STAR CROSSING

A look at the science behind science fiction, at least as it relates to space travel: the historical musings of Rostand and Jules Verne; Goddard's early experiments; the Apollo moon flight; early nuclear rocket experiments; and some far-out (but theoretically possible) mechanisms—Bussard ramjets, antimatter, and the use of tachyons (faster-than-light particles that may be the result only of fevered mathematical imagination). The author points out that the best that's been done with our rockets' thunderous noise and flame is little better than 70% of the velocity required to escape Earth's gravity, so space travel is hardly in hand. The style is breezy and informal, even when Herbst is describing complex ideas, making the book accessible even to casual readers. There are some glitches: a spaceship traveling at 15% of the speed of light would take more than 40 years—not 36—to go six light-years; a falling object falls 16 feet in the first second and 48 feet in the next, not 32 and 64 feet. And Herbst doesn't explain how, if we can't achieve escape velocity, the Voyager probes actually journeyed beyond the solar system (by using the gravity of the sun or another planet to increase their velocity.) Still: useful information, entertainingly presented. Bibliography; photos, diagrams, & index not seen. (Nonfiction. 12+)