A fascinating documentary by master filmmaker Errol Morris ("The Thin Blue Line," "Gates of Heaven"), "A Brief History of Time" is an adaptation of the best-selling book by handicapped British physicist Stephen Hawking, a complex explanation of his theories of the universe.

But don't let that chase you away. Morris cleverly, with the use of dazzling film technique, integrates these theories with a biographical story, Hawking's life. The result is a highly entertaining film that allows Hawking's views to become (somewhat) accessible along the way. Hawking's own delightful sense of humor also helps and his uniquely optimistic outlook on life permeates the project from beginning to end.

Hawking suffers from amyotrophic lateral sclerosis, better known in this country as Lou Gehrig's disease. During the film, he sits motionless in a wheelchair, one hand operating a speech synthesizer that sounds like a robot or computer, without emotion.

But, as with Hawking's difficult ideas, Morris knows how to use this to advantage and what results is a compelling film work, combining impossibly large ambitions with the story of one man's difficult but important life.

"Did the universe have a beginning?" Hawking asks, later using for emphasis the age-old question, "Which came first, the chicken or the egg?" Morris illustrates all of this quite imaginatively, with everything from a live chicken placed against computer-generated pictures of the universe to clips from the old Disney science-fiction movie "The Black Hole" (an amusing joke).

Morris also employs traditional interviews, a stirring musical score by Philip Glass and even a narrative device, building a sense of suspense as the audience becomes aware of just how degenerative Hawking's disease is and a question arises about whether he will be able to finish his work before his body gives out completely.

In the end, the film's success is largely a matter of Morris revitalizing the documentary form without ever sacrificing his front-end agenda, which is to tell a story.

If I have a complaint about "A Brief History of Time" it is Morris' penchant for not identifying his talking heads until the end credits. But that's a small complaint for what is, on the whole, an absolutely mesmerizing work.