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Edward Mills Purcell

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Edward Mills Purcell
Born(1912-08-30)30 August 1912
Taylorville, Illinois,U.S.
Died7 March 1997(1997-03-07)(aged 84)
Cambridge, Massachusetts,U.S.
Alma mater
Known for
Awards
Scientific career
FieldsPhysics
Institutions
ThesisThe Focusing of Charged Particles by a Spherical Condenser(1938)
Doctoral advisorKenneth Bainbridge
Other academic advisorsJohn Van Vleck
Doctoral students
Other notable students
Horn antenna used byHarold I. Ewenand Edward M. Purcell at theLyman Laboratory of PhysicsatHarvard Universityin 1951 for the first detection of radio radiation from nuclear atomic hydrogen gas in theMilky Wayat a wavelength of 21 cm. Now atNational Radio Astronomy Observatory.[1]

Edward Mills Purcell(August 30, 1912 – March 7, 1997) was an American physicist who shared the 1952Nobel Prize for Physicsfor his independent discovery (published 1946) of nuclear magnetic resonance in liquids and in solids.[2]Nuclear magnetic resonance(NMR) has become widely used to study themolecular structureof pure materials and the composition of mixtures. Friends and colleagues knew him asEd Purcell.

Biography

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Born and raised inTaylorville, Illinois,Purcell received hisBSEEinelectrical engineeringfromPurdue University,followed by his M.A. and Ph.D. in physics fromHarvard University.He was a member of the Alpha Xi chapter of thePhi Kappa Sigmafraternity while at Purdue.[3]After spending the years ofWorld War IIworking at theMIT Radiation Laboratoryon the development of microwave radar, Purcell returned to Harvard to do research. In December 1945, he discoverednuclear magnetic resonance(NMR) with his colleaguesRobert Poundand Henry Torrey.[4]NMR provides scientists with an elegant and precise way of determining chemical structure and properties of materials, and is widely used in physics and chemistry. It also is the basis ofmagnetic resonance imaging(MRI), one of the most important medical advances of the 20th century. For his discovery of NMR, Purcell shared the 1952 Nobel Prize in physics withFelix BlochofStanford University.

Purcell also made contributions toastronomyas the first to detect radio emissions from neutral galactic hydrogen (the famous21 cm linedue tohyperfine splitting), affording the first views of the spiral arms of theMilky Way.[5]This observation helped launch the field ofradio astronomy,and measurements of the 21 cm line are still an important technique in modern astronomy. He has also made seminal contributions tosolid state physics,with studies of spin-echo relaxation, nuclear magnetic relaxation, and negative spin temperature (important in the development of the laser). WithNorman F. Ramsey,he was the first to question theCP symmetryof particle physics.

Purcell was the recipient of many awards for his scientific, educational, and civic work. He served as science advisor to PresidentsDwight D. Eisenhower,John F. Kennedy,andLyndon B. Johnson.He was president of theAmerican Physical Society,and a member of theAmerican Philosophical Society,theNational Academy of Sciences,and theAmerican Academy of Arts and Sciences.He was awarded theNational Medal of Sciencein 1979, and theJansky Lectureshipbefore theNational Radio Astronomy Observatory.Purcell was also inducted into his Fraternity's (Phi Kappa Sigma) Hall of Fame as the first Phi Kap ever to receive a Nobel Prize.

Purcell was the author of the innovative introductory textElectricity and Magnetism.[6]The book, aSputnik-eraproject funded by an NSF grant, was influential for itsuse of relativityin the presentation of the subject at this level. The 1965 edition, now freely available due to a condition of the federal grant, was originally published as a volume of theBerkeley Physics Course.The book is also in print as a commercial third edition, as Purcell and Morin. Purcell is also remembered by biologists for his famous lecture "Life at LowReynolds Number",[7]in which he explained forces and effects dominating in limiting flow regimes (often at the micro scale). He also emphasized the time-reversibility of low Reynolds number flows with a principle referred to as theScallop theorem.

Purcell died on March 7, 1997, inCambridge, Massachusetts,aged 84.

See also

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References

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  1. ^"E. M. Purcell - Biography".The Nobel Prize in Physics 1952 Felix Bloch, E. M. Purcell.The Nobel Foundation.1952.Retrieved22 May2012.
  2. ^Bleaney, B.(1999)."Edward Mills Purcell. 30 August 1912 -- 7 March 1997: Elected For.Mem.R.S. 1989".Biographical Memoirs of Fellows of the Royal Society.45:437–447.doi:10.1098/rsbm.1999.0029.
  3. ^"Famous Phi Kappa Sigma's - Famous Fraternity & Sorority Greeks - Greek 101".greek101.com.Archived fromthe originalon 2016-03-03.Retrieved2008-10-04.
  4. ^Purcell, E.;Torrey, H.; Pound, R. (1946)."Resonance Absorption by Nuclear Magnetic Moments in a Solid".Physical Review.69(1–2): 37–38.Bibcode:1946PhRv...69...37P.doi:10.1103/PhysRev.69.37.
  5. ^Ewen, H. I.;Purcell, E. M.(1951). "Observation of a Line in the Galactic Radio Spectrum: Radiation from Galactic Hydrogen at 1,420 Mc./sec".Nature.168(4270): 356.Bibcode:1951Natur.168..356E.doi:10.1038/168356a0.S2CID27595927.
  6. ^Purcell, Edward M.; Morin, David J. (2013-01-21).Electricity and Magnetism.Cambridge University Press.ISBN9781107014022.
  7. ^Purcell, E. M.(1977)."Life at low Reynolds number"(PDF).American Journal of Physics.45(1): 3–11.Bibcode:1977AmJPh..45....3P.doi:10.1119/1.10903.hdl:2433/226838.
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