Ramsey, Norman Foster (1915-...), is 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 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 very fine measurements with great stability and accuracy. A by-product of this research was a new type of atomic clock (an instrument for measuring time by measuring 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 for physics.