When was the compass, one of the four great inventions, invented?

According to March 1982 Guangming Daily, Cishan (in present-day Wu 'an, Handan City, Hebei Province) is the birthplace of the compass, one of the four great inventions in China. According to ancient mine records, Geography of Ming Dynasty said: "There is a magnetic mountain in the southwest of Wu 'an County, Cizhou, which produces magnetite. "

The Ming Yi Award also said: "There is a magnetic mountain in the southwest of Wu 'an County, Cizhou, which produces magnetite. "Ancient Mine Records" also records the theory of "Ming Yi Governance": Cishan, 30 miles southwest of the county seat, is a primary mine, hence the name Zhou. Cishan, the hometown of compass.

The things about compass recorded in ancient books and the authors of ancient books are located in Zhao Yan Cultural District centered on Guhan. Compasses in ancient China, recorded in the classic range, were all made of natural magnets.

According to pre-Qin classics, only Wu 'an Cishan (now Wu 'an, Handan City, Hebei Province) produced natural magnets. During the Spring and Autumn Period and the Warring States Period, it was possible to create Sina, only the Zhao Yan Cultural District centered on Handan, and Wu 'an was probably the hometown of compass.

Compass, called Sina in ancient times, is mainly composed of magnetic needles installed on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangential direction of magnetic meridian. The north pole of the magnetic needle points to the north pole, so this property can be used to identify the direction.

It is often used in navigation, geodesy, tourism and military affairs. The invention of the compass with physical direction indication has three parts, namely Sina, compass and magnetic needle, all of which belong to the invention of China.

Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization. In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at Feng Shui.

Extended data

Sina is the earliest magnetic conductor. The name "Sina" began in the Warring States Period (475 BC-22 BC1year) and ended in the Tang Dynasty (665438 AD+08 AD-907 AD). Because Sina's ancient meaning has been constantly evolving, it has forged an indissoluble bond with a series of ancient inventions.

The earliest document that recorded Sina was Guiguzi, which wrote: "Zheng people take jade and will take Sina's car because they are not confused." As can be seen from the records in Guiguzi, in order to avoid getting lost, Zheng people must take Sina with them to "get jade".

In the mention of Sina, Chong Wang's account number is the most important. He clearly pointed out: "Sina's shovel, thrown to the ground, is its guide." "Spoon" means spoon. Sina should be a magnetic director with this "guide". However, the "land" here refers to the "ruins" in the ancient mechanical disk.

The mechanical disk was invented in Qin and Han dynasties and used for games or divination. There are 24 directions around the site, and the symbol of the Big Dipper is engraved in the center. According to these records, Wang Zhenduo, a famous modern historian of science and technology and expert in cultural relics reproduction in China, successfully restored Sina in the Han Dynasty (as shown in figure 1).

Sina model (restored by Wang Zhenduo) spoon-shaped Sina has not been unearthed, but there are pictures similar to spoon-shaped Sina on the stone reliefs in Han Dynasty, which shows that Wang Chong's records should be credible. In this stone statue, we can see that the main body of the picture is the magician and acrobat who are performing, and the people above are the aristocratic audience. There is a long-handled spoon suspected of Sina on the small square in the upper right corner (see the small illustration outside the picture), and a person is kneeling to observe.

The stone reliefs of the Han Dynasty (this picture is quoted from Joseph Needham's History of Science and Technology in China, Physics Volume) collected in the Ritburg Museum in Zurich. Judging from the materials left, it is the earliest form of magnetic pointing device to point to the polar Sina with a magnet.

The appearance of magnetic orientation instrument makes people change from passive orientation of observing celestial bodies to active orientation using geomagnetism. The earliest magnet orientation device of mankind is Sina made of natural bar magnets, which was further developed in the Han Dynasty at the end of the Warring States period (the first three centuries).

The appearance of Sinan instrument is of great historical significance, because it is a new guiding device based on the magnetic principle completely different from the astronomical orientation principle. It can work day and night in any weather conditions, quickly point out the direction, and is easy to operate and carry.

Initially, "SiNa" refers to the surface pole of shadow measurement. For example, "Everything is done wrong" said, "Therefore, Wang Li Sina is the first to seize the day." "Sooner or later" means just east and west, and it is extended to determine the direction of east, west, north and south. Lisina originated from Jong Li in Oracle Bone Inscriptions in Shang Dynasty and Li Mingji in Warring States Period. They are both going to set up a watch to measure the shadow of the sun.

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