CHAPTER XXV

Wei Gonggong couldn't count on it, they just tried to fool Zhengde, and they didn't think about how to make an accurate map at all.

Zhu Houhuang had no choice but to come by himself.

It was only when he collected all the tips on ancient Chinese cartography that he finally discovered that cosmology was too important for the drawing of maps.

Ancient China was ruled by the heavens and the earth for a long time, so much so that the map drawn was always a plan.

You may say, isn't the map you're looking at a floor plan?

False, the earth is a sphere, is the surface of the sphere a plane? The first problem Zhu Houhuang faced was how to draw a sphere on a flat surface.

In fact, there is a gap between the map that everyone sees now and the real one, Zhu Houhuang vaguely remembers that this is the so-called projection method, but how to project and how to calculate it, Zhu Houhuang has to admit that he has long forgotten, but this must be a mathematical problem, this is a blind spot problem, it seems to be a geographical problem, but it is actually a mathematical problem.

Zhu Houhuang immediately wrote in his small notebook that he must find a mathematician.

It's just that who was the famous mathematician of the Ming Dynasty?

Zhu Houhuang had to admit that he still did too little homework.

And even if Zhu Houhuang finds a solution, he has to face the problem of basic data.

Zhu Houhuang had read all the countless maps in Ouchi, and he was a little desperate about the accuracy of these maps.

Perhaps, it is not that these raw data are inaccurate, but the difference in the expressions of the two sides, Zhu Houhuang even found a big mountain painted by Gongbi on a map, this mountain is very beautifully drawn, very unique, but can you explain why he is still on the map?

Zhu Houhuang has to admit that it is definitely not a matter of one or two years to draw an accurate picture from scratch.

However, Zhu Houhuang felt that it was necessary for him to first design a complete set of mapping techniques, then train a large number of surveyors, and finally, after a few years of careful drawing, there would be an accurate map of East Asia.

Zhu Houhuang was a little depressed: "I just want an accurate map, why is it so difficult." ”

But no matter how hard it is, things have to be done.

Ancient Chinese cartographic methods, mainly the Western Jin Dynasty cartography six methods, that is, the fraction, quasi-hope, Daoli, Gaoxia, Fang evil, roundabout, in which the fraction, is the scale, the quasi-hope is the correct direction, the road is the measurement of the road, the height is the measurement, the square evil is the use of the Pythagorean theorem, and the straight, is the measurement of straight lines and curves. In the Northern Song Dynasty, Shen Kuo felt that the six laws of this system were somewhat inaccurate, so he changed the Daoli to the direction. He believes that after knowing the exact location, the Tao can be calculated, so there is no need for this method.

The plan is the pinnacle of China's map making.

It is a method of drawing maps at scale, because it is a method used on Chinese maps to make the map graphics downsized correctly. When drawing, first fill the map with squares, and the length of the square represents the number of miles in the field.

Zhu Houhuang immersed himself in reading for a while, and he realized that in terms of drawing ideas, he was not much more clever than the ancients, but he only had one more warp and weft cartography.

The reason why these maps made Zhu Houhuang look so unpleasant was that the difference in map making methods was that in the eyes of the ancients, the sky was round and the problem of projection was not considered at all. The modern maps that Zhu Houhuang has seen are all projection maps, and there is a difference in this point. The second is that the terrain has changed over the centuries. Many places are not the same, especially the coastline, which is different from the coastline of modern times. Third, it is the manpower and material resources used for drawing in ancient times, and the instruments are far inferior to the present, so it is normal to have errors.

None of these can be solved by Zhu Houhuang.

Through the matter of cartography, Zhu Houhuang finally knew.

How difficult it is to promote the development of the whole world, it is very simple, some time-travelers have figured out the staff system in ancient times, and in the world where there is not even an accurate map, what is the use of making a staff system?

Zhu Houhuang had to pack up all his thoughts and honestly go to Qin Tianjian to see how Zhu Yu had done with the longitude and latitude method.

When Zhu Houhuang saw Zhu Yu, he almost couldn't recognize Zhu Yu.

