"Mr. Roboto" and "Ziggy Stardust" aside, the combination of science fiction and rock 'n' roll rarely, if ever, produces anything great. Even then, Styx's Kilroy may as well have been a toaster when compared to the conflicted characters of futurists like Robert A. Heinlein and Philip K. Dick.

You'll never find song characters as complex and confounding as Dick's could-be android Rick Deckard, or Heinlein's messianic "alien" Michael Valentine Smith. To find characters who ride that line between the real and the artificial, you need to focus on a group of five white-faced, unwashed rock 'n' rollers from Williamsburg.

These five beings of course are the Strokes--a group that, since sparking the revival of rock with its 2001 debut, Is This It?, has been scrutinized by the media and music geeks alike. The question on everyone's mind isn't "do they rock?" They invariably do. The question is "are they real?"

For true music fans, finding the answer to that question is everything.

When stripped of story lines and lyrical narratives, both rock and science fiction share the same core principle: a search for history, true beauty and humanity--or, if you want to shorten it up, a search for authenticity. The science-fiction writer, like the idealized musician or the very real music geek, is obsessed with separating the real from the fake. When anyone argues about music, they argue about this realness: Bob Dylan = real, John Mayer = fake.

Philip K. Dick was having the same argument on a somewhat more theoretical level. His 1968 novel Do Androids Dream of Electric Sheep?--made popular by the Ridley Scott film Blade Runner--was probably science fiction's most eloquent exploration of this divide. In Dick's story, distinguishing androids--or "replicants," as they are known in the film--from humans is paramount to survival. In the world of rock 'n' roll, the stakes are just as high--the trueness of the trumpeted "return of rock" hinges on it.

The honest music fan will admit that this trueness took a hit with the release of the Strokes' sophomore album.

Room on Fire strikes while the iron is still hot, with leadman Julian Casablancas' vocals out front, drunk and affected to a perfect pose, as hypnotic guitar tremolos give way to the occasional perfectly placed solo, and the rhythm section stays tight as a drum machine. Casablancas constructs a world that is simply cool as all hell. On "12:51" he's drinking 40s with a girl, as his band shakes and shimmies; on "Under Control," he turns into a drunk Lionel Richie, crooning, "I don't want to change the world/ I just want to watch it go by."

When the band plays the Roseland Theater Thursday, Casablancas will hang on the mike and, perhaps, say a few words to the audience while the rest of his band makes a studied attempt to not look into the throng of fans. The crowd will shake and bop at the mercy of the infectious music. Unwashed and unaffected, Casablancas and his bandmates will be the coolest guys in the room, in the exact same way they were when they first played songs from their first album in much smaller clubs in 2001.

And that's why the Strokes, and rock 'n' roll, are in a danger zone.

Blade Runner's hero, Deckard, had a test to separate the replicants from the humans. It was called the Voight-Kampff test, and it measured emotional responses: If a subject didn't respond to a scenario--a belly-up turtle struggling to flip itself, say--it was deemed a replicant and "retired."

Unfortunately, there is no Voight-Kampff for rock, but if there were, the Strokes would not be doing too well...in fact, they'd be fried by this point. Their cool is still so controlled that it sometimes seems calculated, distilled as it is from a formula that relies on Lou Reed, the Stooges and other x's and y's of the late '60s and early '70s. Journalists pry and pry, but the response is always the same: indifference.

Of course, all artists play the replicant at some point, pulling from a handful of artists. What truly exposes the replicant, though, is an artist's ability to change and adapt to the greater world. Beck, whose next move is always anybody's guess, is not a replicant; Bush, the band that cemented the progression of grunge, is.

Half the fun of being a music fan is trying to separate the real from the fake. The real tension in Blade Runner, and the reason it is held in such high esteem, arises when the humanity of Deckard himself is called into question. Arguing over whether Deckard is a replicant is akin to arguing over whether the Strokes are a real band. That's why the music world is obsessed with the Strokes. They make us question realness by striking a constructed pose while making music with so much soul.

The jury is still out on the band. If they are artificial, as so many of their critics claim, their life force is likely to fade, like the Blade Runner replicants, after four years. If not, they'll bring something new to the table next time.

Until then, you may as well dance.

The Strokes play with the Raveonettes Thursday, April 15, at Roseland Theater, 8 NW 6th Ave., 224-2038. 8 pm. SOLD OUT. All ages.