In the Wenhua Palace, the emperor's ministers watched dumbfounded, and Zhao Hao used the model of the solar system to demonstrate the causes of the solar eclipse, lunar eclipse and moon phase.

But to be honest, except that the phases of the moon are placed there because of the waxing and waning of the moon, there is no need to prove it. As for the causes of solar and lunar eclipses, it is so simple, everyone still can't believe it.

It is a clear demonstration of why a solar eclipse occurs only on the first day of the new lunar month, and a lunar eclipse only occurs on the fifteenth day of the lunar calendar.

However, this evidence is far from enough to convince the public.

So everyone's eyes looked at Qin Tianjian Zheng Pei Peijia, hoping that this old yin and yang man with family roots could solve everyone's doubts.

Bei Peijia helplessly put down his hand, he still heard for the first time that the earth revolves around the sun.

I only heard Zhao Hao say that he was well versed in the psychology of everyone: "Until this time, you will definitely say, what is the difference between this and Xunzi's 'Heavenly Theory'?" It's just a hypothesis. ”

The officials smiled and nodded, no.

As Zhao Hao said, in their view, the so-called 'solar system' is just an idea. There is no essential difference with the 'Hun Tian Theory', 'Gai Tian Theory', and 'Xuanye Theory', they are all hypotheses.

If you believe it, believe it, and if you don't believe it, you will pull it down. So they don't care too much, they just have a novel experience.

"But what I want to tell you is that this model is not imaginary, but is precisely calculated from detailed observational data."

I heard Zhao Haoshi say in shock: "Therefore, we can calculate the time and observation direction of each solar and lunar eclipse, and even the time and observation direction of various celestial phenomena such as Venus conjunction and moon, glow and guarding." ”

"Can you figure it out exactly?" At this time, Bei Jianzheng finally couldn't help but shout: "Brag! ”

Yu Shi, who maintained order, was about to scold, but when he saw Xu Ge Lao shaking his head slightly, Yu Shi obediently closed his mouth.

The day before yesterday, Xu Ge Lao called Bei Jian Zheng to the cabinet to teach him face-to-face, and today he is asking him to take the lead!

"Isn't that unusual?" Zhao Hao said with the arrogance of this 'problem is such an idiot':

"Astronomy has been called the science of heavenly calculations since ancient times, doesn't it rely on observation and calculation? Liu Hui's "Island Sutra" of the Western Jin Dynasty has written the methods clearly. Zu Chongzhi of the Northern and Southern Dynasties could accurately calculate the orbits of the five planets of wood, water, fire, metal, and earth in the sky, the time it takes to orbit and orbit for one week, as well as the more accurate five-star conjunction period. Even Guo Shoujing of the previous dynasty can calculate the intersection of Huang and Chijiao......"

"Speaking of Guo Shoujing, isn't the "Time Calendar" of the previous dynasty used to predict a solar eclipse? It's just a lack of precision. As he spoke, he glanced strangely at the Bei Jian Zhengdao:

"It's hard to imagine that a Qin Heavenly Eunuch would ask such a question."

Pei Jian Zhengdeng's old face turned red, and Zhao Hao said that he was hit by the sore spot, because this was the fatal flaw of the Great Ming Qin Heavenly Prison.

He knew that the "Chronological Calendar" could predict solar eclipses, but he couldn't understand it......

Because the mathematics of the Ming Dynasty is broken!

As I said before, in the middle of the Yuan Dynasty, China's world-leading mathematics declined sharply.

In addition to the reasons for cultural regression and neglect by readers. The popularization of the abacus during this period made the ancient mathematical system based on calculation fall apart, and the Quaternary, Tianyuan, Dayan and Seeking One, and the multiplication of the opening of the square were completely lost to this dynasty.

Without these mathematical tools, Qin Tianjian would not have been able to understand the "Time Granting Calendar" deduced from the Tianyuan technique, and the solar and lunar eclipses they calculated based on the current "Great Unification Calendar" were full of mistakes and had no reference value.

So much so that the Qin Tianjian is generally considered to be a simple celestial observation organization.

In the eyes of the hundred officials, their daily work was to look up at the sky, record abnormal celestial phenomena, and then inquire about divination books, copy the books and submit them to the imperial court. You don't need to be at a high level at all, you just need to be literate.

