Abstract
During the past 15 yr surface science has experienced extensive and profound changes. This historical review is devoted to the development of the theme that these changes considered collectively constitute a scientific revolution in the sense described by Thomas Kuhn. The recognition of the consequences of inelastic collisions of fast electrons played a key role in initiating the modern era in surface science. The resulting explosive development of surface characterization spectroscopies is discussed and shown to have led to a fundamental alteration in our perception of a surface or interface. Whereas in the mid-1960’s an interface was regarded merely as the boundary between two bulk media, today it is seen as an independent entity: a state of matter determined by its history and exhibiting its own unique composition, structure, and electronic properties. The review concludes with a brief indication of the role of the American Vacuum Society in promoting and facilitating the development of surface science and the diffusion of its results during this formative period.