Born: Taylorville, Illinois - August 30, 1912.
Died: Friday, March 7, 1997 of respiratory failure (source: NY Times obituary)
Occupation: Physicist
1952 Nobel Laureate in Physics (Prize shared with Felix Bloch)
for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith.
Summary
Edward M. Purcell's life shines as an example of the good one man can bring to humanity through his research. The applications of the technologies he pioneered remain in use today in many forms: the
MRI and
radio astronomy both owe a lot to his discovery of
nuclear magnetic resonance, or
NMR. Additionally, the decisions he made in his life and coincidences that led to discoveries are quite interesting.
Background
Edward Mills Purcell was born in
Taylorville, Illinois to
Edward A. Purcell and
Mary Elizabeth Mills on August 30, 1912. He was the elder of two sons - his younger brother's name is
Robert W. Purcell. His father was the manager of a regional
telephone company, while his mother was a
Vassar College alumnus and taught
Latin at Taylorville High School before she married. Both parents influenced Edward's interests, though it is easiest to see the influence which his father's career had upon him. Throughout his childhood, young Edward found inspiration for future pursuits in toying with old telephone equipment and reading issues of the Bell System Technical Journal. These were received through his father's company, which was not technically part of the Bell system but maintained some of the local lines for the company. Purcell said in 1977 of these
periodicals:
"They were fascinating because for the first time I saw technical articles obviously elegantly edited and prepared and illustrated, full of mathematics that was well beyond my understanding. It was a glimpse into some kind of wonderful world where electricity and mathematics and engineering and nice diagrams all came together."
- interview by Katherine Sopka
When Edward was 14, his father moved the family to nearby
Mattoon, Illinois to become the general manager of the Illinois Southeastern Telephone Company, which was an independent regional company at that time. Purcell attended public schools in Taylorville and Mattoon, and entered
Purdue University in
1929,
majoring in
electrical engineering. Purdue's electrical engineering program was founded in 1888 as the School of Electrical Engineering, thus it probably had a strong reputation for excellence
(not to say that it doesn't now!), especially in the
midwest. Perhaps the most important discovery Purcell made in college was the personal insight that his interests rested more in physics than electrical engineering. In his junior year, while still technically in engineering, he signed up for an independent study course with the physics department, which recently had brought
Karl Lark-Horovitz in as the head of the department and began offering graduate research. As part of his duties for the course, he had to refurbish a
spectrometer with a
Rowland grating. This experience confirmed his desire to pursue physics, and his senior year he worked under
H.J. Yearian, a graduate student working with electron diffraction. He graduated from Purdue in 1933 with a B.S.E.E. (Bachelor of Science in Electrical Engineering), though he stayed that summer to write his first two papers, one in
electron diffraction (1934) and another which described a method for making
thin films (1935).
After graduation, Purcell received an exchange fellowship to the Technische Hochschule in Karlsruhe, Germany. This was the same town in which Heinrich Hertz first produced radio waves in 1885 - Purcell either did not realize this or did not investigate this at the time, and later expressed regret that he did not take more interest while there. Owing much to chance, Purcell met another exchange student, named Beth C. Busser, from Bryn Mawr, on the travel across the Atlantic. She was visiting Munich to study German literature, but Purcell convinced her to take in a physics lecture in Munich given by Arnold Sommerfeld. This she had absolutely no understanding of, but went anyways, and took notes for him. They were married four years later (1937) in Cambridge, Massachusetts.
After his year of study abroad, Purcell was admitted to Harvard's physics department for graduate study and earned his Master's and Ph.D. there. During his graduate education, one course that particularly inspired him was a study of electric and magnetic susceptibilities, taught by John H. Van Vleck, who was a new addition to Harvard's faculty, hailing from the University of Minnesota and the University of Wisconsin. As a term paper for the class, Purcell and Malcolm Hebb (the only other student of the class) wrote an analysis of experiments in cooling by adiabatic demagnetization which was at that time being carried out mostly in The Netherlands and Great Britain.
