North America

The age of the earth

Katherine Johnson, computer for NASA

Johnson was part of a group of African American women mathematicians who worked as “computers” during the early days of NASA...

Elmer Imes and infrared spectroscopy

The second African American to earn a PhD in physics, Imes’ work in infrared spectroscopy pinpointed the distances between atoms in molecules and helped verify quantum theory...

Mary Agnes Chase, feminist and botanist

Ynes Mexia, plant explorer

Mexia found her calling late in life, but her contributions to botany are impressive...

Carlos Finlay and the Yellow Fever vector

Cuban Doctor Carlos Finlay successfully identified mosquitos as the vector for the transmission of deadly Yellow Fever...

Emmy Noether and a revolution in algebra

Noether was recognized as one of the most important mathematicians of her time, but, as a Jewish woman, the Nazi’s rise to power forced her from her (already precarious) university position in Germany...

Percy Lavon Julian and synthetic chemistry

The grandson of slaves, Julian fought against a racist society to become a leading American chemist...

Chien-Shiung Wu and nuclear physics

Chien-Shiung Wu was a Chinese immigrant to the United States who participated in the Manhattan Project. She made major contributions to subatomic physicis...

Ernest Everett Just and cell biology

A brilliant experimentalist, Just illuminated the complex biology of fertilization and development. As a black man, he faced difficulty obtaining a research appointment at an American university...