I've seen commentary somewhere about split infinitives and Star Trek ("To boldly go!"), but it only recently clicked with Star Wars and "These are not the droids for which you are looking for," with its preposition. I've written about Victorian grammar rules before (and according to Google I am pretty much the only person who refers to them as that, which is... odd... given that I didn't make up the phrase) and a piece by David Foster Wallace about such things.
Now, if anyone can pull off using formal written English when using spoken English, Alec Guinness was one of those people, but it would have been jarring.
For the Star Trek intro quote, splitting the infinitive makes for better cadence/rhythm/meter.
If we look at sci-fi as being about the possible, well, there you have it.
