I have strong opinions about this. My criteria for a book being science fiction and not fantasy is that is must be based on scientific thinking. The author must

I have strong opinions about this. My criteria for a book being science fiction and not fantasy is that is must be based on scientific thinking. The author must have done some work to determine whether whats happening in his book is at least plausible according to real science, and then work out the details of how it would actually function. So I regard most "science fiction" books and almost all "science fiction" films as really being fantasy. Essentially they are works of fantasy or dramatic fiction re-skinned with lasers and aliens instead of magic and goblins (to a great or lesser extent). So dune is a great book but it is 90% fantasy, there is only a little bit of research done by the author on desert ecosystems. My favourite real science fiction author is Arthur C clarke. some good books by him... earthlight the fountains of paradise islands in the sky the sands of mars rama songs of distant earth Also would recommend accelerando by Charles Stross and the mars series by Kim Stanley Robinson