Why did you use a compass to navigate in ancient times?

Compass, called Sina in ancient times, its main part includes a magnetic needle mounted on the shaft, starting with a spoon, and finally converted into two thin magnetic sheets, and finally converted into a magnetic needle. The principle of direction measurement is that the magnetic needle can rotate freely under the action of natural geomagnetic field and keep in the tangent direction of magnetic meridian, and the north pole of the magnetic needle points to the north pole. It is often used in navigation, geodesy, tourism and military affairs. ? According to ancient mine records, it first appeared in the Cishan area during the Warring States Period.

In the Western Han Dynasty, there was an alchemist named Luan Da. He used the principle that like-sex magnets repel each other and opposite-sex magnets attract each other to make two magnets. The phenomenon of same-sex repulsion is called chess war. Later, Luan Dafang dedicated this kind of chess fighting to Emperor Wu of the Han Dynasty and personally demonstrated it in front of Emperor Wu of the Han Dynasty. Emperor Wu of the Han Dynasty thought it was novel and named Luanda General Wuli. Before the Northern Song Dynasty, China's compass was used in military war, sacrifice and geomantic omen. The application of military war was first seen in the appearance of compass in the period of the Yellow Emperor. Sacrifice and geomantic omen are ancient people's belief that magnetic field is pulse, and according to five lines of gossip, they infer the good or bad luck of a region.

Until the Northern Song Dynasty, due to the development of commerce, a large number of businessmen began to develop maritime trade. Because they can't tell the direction, the direction is too unstable only by the position of the stars. So Sina has been simplified as a compass and magnetic needle for maritime trade, and of course it still works for the military. Compasses are still used for sacrifice and geomantic omen. The appearance of compass promoted the development of world navigation and made people discover many new continents.

In fact, the function of compass seems to be mainly used for navigation, but it also has applications in military and Feng Shui industries. It's just that most people only know that it is widely used in navigation.

It is precisely because of the rise of modern navigation industry that compasses are more and more used in navigation.