Comment by lazide

That could be one.

But I was referring to the possibility that it’s energetically impractical to ever get out of the solar system (or even travel within our solar system) in a way that any human is likely to ever want to do it. (Aka no FTL, or even near light speed)

And this likely applies to anything we’d call ‘life’ too.

And that time is actually one way, so no do overs, and no time travel. (Either because of the 2nd law of thermodynamics, or the 2nd law is an effect of this!)

If we accepted that, it would kill what - 95% of all Sci-fi ever?