What scientific and technological inventions were there in Song Dynasty?

Movable type printing, China ancient people invented movable type printing as early as 1 1 century in the Northern Song Dynasty. Printing, as one of four great inventions of ancient china, has a great influence on the process of world civilization and the development of human culture. The invention of movable type printing is a great technological revolution in the history of printing. It is a printing method, which replaces the traditional copied or non-reusable printing plate with movable metal or mud. The compass, invented in the Northern Song Dynasty, is the result of the long-term practice of the working people of the ancient Han nationality in understanding the magnetism of objects. 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 sacrifice, etiquette, military affairs and divination, and was used to determine the orientation when looking at geomantic omen. 1 1 At the end of the year or at the beginning of 12, China ships began to use compasses for navigation. The predecessor of compass is Sina, one of the four great inventions in ancient China. Its main component is a magnetic needle that can rotate freely on the shaft.