Edward Mills Purcell (August 30, 1912 – March 7, 1997) was an American physicist who shared the 1952

Nobel Prize for Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

for his independent discovery (published 1946) of nuclear magnetic resonance in liquids and in solids.

Nuclear magnetic resonance Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a ...

(NMR) has become widely used to study the

molecular structure Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths, bond angles, torsional angles and any other geometrical parameters that deter ...

of pure materials and the composition of mixtures. Friends and colleagues knew him as Ed Purcell.

Biography

Born and raised in

Taylorville, Illinois Taylorville is a city in and the county seat of Christian County, Illinois, United States. The population was 10,506 at the 2020 census, making it the county's largest city. History Taylorville was founded on May 24, 1839, and was named after J ...

, Purcell received his BSEE in electrical engineering from

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and mone ...

, followed by his M.A. and Ph.D. in physics from

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

. He was a member of the Alpha Xi chapter of the

Phi Kappa Sigma Phi Kappa Sigma () is an international all-male college secret society and social fraternity. While nicknames differ from institution to institution, the most common nicknames for the fraternity are Skulls, Skullhouse, Phi Kap, and PKS (the fi ...

fraternity while at Purdue. After spending the years of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

working at the

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...

Radiation Laboratory on the development of microwave radar, Purcell returned to Harvard to do research. In December 1946, he discovered

nuclear magnetic resonance Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a ...

(NMR) with his colleagues

Robert Pound Robert Vivian Pound (May 16, 1919 – April 12, 2010) was a Canadian-American physicist who helped discover nuclear magnetic resonance (NMR) and who devised the famous Pound–Rebka experiment supporting general relativity. He became a tenured ...

and Henry Torrey. 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 of magnetic 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 with

Felix Bloch Felix Bloch (23 October 1905 – 10 September 1983) was a Swiss-American physicist and Nobel physics laureate who worked mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of new ...

of Stanford University. Purcell also made contributions to

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

as the first to detect radio emissions from neutral galactic hydrogen (the famous

21 cm line The hydrogen line, 21 centimeter line, or H I line is the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms. This electromagnetic radiation has a precise frequency of , w ...

due to

hyperfine splitting In atomic physics, hyperfine structure is defined by small shifts in otherwise degenerate energy levels and the resulting splittings in those energy levels of atoms, molecules, and ions, due to electromagnetic multipole interaction between the nuc ...

), affording the first views of the spiral arms of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

. This observation helped launch the field of

radio astronomy Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation comin ...

, and measurements of the 21 cm line are still an important technique in modern astronomy. He has also made seminal contributions to solid state physics, with studies of spin-echo relaxation, nuclear magnetic relaxation, and negative spin temperature (important in the development of the laser). With Norman F. Ramsey, he was the first to question the

CP symmetry In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge symmetry) and P-symmetry (parity symmetry). CP-symmetry states that the laws of physics should be the ...

of particle physics. Purcell was the recipient of many awards for his scientific, educational, and civic work. He served as science advisor to Presidents

Dwight D. Eisenhower Dwight David "Ike" Eisenhower (born David Dwight Eisenhower; ; October 14, 1890 – March 28, 1969) was an American military officer and statesman who served as the 34th president of the United States from 1953 to 1961. During World War II, ...

John F. Kennedy John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and the nickname Jack, was an American politician who served as the 35th president of the United States from 1961 until his assassination ...

, and

Lyndon B. Johnson Lyndon Baines Johnson (; August 27, 1908January 22, 1973), often referred to by his initials LBJ, was an American politician who served as the 36th president of the United States from 1963 to 1969. He had previously served as the 37th vice ...

. He was president of the American Physical Society, and a member of the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

, the National Academy of Sciences, and the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

. He was awarded the

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social scienc ...

in 1979, and the Jansky Lectureship before the National Radio Astronomy Observatory. Purcell was also inducted into his Fraternity's (

) Hall of Fame as the first Phi Kap ever to receive a Nobel Prize. Purcell was the author of the innovative introductory text '' Electricity and Magnetism''. The book, a Sputnik-era project funded by an NSF grant, was influential for its use of relativity in 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 the ''

Berkeley Physics Course The Berkeley Physics Course is a series of college-level physics textbooks written mostly (but not exclusively) by UC Berkeley professors. Description The series consists of the following five volumes, each of which was originally used in a one-s ...

''. 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 Low Reynolds Number", 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 the Scallop theorem. Purcell died on March 7, 1997 in

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. As part of the Boston metropolitan area, the cities population of the 2020 U.S. census was 118,403, making it the fourth most populous city in the state, behind Boston ...

at age of 84.

References

External links

* * {{DEFAULTSORT:Purcell, Edward Mills 1912 births 1997 deaths 20th-century American physicists American Nobel laureates American nuclear physicists Experimental physicists Fellows of the American Academy of Arts and Sciences Harvard University alumni Harvard University faculty Massachusetts Institute of Technology faculty National Medal of Science laureates Nobel laureates in Physics People from Taylorville, Illinois Purdue University College of Engineering alumni Winners of the Beatrice M. Tinsley Prize Members of the United States National Academy of Sciences Foreign Members of the Royal Society Nuclear magnetic resonance Time Person of the Year Presidents of the American Physical Society

Biography

See also

References

External links