Editing Zhang Heng (section)

==Legacy==

===Science and technology===
[[Image:Astrology della Robbia OPA Florence.jpg|thumb|right|200px|A [[Florence|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<ref name="jin fan liu 1996 170"/>]]

Zhang Heng's mechanical inventions influenced later Chinese inventors such as Yi Xing, Zhang Sixun, Su Song, and Guo Shoujing. Su Song directly named Zhang's water-powered armillary sphere as the inspiration for his 11th-century [[clock tower]].<ref name="needham 1986 volume 4 part 2 466">Needham (1986), Volume 4, Part 2, 466.</ref> The cosmic model of nine points of Heaven corresponding with nine regions of earth conceived in the work of the scholar-official [[Chen Hongmou]] (1696–1771) followed in the tradition of Zhang's book ''Spiritual Constitution of the Universe''.<ref name="rowe 2001 88">Rowe (2001), 88.</ref> The seismologist John Milne, who created the modern seismograph in 1876 alongside Thomas Gray and [[James Alfred Ewing|James A. Ewing]] at the [[Imperial College of Engineering]] in [[Tokyo]], commented in 1886 on Zhang Heng's contributions to [[seismology]].<ref name="needham 1986 volume 3 626">Needham (1986), Volume 3, 626.</ref><ref name="yan 2007 124">Yan (2007), 124.</ref> The historian Joseph Needham emphasized his contributions to pre-modern Chinese technology, stating that Zhang was noted even in his day for being able to "make three wheels rotate as if they were one."<ref name="needham 1986 volume 4 85">Needham (1986), Volume 4, Part 2, 85–86.</ref> More than one scholar has described Zhang as a [[polymath]].<ref name="yan 2007 127"/><ref name="krebs 2003 31">Krebs (2003), 31.</ref><ref name="mair 2001 251"/><ref name="dillon 1998 378">Dillon (1998), 378.</ref> However, some scholars also point out that Zhang's writing lacks concrete scientific theories.<ref name="jin fan liu 1996 170">Jin, Fan, and Liu (1996), 170.</ref> Comparing Zhang with his contemporary, Ptolemy (83–161) of [[History of Roman Egypt|Roman Egypt]], [[Jin Guantao]], Fan Hongye, and Liu Qingfeng state:

::Based on the theories of his predecessors, Zhang Heng systematically developed the celestial sphere theory. An armillary constructed on the basis of his hypotheses bears a remarkable similarity to Ptolemy's earth-centered theory. However, Zhang Heng did not definitely propose a theoretical model like Ptolemy's earth-centered one. It is astonishing that the celestial model Zhang Heng constructed was almost a physical model of Ptolemy's earth-centered theory. Only a single step separates the celestial globe from the earth-centered theory, but Chinese astronomers never took that step.

::Here we can see how important the exemplary function of the primitive scientific structure is. In order to use the Euclidean system of geometry as a model for the development of astronomical theory, Ptolemy first had to select hypotheses which could serve as axioms. He naturally regarded circular motion as fundamental and then used the circular motion of deferents and epicycles in his earth-centered theory. Although Zhang Heng understood that the sun, moon and planets move in circles, he lacked a model for a logically structured theory and so could not establish a corresponding astronomical theory. Chinese astronomy was most interested in extracting the algebraic features of planetary motion (that is, the length of the cyclic periods) to establish astronomical theories. Thus astronomy was reduced to arithmetic operations, extracting common multiples and divisors from the observed cyclic motions of the heavenly bodies.<ref name="jin fan liu 1996 170"/>

===Poetic literature===
Zhang's poetry was widely read during his life and after his death. In addition to the compilation of Xiao Tong mentioned above, the [[Eastern Wu]] official [[Xue Zong]] (d. 237) wrote commentary on Zhang's poems "Dongjing fu" and "Xijing fu".<ref>Cutter (1984), 11 (footnote 61), 15, (footnote 80), 26 (footnote 141).</ref> The influential poet Tao Qian wrote that he admired the poetry of Zhang Heng for its "curbing extravagant diction and aiming at simplicity", in regards to perceived tranquility and rectitude correlating with the simple but effective language of the poet.<ref>Yim-tze (1989), 63.</ref> Tao wrote that both Zhang Heng and Cai Yong "avoided inflated language, aiming chiefly at simplicity", and adding that their "compositions begin by giving free expression to their fancies but end on a note of quiet, serving admirably to restrain undisciplined and passionate nature".<ref name="hightower 1954 169 170">Hightower (1954), 169–170.</ref>

===Posthumous honors===
Zhang was given great honors in life and in death. The philosopher and poet [[Fu Xuan]] (217–278) of the [[Cao Wei|Wei]] and [[Jin dynasty (265–420)|Jin]] dynasties once lamented in an essay over the fact that Zhang Heng was never placed in the [[Nine Ministers|Ministry of Works]]. Writing highly of Zhang and the 3rd-century mechanical engineer Ma Jun, Fu Xuan wrote, "Neither of them was ever an official of the Ministry of Works, and their ingenuity did not benefit the world. When (authorities) employ personnel with no regard to special talent, and having heard of genius neglect even to test it—is this not hateful and disastrous?"<ref name="needham 1986 volume 4 42">Needham (1986), Volume 4, Part 2, 42.</ref>

In honor of Zhang's achievements in science and technology, his friend Cui Ziyu (Cui Yuan) wrote a memorial inscription on his burial stele, which has been preserved in the ''Guwen yuan''.<ref name="xiao knechtges 1996 398">Xiao & Knechtges (1996), 398.</ref> Cui stated, "[Zhang Heng's] mathematical computations exhausted (the riddles of) the heavens and the earth. His inventions were comparable even to those of the Author of Change. The excellence of his talent and the splendour of his art were one with those of the gods."<ref name="needham 1986 volume 3 359">Needham (1986), Volume 3, 359.</ref> The minor official Xiahou Zhan (243–291) of the Wei dynasty made an inscription for his own commemorative stele to be placed at Zhang Heng's tomb. It read: "Ever since gentlemen have composed literary texts, none has been as skillful as the Master [Zhang Heng] in choosing his words well&nbsp;... if only the dead could rise, oh I could then turn to him for a teacher!"<ref name="declercq 1998 247">Declercq (1998), 247.</ref>

Several things have been named after Zhang in modern times, including the lunar crater [[Chang Heng (crater)|Chang Heng]],<ref>''Lunar Names Proposed'', 290.</ref> the asteroid [[1802 Zhang Heng]],<ref name="schmadel 2003 144">Schmadel (2003), 144.</ref> and the mineral [[zhanghengite]]. In 2018, China launched a research satellite called China Seismo-Electromagnetic Satellite (CSES) which is also named Zhangheng-1 (ZH-1).<ref>{{Cite web|url=https://www.nasaspaceflight.com/2018/02/long-march-2d-zhangheng-1-earthquake-investigator/|title=Long March 2D launches Zhangheng-1 Earthquake investigator – NASASpaceFlight.com|website=www.nasaspaceflight.com|date=2 February 2018|language=en-US|access-date=2018-02-05}}</ref>