History live broadcast: My audience is the ancestors

Chapter 187 Guo Shoujing

Su Yue looked at the sudden change of style in the comment area, and she was still a little uncomfortable with it, but it was better than discussing food.

She was really afraid of having another meal on her own!
Su Yue felt her belly, it was okay and seventy percent full.

But I can't eat it now. If I eat it again, I won't be able to sleep.

She rubbed her belly and said, "Okay, now let's take a look at the next inventor - Guo Shoujing!"

Guo Shoujing (1231-1316), whose courtesy name was Ruosi.

A native of Xingtai County, Xingzhou (now Xindu District, XT City, HEB Province).

An astronomer, mathematician, water conservancy expert, and instrument manufacturer in the Yuan Dynasty of China.

Guo Shoujing studied under Liu Bingzhong and Zhang Wenqian in his early years. He rose to the rank of Taishi Ling, became a bachelor of Zhaowen Hall, and knew the affairs of Taishi Academy. He was known as "Guo Taishi" in the world.

Starting from the thirteenth year of Zhiyuan (1276), he, Xu Heng, Wang Xun and others were ordered to revise the new calendar. It took four years to formulate the "Time Calendar", which became the most advanced calendar in the world at that time and was widely used for years. Ten years.

In order to revise the calendar, Guo Shoujing also restructured and invented twelve new instruments, including simple instruments and high tables. In the first year of Zhiyuan (1264), he was ordered to repair the ancient canals in Xixia and build sluices and weirs so that local farmland could be irrigated.

In the twenty-eighth year of the Yuan Dynasty (1291), he was appointed Water Supervisor of the capital, responsible for repairing the canal from Dadu to Tongzhou. It took one year to complete the entire project, named it Tonghui River, and developed north-south transportation and water transportation.

In the third year of Yanyou's reign (1316), Renzong of the Yuan Dynasty, Guo Shoujing passed away at the age of eighty-six.

He is the author of fourteen astronomical calendar works such as "Pui Bu" and "Li Cheng".

Guo Shoujing has made outstanding achievements in astronomy, calendar, water conservancy and mathematics, and has a high status in the history of world science and technology.

In 1970, the International Astronomical Society named a crater on the moon "Guo Shoujing Crater" after Guo Shoujing.

In 1977, the International Minor Planet Center named the asteroid 2012 "Guo Shoujing Asteroid".

The National Astronomical Observatory of the Chinese Academy of Sciences also named the LAMOST telescope, a major national scientific and technological infrastructure, as the "Guo Shoujing Astronomical Telescope."

My charming and short-lived ancestor: I’ll go! Boss!

I send my thoughts to the bright moon: I think you should discuss this with Zhang Heng!

Lianlian: Agreed! These two people are very close professionally!

Who in the clouds sent me a brocade book: Who says it’s not the case, but it seems that this person has no scandals

Wudubuyi: It seems that none of the inventors Yueyue mentioned have any scandals, right?
Pay attention, this woman’s name is Xiaomei: It seems so, but what on earth did he do to be so powerful?

My charming and short-lived ancestor: there are so many of them that I can’t even finish them in a short while!
Su Yue looked at the comment area and said, "Then let's see what he did!"

Compile the "Time Calendar"

Astronomical observation
Guo Shoujing used the astronomical instruments he improved and created to conduct many precise astronomical observations, thus providing a reliable observational basis for the compilation of the "Time Calendar".

He has engaged in and led many observation projects, such as the winter solstice time, the distance and star catalog of the 28 constellations, the Four Seas Survey, the determination of the yellow and red angles, and some epochal times. Most of the data are the most accurate in the history of ancient Chinese calendars, or Close to the best.

One of the more well-known is the Sihai Test.

Four Seas Test
In the 1279th year of the Yuan Dynasty (), Guo Shoujing proposed to Kublai Khan, the founder of the Yuan Dynasty: The territory of the Yuan Dynasty is now much larger than before. The length of day and night is different in different areas, and the time of day and night is different in different areas. The old calendar is no longer applicable. , so nationwide astronomical observations were needed to compile a new calendar. Kublai Khan accepted Guo Shoujing's suggestion and sent fourteen prison guards to conduct astronomical observations in twenty-seven places. Later generations called it the "Four Seas Test."

