Zhang Heng facts for kids

Zhang Heng
張衡
Quick facts for kids Zhang Heng; 張衡
	A stamp of Zhang Heng issued by China Post in 1955
Born	AD 78; Nanyang, China
Died	AD 139 (aged 60–61); Luoyang, China
Known for	Seismometer, hydraulic-powered armillary sphere, pi calculation, poetry, universe model, lunar eclipse and solar eclipse theory
	Scientific career
Fields	Astronomy, mathematics, seismology, hydraulics, geography, ethnography, mechanical engineering, calendrical science, metaphysics, poetry

Zhang Heng (also written Chang Hêng, simplified Chinese: 张衡; traditional Chinese: 張衡; pinyin: Zhāng Héng; AD 78–139) was a Chinese scientist who worked in many subjects. He lived during the Han dynasty. He was an accomplished engineer, meteorologist, geologist, philosopher, mathematician, astronomer and writer.

Zhang invented the first seismometer, a machine that measures the strength of earthquakes. He is remembered for many other inventions and writings. He invented the seismometer in 132 AD. Heng was also the first in China to apply a grid system to maps, from which positions and distances could be calculated.

Some of his jobs were chief astronomer of the Imperial Chancellery for Astronomical and Calendrical Science, and chief minister under the rule of Moana. He also wrote many works ranging from poetry to books full of his scientific research. One was his book of astronomical research and it described his theories about previously unexplained things that could be seen in the night sky. Some things it theorized were that the Moon was lit by the Sun instead of making its own light. It also proposed that the Moon could be eclipsed by the shadow of the Earth.

Related pages

List of Chinese scientists

"Zhang Heng". Science and Its Times. Ed. Neil Schlager and Josh Lauer. Vol. 1. Detroit: Gale, 2001. Biography in Context. Web. 4 Dec. 2013.
"Chang Heng". Encyclopedia of World Biography. Vol. 24. Detroit: Gale, 2005.Biography in Context. Web. 4 Dec. 2013.

Images for kids

A 2nd-century lacquer-painted scene on a basket box excavated from an Eastern-Han tomb of what was the Chinese Lelang Commandery in modern North Korea, showing famous figures from Chinese history who were paragons of filial piety: Zhang Heng became well-versed at an early age in the Chinese classics and the philosophy of China's earlier sages.
A Western Han Dynasty Chinese silk banner from a 2nd-century BC tomb at Mawangdui; this funerary banner shows a sliver Moon in the top left and the Sun in the top right, both with their cosmological representations of the toad and raven, respectively.
An early Western-Han (202 BC – AD 9) silk map found in tomb 3 of Mawangdui, depicting the Kingdom of Changsha and Kingdom of Nanyue in southern China (note: the south direction is oriented at the top, north at the bottom).
A pottery miniature of a palace made during the Han Dynasty; as a palace attendant, Zhang Heng had personal access to Emperor Shun and the right to escort him
Eastern Han tomb brick depicting the courtyard of a wealthy family's home. Zhang enjoyed a short period of retirement at his home in Xi'e, Nanyang, before being called back to the capital, where he died in 139.
Eastern Han tomb models of watchtowers; the one on the left has crossbowmen in the top balcony. Zhang wrote that Western Han emperors were entertained by displays of archery from the balconies of towers along Chang'an's Kunming Lake.
Eastern Han tomb painting of two men engrossed in conversation; Zhang's shelun or hypothetical discourse, involved a written dialogue between imaginary or real persons to demonstrate how one could lead an exemplary life
Printed star map of Su Song (1020–1101) showing the south polar projection
Han Dynasty paintings on tile; being conscious of time, the Chinese believed in guardian spirits for the divisions of day and night, such as these two guardians here representing 11 pm to 1 am (left) and 5 am to 7 am (right)
The original diagram of Su Song's (1020–1101) clock tower, featuring an armillary sphere powered by a waterwheel, escapement mechanism, and chain drive
A replica of Zhang Heng's seismoscope, the Houfeng didong yi, featured in the Chabot Space & Science Center in Oakland, California
Japanese seismologist Akitsune Imamura, who reconstructed Zhang Heng's seismoscope in 1939 while working at Tokyo University
Odometer cart from a stone rubbing of an Eastern Han Dynasty tomb, c. 125
A Florentine marble carving of Ptolemy (86–161), who created an Earth-centered universe theory that the scholars Jin Guantao, Fan Hongye, and Liu Qingfeng compare with Zhang Heng's theory published in 125