1, papermaking
It is one of the four great inventions in China. During the Western Han Dynasty, people had understood the basic methods of papermaking. Cai Lun, the eunuch of the Eastern Han Dynasty, summed up the previous experience, improved the papermaking technology, and made paper with plant fibers such as bark, hemp head, rags and old fishnets as raw materials, which greatly improved the quality of paper. This kind of paper is easy to find, cheap and easy to popularize.
2. Compass
In ancient times, it was called Sina, and its main component was a magnetic needle mounted on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangent direction of magnetic meridian, and the south pole of the magnetic needle points to the geographical south pole, so the direction can be distinguished by using this property. It is often used in navigation, geodesy, tourism and military affairs.
3, gunpowder
It is one of the four great inventions in China. It is a substance that can burn quickly and regularly under the action of appropriate external energy, and at the same time produce a large number of high-temperature gases. Militarily, it is mainly used as gunpowder for bullets and shells, propellant for driving devices such as rockets and missiles, and is an important part of ammunition. Outstanding achievements in the history of human civilization.
Step 4 print
It is one of the inventions of working people in ancient China. Engraving printing was invented in the Tang Dynasty and was widely used in the middle and late Tang Dynasty. Song Renzong and Bi Sheng invented movable type printing, which marked the birth of movable type printing. He was the first inventor in the world, about 400 years before Johannes Gutenberg invented movable type printing, which marked the birth of movable type printing.
The historical significance of the four great inventions:
The statement of the four great inventions originated from the British sinologist Joseph Needham. The four great inventions greatly promoted the development of politics, economy and culture in ancient China, spread to the west through various channels, and had a great impact on the history of world civilization. The four great inventions are a series of glorious footprints left by China's ancient ancestors to the world, and they are symbols of great contributions made by human civilization and progress.
The invention of papermaking provided economical and convenient writing materials for human beings and set off a revolution of human writing carrier; Engraving printing has greatly promoted the spread of culture; Compass provides conditions for European navigators' navigation activities; The use of gunpowder weapons changed the way of fighting, helped the European bourgeoisie destroy feudal fortresses and accelerated the historical process of Europe.
The above contents refer to Baidu Encyclopedia-Compass Baidu Encyclopedia-Print.