So, I am in a process of finding a good name for myself in Chinese. I wanted it to be somehow connected to space, maybe astrophysics, maths etc. The thing that actually inspired me to sign up for a Chinese course was 三体 book, and I was just wondering if taking a name from it would be considered stupid?
It's OK from 三体, since names from it are generally 'normal', however in many literature works the names are very unusual and awkward if they were used in real world, since they are carefully picked to make the possibility that there are people with the same names in the real world. (since which may cause problem) I haven't read much western literature but I guess things are probably the same.
I was just wondering if taking a name from it would be considered stupid?
Depend on how common the name is. Names like 國強 or 家明 are like John or David in English. Even the main character in a famous novel is named John, no one would think it is stupid to name yourself John. Only you know this name was inspired by that John in that famous novel.
If we know which character you are talking about just by the name, it is probably not a good idea. For example, a name that appeared only in one particular book.
Family name matter too. No Chinese whose last name is 周 would name his child 周恩來 (蔡恩來 would be ok). ; No English speaker would name a child Harry Potter, but Harry with any other last name would be fine because Harry is such a common name
Although 《三体》 is a famous sci-fi series, not everyone have read it, and many people actually don't remember names of people except some main characters or those with distinct characteristics (e.g. some that I remember: 叶文洁，罗辑，章北海，丁仪).
So in your case, my suggestion is that it will be fine to choose a name from the book, as long as it is not of famous characters. Most likely other people will not find where you take that name from.