# 5557a - 2021 First-Class Forever Stamp - Imperforate Chien-Shiung Wu

US #5557a
2021 Chien-Shiung Wu (Imperforate)

• Honors Chien-Shiung Wu, a famous female nuclear physicist and advocate for women in science

Stamp Category:  Commemorative
Value:  55¢ First Class Mail Rate (Forever)
First Day of Issue:  February 11, 2021
First Day City:  New York, New York
Quantity Issued:  18,000,000 (Includes die-cut AND imperforate stamps.  The exact quantity of imperforate stamps is unknown, but it is only a tiny fraction of the total print quantity, making the imperforates much scarcer than traditional die-cut stamps.)
Printed by:  Ashton Potter (USA) Ltd.
Printing Method:  Offset, Microprint
Format:  Panes of 20
Tagging:  Nonphosphored Type III, Block Tag

Why the stamp was issued:  To commemorate world-renowned nuclear physicist Chien-Shiung Wu.

About the stamp design:  Pictures a highly detailed graphite and egg tempera portrait of Chien-Shiung Wu. In the portrait, Wu is wearing a black and white traditional Chinese gown called a qipao.

Special design details:  The blue background was painted with lapis lazuli pigment, a historically highly valued color traditionally reserved for paintings of angels, nobility, or the Virgin Mary.

First Day City:  The First Day of Issue Ceremony was held virtually due to the ongoing Covid-19 pandemic. The First Day of Issue Cancellation was from New York City, appropriate given Wu’s work at Columbia University as well as with the Manhattan Project.

History the stamp represents:  Chien-Shiung Wu (May 31, 1912 – February 16, 1997) was a Chinese-American experimental physicist. She is best known for her work in nuclear physics and her participation in the Manhattan Project. In fact, she became a legend in the scientific community, with nicknames such as “First Lady of Physics,” Chinese Madame Curie,” or “Queen of Nuclear Research.”

Chien-Shiung Wu was born in a small town called Liuhe in the Jiangsu province of China. She was a star student from an early age and graduated high school at the top of her class. She later attended National Central University (later renamed Nanjing University) and several other schools before traveling to the United States for her PhD. Originally Wu planned to attend the University of Michigan, but changed her mind and instead enrolled at the University of California, Berkeley.

Wu thrived in America and earned her PhD in June 1940. Four years later, she joined the Manhattan Project at Columbia University. From there, she became a leading authority in the field of nuclear physics, overcoming prejudices stemming from both her race and gender.

Wu continued her research throughout her life. Without Chien-Shiung Wu, we would likely not have the success with nuclear energy that we do today.