people can imagine flying in the sky because they see birds flying in the sky. We can compare the sci-fi movies of 3 years ago with the sci-fi movies of today, which is more like describing the future world hundreds of years later? Now, obviously. In an old sci-fi movie, the hero wants to make a video call, but he actually needs to hold a receiver in one hand. In those old sci-fi movies, the control room of the spacecraft in the future world was filled with all kinds of keyboards and indicator lights, but now the movies are all super-large and ultra-thin with transparent touch screens. If you don't invent a touch screen for them in real life, these filmmakers who specialize in imagination will never forget the keyboard.

Kong Qingdong once had an argument that there were many novels about chivalrous men in ancient China, but "hidden weapons" hardly appeared. And now the books of martial arts all contain hidden weapons. Why can't the ancients imagine hidden weapons? Because hidden weapons was imagined by modern novelists inspired by pistols. Without knowledge, you can think casually and you can't think of it.

I think there are two levels of imagination for science fiction and fairy tales.