Black Holes and Baby Universes

British theoretical physicist Hawking ( A Brief History of Time ) here delivers a potpourri of lucid, succinct scientific articles and lectures and short autobiographical sketches. He speculates that spaceships or objects that fall into a black hole may go off into ``a little baby universe of their own,'' a small, self-contained world that branches off from our region of space-time. These baby universes, he adds, exist in imaginary time, ``at right angles to real time, in which the universe has no beginning or end.'' In other pieces Hawking assesses physicists' search for a complete, unified ``theory of everything''; argues in favor of the tenet that people have free will; calls for large cuts in armaments; and describes his triumph over Lou Gehrig's disease, which has confined him to a wheelchair and forced him to communicate via a personal computer and speech synthesizer. In a concluding interview reprinted from the BBC, Hawking discusses his love of music and the role of intuition in his work. (Sept.)