In this regard, Bei Jian is very angry - at least the annual compilation of the imperial calendar, it is still very technical!

~~

It was because Bei Jian had red ears on his face for a while, and Fang gritted his teeth at Zhao Hao and said: "Yes, this official can't be calculated, but I believe that no one in the entire Ming Dynasty can calculate it!" ”

"I can." Zhao Hao smiled faintly and said, "And my disciple can too." ”

"Then you can forget it!" Supervisor Bei Zheng smiled and said: "If you can really calculate it, what if the official worships you as a teacher on the spot?" ”

"You're taking advantage of me." Zhao Hao put up a score. "It's not that easy to worship me as a teacher."

Li Ge Lao and Chen Ge Lao thought that their sons-in-law were still solving geometry problems at home......

"Zhao Hao, what kind of place are you?!" Xiao Ge Lao finally couldn't help it, and said, "Don't be presumptuous here!" ”

"You're the one who is presumptuous, isn't it?" Zhao Hao glanced at him with a sneer and said, "Don't you know that it's rude to interrupt others?" ”

"You!"

"Silence!" Seeing that Yushi's mouth was pierced, Teng Xiang had no choice but to scold: "Don't make noise, talk well." ”

Only then did Zhao Hao turn his head and say to Bei Jian Zheng: "For the sake of Your Majesty's face, I will make an exception and accept you as a registered disciple." ”

"You figure it out first!" Supervisor Bei was crying and laughing, and said in his heart that I was a five-grade official, but I was actually disgusted by a small edict.

There are many crazy people to be edicted, and it is really true.

"Well, given your limited math skills, I'll teach you a simple algorithm." Zhao Hao cleared his throat and said loudly:

"As we have already demonstrated, both solar and lunar eclipses are caused by the movement of the sun, the earth, and the moon to a special position. The cycle and orbit of the earth around the sun and the moon around the earth are regular, so the occurrence of solar and lunar eclipses must also be regular. ”

"The astronomers of the Han Dynasty called the earth's orbit the ecliptic and the moon's orbit the white path. Moreover, it has been found that the two are not on the same plane, but there is a yellow and white angle of five degrees and nine minutes. Then Zhao Hao pointed to the model, the orbits of the earth and the moon and said:

"Now, let's look at the conditions under which an eclipse can occur – it can only happen on a new day, and the sun and moon must be in a straight line."

While speaking, Yu Shenxing put on the model the relative positions of the sun and the moon during the solar eclipse.

"As you can see, in the event of a solar eclipse, both the sun and the moon must be near the yellow and white nodes." Zhao Hao said, and Yu Shenxing pushed the three balls to rotate along the track:

"Suppose that after many days, the Sun and the Moon have moved almost exactly the same position, a similar eclipse will be observed on Earth."

The astronomy of the Ming Dynasty is indeed a mess, this is very common knowledge in the Han Dynasty, only Pei Jianzheng and his deputies can keep up, and the eyes of the rest of the people have been scattered, just like you who see here......

Seeing that Bei Jian was nodding, obviously understanding, Zhao Hao continued with a little relief:

"So as long as there is the time it takes for the sun to pass through the yellow and white nodes in a row, and the time it takes for the moon to pass through the yellow and white nodes twice in a row, and then find the least common multiple of these two numbers and the number of days in the month, which is the number of days required to repeat once!"

"The average of a month is 29.53 days. An node month is 27:21. An eclipse year is 346.62 days. ”

The data of the month of the node and the year of the eclipse have been available since ancient times, and Bei Jian Zheng can say it casually.

Obviously, the uncle doesn't eat dry rice either.

"Will you count then?" Zhao Hao asked expectantly.

Bei Jian was shaking his head, tears were about to fall.

"Okay, I'll teach you." After all, Zhao Gongzi is a good teacher, so he taught him how to decompose prime factors.

Who knew that as soon as the uncle taught, he immediately put pen to paper and calculated, and after a while, he reported the number and said: "When it is six thousand five hundred and eighty-five and one-third days." ”

ps. The first update, the back has not been checked, slow down...... Ask for monthly passes, recommended tickets~~