I can't speak to that discrepancy, but I like the expanse as an example of hard sci-fi primarily because it makes very few tech jumps to build its universe. Ign

I can't speak to that discrepancy, but I like the expanse as an example of hard sci-fi primarily because it makes very few tech jumps to build its universe. Ignoring the alien tech, the only real innovation that appears outlandish to us now that they gloss over in the series are those fusion starships. But as with any sci-fi, you have to have some amount of suspension of disbelief when talking about new tech. If the author knew everything about the tech they talk about, they wouldn't be writing science fiction because they would have invented it, and we'd be reading nonfiction instead.