How to identify the direction of a method or natural phenomenon.

Observe the direction of the sun: at noon, the sun in the northern hemisphere is south at the zenith, while the sun in the southern hemisphere is north at the zenith. Observe the direction of Polaris: the direction of Polaris is due north. Observe the direction of sunflower: Sunflower is a plant with strong phototropism, always facing the sun, and the sun rises and sets in the west. Sunflowers face east in the morning and west at night. Observe the flying direction of geese: in spring, geese fly north; In autumn, geese fly to the south. Observing tree rings: Many trees in the north of China have clear rings in the cross section, sparse rings in the south and tight rings in the north.

The Big Dipper will appear in different directions in the northern hemisphere sky in different seasons and at different times at night, so the ancients decided the seasons according to the direction pointed by bucket handle when he first fainted. The ancient book "Guo Guanzi" records: bucket handle refers to the east, and the world is spring; Guide to barrel handle, it's summer in the world; Bucket handle refers to the west, and the world is autumn; The barrel handle refers to the north, and it is winter all over the world. The alternation of seasons is closely related to the "intersection of the yellow and the red", which is the fundamental reason for the change of the four seasons and the division of the five zones on the earth, and affects the physical and geographical phenomena closely related to it. According to the direction of the Big Dipper in the night sky, ancient people can guide agricultural production not to miss the season. As the old saying goes, "Look at the Beidou at night and know the north and south".