Ernest Rutherford (1871–1937) was a New Zealand physicist who was a pioneering researcher in both atomic and nuclear physics. In early work, Rutherford discovered the concept of radioactive half-life, the radioactive element radon, and differentiated and named alpha and beta radiation. This work formed the basis for a Nobel Prize in Chemistry, awarded in 1908. With Thomas Royds, Rutherford developed the theory that alpha radiation is helium nuclei, and also theorized that atoms have their charge concentrated in a very small nucleus, and thereby pioneered the Rutherford model of the atom. He went on to perform the first artificially induced nuclear reaction in 1917 in experiments where nitrogen nuclei were bombarded with alpha particles. As a result, he discovered the emission of a subatomic particle which became known as the proton. Rutherford spent his later years as director of the Cavendish Laboratory in Cambridge. The chemical element rutherfordium was named after him in 1997. This photograph of Rutherford, published by the Bain News Service, was most likely taken in the 1920s.Photograph credit: Bain News Service; restored by Bammesk