The astronomical inventions of Zu Chongzhi, Yixing and Guo Shoujing

Zu Chongzhi: introducing precession to create the Daming calendar
Monk Yixing: Calculation of meridian
Guo Shoujing: making calendar

What did Zu Chongzhi, Zhang Heng, dunshoujing, and the monks create?

Zu Chongzhi created a new calendar called "Daming calendar"
Zhang Heng created the Houfeng seismograph, which is a modern seismograph
Dun Shoujing: he created altimeter and simple instrument, presided over nationwide astronomical survey, and compiled the calendar of time service
Monk Yixing: making Dayan calendar

What else did Zhang Heng invent

Ancient Chinese astronomer: Zhang Heng
Zhang Heng (78-139), a native of Xie, Nanyang (now Shiqiao Town, Nanyang County, Henan Province), was a great astronomer in the Eastern Han Dynasty and made an indelible contribution to the development of astronomy in China. In mathematics, geography, painting and literature, Zhang Heng also showed extraordinary talent and broad knowledge
Zhang Heng is one of the representatives of huntian theory in the Middle Eastern Han Dynasty. He pointed out that the moon itself does not shine, and the moon is actually a reflection of sunlight. He also correctly explained the cause of the eclipse, and realized the infinity of the universe and the relationship between the speed of planetary motion and the distance from the earth
Zhang Heng has observed and recorded 2500 stars, created the world's first water rotating armillary sphere that can accurately perform the astronomical phenomena, the first instrument for testing earthquakes - the Houfeng seismograph, and also produced a guide car, an automatic drum car, and a wooden bird that flies for miles
Zhang Heng has written 32 scientific, philosophical and literary works, among which astronomical works include Lingxian and Lingxian map
In memory of Zhang Heng's achievements, people named a crater on the back of the moon "Zhang Heng crater" and asteroid 1802 "Zhang Heng asteroid"
Guo Moruo, a famous Chinese writer and historian in the 20th century, commented on Zhang Heng: "such a person with all-round development is rare in world history. It is admirable to worship him for thousands of years."
Astronomy in China has a long history. In the Han Dynasty, there were Gaitian, Xuanye and huntian schools. Gaitian thought that the sky was like Gai, gaixin was the north pole, tiangai rotated left, and the sun, moon and stars turned right. Xuanye thought that the sky was amorphous, and the sun, moon and stars "floated naturally in the void" and did not attach to the "celestial body", At the same time, instruments for observing celestial phenomena also appeared. For example, luoxiahong in Emperor Wu made the armillary sphere, Geng shouchang in Emperor Xuan made the armillary sphere, and Jia Kui, Cui yuan's teacher in Emperor Xuan, made the bronze instrument of the ecliptic
Zhang Heng inherited and developed the achievements of his predecessors. After he was appointed as the supreme historian, he "studied Yin and Yang" more diligently, and finally "achieved the perfection of Xuanji". In the fourth year of the Yuan Dynasty (A.D. 117), a copper casting armillary sphere with unprecedented achievements was made by Zhang Heng
The main body of the armillary sphere is a circle which can be operated in several layers. The circumference of the outermost layer is 10.4 feet 6 inches. Each layer is engraved with inner and outer rules, South, north, yellow, equator, 24 solar terms, 28 constellations, as well as "middle" and "outer" stars, sun, moon, five latitude and other celestial phenomena, The circle turns slowly according to the scale. Then all kinds of astronomical phenomena appear in front of people's eyes. This instrument is placed in the secret room of Lingtai hall. At night, the indoor observers report the astronomical phenomena that appear at a certain time to the observers on Lingtai in time. The result is that the astronomical phenomena on the instrument and in the sky are exactly the same
On both sides of the bronze instrument, there is a jade dragon (Dragon), which spits water into the pot. On the left side is night, and on the right side is day. On the pot stand the golden copper immortal and Xu Tu, who hold the arrow in their left hand and carve it in their right hand, so as to distinguish the day from the morning and the evening. What's more, under the steps, there are Rui wheel and amplitude pod, which are connected with the two pots, Zhang Heng made a model with bamboo strips, called Xiao Hun, one year before the birth of this instrument, and carried out a series of experiments and corrections, Then it was made into a great instrument. The armillary sphere is the crystallization of Zhang Heng's blood and sweat. He then wrote two books of notes on the diagram of the armillary sphere and notes on the water leakage turning to the armillary sphere. He also wrote a Book of Lingxian and drew a picture of Lingxian. In these books, Zhang Heng systematically expounded his own astronomical theory, He thinks that the universe is infinite and the movement of celestial bodies is regular. The moon is the reflection of sunlight. The eclipse of the moon is caused by the earth covering the sun. The moon goes around the earth and rises and falls. He realizes some laws of the sun's movement (which should be the revolution of the earth), He pointed out that there are 2500 stars that can be seen in the Central Plains, which is a little close to what people know today. Through the observation of the movement of some celestial bodies, he came to the conclusion that one day is 365 degrees and one fourth degree, which is almost the same as the value of 365 days, 5 hours, 48 minutes and 46 seconds of the earth's orbit around the sun measured in modern times
As a result of studying astronomy, calendar and making instruments, Zhang Heng's research on mathematics has been strengthened correspondingly. After he made the armillary sphere, he wrote "Suan Wang Lun" to "calculate the network heaven and earth". He used the "progressive fraction" method to calculate the square root of PI 10, which is 3.16. This is a big step forward than the value of π = 3 recorded in "Zhou Bi". Until five to seven centuries later, he calculated the square root of PI 10, Only Indian and Arab mathematicians came up with this number
In the first year of Jianguang (A.D. 121), Zhang Heng was transferred to the post of bus Sima Ling, who was in charge of the imperial edicts. He was not submerged by the complicated official business, and went into the field of physics and mechanical manufacturing, and made many amazing achievements. He became the leading expert in mechanical manufacturing at that time, and was called the "wood saint" by people, He used the principle of differential gears to build a guide car and a Ji Li drum car. He also meticulously built a wooden bird, which could fly for miles with a feather in his stomach. It was simply the only wooden "airplane" in the world at that time. Unfortunately, like many of his masterpieces, most of its real objects and detailed construction methods were lost later
Zhang Heng also made a kind of shadow measuring instrument, tugui, which was used to study astronomy and geography. He drew a topographic map, which spread to the Tang Dynasty. He was good at painting landscapes and animals, and was one of the four great painters in the Eastern Han Dynasty with Zhao Qi, Liu Bao, and Cai Yong (the father of Wenji). He also had profound research on music and dance, He once skillfully described the dancer's dancing skills as follows: "a continuous stream of dancing, a sudden continuation, a train like flying Luan, sleeves like snow."

Among the following scientists, Zhang Heng B, Cai Lun C, Zhang Zhongjing D and Hua Tuo have made the greatest contribution to the spread of human culture

B
So Cai Lun, who invented papermaking, made the greatest contribution to cultural communication

The astronomical inventions of Zu Chongzhi, Yixing and Guo Shoujing