This morning I went through the closet in my old room at my parents’ house and pulled out some old toys for my son: some Buffy the Vampire Slayer action figures, a Harley Quinn doll (with two hyenas!), and a very perplexing Jonny Quest figurine (Hadji in… a mech suit? With a machine-gun arm?). The kid is pretty dang into them. And that’s not the only connection between past and future that’s going on today.
I haven’t really written much (any) sci-fi before, but one of my current WIPs is “cli-fi,” aka “climate change fiction.” It’s about as sci-fi-y as The Hunger Games, in that I’m aiming for a world that seems basically like ours only after some kind of disaster, with some technology that’s basically magic and just there for plot reasons (sort of like in Star Wars, only there’s no Force. Yet?).
Obviously even when you’re writing something set in a contemporary world, you have to do worldbuilding: small town? Big city? What details of technology give the setting? Buffy is contemporary to when it aired (and boy do the outfits look hilarious nowadays, except for the ones that are somehow back on-trend) but still has tons of worldbuilding around the magical/supernatural elements.
Something like Burn Notice has a world built up of some real places and organizations (Miami, the CIA, the IRA) and lots of fake people (all of the characters except Sam Axe, because I refuse to live in a world where Sam Axe isn’t real).
Worldbuilding for a world that’s not our own is trickier… but pretty fun.