I've never understood the association with relative time in regards to science fiction.
SF is typically futuristic, but that bears jack all as to whether it takes place in the past, present, future, or even anything relative to our planet.
Science, in that it pledges greater allegiance to, extrapolates, or invents in an internally consistent way. But not time.
Scifi is fiction about where science might take us, how modern tech might impact society. It is foreshadowing a potential future. So stuff set in the past, generally, isnt considered scifi unless it somehow describes a potential future. This separates scifi from technothrillers (tom clancy et al) that are tech-heavy but set today rather than in the future.
> So stuff set in the past, generally, isnt considered scifi unless it somehow describes a potential future.
This makes literally no sense to me. Any definition of the future that doesn't include the past is just fiction, and consequently, any past is a potential future.
What you're saying sounds more like "If it doesn't have greater than present levels of 'technology', then it's not science fiction."
Which seems incredibly limiting and ignoring of the central genesis of the genre, as you've pointed out -- science.
Science is a verb, not a noun.
The idea of pointing at something in a book and saying "That's science" (and correspondingly, pointing at something in other fiction and saying "That's not science") is odd.
Where do Mary Shelley, Jules Verne, or H.G. Wells fit in your definition?
What makes Star Wars a fantasy series and not sci-fi is that it doesn't even try to be sci-fi. It's a fantasy story reskinned with robots and spaceships. Not being sci-fi doesn't have much to do with being set in the past vs. the future (BSG spoiler alert: for example, Battlestar: Galactica is a proper sci-fi and happens to be set in the past).
>Battlestar: Galactica is a proper sci-fi and happens to be set in the past
Battlestar Galactica - the Christian allegory with angels and gods and literal miracles reskinned with robots and spaceships?
Everyone is entitled to their opinion but that's all anyone has here, including myself: opinions. There is no objective and universally accepted definition of science fiction which requires rigid conformity to scientific principles, or a lack of mythological or religious themes. The lines people draw between "science fiction" "science fantasy" and even "fantasy" are based on marketing and personal taste.
Star Wars is sci-fi, no less so than Galactica or even Star Trek, and all of it is also science fantasy. These aren't separate categories, but poles on a spectrum of speculative fiction.
Though, I agree Star Wars is not very sci fi, it's a fantasy epic with sci-fi stuffs in it.