According to legend, Emperor Qianlong of the Qing Dynasty put on casual clothes and traveled to the edge of a red sorghum field. He saw that red sorghum was just the season of flowering and drying rice, and it grew gratifying. When the emperor was happy, he conveniently folded one and held it in his hand to enjoy it. Just when I was happy, I met an old lady in the countryside. The old lady said rudely, Your gentleman is very ignorant. This sorghum is the season for drying rice. Isn't it a pity that you broke it? This ear of sorghum needs to be plowed for several meters, so we are looking forward to a bumper harvest when we farm. Do you know how hard it is? !

Emperor Qianlong was scolded by the old lady and had to apologize quickly.

When Emperor Qianlong returned to Beijing, one morning he gave his ministers an examination question: What is the heaviest thing in the world? Ministers talked about gold and lead, etc. The emperor said: poor. None of what you said is right. Only the principle is the heaviest in this world, and no one can move it. Then I told you what happened to me, saying that as the king of a country, I was scolded by an old woman in the countryside for her red sorghum. I was speechless because the old lady was right. No one can move the word "reason". Throughout the ages, reason can travel all over the world.