When I read Nova I noted how unusually fast the faster-than-light was. The ship goes from Alkane to the Dim Dark Sister in five hours, and from the Pleiades to Earth in three days. These are cars-in-the-US velocities, the whole inhabited galaxy is about as far apart emotionally as New York and San Francisco. And they land directly on the planets too, and can be used on the planet to whizz around to the other hemisphere.
Normally in science fiction, faster than light has a speed that has nothing to do with Einstein and everything to do with self-referentiality and the way other science fiction has done itfaster than light ships go at the speed of sailing ships, taking months to go between stars. They are wormholes or Jump or something letting them go faster than light, but it takes months of the crew’s real time. And when they get there, they can’t land on planets, any more than sailing ships can (outside of Dunsany) sail on land, they need space stations to be their ports, and they need dedicated career sailors and officers.
There’s nothing wrong with doing the Napoleonic Wars in space, as Honor Harrington does, and the Misdhipman’s Hope books, and perhaps Dread Empire’s Fall too. And if that’s what you’re doing, it’s reasonable that your ships work that way. But there are a lot of books where there isn’t an explicit analogy, where the ships aren’t even Naval vessels but commercial shipping. Cherryh’s Union/Alliance and Chanur, Bujold’s Vorkosigan books, Elizabeth Moon’s Vatta’s War books and her Aunts in Space series, Larry Niven’s Known Space, George R.R, Martin’s Dying of the Light universe. That’s a lot of really different kinds of books that have this kind of “standard” FTL.
I don’t know where it comes from. Was there some ur-novel that did it at this speed and everyone copied it? If so, what? Was it Citizen of the Galaxy? Or was it from the influential role-playing game Traveler, or even the influence of Star Trek?
And what’s the appeal? Is it that it gives you lots of time in space, in a contained environment where adventures can happen, coming to planets as ports at usefully specified intervals? Because I can see how it’s plot-useful, but there isn’t any natural law saying that this is how FRL will work.
And then there’s the ever brilliant Vernor Vinge who always thinks about what he’s doing, with a whole range of speeds of faster than light in A Fire Upon the Deep, and “nearly as fast as light, plus coldsleep” in A Deepness in the Sky.
I think at this point, if you’re writing anything with FTL, it would be worth considering other models than the sailing ship. Delany did long car trip distances. We could also consider commercial planes, getting us around North America in a few hours, and across the world in half a day. And there are always trains, either long distance or commuter railand how about freighters as long haul trucks? I don’t mean copy them slavishly, just take the internalised emotional truth of the way they work and try it on a larger scale. Never mind leaving Earth and putting in at Madeira’s Star for water in a month’s time, how about leaving Earth and spending seven hours in cramped seats eating awful food and ending up in Andromeda. It doesn’t mean people would do it all the time, how often do you cross the Atlantic, after all, and anyway, a universe where people did it all the time would be an interestingly different universe. Best of all, how about something that isn’t an Earth model, something that will make me look up from the book and say “Wow, wow, you’ll never believe the way they did faster than light in this one!”