It’s curious, as a Science fiction writer that actually has a go at writing Science in fiction to look at how science and fiction have merged and parted company over the passage of time since various books were written. Science fiction writers hoping for any kind of immortality-in-text have a double whammy – far more so than other books which merely date and – in some cases – become dated. With us, reality catches up too.
Now I never met a writer who did not really want their book to be enjoyed by people from now and unto generation unborn… and some do manage this well. Shakespeare, Austen, Heyer, Tolkien, and Herbert’s Dune all spring to my mind. On the other hand there are plenty of books — SF and otherwise — which are nearly incomprehensible or boring now. So how do they do this?
Well, I’m hoping you’ll tell me, but here are a few of my strange ideas.
1) It’s about people, stupid. Relationships remain interesting – even if the Characters are Mr Darcy et al, or a Regency Buck.
2) If you write a period piece it stays correct. So: Heyer detective stories are dull now – because she assumed her stories were contemporary and for contemporary audiences — and much of the background therefore is implicit and not clear. Her Regencies on the other hand, actually are quite explanory, as she assumed her audience wouldn’t know. If she’d written her detective stories like that we’d enjoy them now, but readers then would have been disgusted.
3) While sf too far in the future risks alienating your audience if the science becomes incomprehensible, too close risks being overtaken. Therefore I tend (as in Dune for example) to write reasonably far future, but with reasons that science has not moved the characters so far that they’re not easy to identify with (thus, often, my books are period pieces – RATS, BATS & VATS is a WW1 piece – despite being sf.
So: what thinkest thou?
Mad Genius Club 
What an intersting thought. I’ve lately been playing with parallel worlds. Pretty much 100% guaranteed to be wrong. How many years until I’m “bad science” and flung across the room? Or will my stuff be “a charming fantasy, based on an antique understanding of the Universe. Read it dear, the characters are mahvelous!”
This would explain a lot of the profusion of Alternate History and Alternate Universe stuff lately. If you can simply explain away divergence with “well it’s an alternate timeline…” it helps keep stuff from getting dated. Tricky, you authors are!
Until there’s more multiverse research, then we’ll get laughed at as hopeless simpletons. Or utterly forgotten, if the characters and problems don’t hold interest, once the background world is passe.