Zhang Heng

Zhang Heng

Zhang Heng (78-139 years), the word Pingzi, Nanyang County, xi'e county (now Shiqiao Town, Nanyang City, Henan Province) people. He was an outstanding astronomer, mathematician, inventor, geographer and writer in the Eastern Han Dynasty, and the grandson of Zhang Kan, the prefect of Shu county.

He was born in Xiaolian, and served as a doctor, a magistrate, a servant and a Hejian. In his later years, because of illness, he entered the court as minister. Yonghe four years (139), died at the age of 62. In the Northern Song Dynasty, he was granted the title of Bo in xi'e county.

Zhang Heng wrote Lingxian and Hunyi Tu Zhu in astronomy; suanlanglun in mathematics; Erjing Fu and Guitian Fu are the representatives of his literary works, which are called "four masters of Han Fu" together with Sima Xiangru, Yang Xiong and Ban Gu. There are 14 volumes of Zhang Heng Ji in Sui Shu Jing Ji Zhi, which has been lost. Zhang Pu, a scholar of Ming Dynasty, compiled Zhang Hejian collection.

Zhang Heng made outstanding contributions to the development of astronomy, mechanical technology and Seismology in China. He invented the armillary sphere and the seismograph. He was one of the representatives of the theory of the Middle Eastern Han Dynasty. Later generations hailed him as "Mu Sheng" (Ke Sheng). Because of his outstanding contributions, the UN astronomical organization named a crater on the back of the moon "Zhang Heng crater", which is the 1802 small walk in the solar system The star was named "Zhang Hengxing". Later generations built a museum in Nanyang to commemorate Zhang Heng.

(source: the portrait of Zhang Heng painted by Jiang Zhaohe)

Life of the characters

Broadcom classics

Zhang Heng's family has been a local surname for generations. His grandfather, Zhang Kan, was known as Shengtong because of his high ambition since he was a child. He once gave his nephew millions of family surplus. After Emperor Guangwu Liu Xiu ascended the throne, Zhang Kan was appointed as the prefect of Shu county. He made great contributions with the great Sima Wu and Han to attack Gongsun Shu, who was under the separatist regime of Yizhou. After that, he led the army to fight against the Huns and was worshipped as the Yuyang prefect. Thousands of cavalry were used to defeat the ten thousand soldiers who were attacked by Xiongnu. After that, during his term of office, the Huns did not dare to invade any more. He also taught the people to cultivate and open up eight thousand hectares of rice fields, which made the people rich. Therefore, there is a folk song praising him, saying: "Zhang Jun is very happy to be in charge of politics." Zhang Kan is a clean and honest official. He was the first to invade Chengdu when he conquered Shu, but he had nothing to do with the mountain of treasures left by Gongsun Shu. Shu county is known as Tianfu, but when Zhang Kan was transferred to be the prefect of Shu County, he took a broken car with only a roll of cloth bags.

Like his grandfather, Zhang Heng studied hard since he was a child, and he would write when he was young. After 16 years old, he left his hometown to study abroad. He first went to Sanfu, the academic and cultural center at that time (now Xi'an, Shaanxi Province). The magnificent mountains and rivers in this area and the grand ruins of the ancient capital of Qin and Han Dynasties provide him with rich literary materials. Later, he went to Luoyang, the capital of the Eastern Han Dynasty. There, he went to Taixue, the highest University at that time, met Cui yuan, a later famous scholar, and became close friends with him. Zhang Heng had a wide range of interests. He taught himself the five classics and mastered the six arts. He also liked to study arithmetic, astronomy, geography and mechanical manufacturing. But in his youth, most of his interests were in poetry, Fu and prose. Although he was above the world, he was not proud. Ordinary people don't like to be indifferent.

Stepping into official career

During the reign of emperor Yongyuan of the Han Dynasty (89-105), Zhang Heng was elected Xiaolian, but he did not accept it, and the government did not recruit him several times. At that time, the country was peaceful for a long time, and there was no extravagance under the princes. Zhang Heng imitated Ban Gu's "two capitals Fu" and thought hard for ten years before he made "Er Jing Fu" to satirize and admonish the imperial court. General Deng Ji appreciated Zhang Heng's talent and recruited him many times, but Zhang Heng didn't answer his orders.

In A.D. 100 (the 12th year of Yongyuan), Zhang Heng, at the request of Bao De, the governor of Nanyang, made his book and took charge of the clerical work. Eight years later, Bao de was transferred to the capital, and Zhang Heng resigned.

In charge of the Taishi

Zhang Heng is good at machinery, especially in astronomy, yin and Yang, calendar. I usually like Yang Xiong's taixuan Sutra and said to Cui yuan, "I only know the wonderful number of Ziyun (Yangxiong character) when I read taixuan, but compared with Wujing, it's not just biography, which makes people argue about Yin and Yang. It's a Book of 200 years in the Han Dynasty. Will taixuanjing decline in another 200 years? Because the author's fate will be obvious for a lifetime, which is a natural proof. In the 400 years of the Han Dynasty, the study of Xuan would still rise. " Emperor Han an had long heard that Zhang Heng was good at learning skills. In 111 A.D. (the fifth year of Yongchu), Zhang Heng was taken to Beijing by the imperial court, worshipped as a doctor, and then promoted to the rank of Taishiling. So he studied Yin and Yang, mastered astronomy and calendar, made armillary sphere, and wrote Lingxian and suanlanglun in detail. Although he was transferred to another post in the early years of Emperor Shun's accession to the throne, he was later appointed as the supreme historian, and Zhang Heng held this post for 14 years. Many of his important scientific research work was completed in this stage.

