A collection of a dozen science stories, each of which focuses on the drama of instant insight---the "eureka moment"---that has accompanied many scientific discoveries. From amateur scientist Joseph Priestly, who in the eighteenth century stumbled onto the existence of oxygen without having any real idea of what he was doing, to television pioneer Philo Farnsworth, whose idea for the TV screen was born while the 14-year-old plowed the fields of his family's Idaho farm, the scientists profiled range from the well-known (including Darwin, Einstein, and Watson Crick) to the somewhat obscure (chemist von Kekule, and fractal creator Mandelbrot). In each case, luck, good timing, and the "prepared mind" combine to produce some of the most significant and remarkable scientific breakthroughs of all time.