Chapter 659: Astronomical Calendar

The gains and losses of Hezhou and the imminent solar eclipse made Wang Anshi finally make up his mind, ignoring the opposition of Lu Huiqing and others, and played Zhao Ji, demanding that the new law be adjusted.

On the morning of March, Si Tian said that in April, the sun should be eclipsed for nine minutes.

The edict was sent to Ding Si to avoid the palace and reduce the meal, and the prisoners in the world were reduced to the first class, and he was released.

Exempt the principal and interest of the loan owed by the landless households in the world, and exempt from military service.

Lu Jia asked the establishment of the City Easy Arrival Office to recover the principal and interest of the loans owed by each household.

Su You, please slow down, and please divide the power of the city.

Xue Xiang impeached the city's Yi Si for improper measures, resulting in huge losses for Bianjing wine households, 27 wine households on the verge of bankruptcy and bankruptcy, and the losses on both sides of the wine shop and the wine shop added up, totaling one million yuan; This year, Bianjing City will face a situation where no one is in the wine shop, there is no wine to be produced in the wine shop, and there is no wine to drink in Bianjing.

Just as the Mingtang ceremony was completed, there was a division that mistakenly moved Xue Xiang as the right counselor, and Zhao Ji punished the officials, but did not take the promotion of the old man, and asked Wang Anshi to find another candidate for the third envoy.

Wang Anshi recommended Zeng Bu as the third envoy, and asked the City Yi Division to suspend business and let Zeng Bu investigate the situation.

Lu Jiawen thought that he should be the third envoy, and it was a big grievance.

……

In front of the Kaifeng Mansion, the prison was opened, and hundreds of loan debtors who were caught here were all released by Su You.

During the detention period, Su You asked the magistrate Shen Chen to organize the sinners to clean up, clean up the prison environment, disinfect and kill insects, bathe and cook clothes, and then treat those who are sick, and no one will be killed.

The people were grateful to Dade and knelt on the ground in the school yard to see Fu Yin.

Su You had no choice but to come out softly and comfort, and let them each go home to make a living, and soon the imperial court should adjust the affairs of the city, please trust the government.

The prison was empty, and the reputation of Xiao Su Qingtian in Kaifeng Mansion resounded in the city.

The little sister came out of the palace and said that the queen mother of the two palaces was very pleased with his Xuandemen case and the way the people owed interest by the city Yi Division.

Su You looked at the little sister's stomach: "You don't have to worry about these things, Jingrun is too busy in Zhengzhou, I will transfer him back to be a young eunuch." Why don't you resign as the mountain chief? ”

Xiaomei said: "The Queen Mother said that they are not at ease if they change others. After all, I'm a woman, and I won't get into the office. ”

Su You was anxious: "Then I'll go and tell the Queen Mother." ”

The little sister pulled Su You's sleeve: "No, the Queen Mother granted me a year's leave and let Zongyou take over temporarily." ”

Su You was a little speechless: "Zhao Zongyou, he is still a child......"

Xiaomei smiled: "Seventeen, it's not a child." Brother, find me something to do, I'm about to suffocate. ”

Su You pondered: "There is really something wrong, the Japanese officials of Si Tianjian have long lost the skills of their ancestors, and they are all mediocre sellers. I don't know anything about the magic image, the diagram, the armillary sphere, the scenery table, and the five pots of floating leaks. ”

"Relying on them, my brother thinks that sooner or later this head will be accepted by His Majesty for specimens."

The little sister sneered: "Then what do you want?" ”

Su You touched his chin: "I want those people to hand over all the family heirloom classics, and then find someone to translate them into reference books using the writing method of science and technology." If nothing else, according to the accurately calculated precession, and then work backwards to the record of the 3,000-year-old solar and lunar eclipse in China, the five-star track, this is a big deal. ”

"After that, we had to make a map of the whole country, make a star map, make accurate measuring tools, modify astronomical observation instruments, and list accurate calendars...... Most importantly, my brother wants to build an artifact that measures time mechanically. ”

The little sister said: "Zhaoming should be able to help." ”

Su You said: "Yes, I am going to ask Your Majesty to recruit the world's Taishi Zhanshu, miscellaneous scholars, and separate five subjects, but it is different from the past, with five categories: calendar, astronomy, geography, mathematics, and instrumentation." ”

"I wanted to ask my uncle to come back to preside over this matter, but Wang Xianggong refused. Therefore, I can only be in charge, and then invite Jing Run, Cunzhong, as well as Shi Lao, Wei Lao, Qiuguan Huangfu Yu, and Han Gonglian, the instrument master recommended by the clan brother, to tackle the problem together. ”

"There is also the Heavenly Master's Mansion, you, the two foreigners, are also involved."

