> What, you thought early era SF used accurate science?

It depends on the author I guess. Stanislaw Lem for instance mostly separated his "silly-fiction universes" (e.g. the Ijon Tichy and 'robot fairytales' novels) from his "hard sci-fi" universes (for instance the Pilot Pirx novels) - and there it was mostly about the restrictions of space travel (where space travel is usually just plain old cargo hauling), Pirx never left the solar system because it simply wasn't possible during his lifetime (part of him eventually did - maybe - in his last book 'Fiasco'), instead the Pirx novels were mostly occupied with typical 'space trucker' problems like oil leaks on his rocket boosters, wrestling with space harbour bureaucracy or the occasional humanoid robot going into a mode that could be described as 'mad' or 'depressed'.

For instance: Isaac Asimov's Three Laws of Robotics aren't based on any practical science, they exist as a plot device for setting off mystery stories with robots and morality plays about hubris. And the reason robots have positronic brains is that positrons were recently discovered at the time, and it sounded cool. Yet people will swear Asimov is one of the hardest SF authors around.

Sometimes you might get a SF author who's an expert in a particular field or has a specific hyperfixation, and that one aspect of their stories might be grounded somewhat in plausibility, but everything else turns out to be complete nonsense.