It is suitable for people born in the earth to use the word "ai" in their names, because the five elements of the word "ai" belong to the earth, and when used as a name, it means quietness, auspiciousness, happiness and ease, so it is suitable to be used in names. But these are all feudal superstitions and have no scientific basis. We have to believe in science. This answer is for reference only, please do not be blindly superstitious.