The physicist whose experiment won a Nobel Prize — for two men who weren't her

In 1956 Chien-Shiung Wu tested whether radioactive cobalt-60 nuclei emit particles symmetrically in all directions, as physicists had long assumed. They didn't — proving that a basic symmetry of nature, parity, can be violated. The theorists who predicted this, Lee and Yang, won the 1957 Nobel Prize; Wu, whose experiment proved it, did not.

— Chien-Shiung Wu et al., Experimental Test of Parity Conservation in Beta Decay — Physical Review, 1957