Sir John Douglas Cockcroft was a British experimental physicist who shared the 1951 Nobel Prize in Physics with Ernest Walton for their splitting of the atomic nucleus, which led to the development of nuclear power and weapons. The Nobel Prize in Physics 1951, announced November 15, 1951. John Cockcroft and Ernest T.S. Walton, “for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles”. John Cockcroft: born 1897, Todmorden, United Kingdom. Ernest T.S. Walton: born 1903, Dungarvan, Ireland. Wiki link Wiki link Data: the Nobel Foundation (CC0).