Hal 2001, the eerily human-like computer aboard the Discovery space ship, represents technological advancement. It is symbolic of many long-held concerns about technology. First, Hal is artificially intelligent. It can think as well as, if not better than, any human. Second, its inner workings are not completely understood by his creators. With Hal, people have created a very powerful technology that they cannot fully control. When Hal begins to think on its own and deviate from the way in which it has been instructed, this is an expression of the fear many people held that our own technological advancement would come back to haunt us unexpected and unforeseen ways.
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