to support him, "Professor Galileo, are you feeling unwell?" ”

"Could it be that Bruno and I are both wrong? Is it true that as His Highness said, there is no center in the universe? ”

Galileo had just used Li Shouhan's own astronomical telescope to peek into the vast universe, trying to find a basis that could overturn Li Shouhan's absurd theory. However, looking into the sky with the telescope that the Shouhan himself "polished", it seemed that there were many more stars in the sky today than in the past.

"This telescope of mine has a lower magnification, and the lenses you have are much higher than mine, and I am sure that you will disprove your theory. Besides, though you may live with me in peace, I trust that your so-called Inquisition will not come to my land to trouble you. You can also conduct your research here, and by the way, come up with several new optical instruments to support your research and improve your life. ”

A table of dinner was set up in the water pavilion, and the sumptuous feast made the three European guests a little dizzy, and they couldn't stop asking Mr. Van Basten what this dish was and what the other was.

Mr. Basten, whose eyes were full of delicacies, but who couldn't let go of the munching because of the disturbance of these three turtles, naturally didn't give them a good voice, "Just eat, can an oriental monarch give you something bad?" ”

The eyes of the three turtles choked in one sentence turned white, but when you think about it, the table in front of you looks like a delicious delicacy, and those princes who came to Europe have never seen it, so why bother with what it is, just eat it until it tastes good in your mouth!

"Your Highness, I wonder if I can eat such a delicacy every day in your territory?"

Although not as famous as Galileo and Descartes, Frank, as a mathematician and businessman, was keenly aware of the value of his own affairs to Shouhan, a mystical ruler of the East.

"He was a monarch, how could he have so much time to study academic issues? And we, just like us, can use our research in exchange for the cost of living here. ”

This is the result of a quiet discussion between Frank and Descartes when they go to find the place of reincarnation.

So Frank began to play a role similar to that of an agent. Begin to bargain for yourself and your friends to be able to sell for a good price.

"In the general's territory, the price of goods is very low, as long as you have gold coins in your hands, what kind of food you want to eat will be easier than rubbing your hands."

Damn it! Listening to Van Basten's words, Descartes and Frank cursed in their hearts almost at the same time. Of the three, one of them is a criminal who has just escaped from the iron claws of the Templars, and has been hiding in the cargo hold for many days, presumably without much money, while the other two are also not so rich, how can they maintain such a life?

"We want to do our own research here, and we would be honored if you could generously support our academic research!"

In the end, Galileo was older and had much more experience than Descartes and others, so he simply bypassed those links and directly asked to work for Li Shouhan. And also to carry out your own academic research activities! (To be continued......)