Isidor Isaac Rabi (Born On July 29, 1898)

"I think physicists are the Peter Pans of the human race. They never grow up, and they keep their curiosity." - Isidor Isaac Rabi.

Wikipedia:

Isidor Isaac Rabi (29 July 1898 – 11 January 1988) was a Galician-born American physicist and Nobel laureate, recognized in 1944 for his discovery of nuclear magnetic resonance, which is used in magnetic resonance imaging. He was also involved in the development of the cavity magnetron, which is used in microwave radar and microwave ovens.
.
.
During World War II he worked on radar at the Massachusetts Institute of Technology Radiation Laboratory and on the Manhattan Project. After the war, he served on the General Advisory Committee (GAC) of the Atomic Energy Commission, and was chairman from 1952 to 1956. He also served on the Science Advisory Committee (SAC) of the Office of Defense Mobilization, and was Science Advisor to President Dwight D. Eisenhower. He was involved with the establishment of the Brookhaven National Laboratory in 1946, and later, as United States delegate to UNESCO, with the creation of CERN in 1952. When Columbia created the rank of University Professor in 1964, Rabi was the first to receive such a chair.

An excerpt from, "The Nobel Prize in Physics 1944 - Isidor Isaac Rabi - Biographical":

His early work was concerned with the magnetic properties of crystals. In 1930 he began studying the magnetic properties of atomic nuclei, developing Stern's molecular beam method to great precision, as a tool for measuring these properties. His apparatus was based on the production of ordinary electromagnetic oscillations of the same frequency as that of the Larmor precession of atomic systems in a magnetic field. By an ingenious application of the resonance principle he succeeded in detecting and measuring single states of rotation of atoms and molecules, and in determining the mechanical and magnetic moments of the nuclei.

Wikipedia:

Because France had just fallen to the Nazis and Britain had no money to develop the magnetron on a massive scale, Churchill agreed that Sir Henry Tizard should offer the magnetron to the Americans in exchange for their financial and industrial help (the Tizard Mission). An early 6 kW version, built in England by the General Electric Company Research Laboratories, Wembley, London (not to be confused with the similarly named American company General Electric), was given to the US government in September 1940. At the time the most powerful equivalent microwave producer available in the US (a klystron) had a power of only ten watts. The cavity magnetron was widely used during World War II in microwave radar equipment and is often credited with giving Allied radar a considerable performance advantage over German and Japanese radars, thus directly influencing the outcome of the war. It was later described by America as "the most valuable cargo ever brought to our shores"