The U.S. Postal Service (USPS) held a First-Day-of-Issue Ceremony for the Chien-Shiung Wu Commemorative Forever^® Stamp on February 11, 2021. This virtual ceremony was carried on the Postal Service’s social media channels on Facebook and Twitter. 

Dr. Chien-Shiung Wu (1912-1997) was a Chinese immigrant who became a nuclear physicist in an almost entirely male-dominated field in the 1950s. She worked with Oppenheimer and Fermi on the Manhattan Project, helping develop the method for separating nonfissionable uranium 238 from fissionable U-235—the bomb’s key fuel. Her experiment on the non-conservation of parity disproved a fundamental law of physics that had been considered incontrovertible for 30 years. The male theoretical physicists she worked with were awarded the Nobel Prize in 1957, but she did not get the award this time, nor for earlier work on Beta decay that was also considered Nobel-worthy. She was awarded the inaugural Wolf Prize in Physics in 1978. Her expertise in experimental physics evoked comparisons to Marie Curie. She's one of only two individuals being honored with stamps this year, and in a year that the USPS is honoring Asian-American achievement. The art for her stamp was done by Asian-American painter Kam Mak.  

To watch the ceremony: https://www.facebook.com/USPS/videos/1297548877293468/h 

To purchase the commemorative stamp: https://store.usps.com/.../chien-shiung-wu...  

To learn more about Chien-Shiung Wu: