May 20

Sébastien Vaillant was a leading French botanist who made seminal contributions to plant taxonomy and mycology. Born in Paris, he spent his career at the Jardin des Plantes, classifying hundreds of plant species and publishing detailed illustrations. His research on plant sexual organs challenged prevailing Linnaean ideas and influenced future botanical studies. Vaillant authored the influential "Botanicon Parisiensis," a comprehensive flora of the Paris region. His meticulous observations and classifications laid the foundation for modern botany.

William Emerson was an English mathematician and fellow of Trinity College, Cambridge, celebrated for his work on fluxions and algebra. Born in 1701, he became Plumian Professor of Astronomy and Experimental Philosophy in 1760. Emerson published "The Elements of Trigonometry and of the Conic Sections," which became a standard text for university students. His lectures emphasized clarity and practical applications, influencing the teaching of mathematics in Britain. He corresponded with leading scientists of his day and helped popularize Newtonian methods in continental Europe.

Charles Bonnet was a Swiss naturalist and philosopher whose pioneering research in botany and embryology earned him widespread acclaim. Born in Geneva, he introduced the idea of epigenesis in plant reproduction and conducted groundbreaking experiments on parthenogenesis in aphids. Bonnet’s major work, "Traité d’insectologie," detailed insect life cycles and influenced modern entomology. He also wrote philosophical essays on the evolution of organisms and the continuity of life. His interdisciplinary approach connected scientific observation with broader metaphysical questions, establishing him as a key figure of the Enlightenment.

Jacob Ellehammer was a Danish inventor and aviator born in 1871 who conducted one of the first manned powered flights in Europe in 1906. A self-taught engineer, he designed and built engines, motorcycles, and experimental aircraft including a tethered triplane. Ellehammer also explored early rotorcraft concepts and founded an aircraft workshop to advance aeronautical research. His inventive spirit and technical skill helped lay the foundation for Denmark's aviation industry. Ellehammer's contributions are celebrated among the pioneers of flight for their innovation and daring experimentation.

Philipp Lenard was born in 1862 and received the 1905 Nobel Prize in Physics for his pioneering experiments on cathode rays. He developed apparatus such as the 'Lenard window' to study the properties of electrons and contributed to early atomic theory. Lenard served as a professor at the University of Heidelberg, publishing extensively on electromagnetic phenomena. Later in his career, he became involved in nationalist politics and supported the Nazi regime, complicating his scientific legacy. Despite controversies, his experimental work provided key insights that influenced the development of modern physics.

Sir John Richard Hicks was born in 1904 and became one of the most influential economists of the 20th century. His seminal work 'Value and Capital', published in 1939, laid the foundations for modern general equilibrium analysis. Hicks introduced the IS-LM model in his book 'Mr. Keynes and the Classics', providing a clear framework for understanding Keynesian economics. For his pioneering contributions to welfare economics and general equilibrium theory, he was awarded the Nobel Prize in Economic Sciences in 1972. Hicks held professorships at the London School of Economics and the University of Oxford, mentoring generations of economists. He passed away on May 20, 1989, leaving a profound legacy in economic theory.

Stephen Jay Gould was born in 1941 and became a professor of geology and zoology at Harvard University. Alongside Niles Eldredge, he introduced the theory of punctuated equilibrium, reshaping views on the tempo of evolutionary change. Gould was a prolific essayist for Natural History magazine and authored bestselling books like 'The Panda's Thumb' and 'The Mismeasure of Man.' He challenged prevailing notions of biological determinism and critiqued the misuse of intelligence testing. His eloquent and engaging writing brought complex scientific ideas to a broad audience. Gould received numerous honors, including the National Book Award, and was a leading public intellectual until his death. He passed away on May 20, 2002, leaving a profound impact on evolutionary biology and science communication.

Leela Dube (1923–2012) was an influential Indian anthropologist whose research reshaped the understanding of gender and family structures in South Asia. Her groundbreaking studies on kinship, marriage, and women's roles challenged traditional anthropological frameworks. Dube co-founded the International Council for Research on Women and contributed extensively to feminist scholarship. She held academic positions in India and abroad, mentoring students and advocating for social justice. Her interdisciplinary approach combined fieldwork with theoretical rigor, leaving an enduring impact on anthropology and gender studies.

David Littman (1933–2012) was an English-Swiss historian and writer whose scholarship focused on the Holocaust and Jewish history. He authored several books and academic papers that revealed overlooked aspects of wartime experiences and persecution. Littman served as a professor at universities in Europe, mentoring a generation of historians. Beyond academia, he was a vocal advocate for human rights and historical memory, participating in conferences and public debates. His meticulous research and commitment to truth have made his work a cornerstone in Holocaust studies.

Born in 1915 in Chicago, Polley began his career at Zenith Electronics. In 1955, he invented the Flash-Matic, the first wireless television remote control. His innovation revolutionized home entertainment, allowing viewers to change channels without leaving their seats. Polley held over 18 patents in remote control and television technology. He was honored by the Consumer Electronics Hall of Fame for his pioneering work. His designs paved the way for modern smart remotes and home automation. He passed away on May 20, 2012, leaving a lasting legacy of engineering ingenuity.

Born in 1944, Bem earned her PhD in psychology and became a professor at the University of California, Berkeley. She developed the Bem Sex-Role Inventory, a groundbreaking tool for measuring gender identity. Bem introduced gender schema theory, reshaping understanding of how culture and cognition influence gender development. Her work challenged traditional stereotypes by exploring psychological androgyny. She authored numerous influential publications and received multiple awards for her contributions to social psychology. Bem's research continues to guide scholars in gender studies and behavioral science. She passed away on May 20, 2014, leaving a transformative legacy in psychology.