The Experiment That Overturned A Basic Law of Physics

Illustration for article titled The Experiment That Overturned A Basic Law of Physics

In the 1950s, physicist Chien-Shiung Wu was doing research at Columbia University when two other physicists approached her with a bold idea, but no way to prove it—until Wu found one.

io9’s comment of the day comes from commenter Rak who sketched out this history of Wu’s life and work in physics:

Born in 1912 China, heavily involved in politics and protests as a student, came to the US in 1936, and enrolled at Berkeley for physics because her first choice school (Michigan) wouldn’t even allow women to use the front door. Her family couldn’t attend her wedding because WWII had broken out in the Pacific theater. She worked on the Manhattan Project, and went on to conduct the famous experiment that demonstrated parity violation (among many other things). She continued as an activist both in the US and internationally til her death. They called her the “First Lady of Physics.” Movie. We need one.


Wu’s famous experiment on parity conservation is indeed what she is best known for—but the history of that experiment, and what happened after, is a complicated one.

Physicists Tsung-Dao Lee and Chen Ning Yang initially began work around the hypothetical physics concept on their own, but neither of them had a plan for an experiment that would help prove their ideas. That’s when they turned to Wu for help. Berkeley’s Nuclear Research Center explains the experiment that she devised and carried out:

Lee and Yang worked out the pencil and paper design of several experiments for testing the “Conservation of Parity” in the laboratory. Lee then turned to Wu for her expertise in choosing and then working out the hardware manufacture, set-up, and laboratory procedures for carrying out the experiment. Wu chose to do this for an experiment that involved taking a sample of radioactive cobalt 60 and cooling to cryogenic temperatures with liquid gasses. Cobalt 60 is an isotope that decays by beta particle emission, and Dr. Wu was also an expert on beta decay. The extremely low temperatures were needed to reduce the amount of thermal vibration of the cobalt atoms to practically nil. Also, Dr. Wu needed to apply a constant and uniform magnetic field across the sample of cobalt 60 in order to cause the spin axes of the atomic nuclei to all line up in the same direction.

While her two colleagues went on to win the 1957 Nobel Prize in Physics for their work, however, Wu and her experiment were left out from the final determination. Her work didn’t go unrecognized in her lifetime, though. More than twenty years later, Wu’s experiment was honored with the first Wolf Prize in Physics.

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They called her the “First Lady of Physics.” Movie. We need one.

Don’t be surprise Hollywood casting a white woman for that role if it ever gets green lit.