With most science fiction films, the more science you understand the less you admire the film or respect its makers. An evil interstellar spaceship careens across the screen. The hero's ship fires off a laser blast, demolishing the enemy ship -- the audience cheers at the explosion. But why is the laser beam visible? There is nothing in space to scatter the light back to the viewer. And what slowed the beam a billionfold to render its advance toward the enemy ship perceptible? Why, after the moment of the explosion, does the debris remain centered in the screen instead of continuing forward as dictated by the laws of inertia? What could possibly drag and slow down the expanding debris (and cause the smoke to billow) in the vacuum of outer space? Note too the graceful, falling curve of the debris. Have the cinematographers forgotten that there is no gravity -- no "downward" -- in outer space? Of course, the scene is accompanied by the obligatory deafening boom. But isn't outer space eternally silent? And even if there were some magical way to hear the explosion, doesn't light travel faster than sound? Shouldn't we see the explosion long before we hear it, just as we do with lighting and thunder? Finally, isn't all this moot? Shouldn't the enemy ship be invisible anyway, as there are no nearby stars to provide illumination?

But with other, less numerous films, the more science you know the more you appreciate a film and esteem its makers. 2001 is, of course, the premier example of this phenomenon. Director Stanley Kubrick and author Arthur C. Clarke consulted scientists in universities and industry and at NASA in their effort to portray correctly the technology of future space travel. They tried to be plausible as well as visionary. Every detail -- from the design of the space ship, the timing of the mission, and the technical lingo to the typography on the computer screens and the space stewardesses' hats (bubble-shaped and padded to cushion bumps in the zero gravity of space travel) -- was carefully considered in light of the then-current technology and informed predictions. The film, which has been used in the training of NASA astronauts, doesn't look dated even though thirty years have passed since its release.

We acknowledge, of course, that science fantasy is a literary or cinematic genre and need not get the science right to succeed as art. Indeed, 2001 succeeds on the strength and boldness of its vision, the profundity of its central thesis, and the clarity and unsurpassed mastery of its cinematic technique. Nevertheless, the incorporation of science and technology -- real science and technology -- is a vital part of its success, a part that has not, until now, received adequate consideration.

It is widely believed that architects design their best buildings when they are confronted by obstacles and challenges. Think of Frank Lloyd Wright's Fallingwater house, nestled among rock outcrops and perched over a stream. So too, faithfulness to scientific constraints led Kubrick and Clarke to create especially brilliant cinematic solutions. Would a lesser director have obeyed the laws of physics and portrayed Frank's murder or Dave's reentry through the emergency airlock in silence?

Virtually all the film's rare departures from scientific veracity were deliberate compromises by Kubrick and Clarke. For instance, even though Discovery's speed is extremely high by terrestrial standards, the ship would not appear to move relative to the stars. The filmmakers were well aware of this. But when test sequences showing the stars motionless in the background made the ship look too static, they compromised and introduced a slow drift of the stars. (This solution was immensely challenging technically and required meticulous microalignment of many separate sequences.) Similarly, although in reality half of Discovery would have been invisible to any cosmic viewer -- because it would receive no light from the sun -- Clarke and Kubrick, realizing that such a half-visible ship would distract the audience, reluctantly illuminated all of it. In short, the filmmakers knew and cared about getting the science right and made as few artistic exceptions to accuracy as possible. Their care extended, too, to HAL, the central and surely the most memorable character in the film.

But before we turn to HAL, we might ask: Why analyze the science in the film at all? Why not just consider the film as art, with its own conventions and logic? We believe that, just as an art history book can deepen our understanding of a painting or sculpture, scientific analyses can lead to a richer aesthetic experience of the film. We seek to see the film from an additional, fresh perspective -- not to diminish its art, but to appreciate it more fully. Such a scientific analysis also provides those of us who are not working scientists an opportunity to learn more about the research going on in real laboratories and about the recent history of science -- computer science in particular.

Consider, for example, how such a perspective augments a traditional cinematic view in relation to the issue of software. In Clarke's novel (adapted from the screenplay), HAL's birthday is January 12, 1997, whereas in Kubrick's passage in the screenplay it is 1992. Why the difference? A traditional analysis (centered on character development, plot devices, and so forth) might suggest that Kubrick wanted to make HAL's life somewhat longer in order to make his death more poignant. But from our -- and Clarke's -- technological perspective, the 1992 date is implausible; there is simply no need for such a long history. Who would use a nine-year-old computer on the most technologically sophisticated and challenging adventure in the history of mankind? In fact, HAL's software could be downloaded onto a 1997-vintage computer in a few days (and wouldn't require inserting millions of floppy disks). Consequently, there is no scientific reason for the early birthday.