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The magnetic compass was first invented as a device for divination as early as the Chinese Han dynasty and Tang dynasty (since about 206 BC). [1] [3] [34] The compass was used in Song dynasty China by the military for navigational orienteering by 1040–44, [22] [35] [36] and was used for maritime navigation by 1111 to 1117. [37]
The compass was an addition to the ancient method of navigation based on sightings of the sun and stars. It was invented during the Chinese Han dynasty and had been used for navigation in China by the 11th century. It was adopted by Arab traders in the Indian Ocean. The compass spread to Europe by the late 12th or early 13th century. [33]
The period of a harmonic oscillator is completely dependent on the physical characteristics of the oscillating system and not the starting conditions or the amplitude. [ 125 ] ( left and center ) The first pendulum clock , invented by Christiaan Huygens in 1656.
The discovery of this document marks the end of the prehistory of the Philippines at 900 AD. During this historical time period, the Philippine archipelago was home to numerous kingdoms and sultanates and was a part of the Indosphere and Sinosphere. [1] [2] [3] [4]
The compass's origins may be traced back to the Warring States period (476–221 BC), when Chinese people utilized a device known as a si nan to point in the right direction. During the early Song dynasty, a spherical compass with a small needle made of magnetic steel was created after steady development.
In the latter cases, only an approximate time frame will be given. For example, the Deva dynasty is believed to have ruled during the 12th and 13th centuries AD, but the exact dates are disputed. The year of establishment and/or the year of collapse of a dynasty could differ from its period of rule over a particular realm and/or geographic region.
A canal lock system in modern-day France which uses the pound lock system developed during the Song dynasty. In ancient China, the sluice gate, the canal lock, and flash lock had been known since at least the 1st century BCE (as sources then alluded that they were not new innovations), during the ancient Han dynasty (202 BCE–220 CE). [67]
As of 1054, Shen began serving in minor local governmental posts. However, his natural abilities to plan, organize, and design were proven early in life; one example is his design and supervision of the hydraulic drainage of an embankment system, which converted some one hundred thousand acres (400 km 2) of swampland into prime farmland. [13]