alt Hacker News> Soft vs hard is based on how closely the world tracks with modern physics/science
Maybe it's not productive to quibble about definitions like this, but FWIW I don't agree with this criteria. I would argue Greg Egan's work, for example, is just about the "hardest" sci-fi there is, and yet much of that work takes place in universes that are entirely unlike our own.
Personally, I think what makes for "hard" sci-fi is that the rules of the universe are well-laid-out and consistent, and that the story springs (at least in some significant part) out of the consequences of those rules. That may mean a story set in the "future", where we have new technology or discover new physics, or "alternate universe" sci-fi like Egan's.
If changing the laws of the universe is fine, then nothing gets excluded even Harry Potter. It’s one of those definitions that allows anything and ultimately only feels fine because you’re adding some other criteria.
In defense of hard science fiction, it’s a meaningful category to talk about even if it’s not something you personally care about. People often want to weaken it but that just opens a door for a new category say “scientific science fiction” and we are back to square one.
Asking questions like what does AGI look like when they can’t just magically solve all issues can be fun. Hand waving the singularly as some religious event can also make interesting stories but so is considering how chaos theory limits what computation can actually achieve.