Scientific explanation of superstitious activities

First of all, what is superstition? Superstition refers to blindly believing something without knowing it. So, as you described, I think your friend is not superstitious about so-called superstitious activities, but superstitious about science. Some superstitious activities, such as what you said, are mysterious things in themselves, and you have to explain them with so-called science, which makes people feel neither fish nor fowl.