Brian David Josephson was born on 4 January 1940 in Cardiff, Wales, and attended Cardiff High School, where his talent for mathematics and science was already clear. He went on to Trinity College, Cambridge, completing his PhD there in 1964, and has spent the great majority of his academic career at Cambridge as a theoretical physicist.
While still a postgraduate student in 1962, Josephson predicted what became known as the 'Josephson effect' — the quantum mechanical phenomenon by which a supercurrent can tunnel through a thin insulating barrier separating two superconductors. The prediction was confirmed experimentally soon after, and for it he was awarded a share of the 1973 Nobel Prize in Physics, at the age of just 33. The effect underpins the SQUID (superconducting quantum interference device) and is used today in ultra-precise measurement, quantum computing research, and the international standard for the volt.
In later decades Josephson became known for pursuing research interests well outside mainstream physics, including the relationship between consciousness and physical theory, and topics such as parapsychology. These interests have been controversial within the scientific community, but Josephson — an emeritus professor at Cambridge's Cavendish Laboratory — has continued to argue that science should not shy away from investigating open questions, whatever their origin.