 |
Zhang HengChinese astronomer, mathematician, geographer, inventor, artist, poet, literary critic and statesman
Country:
 China |
Content:
Biography of Zhang Heng
Early Life and EducationZhang Heng, a Chinese astronomer, mathematician, geographer, inventor, artist, poet, literary scholar, and statesman, was born in 78 AD in the Nanyang district. He came from a noble but not very wealthy family. Zhang's father, a poor official, passed away when he was ten years old. He was raised by his grandmother and mother. At the age of 95, Zhang left his hometown and traveled to the ancient capitals of Chang'an and Luoyang.
Academic Pursuits and Career
After studying for several years at the Taixue, the imperial academy, Zhang became well-versed in classical literature and befriended notable individuals such as mathematician and calligrapher Cui Yuan and philosopher Wang Fu. At the age of 23, Zhang returned home and declined tempting offers to hold prestigious positions. He became responsible for documentation during the governance of Governor Bao De and gained experience in drafting official documents. During this time, Zhang dedicated much of his time to composing rhapsodies and achieved the position of Minister of Finance. Around the age of 30, Zhang began his research in astronomy and started publishing his mathematical works.
Imperial Service
In 112 AD, Zhang was summoned by Emperor Han, who had heard of his scholarship. He soon began working in the imperial secretariat and was later promoted to Chief Astronomer. Zhang served in this position for two terms, first from 115-120 AD and later from 126-132 AD. During Zhang's tenure, the literacy test for all candidates in the imperial secretariat and censorate became more rigorous. Candidates were now required to know at least nine thousand Chinese characters and be proficient in all major writing styles.
Challenges and Exile
In 123 AD, Zhang opposed the acceptance of certain apocryphal teachings that would have led to changes in the Chinese calendar. As a companion of Emperor Shun, Zhang tried to persuade him that the palace eunuchs posed a real threat to the imperial court. He cited examples of past court intrigues involving eunuchs and insisted on restricting their influence. The eunuchs attempted to slander Zhang, who responded to their attacks with his work "Contemplating the Cosmos." Nevertheless, the opponents managed to sow doubt in the emperor's heart, and in 136 AD, Zhang was sent into exile to Hejian, where he served as chancellor.
Legacy
Zhang Heng passed away in 139 AD. He received numerous posthumous honors for his knowledge and inventiveness. Some scholars recognize him as a polymath and encyclopedic thinker. Zhang made significant contributions in various fields, including inventing the world's first celestial globe (armillary sphere) powered by water, improving water clocks with an additional capacity, and inventing the world's first seismograph capable of detecting earthquakes within a 500 km range. He also enhanced the previous Chinese calculation of the value of pi and made contributions to astronomy, geography, and poetry. Zhang's enthusiastic speeches and poetry gained recognition and were later quoted by Chinese writers. In his honor, the lunar crater Chang Heng, asteroid 1802 Zhang Heng, and the mineral Zhanghengite were named after him.
