Earlier quoted context omitted.
> And it's hard sci-fi because they were AIs made of protons, not actual fairies Does mentioning your faeries are made out of atoms stop them being fantasy? > That's how it goes with sci-fi, innit. You can come up with anything you like as long as it's obvious that it's just advanced technology, not magic. Sure, I mean, even Star Wars is still considered within the genre despite it all being completely made-up - but…
My opinion on this might be controversial but I think there's very little difference between even "hard" sci-fi and all-out fantasy (but, with spaceships). There is very little space left to write a story that is interesting and compelling if one wishes to respect the bounds of what is scientifically plausible. Then again, if one starts to stretch the definition of "scientifically plausible" there's all sorts of thin…
Are we living in the same world? Quantum mechanics, relativistic effects, mathematics ( game theory anyone? ) are blowing my mind. The world is more phantastic than anything one could imagine and we know that we don't know everything. The constraint to stay in this world is the least limiting for an interesting and compelling story.