@i-am-insane there’s one book that I always think of when I read that sort of story. Flux, by Stephen Baxter, is about very small people in the far future, living inside of a neutron star and the kinds of problems they’d have to deal with in an environment on that scale. It’s ostensibly “hard” science fiction, and the author is pretty well-known for the outlandish but supposedly plausible concepts that he brings into his stories. He’s also one of the grimmest hard SF writers I’ve read. His worlds are just very, very bleak. BUT he wrote a story that deals with the actual physics of a society of microscopic people, so props for that.