Haldan Keffer Hartline’s story is at the same time ordinary and extraordinary. And so the story of his turn of the century American childhood is a familiar one. Born in 1903 and raised in central Pennsylvania, Hartline was the son of well-educated parents, both of whom taught at the Bloomsburg State Normal School (Nobelprize.org 1967), Keffer, as everyone would come to all him, was “brought up to become an ardent naturalist” (Grant and Ratliff 1985). Every recounting of his early childhood (G&R 1985, Barlow 1986, Ratliff 1990) remarks on his native naturalist spirit--his love of hiking, joining his father’s classes on geological field trips, and his parents’ careful cultivation of his inquisitive mind. Usually somewhere early into these romantic childhood accounts, Louis Agassiz’s dictum “Study Nature, not books” is invoked, with Keffer offered up as the child exemplar: a scientist by nature and nurture.
Somehow we expect stories like this to be told of a child who would grow up to win a Nobel Prize: it fits our most romantic view of science and history – a genius, destined for greatness from birth, shows up to solve problems no one else can. Well, there’s more to Hartline and his science than that, and in what follows I offer an account of two of his most important experiments in an attempt to temper the archetype of the scientific genius and deepen appreciation for the working scientist – for Haldan Keffer Hartline. As we will see, Hartline’s successes were due to his hard work, and his good luck: the basic ingredients of all discovery.