The U.S. Postal Company on Thursday unveiled a new postage stamp honoring Chien-Shiung Wu, a trailblazing Chinese American nuclear physicist whose myriad achievements attained her the nickname “the Initially Lady of Physics.”

The stamp’s release was timed to coincide with the Worldwide Working day of Girls and Ladies in Science, an once-a-year occasion that was set up by the United Nations General Assembly in 2015 to celebrate woman scientists and promote equal access for women and women in science and know-how.

The new stamp showcasing Chien-Shiung Wu.United States Postal Services

Kristin Seaver, executive vice president of the Postal Support, termed Wu “a person of the most influential nuclear physicists of the 20th century.”

Wu “created massive contributions to our knowledge of radioactivity and the composition of the universe,” Seaver stated Thursday in a taped digital ceremony to mark the stamp’s initially day of issue.

Wu was born in China in 1912 and moved to the United States at the age of 24. She been given a doctorate from the University of California, Berkeley.

Wu is ideal recognised for her experiments in the 1950s on a quirky but essential property in physics recognized as parity symmetry. Physicists at the time assumed that procedures in the serious planet — simple interactions this sort of as electromagnetism, for occasion — ought to be indistinguishable when these exact same processes are viewed in a mirror. In other phrases, whilst a mirror may possibly interchange still left and correct, it was imagined that character did not distinguish amongst the two.

But Wu’s analysis in 1956 with two theoretical physicists, Tsung-Dao Lee and Chen Ning Yang, located that when some radioactive particles decay, they defied parity symmetry.

The discovery was manufactured using a sample of cobalt-60, a radioactive type of cobalt, which emits particles that spin both in a remaining way or a right direction as it decays.

“She showed that the mirror graphic of the decay approach that was occurring in the laboratory could never come about in the real planet,” Brian Greene, a professor of physics and arithmetic at Columbia University, claimed for the duration of Thursday’s ceremony.

“That founded that this remaining-suitable symmetry that we believed was just a convention — the universe doesn’t treatment about remaining or suitable — she confirmed that the universe does care about still left and ideal,” Greene stated, adding that the breakthrough, “pushed the boundaries of comprehending in a profound way.”

Lee and Yang were awarded the 1957 Nobel Prize in Physics for the discovery, but not Wu. A lot of felt her contributions have been unfairly missed, specially since the groundbreaking research had been recognized as the “Wu experiment.”

Prior to her operate on parity violation, Wu assisted with the Manhattan Venture, experimenting with uranium enrichment all through Planet War II. Afterwards in her occupation, she examined molecular improvements in purple blood cells that aided reply essential issues about sickle cell illness.

Wu, who used most of her profession at Columbia University, was also an advocate for females in science and academia.

“She would always mention that the range of ladies in senior faculty member positions was really constrained. She believed that was not fair,” explained Vincent Yuan, her son, a nuclear physicist at Los Alamos Nationwide Laboratory. “She believed it was terrible that girls could not have essentially the similar ambitions and hopes that gentlemen could, if those people chances ended up limited.”

Wu’s achievements about her 40-yr profession aided pave the way for subsequent generations of feminine researchers in a area that was, and continue to is, dominated by males. She retired from Columbia College in 1981, and died in New York Metropolis in 1997 at the age of 84.

The new postage stamp was developed by Ethel Kessler, with original art by Kam Mak. The portrait attributes Wu in a black-and-white, substantial-collared regular Chinese gown.

With the launch of the stamp, Wu joins an elite club of researchers who have acquired such honor from the Postal Provider. Other experts who have experienced their likenesses emblazoned on stamps contain the physicists Albert Einstein and Richard Feynman, the geneticist Barbara McClintock, the astronomer Edwin Hubble and the theoretical physicist Maria Goeppert Mayer.

Any individual can be nominated to appear on a commemorative stamp, and the Postal Service receives tens of hundreds of submissions every single yr. Purposes are reviewed by the Citizens’ Stamp Advisory Committee, which then submits suggestions to the Postmaster Basic.