Reference: Public Forum
Compass is a tool to indicate the direction, which is widely used in navigation, field exploration and other fields. There are two kinds: one is a geomagnetic compass based on the polarity of the earth's magnetic field, but the north-south direction indicated by this compass is different from the real north-south direction, and there is a magnetic declination; The second is the electronic compass, which adopts the magnetic resistance (MR) technology of the magnetic field sensor, which can correct the magnetic declination problem well and has been widely used in GPS positioning equipment. Joseph Needham, a British sinologist, called the compass one of the "four great inventions of ancient china". Historically, the compass used to indicate the direction in the circle of Chinese civilization was earlier than that in Europe, but whether the practical magnetic compass was invented in China or Europe is controversial. Sina has a view that "Sina" recorded in ancient China is the earliest form of compass. In the Eastern Han Dynasty, Wang Chong's Lun Heng (Ming Jiajing Edition) (AD 27 ~ about 97) volume 17 is a guide to the response to Article 52, "SiNa's shovel, cast on the ground, its shovel". Although this record is not the earliest, it is the first one to be clearly stated. But the specific form of Sina is controversial. Early researchers decided to use natural magnets as spoons to cooperate with websites. Although there are Sina spoon maps unearthed in Han Dynasty and stone carvings unearthed in Donghan Tomb in Nanyang, Henan Province, they do not fully cooperate. During the period of 1950, Chinese historians of science and technology tried to make a spoon-shaped Sina with natural magnets, but failed because of the small magnetic distance and high friction at the bottom. In 2005, Ji Sun, a researcher at the National Museum of China, decided that the word "Sina's ladle" was indeed appropriate according to Lun Heng, a remnant Song edition collected by the former Beiping History Museum, so it seems that "its ladle guide" does not refer to the handle of the ladle. Although it can't be denied that Sina mentioned by Wang Chong is a kind of compass with a magnet as the key to match the venue, before the invention of practical magnetic compass, the main form of compass was water floating compass, and there were other forms such as side leaning, wire hanging and spire. At present, the earliest compass used for navigation is recorded in Zhu's Talking in the Song Dynasty: "Sailors know geography, watch the stars at night, watch the sun by day, and watch the compass in the dark." Zhou Ping Ketan was written in111year-117 years, but it was about1086 [/kloc-]. This is about a century earlier than what Alexander Nekem might have written in 1 190 in "Transmutation is rerum": "When sailing, the sun is covered with white clouds, or when it is dark at night, rub the iron needle with a magnet, and when the needle stops, it refers to the north and south." Almost at the same time as Britain, France and later Italy also recorded the first compass. Floating compass can also be used for navigation, because it is not as easy to overflow as some people think. Recently, porcelain floating compasses of the Ming Dynasty were found in Qingdao and Hainan, and the size was as large as: the maximum outer diameter was 9.5 cm; There are concentric circles containing water, with a hole diameter of 4.4 cm and a hole depth of 2.3 cm. The periphery is marked by blue and white glaze, and the base and walls are thick and solid. I guess it's water collection. Add water when you use it. The basic principle of modern liquid compass is similar, but the sealing technology is improved.
Compass is a magnetic pointer, which is combined with the steering wheel to form a compass. The invention of compass plays an important role in the development of human civilization, and it is called four great inventions of ancient china together with papermaking, printing and gunpowder. The British philosopher Francis Bacon (156 1- 1626) pointed out in his book New Tools that the three great inventions of printing, gunpowder and compass have changed the whole face and situation of all kinds of things in the world, which has caused countless changes. It seems that any empire or sect has influenced mankind. In fact, the appearance of compass and its application in navigation, combined with China's ancient shipbuilding technology, navigation technology and astronomical knowledge, will undoubtedly have a far-reaching impact on the development of navigation in China and even the world. The creation of the compass should have a certain magnetic knowledge base, including the knowledge that the long magnetic bar has the property of taking the north-south direction, the knowledge of the properties of magnetic induction, magnetic polarity, magnetic attraction and magnetic repulsion, and the knowledge of geomagnetic declination, that is, the north-south direction pointed by the compass does not completely coincide with the geographical north-south direction, and the included angle between their directions is called geomagnetic declination. Also understand that the magnetic declination will change with different geographical locations. Only when the compass is invented on the basis of this knowledge can it be called a real invention.
