Welcome to CWP at UCLA 

86 Eminent Physicists

Search the Archive

Fascinating Documents

AnnotatedPhoto Gallery

In Her Own Words

Some Physics History

500+ Books and Articles

Project Staff

Field Editors

Project Support

Photo Credits

Nuclear Physics

Picture of Chien-Shiung Wu

Chien-Shiung Wu

1912 - 1997

Additional Information

Some Important Contributions

Demonstrated experimentally that parity is not conserved in nuclear beta decay. By showing that parity is violated in the weak interactions, she gave experimental evidence to support Lee and Yang's proposed solution of the tau-theta puzzle. Below she describes an early conversation between herself and Lee which led to her design and execution of the experiment.
    "One day in the early spring of 1956, my colleague Prof. T.D. Lee came up to my office on the 13th floor of Pupin Physics Lab. He asked me a series of questions concerning the status of the experimental knowledge of beta-decay. I could not supply him with any information on [a pseudoscalar quantity] from experimental results of beta-decay. Before T.D. left my office, I asked him whether anyone had any ideas about doing this test. He said that some people had suggested using polarized nuclei produced during nuclear reactions or using a polarized slow neutron beam from a reactor. Somehow I had great misgivings about using either of these two approaches. I suggested that the best bet would be to use a Co60 beta-source polarized by the adiabatic demagnetization method by which one could attain polarization as high as 65%. Dr. Lee was very interested in the possibility of such a strongly polarized Co60 beta-source and asked me to lend him a reference book on the method." ref

Gave important experimental confirmation of the conservation of the vector current in nuclear beta decay.

Though the general features of nuclear beta decay predicted by Fermi's theory were experimentally confirmed soon after it was proposed, experimental confirmation of its detailed predictions took almost twenty years. Wu's post WWII experimental program was important in resolving this problem. It demonstrated her great experimental skills.  Recent developments.

Observed that polarized electromagnetic radiation i released on electron-positron annihilation, a phenomenon predicted by Dirac' theory of the electron.

While working on the Manhattan Project, developed a process for separating U235 from U238 by gaseous diffusion; also helped develop more sensitive Geiger counters.

Research on sickle-cell anemia using advanced biophysics.

Some Important Publications

"Experimental test of parity conservation in beta decay," Phys. Rev. 105: 1413 (1957), with E. Ambler, R. W. Hayward, D. D. Hoppes, and R. P. Hudson.

"Experimental test of the conserved vector current theory of the beta spectra of B12 and N12," Phys. Rev. Letters 10: 253 (1963), with Y. K. Lee and L. W. Mo, and "The universal Fermi interaction and the conserved vector current in beta decay," Rev. Mod. Phys. 36: 618 (1964) where a fuller account of this experimental result and its significance is given.

"Recent investigation of the shapes of beta-ray spectra," Rev. Mod. Phys. 22: 386 (1956).

"The angular correlation of scattered annihilation radiation," Phys. Rev. 77: 136 (1950), with I. Shaknov.

"Muonic atoms and nuclear structure," Annual Reviews of Nuclear Science 19: 527 (1969), with L. Wilets.

Published book:

Beta Decay, Interscience Publishers, New York 1966, with S. A. Moszkowski.

Editor of the following books:

Nuclear Physics, Academic Press, New York 1961, with L. Yuan.

Muon Physics (3 volumes), Academic Press, New York 1975-77, with V. Hughes.


Member National Academy of Sciences (elected 1958)
Research Corporation Award 1958
Achievement Award, American Association of University Women 1960
Comstock Award, National Academy of Sciences 1964
Chi-Tsin Achievement Award, Chi-Tsin Culture Foundation, Taiwan 1965
Scientist of the Year Award, Industrial Research Magazine 1974
Tom Bonner Prize, American Physical Society 1975
National Medal of Science (U.S.) 1975
Wolf Prize in Physics, Israel 1978
Honorary Fellow Royal Society of Edinburgh
Fellow American Academy of Arts and Sciences
Fellow American Association for the Advancement of Science
Fellow American Physical Society

Honorary degrees:

D.Sc. from Princeton University (1958), Smith College (1959), Goucher College (1960), Rutgers University (1961), Yale University (1967), Russell Sage College (1971), Harvard University (1974), Bard College (1974), Adelphi University (1974), and Dickinson College (1975).

L.L.D. from Chinese University, Hong Kong (1969).

Honorary Professorships:

Nanking University, Science and Technology University, Beijing University, Tsao Hwa University, Nan Kai University, and Padua University (Italy).


1940-42 Resident Fellow and Lecturer, University of California, Berkeley
1942-43 Assistant Professor, Smith College
1943-44 Instructor, Princeton University
1944-46 Scientific Staff, Division of War Research ("Manhattan Project"), Columbia University
1946-52 Research Associate, Columbia University
1952-57 Associate Professor, Columbia University
1958-72 Professor of Physics, Columbia University
1972-81 Michael I. Pupin Professor of Physics, Columbia University
1975-82 Member, Advisory Committee to the Director, National Institutes of Health


B.S. National Central University, Nanking, China 1934
Ph.D. University of California, Berkeley 1940

References consulted

[1K N20], [4 AMWS], [12A GKS], [17 MWR2], [26 SBM], [29 WWWS], [33U LSG], [34 WIP], [39H CBY], [51 MJB], [54 JSB], [56 EAV], [58 SH], [60 CCDS], [oibdpp1996cw].

Recommended reading:Madame Wu's first-hand account of her experimental determination of parity violation [oibdpp1996cw].

Additional Information/Comments

Recommended reading: New York Times obituary

An asteroid was named in her honor in 1990.

Sentiment in the physics community to the contrary, she was not awarded the Nobel Prize along with Lee and Yang for the discovery of parity violation.

Chien-Shiung Wu's father, Wu Zhong-Yi, opened the first school for girls in China. He advised hi daughter when she embarked on her scientific career: "Ignore the obstacles... just put your head down and keep walking forward." [npw1993sm] Chien-Shiung's name means "strong hero" in Chinese.

Chien-Shiung Wu is said to have said

    "There is only one thing worse than coming home from the lab to a sink full of dirty dishes, and that is not going to the lab at all."
Married Luke Yuan in 1942 and they have a son Vincent.

List of firsts
First female instructor in the physics department of Princeton University.
First woman to receive an honorary doctorate from Princeton University.
First woman to be elected President of The American Physical Society (1975).

For more about Professor Wu' life and work, see the chapter about her in Nobel Prize Women in Science by Sharon Bertsch McGrayne [npw1993sm].

Cited by:

Loretta Johnson
<Johnson@kuphsx.phsx.ukans.edu >

Field Editors: Professors S.A. Moszkowski / C.W. Wong

<stevemos@ucla.edu> / cwong@physics.ucla.edu>

Copyright © CWP and Regents of the University of California 1997 - 2001

To cite this citation:
" Wu, Chien-Shiung." CWP < home >


latest revision {4/30/97 mjw} 3/16/01 nb