Brian Josephson. Portrait of Brian David Josephson (born 1940), British physicist and superconductor pioneer. In 1962 he theoretically deduced the existence of the Josephson effect, a phenomenon which occurs where two superconductors are separated by an electrical insulator. At such a Josephson junction an electric current can flow between the two superconductors in the absence of an applied voltage. If a direct current (D.C.) current is applied it will induce an alternating current (A.C.) in the insulator. Josephson junctions have found uses in sensitive measurement devices and as fast switches in computers. Josephson won the Nobel physics prize in 1973.