JOSEPHSON EFFECT, the flow of electric current, in the form of electron pairs (called Cooper pairs), between two superconducting materials that are separated by an extremely thin insulator (see Superconductivity). Rapidly alternating currents occur within the insulator when a steady voltage, as from a battery, is applied across the superconductors. A steady flow of current through the insulator can be induced by a steady magnetic field. The current flow is termed Josephson current, and the penetration ("tunneling") of the insulator by the Cooper pairs is known as the Josephson effect. Named after the British physicist Brian D. Josephson, who predicted its existence in 1962, the Josephson effect has found application in devices that detect and generate high-energy Electromagnetic Radiation, and in the detection of extremely weak magnetic fields.