Georgia on My Mind, and Other Places

Physicist Sheffield's (Godspeed) sixth collection of short stories, written in the late 1980s and early '90s, affirms his place as a central exponent of hard SF. ``Georgia on My Mind,'' which won a Nebula Award, features a narrator who displays less personality than the letters and diaries of the mysterious ``L.D.,'' the putative author of a 150-year-old manual for a mechanical computer. Sheffield proceeds on the understanding that hard SF is well suited to the form of the mystery, in which a narrator takes second seat behind the plot and its specific expression (as, for example, Doyle's Dr. Watson in the Sherlock Holmes mysteries). His spare prose serves as background lighting, revealing no more than needs to be shown. Tales such as ``The Feynman Saltation'' and the exemplary ``Humanity Test'' are effective for discoveries that do not depend on their main characters' intuition. Occasionally, as in ``Trapalanda,'' the payoff is inadequate, but generally these 15 stories satisfy, presenting the readers with valuable ideas from a master craftsman. (Feb.)