Ramsey, Norman Foster (1915-2011), was an American physicist who did important research into the electrical and magnetic properties of atoms and molecules. Ramsey invented the separated oscillatory field method for obtaining uniform magnetic fields—fields that have constant strength and direction. This method enabled him to measure a huge variety of electrical and magnetic properties of atoms and molecules. With the help of Daniel Kleppner, a former student, Ramsey invented the atomic hydrogen maser, which made measurements with great stability and accuracy. A by-product of this research was a new type of atomic clock (an instrument for keeping time by counting atomic vibrations). For the invention of the separated oscillatory fields method, and its use in the hydrogen maser and other atomic clocks, Ramsey received the 1989 Nobel Prize in physics.
Ramsey was born in Washington, D.C., on Aug. 27, 1915. He entered Columbia University in New York City in 1931. He first studied engineering but changed to mathematics. After Ramsey graduated in 1935, Columbia awarded him the Kellett Fellowship to Cambridge University, England. There, he earned his second bachelor’s degree, this time in physics.
Returning to Columbia in 1937, Ramsey worked with the Austrian-born American physicist I. I. Rabi and his associates in the new field of molecular beam magnetic resonance. A molecular beam is a stream of molecules moving in about the same direction and at approximately the same speed. When molecular beams strike surfaces of materials, they reveal detailed information about the molecular structure of atoms in the beam or the surface.
From 1940 to 1942, Ramsey developed radar technology at the MIT (Massachussets Institute of Technology) Radiation Laboratory for use in World War II (1939-1945). In 1943, Ramsey moved to Los Alamos, New Mexico. There, he worked on the Manhattan Project, helping to develop the first atomic bomb.
After the war, Ramsey returned to Columbia as a professor and research scientist. He and Rabi revived the molecular beam laboratory at Columbia. They also helped to found the Brookhaven National Laboratory, on Long Island, New York. From 1947 to 1987, Ramsey taught at Harvard University, continuing to work with molecular beams. He died on Nov. 4, 2011.