Zhu Yu's eyes were bloodshot, his entire eye socket was sunken, and he didn't know how long he hadn't taken a bath. It's like a wild man.

Zhu Houhuang said: "What's wrong with you? “

Zhu Yu said happily: "Thank you Shizi, it seems that the heliocentric theory is correct and has solved many of my problems." Zhu Yu didn't look at Zhu Houhuang's reaction, it seemed that he hadn't communicated with anyone for a long time, and he kept saying: "Shizi, heliocentrism has solved many of my problems, especially in the calendar, I have a new idea, and I am ready to use the sun as a calendar again and improve a set of calendars." Then take the etheric yin as a calendar, as a supplement. It can definitely make the 24 solar terms without error. ”

Zhu Houhuang said: "Very good. Zhu Houhuang was very happy, because he finally didn't have to talk about chickens and ducks, anyway, whatever he said, Father-in-law Wei was perfunctory everywhere, not to mention talking to a happy person like Zhu Yu.

Zhu Houhuang is still very relieved about Zhu Yu's attainments in astronomy, after all, Zhu Houhuang only knows the heliocentric theory, but how to verify the heliocentric theory, what problems the heliocentric system solves in astronomy, Zhu Houhuang doesn't know. Looking at Zhu Yu's appearance, he did not simply agree with the heliocentric theory, but verified it.

"So, do you want to find out the method of measuring the latitude and longitude?"

Zhu Yu looked at Zhu Houhuang as if he had seen a monster, and said, "Shizi, you are a noble member of the Ming royal family, how can you not distinguish between priorities and priorities." The Ming calendar is not accurate, so that the four seasons are not divided, and the wheat and rice are not timely. Is this a very serious problem? How do you abandon the calendar and go for the latitude and longitude trail? ”

Zhu Houhuang's face darkened suddenly, and he said, "You mean, you haven't studied at all. ”

Zhu Yu said: "For the fourth time of the world, such a major problem has not been solved, how can I solve any longitude and latitude problems? ”

Zhu Houhuang has to say that Zhu Yu said it beautifully.

In the Ming Dynasty, which focused on agriculture, solving the problem of the calendar was a big problem related to agricultural production.

It is indeed politically incorrect not to solve this big problem, but to study what latitude and longitude are above. Zhu Houhuang was speechless.

Zhu Houhuang gritted his teeth and said, "Can you not take out a few people to solve this problem, you can go and guide it." No, it doesn't work. ”

Zhu Houhuang's nose was about to erupt into flames. Zhu Yu was so frightened by Zhu Houhuang that he practiced and retreated, and after saying something just now, Zhu Yu remembered that he was facing the cousin of the current emperor, a first-class Tianhuang noble. It's someone who can pinch him to death. Coupled with Zhu Houhuang's appearance that he was about to erupt into flames, all his courage disappeared, and he said, "But, but." “

"But!" Zhu Houhuang's anger could barely be suppressed.

"But if you want an accurate moon schedule, you also need a standardized calendar?"

"What?"

The calendar is a thing that doesn't seem to be important now, something that everyone is accustomed to, but in fact, this thing is very important, as big as the political correctness of a dynasty, what the so-called orthodoxy is, many times it is above the calendar. As small as spring planting and autumn harvest in agricultural production, it must be determined by calendar.

The calendar of the Ming Dynasty is a direct inheritance of the calendar of the Yuan Dynasty, the martial arts of the Yuan Dynasty are extremely prosperous, but the cultural governance is so-so, the Ming Dynasty inherited the calendar of the Yuan Dynasty, the calendar of the Yuan Dynasty has omissions a lot, the Ming Dynasty has been tinkering, has not been done well, until the time of the Chongzhen Emperor, because of the frequent occurrence of natural disasters, the calendar problem has become the top priority, so the Chongzhen Emperor under the leadership, with the help of Western missionaries, the creation of the Chongzhen calendar, that is, the lunar calendar that is still in use.

But it was too late at that time, and the success of the almanac could not save the Ming Dynasty.

In astronomy, sorting out so much information is even more difficult to deal with in the face of countless uncertain dates.