Reference: chiculture/0802
The compass was used to indicate the direction in the circle of Chinese civilization a little earlier than that in Europe, but whether the practical magnetic compass was invented in China or Europe is controversial. [Editor] Sina has the view that "Sina" recorded in ancient China is the earliest form of compass. In the Eastern Han Dynasty, Wang Chong's Lun Heng (Ming Jiajing Edition) (AD 27 ~ about 97) volume 17 is a guide to the response to Article 52, "SiNa's shovel, cast on the ground, its shovel". Although this record is not the earliest, it is the first one to be clearly stated. But the specific form of Sina is controversial. Early researchers decided to use natural magnets as spoons to cooperate with websites. Although there are Sina spoon maps unearthed in Han Dynasty and stone carvings unearthed in Donghan Tomb in Nanyang, Henan Province, they do not fully cooperate. During the period of 1950, Chinese historians of science and technology tried to make a spoon-shaped Sina with natural magnets, but failed because of the small magnetic distance and high friction at the bottom. In 2005, Ji Sun, a researcher at the National Museum of China, decided that the word "Sina's ladle" was indeed appropriate according to Lun Heng, a remnant Song edition collected by the former Beiping History Museum, so it seems that "its ladle guide" does not refer to the handle of the ladle. Although it can't be denied that Sina mentioned by Wang Chong is a kind of compass with a magnet as the key to match the venue, before the invention of practical magnetic compass, the main form of compass was water floating compass, and there were other forms such as side leaning, wire hanging and spire. At present, the earliest compass used for navigation is recorded in Zhu's Talking in the Song Dynasty: "Sailors know geography, watch the stars at night, watch the sun by day, and watch the compass in the dark." Zhou Ping Ketan was written in111year-117 years, but it was about1086 [/kloc-]. This is about a century earlier than what Alexander Nekem might have written in 1 190 in "Transmutation is rerum": "When sailing, the sun is covered with white clouds, or when it is dark at night, rub the iron needle with a magnet, and when the needle stops, it refers to the north and south." Almost at the same time as Britain, France and later Italy also recorded the first compass. Floating compass can also be used for navigation, because it is not as easy to overflow as some people think. Recently, porcelain floating compasses of the Ming Dynasty were found in Qingdao and Hainan, and the size was as large as: the maximum outer diameter was 9.5 cm; There are concentric circles containing water, with a hole diameter of 4.4 cm and a hole depth of 2.3 cm. The periphery is marked by blue and white glaze, and the base and walls are thick and solid. I guess it's water collection. Add water when you use it. The basic principle of modern liquid compass is similar, but the sealing technology is improved. [Editor] Discovery of magnetic declination In the first year of Li Qing in the Northern Song Dynasty (104 1), Yang Wei, an astronomer at Tian Jian University, got the record of Yingyuan. "The guest took it and it should be right at four o'clock. When taking the needle in the middle, it is just right. " Gaiyang was born in Zi, from Zi to C; Yin was born at noon, and it turned from noon to disagreement; Therefore, the king of Bingwu is in the middle of heaven and earth, and the north and south are positive. 1088 Shen Kuo's "Meng Qian Bi Tan" "Fang Jia grinds the needle with a magnet, so it can guide. However, it is often east, not all south. " 1 1 15 "Herbal Yi Yan" "It is also a guide to use a needle to pass through the center of the lamp and float on the water, but it is often biased towards C. [Editor] The modern compass drought compass is the basic form of the modern compass, which is said to have been invented by the Italians. According to the historical records of * * * people, the compass was invented by China, and was introduced to Europe after effective improvement by * * * people. However, the existing record of compass in Europe is earlier than * * *, and the word al-konbas in * * * seems to originate from old Italian. China's drought compass was earlier than that in the west, and there is no clear record at present. Recently, a small statue (marked "Zhang") was found in a Song Dynasty tomb buried in Linchuan 1 198, Jiangxi Province, with something similar to a Feng Shui compass on it, which is also a dry compass. Some people think that the dry compass China may have been used earlier than in the west, but it may have been invented in the coastal areas of the south of the Yangtze River (such as Quanguang) at the earliest, so it is not regarded as Shen Kuo study. After that, the dry compasses of later inland generations were mostly used for feng shui compasses and timing compasses. For example, 174/l 189 Zeng Sanyi's Tongtanlu has a snail, or it has a meridian needle, or it is sewn with a meridian needle. Heaven and earth are facing north and south, so it's time for lunch. "Snail" may be a compass to correct time, and its main purpose is to correct time.