As firm as Mount Tai (wěn rú tài shān), as firm as Mount Tai, unshakable. The formal use of law; As predicate and adverbial; Under the strong attack of the enemy, our position ~. The synonym is rock-solid, motionless and impregnable. The antonym is stormy, scary and dangerous. The source of Han Meicheng's "Writing to the King of Wu" is: "Easy to do whatever you want, content with Mount Tai." The marquis of Wu, relying on high officials and generous officials, fought side by side with the brave brothers, calling himself ~, and was very proud. ★ Li Qing Ruzhen's "Mirror Flower Edge" for the third time

The original meaning of the word "Beidou" refers to a group of stars near the North Pole in the northern night sky, which is shaped like a bucket spoon for scooping water, hence its name. Corresponding to the low latitude "Nandou" star (in equatorial coordinate system). The naming age of the Big Dipper was in the middle and late Neolithic Age. In the Paleolithic Age, humans did not have special equipment for scooping water. We noticed that the bucket is a special device for scooping water, which is closely related to water. The "water" of the "five elements" coincides with the north. Therefore, the naming of "Beidou" should be in the same period as the appearance of the concept and theory of "Five Elements". The name of Beidou must be a resident in the middle latitude (30-40 degrees north latitude). Because Beidou is invisible to the tribes near the equator, it can't be used as a reliable time indicator. The name of Beidou should be farming people. Because the bucket handle of Beidou can indicate the season (Beidou refers to the East, and the world is spring; Beidou guide, the world is summer; Beidou refers to the west, and the world is autumn; Beidou refers to the north, and the world is winter). When the Big Dipper was named, the son of heaven might have appeared. Because Beidou revolves around the North Pole, this implies the concept of "the emperor is in the middle of the world (living in the North Pole)".