Purcell's thesis work was suggested to him by Professor Kenneth T. Bainbridge: the study of the focusing properties of the electric field in the space between two concentric metal spheres forming a spherical condenser (the engineers and physicists today recognize this as a capacitor). This work granted him his Ph.D. and he began teaching at Harvard in 1938.
Work at MIT Radiation Lab
Purcell took a leave of absence from Harvard from 1941 to mid-1946. During this time he worked at the Massachusetts Institute of Technology's new Radiation Lab, which was established in fall 1940. There, he was the leader of the advanced developments group and helped develop microwave radar to contribute to the Allied wartime effort to advance battlefield technology. However, the war ended before Purcell's Nobel prize-winning discovery was made at the MIT Radiation Lab. It was 1945 that first introduced Purcell to nuclear magnetic resonance - he observed it during an after-hours experiment with two others, Henry C. Torrey and Robert V. Pound, while working on a 27-volume set of books on radar.
Upon his return to Harvard, he became Associate Professor of Physics. He advanced to Professor of Physics in 1949. Edward Purcell, along with Harold I. Ewen, a graduate student of his, in 1951 became the first to detect radio emissions from clouds of hydrogen in space, using an antenna on the roof of Harvard's Lyman Laboratory. This horn antenna was built with help from a university carpenter and an investment of $400. The 21 cm hydrogen hyperfine emission had been predicted seven years before by van de Hulst and Oort at Leiden University.
The Nobel Prize in Physics was awarded to him in 1952 in recognition of his discovery of NMR and the many applications which descended from this discovery. Today we owe the MRI and many other imaging applications to Purcell and those that followed him, further developing the technology. At Harvard, Purcell's title was Gerhard Gade University Professor. His research continued in nuclear magnetism, relaxation phenomena, related problems of molecular structure, measurement of atomic constants, and nuclear magnetic behavior at low temperatures.
After suffering leg fractures in a fall in 1996, Purcell succumbed to bacterial lung infections which eventually led to his death of respiratory failure on March 7, 1997 at his home in Cambridge, Massachusetts. His wife, Beth C. Busser, survives him, as do their sons, Dennis, of Medford, Massachusetts, and Frank, of Arlington, Massachusetts. A brother, Robert W., of Houston, also survives.
Works
E.M. Purcell wrote a prominent 500-page physics textbook entitled "Electricity and Magnetism" (ISBN 0070049084). This is the second volume of the Berkeley Physics Course. The book's description sums it up: "The sequence of topics covered include: electrostatics; steady currents; magnetic field; electromagnetic induction; and electric and magnetic polarization in matter. Taking a nontraditional approach, students focus on fundamental questions from different frames of reference. Each chapter has figures and problems to apply concepts studied."
He also co-wrote a book with C. G. Montgomery and R. H. Dicke entitled "Principles of Microwave Circuits" in 1948.
References
Edward Mills Purcell. Personal interview recorded at Harvard by Katherine Sopka. 1977. (transcribed at the Center for the History of Physics of the American Institute of Physics)
New York Times Obituary: http://almaz.com/nobel/physics/obit-purcell.html
http://almaz.com/nobel/physics/1952b.html
http://www.nobel.se/physics/laureates/1952/purcell-bio.html
http://www.news.harvard.edu/gazette/1998/04.09/FacultyofArtsan.html
http://www.physics.purdue.edu/deptinfo/alumni/honor/purcell.html
http://www.nap.edu/html/biomems/epurcell.html
"Purcell, Edward Mills." Encyclopædia Britannica. 2003. Encyclopædia Britannica Premium Service. 13 Jul, 2003: http://www.britannica.com/eb/article?eu=125112
http://scienceworld.wolfram.com/biography/Purcell.html
This was written as a part of Everything Quests: The Nobel Prize winners.