Errol Morris ushers us into the world, or at least over its doorsill, of English cosmologist Stephen Hawking, stricken with amyotrophic lateral sclerosis (Lou Gehrig's disease) in his early twenties, losing the use of his body and eventually his voice, and now getting around in a motorized wheelchair and communicating via VDT and a vaguely Scandinavian-accented "speech synthesizer." The documentary intermixes biography and theoretical inquiry ("Why do we remember the past but not the future?" -- um, ah, er), perhaps a bit heavier on the biography than the theory, and certainly heavier on it than Hawking himself initially wanted: his ideas, on black holes and imaginary time and things, mustn't be seen to be interesting just because they come from a man in a wheelchair. In the end, it's a little light on both, as well as a little conventional and deferential for a filmmaker of Morris's repute (Gates of Heaven, The Thin Blue Line). The background music is by -- but of course -- Philip Glass. Music to ponder the imponderable by. (1992) — Duncan Shepherd