Guo Shoujing traveled thousands of miles from Shangdu (today's Duolun) and Dadu (today's BJ) through Henan to the South China Sea, and personally participated in the test along the way.

At 6 of the locations, the length of the surface shadow and the length of day and night on the summer solstice were specially measured; the average error of the measured altitude of the North Pole was only 0.35; the average error of the newly measured distance of the 5 constellations was less than 1'; The new value of the yellow-red angle was measured, with an error of just over 365.2425'; the length of the tropical year was found to be days, which is completely consistent with the current Gregorian calendar value.

The results of these observations provide scientific data for the preparation of a calendar suitable for the whole country.

compilation of calendar
In the creation of "Time Calendar", although Guo Shoujing had a professional division of labor. He was responsible for instrument making and testing, but he was not completely unrelated to other parts of the entire creation and the overall work.

The compilation of the "Time Calendar" is a large-scale collective work. In the work, there are not only dedicated people who are responsible for the division of labor, but also collective discussions on major issues.

In addition to describing the calendar change in the biographies of Wang Xun and Guo Shoujing, the author of "History of the Yuan Dynasty" also made considerable narrations in the biographies of Xu Heng, Yang Gongyi and others.

These narratives reveal the collective nature of the compilation of the "Time Calendar".

According to the view of contemporary science historian Qian Baocong, it can even be considered that as early as the time when Liu Bingzhong, Zhang Wenqian, Zhang Yi and others were classmates, they had many discussions on calendar issues.

When evaluating Guo Shoujing's role in the collective work system, it should be noted that: on the one hand, the tasks Guo Shoujing is responsible for will definitely absorb the wisdom and labor of others.

For example, the determination of the all-sky star catalog cannot be completed by one person alone.

As for the work of determining the seven responses, it is also inseparable from the calculation of calendars and the processing of data.

Geography

Guo Shoujing once proposed using sea level as a benchmark to compare the difference in terrain between Dadu (today's BJ) and Bianliang (today's Kaifeng, Henan). This was the origin of "altitude", an important concept in geography.
After the completion of the Xixia Water Conservancy Project, Guo Shoujing went up the Yellow River to explore the source of the Yellow River.

As a result, he became a pioneer in exploring the source of the Yellow River for the purpose of scientific investigation itself. No records of his findings have survived.

The first monograph on the results of the investigation of the source of the river that has been handed down to the world today is "Heyuan Ji" written by Du Shi. This is a record of Du Shi's special trip to investigate the source of the river on the orders of Kublai Khan in the seventeenth year of the Yuan Dynasty (1280).

Guo Shoujing's previous inspection must have had a considerable impact on Dushi.

Partially invented by Guo Shoujing

Looking at the astronomical instruments manufactured by Guo Shoujing throughout his life, most of them have the characteristics of scientific design, ingenious structure, precision manufacturing and ease of use, and most of them pay attention to the calibration devices installed on the instruments.

His creations won high praise from his contemporaries and later generations.

Wang Xun, known in history as a proud man, was convinced by Guo Shoujing's new creations every time he saw them.

Some of the instruments he manufactured were later shipped back to BJ in the early Qing Dynasty.

Later, during several projects during the Kangxi and Qianlong reigns of the 18th century, Guo Shoujing's works were treated as copper and melted down.

Other
The equatorial theodolite designed by Guo Shoujing on a simple instrument is the earliest equatorial device in the world. It was not until 1598 AD that a similar device was invented in Europe by the Danish astronomer Tycho.

Guo Shoujing used roller bearings in the simple instrument so that the moving equatorial ring at the southern end of the simple instrument can flexibly run on the fixed equatorial ring.

Similar devices in the West were invented by Italian scientist Leonardo da Vinci two hundred years later.