Zhang Heng didn't admire the fame and wealth of his time, so he was often unable to move up for many years. Five years after leaving the position of historian, he returned to his original position. So we set up the style of "Ke Wen" and wrote "Ying Wen" to express our feelings. At that time, political affairs gradually declined, and eunuchs intervened in politics. Therefore, Zhang Heng went to the imperial court to dissuade and admonish Emperor Shun.

Foreign minister

In 133 A.D. (the second year of Yangjia), Zhang Heng was promoted to serve the emperor. Emperor Shun appointed him to give advice on the political affairs of the country. Emperor Shun asked Zhang Heng about the people he hated. The eunuchs were afraid that he would speak ill of himself. They all glared at him with their eyes. Zhang Heng answered with some elusive words and came out. But the eunuchs were still worried that Zhang Heng would become their disaster in the future, so they began to slander Zhang Heng. Zhang Heng often thinks about how to act. He thought that good fortune, bad fortune and bad fortune were deep and obscure, so he wrote "Si Xuan Fu" to express and repose his feelings.

In 136 ad (the first year of Yonghe), Zhang Heng was transferred to be the Prime Minister of Hejian King Liu Zheng. Liu Zhengjiao was extravagant and unrestrained, and he didn't obey the law and discipline, and there were many powerful people who gathered together to make a mess. After Zhang Heng took office, he strictly regulated the law and discipline, cracked down on the powerful, secretly found out the name of the treacherous party, and was arrested for a while. He was famous for his incorruptness. After three years in office, Zhang Heng applied for resignation and was called up as minister.

He died in his sixties

In 139 ad (the fourth year of Yonghe), Zhang Heng died at the age of 62.

In 1109 ad (the third year of the Grand View of Huizong in Song Dynasty), Zhang Heng was granted the title of xiebe by the Northern Song Dynasty for his achievements in arithmetic.

Later generations called Zhang Heng "wood saint" (Science saint). In order to commemorate Zhang Heng's achievements, the UN astronomical organization named a crater on the back of the moon as "Zhang Heng crater" in 1970, and asteroid 1802 as "Zhang Heng star" in 1977. In 2003, the international asteroid center named asteroid 9092 as "Nanyang star" in memory of Zhang Heng and his birthplace, he Nanyang.

Main impact

invention

In 132 A.D. (the first year of Yangjia), Zhang Heng invented the earliest seismograph, which is called Houfeng seismograph. According to Zhang Heng Zhuan of the later Han Dynasty, the seismograph is made of refined copper, with a diameter of eight feet, a protruding top cover, shaped like a wine bottle, and decorated with the image of turtle, bird and beast in seal script. There is a big pillar in the middle. It runs along eight roads. Turn off the engine. It has eight directions, each with a dragon with a copper bead in its mouth, and a toad corresponding to it below each dragon. If there is an earthquake on either side, the copper beads contained in the Longkou in that direction will fall into the toad's mouth, so that the direction of the earthquake can be determined. After testing, it was in accordance with the established system as God, which has never been recorded in books. Once upon a time, the ground didn't move. Luoyang scholars all blamed the lack of letters. A few days later, the messenger came. Sure enough, an earthquake happened in Longxi, and everyone was convinced. Since then, the court ordered historians to record the place where the earthquake happened.

About the structure of the seismograph, there are two popular versions: Wang Zhenduo model, that is, "Du Zhu" is a cylinder like an inverted wine bottle, and the mechanism controlling the Longkou is around the "Du Zhu". This model has been basically denied. Another model was proposed by Feng Rui of the Seismological Bureau, that is, "duzhu" is a hanging pendulum (see Yuan Hong's "post Han Dynasty"), there is a small ball under the pendulum, and the ball is located at the intersection of the "meter" shaped slideway (i.e. "Guan" in "post Han history · biography of Zhang Heng"). During the earthquake, "duzhu" moves the small ball, and the small ball hits the mechanism controlling the Longkou, making the Longkou open. In addition, Feng Rui's model changed Toad's face from the bottle body to the back of the bottle body and acted as the foot of the instrument. The simulation results of the model are consistent with the historical records.

Earthquakes are frequent in the world, but it is after the 19th century that we can really observe earthquakes with instruments abroad. Houfeng seismograph is the ancestor of seismograph in the world. Although its function is only limited to the location of the epicenter, it has surpassed the development of world science and technology for about 1800 years.

On the basis of the armillary sphere invented by Geng shouchang in the Western Han Dynasty, Zhang Heng created a more accurate and comprehensive "armillary sphere" according to his own theory.

It is a kind of water transport phenomenon. A bronze ball with a diameter of more than four feet is engraved with twenty-eight constellations, Chinese and foreign star officials, yellow equator, North and south poles, twenty-four solar terms, Hengxian circle, Hengyin circle, etc. to form an image. Then a set of rotating machinery is used to combine the image with the leaky pot. In order to display the diurnal apparent motion of stars, such as the presence and absence of stars and the middle sky, the water in a leaky kettle is used to control the image and make it rotate synchronously with the celestial sphere. It also has a subsidiary, ruilunmingcai, which is a kind of mechanical calendar. It is connected by transmission device and hunxiang. From the beginning of each month, it grows a leaf every day; after half a month, it falls a leaf every day. Its two-stage leaky pot is the earliest one known about the

Chinese PinYin : Zhang Heng