At first glance, your average Biggie verse doesn't have much in common with Isaac Asimov. But when you look closer, the connections between hip hop and scifi really aren't so hard to find. Here's a primer, with five visual examples.
"Planet Rock"- Afrika Bambaataa & The Soul Sonic Force.
Hip-hop grew out of disenfranchisement and poverty in New York City in the late 70's and 80's. The reactions can generally be broken down into two categories- realism and escapism. It's pretty easy to spot the difference between the two, the first rap mega-hits- Sugarhill Gang's "Rapper's Delight" and Grandmaster Flash and the Furious Five's "The Message" couldn't be more different.
What you see with the Afrika Bambaataa video above is a synthesis of these two songs. That eerie Kraftwerk sample is from the same school as "The Message", but look at those costumes. Or the dancing. Or the drum machine. Or listen to the vocals. Everyone in this video isn't just trying to escape, they're trying to not be human. They're fusing the electronic and human together, to create something entirely new. Something new that just happened to be great for dancing.
"Virus"- Deltron 3030
There's a political aspect to escapism. Something that imagines crushing those who are causing you to escape in the first place. Deltron 3030 doesn't sound too different then your standard William Gibson character in this one, using some insane version of current technology for worldwide chaos.
"Livin' Astro" - Kool Keith
Sometimes, the fantastic is just the fantastic, nothing more then a spectacle. Kool Keith (a.k.a. Dr. Octagon a.k.a. Dr Dooom a.k.a. Black Elvis) is just that. His rhymes seemingly come out of nowhere, making less and less sense as they move on. Funny and confusing, Kool Keith embodies the idea of an out-of-this-world experience. He's not trying to provoke or anything like that - "I'm for real with this", he reminds the listener. Kind of like Phillip K. Dick's later work, you're never really sure where Kool Keith will take you, and that's for the best.
"You Can't Stop Me Now"- RZA as Bobby Digital
It'd be hard to talk about the overlap of hip-hop and sci-fi if superheroes didn't get a mention. It's impossible to deny that so much of rap is based on the self-created mythos, and no one's made a better mythology for himself then the RZA. The mastermind of the Wu-Tang Clan, RZA has established a mythology-within-a-mythology by casting himself as Bobby Digital, a hedonistic alter-ego who's also a superhero. Even though the video above doesn't really deal with any science fiction per se, the genre's influence is felt throughout. Why exactly does RZA feel the need to identify with a comic book-style hero? Probably the same reason any of us do - he relates to the medium, with all its glory and insanity.
"Love Lockdown"- Kanye West
And it comes full circle with Kanye, definitely the most interesting pop star today. He's always flirted with scifi, but with 808 and Heartbreaks he took the full plunge. Deeply personal music made with impersonal tools, he's a creation of all four sources mentioned above - a living super hero of robotic music, at least in his own mind. You also have to tip your hat to a guy who alludes to Akira in the music video for one of his biggest hits.
Of course, these are just five examples of hip-hop/sci-fi (hip-fi? sci-hop?). By all means, leave other examples in the comments.