Xiaomei nodded: "Well, if our group of people can't come out, no one in the world will be able to figure it out." ”

……

Si Tianjian, observing the astronomical auspiciousness, the bell and drum are missing, writing the almanac, for the altars to worship and sacrifice the name of the god and draw the day.

China is an agricultural civilization, and solar terms are especially important for this country.

Therefore, the most important job of Si Tianjian is to accurately report the time, confirm the solar terms, and calculate the possible changes in the sky.

Due to the precession relationship, that is, the actual solar year, and the year on the calendar will be incorrect, after a certain period of time, the old calendar accumulates too much error, and it needs to be rebuilt.

In fact, as long as this error is accurately calculated and accurately observed, the problem can be solved through adjustment.

But the problem is that once the calendar is made, the ruler will consider it a great achievement of the state, and it generally cannot be easily modified.

In addition, the amount of calculation is very large, and the calculation chips used to be used, and the way of writing records is also troublesome, and the lack of statistical lists will produce huge workload and calculation errors.

Therefore, in general, the calculation and verification are divided into two sections, accounting for two-fifths of the total manpower.

The so-called precession refers to the phenomenon that the long-term precession of the Earth's axis of rotation causes the vernal equinox to move westward along the ecliptic, resulting in a return year shorter than the sidereal year.

The reason for this is that the Earth is an ellipsoid, and the equator is partially uplifted; The equatorial plane does not coincide with the ecliptic plane.

The Sun, Moon and other planets exert additional gravitational pull on their equatorial uplifts, causing a change in the tendency of the equatorial plane, i.e., precession of the Earth's axis.

As a result, the vernal equinox moves westward along the ecliptic for about 50 minutes and 2 seconds per year, about 26,000 years for one week.

Because it makes the return year slightly shorter than the sidereal year, it was called "precession" in ancient China.

The westward shift of the vernal equinox caused by the action of the sun and the moon does not change the angle of the yellow-red junction, which is called "sun-moon precession"; The action of other planets changes the yellow-red angle at the same time, which is called "planetary precession". The sum of the two is called "total precession".

However, the impact of planetary precession is very small, and the precession of the sun and moon is mainly considered.

In the fourth century AD, Yu Xi, an astronomer of the Jin Dynasty in China, found that the position of the stars in the Jin Dynasty was slightly offset from that in ancient times when analyzing the ancient star map and the starry sky, and then discovered the precession, and left a record of the winter solstice receding once every 50 years.

"History of the Song Dynasty and the Chronicles of the Law" recorded: "Yu Xiyun: 'The winter solstice of Yaoshi is short and the stars are more than 2,700 years old, and it is in the east wall, and it is known where the difference is every year. ’”

This is where the term precession comes from.

The great astronomer Zu Chongzhi, in the "Great Ming Calendar" formulated in 463 AD, introduced precession into the calendar calculation for the first time.

Some previous astronomers believed that the Sun traveled on the ecliptic for each return year and then returned to the starting point of the previous year.

After careful observation, Zu Chongzhi believes that the winter solstice point recedes one degree every forty-five years and eleven months.

This makes the Ming calendar more elaborate than the rest of the calendars.

However, the error between this value and the actual precession is still not small, and later generations do not understand the fundamental principle, resulting in the "Daming Calendar" after a long time, it was also abandoned because of the excessive accumulation error.

The Chinese calendar is a combination of the solar calendar and the lunar calendar, so several key data determine whether the calendar is accurate or not.

In Su You's eyes, since Zuda's Da Ming calendar has used precession to solve the problem of calendar accuracy; It was also possible to propose a new leap week of one hundred and forty-four leap months in three hundred and ninety-one years, which was more precise than the leap week of seven leap months in nineteen years; He also calculated that the length of a return year should be three hundred and sixty-five points, two hundred and forty decimal places; The people of today should be better than the ancients.

In the same way, the problem of the length of the year is solved, and the accurate measurement of the winter solstice is related to the beginning of the year.

In the past, the measurement was carried out using a gauge.

The ancients used the Gui watch to measure the length of the shadow at noon every day, which can directly determine the date of the winter solstice, because the longest day of the shadow at noon in a year is the day of the winter solstice.

However, there is a huge error in this thing, which is as large as about one or two days, so the impact of this error must be greatly reduced through the accumulation and averaging of long-term observation data.

The four-minute calendar produced in China during the Warring States period was to solve this problem by using the average accumulation calculation.