Compass is always a guide. What is the principle?

Compass is one of the four ancient inventions that we are proud of, which played a great role in Zheng He's voyages to the West. It can be said that without the help of a compass, it is difficult for many explorers in the world to explore unknown areas. Then someone asked, the compass always points the way. What is the principle? The compass itself has a magnetic field, and the earth is also a huge magnet. Under the action of magnetic field force, the compass can always point to the south. Let's analyze it.

Compass was called Sina in ancient times. Before we know the compass, we must first know its working principle, so as to know why our compass always points to the south. The essence of compass is a sensitive magnetic needle. The two ends of the magnetic needle are divided into North Pole and South Pole. When we were young, we all played with toys like magnets. If two ends with the same polarity are close to each other, repulsive force will be generated. If two ends with different polarities are close to each other, they will attract each other. This is a magnet.

Ancient ancestors would rub a magnetic magnet with an iron needle and let the iron needle follow the magnetism. At this time, a very thin cotton thread is placed in the middle of the needle, so that the magnetic needle will always keep one direction under the magnetic force of the earth's magnetic field, and then corresponding marks can be drawn on the magnetic needle according to the geographical south pole and geographical north pole. It sounds simple to make such a simple compass, but such discovery and invention have gone through a long history.

The invention of compass not only opened the door to the world, but also provided great convenience for our travel. In ancient times, people used Sina to measure the location and feng shui of sacrifices, which shows that their technology of using compass is very mature, so compass embodies the great wisdom of our Chinese nation.