What were the scientific and technological achievements in ancient China?

1. Achievements in astronomical calendar: The ancient calendar in China adopted the combined calendar of Yin and Yang, that is, the cycle of the sun was taken as the year, the cycle of the moon as the month, and the leap month was used to coordinate the relationship between the year and the month. According to the position change of the sun in a year and the evolution order of the ground climate caused by it, the ancients divided the year into 24 segments and 12 months to reflect the four seasons, temperature and phenology.

The calendar of Xia Dynasty is the earliest calendar in China, and the month is determined according to the direction pointed by the Big Dipper in bucket handle. Xia Zhengxiao, preserved in Dali, is an important document about Li Xia and the earliest astronomical calendar work in China.

2. Papermaking is one of the four great inventions in China, which was invented in the Han Dynasty and perfected in the Han Dynasty. Papermaking, especially improved by Cai Lun in the Eastern Han Dynasty (also known as "Cai Hou Paper"), is a revolution in writing materials. It is easy to carry and has a wide range of materials, which has promoted the cultural development of China, Arabia, Europe and even the whole world.

3. 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.

Gunpowder 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 the propellant of bullets and shells, the propellant of rockets and missiles and the energy source of other driving devices, which is an important part of ammunition. Outstanding achievements in the history of human civilization. Because of its lethality and shocking power, gunpowder is one of the important inventions of human civilization, which has brought the functions of relieving armistice and security defense to mankind.

5. Printing is one of the four great 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. The introduction of printing technology into Europe accelerated the process of social development in Europe and provided conditions for the emergence of the Renaissance.

Marx called the invention of printing, gunpowder and compass "a necessary prerequisite for bourgeois development". Printing invented by China people provided the necessary premise for the establishment of modern society.