(CNN)Chien-Shiung Wu isn't a household name, but the pioneering physicist's portrait could be coming soon to a mailbox near you.
Her face is the latest image on a US Postal Service stamp issued on Thursday.
And the timing is no coincidence.
Jada Yuan, Wu's granddaughter, says issuing the stamp that day sends a powerful message.
"She believed in women and girls being in science, and achieving in any field that they put their minds to," Yuan says. "And I think it means a lot that because she's on a stamp, people will learn her story."
Wu got her Ph.D., became a professor and made landmark discoveries in physics at a time when relatively few women in the United States were even going to college.
The Chinese immigrant's work garnered her nicknames like "the queen of physics," and she won numerous accolades. But Wu never won a Nobel prize. And some speculate her gender may have been one reason she was passed over.
'She radically changed our view of the universe'
The stamp featuring Wu's portrait is one of three issued by the USPS this year to honor the achievements and culture of Asian Americans.
Postal officials say they selected Wu, who died in 1997, because she was one of the most influential physicists of the 20th century.
"During a career that spanned more than 40 years in a field dominated by men, she established herself as the authority on conducting precise and accurate research to test fundamental theories of physics," USPS says in its description of the stamp.
The discovery she's most known for: a 1956 experiment disproving conservation of parity, a law of physics that had become an accepted part of quantum mechanics.
"She radically changed our view of the universe," says Brian Greene, a professor of physics and mathematics at Columbia University.
Scientists had long assumed the universe was symmetric and didn't distinguish between left and right. But Wu's experiment showed that wasn't the case, he said.
"The achievement opens the way to a whole new set of explanations of the atom, the world and the cosmos," the New York Herald Tribune reported at the time, comparing its significance to Einstein's discovery of the theory of relativity.
"Her work, you now see it integrated into what is called the Standard Model of particle physics. This is our deepest understanding of nature's ingredients," Greene says. "And Madame Wu's result is written all over those equations."