The structure of a "tumbler" is generally a structure with a heavy top and a light bottom, with a sphere below. The center of gravity of a tumbler is generally lower than the geometric center of an object. When the right hand moves the tumbler, the tumbler leans to one side and the center of gravity rises. After letting go, according to the principle of minimum potential energy, the tumbler is unstable at this time, and it always returns to the minimum potential energy, which is its initial equilibrium position. This explains why the tumbler always returns to the same position.
The greater the inclination of the tumbler, the greater the horizontal distance between the fulcrum and the center of gravity, the greater the swing effect produced by gravity, and the more obvious the trend of restoring it to its original position, so the tumbler will never be pushed down. To put it simply, an object that is light on the top and heavy on the bottom is relatively stable, that is, the lower the center of gravity, the more stable it is. So no matter how the "tumbler" falls, it will always "get up" again.
Introduce the historical exploration of tumbler;
Zhao Yi, a historian and writer in Qing Dynasty, wrote in Textual Research on Yu Cong? It is recorded in Volume 33: "Children play with tumblers and paste paper to make them look like drunkards. Although they are empty and solid, they cannot fall down." According to the Tang Yan written by the kings of the Five Dynasties, the "tumbler" evolved from "catching drunken immortals" in the Tang Dynasty, and was also called "drinking beard" and "drinking beard" at that time, which was a tool for ancient people to persuade wine.
Carve a human figure out of wood, with the upper part thin and the lower part thick. When drinking, people sit around the table and put the "drunken fairy catcher" on a plate and put it in the middle of the table. Older people began to twist it with their hands and make it rotate. When it stops, they will drink at the person pointed by their fingers, and then the drinker will twist it again and again until they have a good time. In the Song Dynasty, Dou Ge wrote a book named "Liquor Spectrum and Liquor Preface", which has a detailed record: "In this world, there are many kinds of liquor prefaces. Those who catch drunken immortals are dangerous people and turn to those who point to seats. "
In the Southern Song Dynasty, Zhang Bangji also described the production and use of this wine-persuading tool in Mo Zhuang Man Lu: "The drinking mat is carved into wood, which is sharp, placed in the plate, standing left and right, dancing like a dance, and still for a long time." Depending on the place they raise, rewarding them with cups is called persuasion. At the end of the Tang Dynasty, Lu Wang wrote an article "Wine Bears Long song", in which he said, "A man with a good appearance becomes interesting, but his temperament is uncertain, and the weight lies with people rather than wine. "