OdometerAn odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Greek ὁδόμετρον, hodómetron, from ὁδός, hodós ("path" or "gateway") and μέτρον, métron ("measure"). Early forms of the odometer existed in the ancient Greco-Roman world as well as in ancient China.
History of science and technology in ChinaAncient 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 binary code, and one of the earliest examples of genetic sequencing, abacus, the sundial, and the Kongming lantern.
Antikythera mechanismThe Antikythera mechanism (ˌæntɪˈkɪθɪərə ) is an Ancient Greek hand-powered orrery, described as the oldest known example of an analogue computer used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad, the cycle of the ancient Olympic Games. This artefact was among wreckage retrieved from a shipwreck off the coast of the Greek island Antikythera in 1901.
BeijingBeijing (beɪˈdʒɪŋ ; ; AUDBeijing pronunciation.oggbei3.jing1), alternatively romanized as Peking (piːˈkɪŋ ), is the capital of the People's Republic of China. With over 21 million residents, Beijing is the world's most populous national capital city as well as China's second largest city after Shanghai. It is located in Northern China, and is governed as a municipality under the direct administration of the State Council with 16 urban, suburban, and rural districts.
CompassA compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°.
MachineA machine is a physical system using power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecules, such as molecular machines. Machines can be driven by animals and people, by natural forces such as wind and water, and by chemical, thermal, or electrical power, and include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement.
Three KingdomsThe Three Kingdoms () from 220 to 280 AD was the tripartite division of China among the dynastic states of Cao Wei, Shu Han, and Eastern Wu. The Three Kingdoms period was preceded by the Eastern Han dynasty and was followed by the Western Jin dynasty. The short-lived state of Yan on the Liaodong Peninsula, which lasted from 237 to 238, is sometimes considered as a "4th kingdom". Academically, the period of the Three Kingdoms refers to the period between the establishment of Cao Wei in 220 and the conquest of the Eastern Wu by the Western Jin in 280.
Jin dynasty (266–420)The Jin dynasty (jin4; ) or the Jin Empire, sometimes distinguished as the Sima Jin (司馬晉) or the Two Jins (兩晉), was an imperial dynasty of China that existed from 266 to 420. It was founded by Sima Yan (Emperor Wu), eldest son of Sima Zhao, who had previously been declared the King of Jin. The Jin dynasty was preceded by the Three Kingdoms period, and was succeeded by the Sixteen Kingdoms in northern China and the Liu Song dynasty in southern China. There are two main divisions in the history of the dynasty.