Chien-Shiung Wu was an accomplished nuclear physicist. To honor her achievements in nuclear physics, the U.S. Postal Service (USPS) created a stamp with her face. In her 40-year career, Wu won the National Medal of Science and had an asteroid named after her. She worked on the Manhattan project and was the first female physics professor at Princeton. One of her experiments disproved a law of physics. It was a very important discovery. Her two colleagues won a Nobel Prize for that research, but Wu was only mentioned in the acceptance speech. The USPS hopes to feature other important scientists on future stamps.