Manual compass simple practice video

The simple video of manual compass is as follows: How to make a simple 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 south pole of the magnetic needle points to the geographical south pole (magnetic north pole), and the direction can be distinguished by using this property.

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. According to ancient mine records, it first appeared in the Cishan area during the Warring States Period.

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 geomantic omen.

The earth is a big magnet. The poles of the earth are close to the geographical south pole and the geographical north pole respectively. When the magnets on the surface of the earth can rotate freely, they will indicate the north and south because of the nature that the magnets repel each other and attract each other-this truth was not understood by the ancients; But this phenomenon has been discovered by the ancients.