page_title: History of science and technology in China
section_title: Han dynasty
hierarchical_section_title: History of science and technology in China / Han dynasty
caption_attribution_description: English: Ancient Chinese crossbow (en:2nd century BCE). Guimet Museum, Paris. Personal photograph, 2004, released in the Public Domain.
context_page_description: Ancient Chinese scientists and engineers made significant scientific innovations, findings and technological advances across various scientific disciplines including the natural sciences, engineering, medicine, military technology, mathematics, geology and astronomy.
  Among the earliest inventions were the abacus, the "shadow clock," and the first items such as Kongming lanterns. The Four Great Inventions, the compass, gunpowder, papermaking, and printing – were among the most important technological advances, only known to Europe by the end of the Middle Ages 1000 years later. The Tang dynasty in particular was a time of great innovation. A good deal of exchange occurred between Western and Chinese discoveries up to the Qing dynasty.
  The Jesuit China missions of the 16th and 17th centuries introduced Western science and astronomy, then undergoing its own revolution, to China, and knowledge of Chinese technology was brought to Europe. In the 19th and 20th centuries the introduction of Western technology was a major factor in the modernization of China. Much of the early Western work in the history of science in China was done by Joseph Needham.
context_section_description: The Eastern Han dynasty scholar and astronomer Zhang Heng (78–139 AD) invented the first water-powered rotating armillary sphere (the first armillary sphere having been invented by the Greek Eratosthenes), and catalogued 2,500 stars and over 100 constellations. In 132, he invented the first seismological detector, called the "Houfeng Didong Yi" ("Instrument for inquiring into the wind and the shaking of the earth"). According to the History of Later Han Dynasty (25–220 AD), this seismograph was an urn-like instrument, which would drop one of eight balls to indicate when and in which direction an earthquake had occurred. On June 13, 2005, Chinese seismologists announced that they had created a replica of the instrument.
  The mechanical engineer Ma Jun (c. 200–265 AD) was another impressive figure from ancient China. Ma Jun improved the design of the silk loom, designed mechanical chain pumps to irrigate palatial gardens, and created a large and intricate mechanical puppet theatre for Emperor Ming of Wei, which was operated by a large hidden waterwheel. However, Ma Jun's most impressive invention was the south-pointing chariot, a complex mechanical device that acted as a mechanical compass vehicle. It incorporated the use of a differential gear in order to apply equal amount of torque to wheels rotating at different speeds, a device that is found in all modern automobiles.
  Sliding calipers were invented in China almost 2,000 years ago. The Chinese civilization was the earliest civilization to experiment successfully with aviation, with the kite and Kongming lantern (proto Hot air balloon) being the first flying machines.
caption: Remains of a Chinese crossbow, 2nd century BC.
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