In other words, children’s issues.
Even in my life as a studio student, I eat with a couple in the bus. In the early spring, the sun is so shining. In front of it is a beginner father with a child, so 4 years old. This is the age when a lot of questions start. Well, and of course the question "And why the sun shines". Dad explained for a long time and with feeling, "Well, all kinds of substances are broken up there, energy is released, part comes to us in the form of heat and light. It is" The child shakes his head and asks the following question: “Dad, what is energy?” The father looks out the window, his enthusiasm has already passed and after the pause issues the "EM CE square".