Ivar Giaever, 1929–, Norwegian-American physicist, Ph.D. Rensselaer Polytechnic Institute, 1964. He was a researcher at General Electric from 1954 to 1988, when he joined the faculty at his alma mater; he retired in 2005 as professor emeritus. With Leo Esaki and Brian Josephson, Giaever received the 1973 Nobel Prize in Physics for his experimental discoveries regarding tunneling phenomena in superconductors (see superconductivity). In the early 1960s, before he had even completed his doctoral work, Giaever built on Esaki's discovery of electron tunneling in semiconductors and showed that the phenomenon also occurred in superconductors. His experiments demonstrated the existence of an energy gap in superconductors, which was an important prediction of the BCS theory of superconductivity, for which Bardeen, Cooper, and Schrieffer had been awarded the Nobel Prize in Physics in 1972.