Answer:
1. Gunpowder. The study of gunpowder began in ancient alchemy. Tang Dynasty alchemist in Tang Dynasty Gaozong Yongchun first year (682) sulfur fire method, with sulfur, saltpeter, ground into powder, and then add saponin seed (containing carbon). Tang Xianzong Yuan and the third year (808) also created a type of fire stone method, with saltpeter, sulfur and aristolochia (containing carbon) burned together. These two formulations, by mixing three kinds of drugs, have initially possessed the ingredients contained in gunpowder.
2, ecliptic and water armillary, astronomical instruments, have played a great role in observing the sky. Nhat Hanh, whose real name was Zhang Sui, was the most famous astronomer of the Tang Dynasty. In the thirteenth year of the New Century, one line also used its own "complex moment diagram" to measure the height of the North Pole and the length of the shadow of the spring equinox, summer solstice, autumn equinox and winter solstice in several places in Henan Province, and measured the length of the Earth's meridian of 1° about 123,700 meters. This is the first measured meridian in the world, which is of great significance.
3. Block printing. Block printing is the earliest form of printing in China. The earliest surviving engraved print with a date is the Diamond Sutra from the ninth year of the Tang Dynasty (868). In 1966, it was discovered in South Korea, engraved between 704 and 751, which is the earliest known block print.
