The final scenes of the film seemed more metaphorical than realistic. Will you discuss them -- or would that be part of the "road map" you're trying to avoid?
No, I don't mind discussing it, on the lowest level, that is, straightforward explanation of the plot. You begin with an artifact left on earth four million years ago by extraterrestrial explorers who observed the behavior of the man-apes of the time and decided to influence their evolutionary progression. Then you have a second artifact buried deep on the lunar surface and programmed to signal word of man's first baby steps into the universe -- a kind of cosmic burglar alarm. And finally there's a third artifact placed in orbit around Jupiter and waiting for the time when man has reached the outer rim of his own solar system.
When the surviving astronaut, Bowman, ultimately reaches Jupiter, this artifact sweeps him into a force field or star gate that hurls him on a journey through inner and outer space and finally transports him to another part of the galaxy, where he's placed in a human zoo approximating a hospital terrestrial environment drawn out of his own dreams and imagination. In a timeless state, his life passes from middle age to senescence to death. He is reborn, an enhanced being, a star child, an angel, a superman, if you like, and returns to earth prepared for the next leap forward of man's evolutionary destiny.
That is what happens on the film's simplest level. Since an encounter with an advanced interstellar intelligence would be incomprehensible within our present earthbound frames of reference, reactions to it will have elements of philosophy and metaphysics that have nothing to do with the bare plot outline itself.
Quanto ao comportamento do Hal...
Why was the computer more emotional than the human beings?
This was a point that seemed to fascinate some negative critics, who felt that it was a failing of this section of the film that there was more interest in HAL than in the astronauts. In fact, of course, the computer is the central character of this segment of the story. If HAL had been a human being, it would have been obvious to everyone that he had the best part, and was the most interesting character; he took all the initiatives, and all the problems related to and were caused by him.
Some critics seemed to feel that because we were successful in making a voice, a camera lens, and a light come alive as a character this necessarily meant that the human characters failed dramatically. In fact, I believe that Keir Dullea and Gary Lockwood, the astronauts, reacted appropriately and realistically to their circumstances. One of the things we were trying to convey in this part of the film is the reality of a world populated -- as ours soon will be -- by machine entities who have as much, or more, intelligence as human beings, and who have the same emotional potentialities in their personalities as human beings. We wanted to stimulate people to think what it would be like to share a planet with such creatures.
In the specific case of HAL, he had an acute emotional crisis because he could not accept evidence of his own fallibility. The idea of neurotic computers is not uncommon -- most advanced computer theorists believe that once you have a computer which is more intelligent than man and capable of learning by experience, it's inevitable that it will develop an equivalent range of emotional reactions -- fear, love, hate, envy, etc. Such a machine could eventually become as incomprehensible as a human being, and could, of course, have a nervous breakdown -- as HAL did in the film.