When Kurt Vonnegut needed protagonist Billy Pilgrim to time-travel in Slaughterhouse Five, he simply had him become "unstuck" in time--still perhaps the most poetic way to trip the chronological fantastic yet devised in literature. But electric engineering professor and science fiction writer Paul Nahin doesn't want you taking short cuts in your epoch-journeying yarns--at least, not because you were lazy about research. Subtitled A Writer's Guide to the Real Science of Plausible Time Travel, this is a tasty blend of quantum theory, worm holes, causal loops, and the famous "grandfather paradox"--the better to sell your heroine's time-skipping to even the most skeptical suspender of disbelief.