Norman Foster Ramsey, Jr.

"Norman Ramsey" redirects here. For the U.S. federal judge (1922–1993), see Norman Park Ramsey.
Norman Foster Ramsey, Jr.
NormanFRamsey.jpg
Norman F. Ramsey
Born (1915-08-27)August 27, 1915
Washington, DC
Died November 4, 2011(2011-11-04) (aged 96)
Wayland, Massachusetts
Residence United States
Nationality United States
Fields Physics
Institutions Harvard University
Alma mater Columbia University, University of Cambridge
Doctoral advisor I. I. Rabi
Doctoral students David J. Wineland, Daniel Kleppner, Howard Berg
Known for Separated oscillatory field method
Notable awards IEEE Medal of Honor
1989 Nobel Prize in Physics

Norman Foster Ramsey, Jr. (August 27, 1915 – November 4, 2011) was an American physicist who was awarded the 1989 Nobel Prize in Physics for the invention of the separated oscillatory field method, which had important applications in the construction of atomic clocks. A physics professor at Harvard University for most of his career, Ramsey also held several posts with such government and international agencies as NATO and the United States Atomic Energy Commission. Among his other accomplishments are helping to found the United States Department of Energy's Brookhaven National Laboratory and Fermilab.[1][2]

Biography

Ramsey was born in Washington, DC on August 27, 1915 to Minna Bauer Ramsey, a mathematics teacher, and Norman Foster Ramsey, a West Point graduate and an officer in the Army Ordnance Corps. He earned his B.A. in Mathematics from Columbia University in 1935. On his graduation, Columbia awarded him a Kellett Fellowship to Cambridge University where he earned a second bachelors degree, this time in physics. His tutor at Cambridge was Maurice Goldhaber, who stimulated Ramsey's interest in molecular beams and in doing research for a Ph.D with I.I. Rabi at Columbia. He received his Ph.D. in physics from Columbia University in 1940.[3] In 1940, he married Elinor Jameson of Brooklyn, New York and moved to the University of Illinois with the expectation of spending the rest of his life there. World War II was, however, raging in Europe, and Ramsey was recruited to the MIT Radiation Lab where he spent the next two years heading up the group developing 3 cm wavelength radar. After a stint in Washington, D.C. as a radar consultant to the Secretary of War, he went, in 1943, to Los Alamos to work on the Manhattan Project. At the end of the war, Ramsey returned to Columbia University as a professor and research scientist. With Rabi, he helped establish the Brookhaven National Laboratory on Long Island, NY, where he became the first head of the Physics Department. In 1947, he moved to Harvard University.,[1] where he taught for the next 40 years, except for visiting professorships a Middlebury College, Oxford University, Mt. Holyoke College and the University of Virginia. His first wife, Elinor, died in 1983, after which he married Ellie Welch of Brookline, Massachusetts. Ramsey died on November 4, 2011, survived by his second wife, seven children and six grandchildren.

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Research

Ramsey's research in the immediate post-war years looked at measuring fundamental properties of atoms and molecules by use of molecular beams. On moving to Harvard, his objective was to carry out accurate molecular beam magnetic resonance experiments, based on the techniques developed by Rabi. However, the accuracy of the measurements depended on the uniformity of the magnetic field, and Ramsey found that it was difficult to create sufficiently uniform magnetic fields. He developed the separated oscillatory field method in 1949 as a means of achieving the accuracy he wanted.[3]

Ramsey and Daniel Kleppner developed the atomic hydrogen maser, looking to increase the accuracy with which the hyperfine separations of atomic hydrogen, deuterium and tritium could be measured, as well as to investigate how much the hyperfine structure was affected by external magnetic and electric fields. He also participated in developing an extremely stable clock based on a hydrogen maser. Since 1967, the second has been defined based on a hyperfine transition of a cesium atom; the atomic clock which is used to set this standard is an application of Ramsey's work,[4] and Ramsey was awarded the Nobel prize in physics in 1989 "for the invention of the separated oscillatory fields method and its use in the hydrogen maser and other atomic clocks".[5] The Prize was shared with Hans G. Dehmelt and Wolfgang Paul.

In collaboration with the Institut Laue–Langevin, Ramsey also worked on applying similar methods to beams of neutrons, measuring the neutron magnetic moment and finding a limit to its electric dipole moment.[3]

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Publications

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References

  1. ^ a b "Norman Ramsey Dies at 96; Work Led to the Atomic Clock". New York Times. November 6, 2011. Retrieved 2011-11-07. "Norman F. Ramsey, the Nobel Prize-winning physicist who developed a precise method to probe the structure of atoms and molecules and used it to devise a remarkably exact way to keep time, died on Friday in Wayland, Mass. He was 96. ..." 
  2. ^ Wineland, D. (2011). "Norman Ramsey (1915–2011)". Nature 480 (7376): 182. doi:10.1038/480182a. PMID 22158235.  edit
  3. ^ a b c Autobiography on Nobel Prize Website
  4. ^ Nobel Prize press release
  5. ^ Nobel Prize citation
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External links

Nobel Laureates in Physics (1976–2000)
1976–2000
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Last modified on 24 April 2013, at 22:11