page_title: History of physics
section_title: India and China
hierarchical_section_title: History of physics / Ancient history / India and China
caption_attribution_description: English: This is a star map for the celestial globe of Su Song (1020-1101), a Chinese scientist and mechanical engineer of the Song Dynasty (960-1279). It was first published in the year 1092, in Su's book known as the Xin Yi Xiang Fa Yao (Wade-Giles: Hsin Yi Hsiang Fa Yao). On this star map there are 14 xiu (lunar mansions) on Mercator's projection. The equator is represented by the horizontal straight line running through the star chart, while the ecliptic curves above it. Note the unequal breadth of the lunar mansions on the map. Su Song's star maps had the hour circles between the xiu (lunar mansions) forming the astronomical meridians, with stars marked in quasi-orthomorphic cylindrical projection on each side of the equator, and thus was in accordance to their north polar distances. Not until the work of Gerard Mercator in 1569 was a celestial map of this projection created in the Western world (Needham, Volume 4, Part 3, 569). This picture appears on page 277 of Joseph Needham's book Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth.
context_page_description: Physics is a branch of science whose primary objects of study are matter and energy. Discoveries of physics find applications throughout the natural sciences and in technology, since matter and energy are the basic constituents of the natural world. Some other domains of study—more limited in their scope—may be considered branches that have split off from physics to become sciences in their own right. Physics today may be divided loosely into classical physics and modern physics.
context_section_description: Important physical and mathematical traditions also existed in ancient Chinese and Indian sciences.
  In Indian philosophy, Maharishi Kanada was the first to systematically develop a theory of atomism around 200 BCE though some authors have allotted him an earlier era in the 6th century BCE. It was further elaborated by the Buddhist atomists Dharmakirti and Dignāga during the 1st millennium CE. Pakudha Kaccayana, a 6th-century BCE Indian philosopher and contemporary of Gautama Buddha, had also propounded ideas about the atomic constitution of the material world. These philosophers believed that other elements (except ether) were physically palpable and hence comprised minuscule particles of matter. The last minuscule particle of matter that could not be subdivided further was termed Parmanu. These philosophers considered the atom to be indestructible and hence eternal. The Buddhists thought atoms to be minute objects unable to be seen to the naked eye that come into being and vanish in an instant. The Vaisheshika school of philosophers believed that an atom was a mere point in space. It was also first to depict relations between motion and force applied. Indian theories about the atom are greatly abstract and enmeshed in philosophy as they were based on logic and not on personal experience or experimentation. In Indian astronomy, Aryabhata's Aryabhatiya (499 CE) proposed the Earth's rotation, while Nilakantha Somayaji (1444–1544) of the Kerala school of astronomy and mathematics proposed a semi-heliocentric model resembling the Tychonic system.
  The study of magnetism in Ancient China dates back to the 4th century BCE. (in the Book of the Devil Valley Master), A main contributor to this field was Shen Kuo (1031–1095), a polymath and statesman who was the first to describe the magnetic-needle compass used for navigation, as well as establishing the concept of true north. In optics, Shen Kuo independently developed a camera obscura.
caption: Star maps by the 11th-century Chinese polymath Su Song are the oldest known woodblock-printed star maps to have survived to the present day. This example, dated 1092,[note 1] employs cylindrical projection.
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