Norman Foster Ramsey is a preeminent physicist whose research has focussed on the properties of molecules, atoms, nuclei, and elementary particles. The numerous awards and honors he won throughout his career culminated in the 1989 Nobel Prize in physics. Although the prize seemed to recognize a lifetime of achievements in the field, the Nobel committee specifically cited his work in developing a method of measuring the differences between atomic energy levels. His findings were key to the development of the cesium atomic clock, which measures time with an accuracy previously unknown.

Ramsey was born in Washington, D.C., on August 27, 1915. He was named after his father, a graduate of the United States Military Academy who was then a general serving as assistant to the Chief of Ordnance. His mother was Minnie Bauer Ramsey. After several years in Washington, his father was transferred to the Command and General Staff School...