In the 12th year of Emperor Han and Emperor Di (100), Zhang Heng became the master book of Nanyang Mansion and was in charge of documents in order to make a living. During this period, it took him 10 years to write five or six thousand words of literary works, namely "Xijing Fu" and "Tokyo Fu", describing the social features of the two capitals with beautiful words, satirizing the current situation with straightforward words, and pushing Han Fu to another peak.
In the second year of Emperor Han 'an (1 15), Zhang Heng was appointed as Taishiling, presided over the observation of astronomy and meteorology, and was in charge of the calendar, which provided convenient conditions for his research. After years of practical observation and painstaking research, I finally wrote immortal works: History of World Astronomy, Illustrated Book of Lingxian and Huntianyi. It broke the theory that "the sky is round and the earth is round", put forward the idea of "muddy sky", expounded the formation and structure of heaven and earth, the essence and movement of the sun, the moon and the stars from a philosophical point of view, and made a scientific explanation of solar and lunar eclipses. In the fourth year of Yuan Dynasty (1 17), Zhang Heng was forty years old. He applied his theory to practice and made the world's first astrolabe which can accurately measure astronomical phenomena.
Another immortal invention of Zhang Heng is the seismograph. In the third year of Han Yonghe (138), Zhang Heng's seismograph accurately monitored an earthquake in southeastern Gansu thousands of miles away. In the same year, Zhang Heng wrote to the emperor to resign and return to China. But the next year after returning to China, this outstanding scientist died. At the age of 62.
In addition, Zhang Heng also calculated pi as 3.1622; He is also very successful in geography, and his maps have been circulated for hundreds of years; His "Erjing Fu" is known as "the extreme track of long editing"; His "Hot Springs Fu", "Return to Talent" and "Four Sorrow Poems" are also masterpieces handed down from generation to generation. In a word, Zhang Heng's life can be described as "thousand-year worship, admirable".