Ernest Walton, born in Dungarvan (County Waterford, Ireland), together with John Cockcroft artificially disintegrates the lithium nucleus by bombarding it with accelerated protons on April 14, 1932 at the Cavendish Laboratory in Cambridge, under Rutherford's direction. It is the first nuclear transmutation produced with artificially accelerated particles, experimentally verifying Einstein's mass-energy equivalence (E=mc²). They receive the Nobel Prize in Physics in 1951. Walton is the only Nobel laureate born in the Republic of Ireland.