Astronomical Discovery

William Herschel first described Uranus as a comet, and H. H. Turner uses that mistake to examine how astronomical discoveries take shape. His six chapters correspond to lectures given in Chicago in 1904. They follow discoveries involving planets, light, the Earth's axis, sunspots and changes in latitude, with special attention to the mixture of chance and sustained observation. Turner begins by testing the familiar image of an astronomer finding something new simply by watching through a telescope.

Bradley's work supplies a different example: careful measurements can contain clues that remain unexplained for generations. Turner discusses the remaining discrepancies in Bradley's observations and the later understanding of changes in the pole's position. He also considers the support and recognition Bradley received at Oxford. For readers of scientific history, these accounts show how instruments, interpretation and institutions influence what astronomers are able to discover.