February 20

Born in 1723 in Marbach, Mayer rose from humble origins to become an influential astronomer. In 1755 he published lunar tables of unprecedented accuracy, enhancing maritime navigation. His tables were later used to solve the longitude problem by British and French expeditions. Elected Fellow of the Royal Society, he received the Copley Medal for his groundbreaking work. Mayer also contributed to the study of sunspots and improved astronomical instruments. He died in 1762, but his methods continued to shape celestial mechanics.

Born in 1678 in Perreux, France, de Mairan became a leading member of the French Academy of Sciences. He conducted pioneering experiments on Earth's thermal variations and the propagation of seismic waves. In 1729 he discovered endogenous circadian rhythms while studying mimosa plant leaf movements. His work laid the groundwork for the fields of geophysics and chronobiology. He also made contributions to astronomy, creating detailed celestial tables. He died in 1771, honored for his multidisciplinary scientific achievements.

Born in 1711 in Bologna, Laura Bassi displayed exceptional talent in mathematics and physics from a young age. She earned her doctorate from the University of Bologna in 1732 at just 21 years old. In 1734 she was appointed to a chair of physics, becoming one of Europe's first female professors. She collaborated with her husband on experimental research and promoted scientific education for women. Her pioneering career paved the way for future generations of female scientists. She died in 1778, revered as a trailblazer in academia.

Born in Paris in 1852, Henri Moissan was fascinated by chemistry from an early age. He developed an innovative electric furnace capable of temperatures above 3,000°C, enabling new chemical reactions. In 1886, Moissan successfully isolated elemental fluorine, a breakthrough in inorganic chemistry. He conducted studies on meteoritic minerals, discovering silicon carbide (moissanite) in nature. In 1906, he was awarded the Nobel Prize in Chemistry for his investigations of fluorine and the electric furnace. Moissan’s work laid the foundation for modern industrial processes and materials science.

Sadri Maksudi Arsal was born in 1878 in Kazan, Russian Empire. He studied law and became an advocate for Tatar cultural rights and autonomy. After the Russian Revolution, he emigrated to Turkey and served as a deputy in the Grand National Assembly. Arsal taught law at Ankara University and published influential works on Turkish legal reform and literature. He played a role in the early years of the Turkish Republic, helping shape its legal and educational institutions. He died in 1957, respected for his scholarship and political service.

Maria Goeppert-Mayer earned her doctorate under Max Born in 1930 and became a pioneering theoretical physicist. She worked as a university lecturer and researcher at Johns Hopkins University and the University of Chicago, contributing to wartime radar and isotope separation projects. In 1950 she proposed the nuclear shell model, explaining the arrangement of protons and neutrons in atomic nuclei. Her model accounted for magic numbers and revolutionized nuclear physics. In 1963 she shared the Nobel Prize in Physics with J. Hans D. Jensen for this discovery, becoming the second woman to win the physics prize. Goeppert-Mayer was also a dedicated mentor for women in science, advocating for equal opportunities in academia. She remained active in research and teaching until her death in 1972.

René Cassin was a distinguished lawyer who served on the French judiciary and international tribunals. After surviving World War I, he became a leading advocate for international law and human rights. Cassin was a principal author of the Universal Declaration of Human Rights adopted by the United Nations in 1948. For this achievement, he was awarded the Nobel Peace Prize in 1968. He also held positions at the European Court of Human Rights and promoted legal education worldwide. Cassin authored several influential texts on civil liberties and constitutional law. His work laid the foundation for modern human rights frameworks and inspired generations of activists. He passed away in 1976, remembered as a founding father of human rights law.

Born in Poland in 1907, Solomon Asch emigrated to the United States and earned his Ph.D. in psychology from Columbia University. In the 1950s, he conducted groundbreaking experiments that revealed the powerful effects of group pressure on individual perception and judgment. Asch’s conformity experiments demonstrated that people might deny clear evidence to align with a unanimous group consensus. His work laid the foundation for modern social psychology and influenced studies on obedience, compliance, and group dynamics. Asch taught at Swarthmore College for nearly forty years and mentored generations of psychologists. He authored several influential books and articles, emphasizing rigorous empirical research methods. Asch was honored with numerous awards before his death on February 20, 1996, leaving a lasting legacy in psychology.

Donella Meadows was born in 1941 and earned a Ph.D. in biophysics from Harvard University. She rose to prominence as a systems analyst and co-author of The Limits to Growth report for the Club of Rome in 1972, which used computer models to examine global resource depletion. Meadows founded the Sustainability Institute (now the Donella Meadows Institute) to advance research on systems thinking and ecological economics. She wrote influential books and articles on environmental sustainability, collaborating with policymakers, academics, and grassroots organizations. Meadows taught at Dartmouth College and served on multiple environmental advisory boards, bridging science and policy. Her work sparked global discussions on human impact, sustainability, and long-term planning. Donella Meadows passed away on February 20, 2001, leaving a profound legacy in environmental advocacy and systems science.

David S. McKay was a renowned planetary scientist specializing in astrobiology. Born in 1936, he served as curator of lunar rocks for NASA's Johnson Space Center. McKay played a key role in analyzing moon samples from the Apollo missions. He co-authored the groundbreaking 1996 paper proposing evidence of fossilized life in the Martian meteorite ALH84001. His interdisciplinary research bridged geology, biology, and the search for life beyond Earth. McKay published extensively and mentored many in the field of planetary science. He passed away in 2013, leaving a lasting impact on our understanding of other worlds.

John C. Willke (1925–2015) was an American obstetrician-gynecologist and a leading figure in the pro-life movement. He served as president of the National Right to Life Committee and campaigned nationwide against abortion. Willke authored seminal guides on family planning and adoption that influenced public policy and grassroots activists. As a physician, he brought medical expertise to legislative hearings and media debates. His work left a lasting mark on bioethics discussions and the national dialogue over reproductive rights.

Mildred Dresselhaus (1930–2017) was an American physicist and materials scientist renowned for her research on carbon nanotubes, fullerenes, and graphite. She became the first female Institute Professor at MIT and mentored generations of young scientists. Dresselhaus chaired advisory panels for the U.S. Department of Energy and supported national science policy. Her accomplishments earned her the National Medal of Science and the Presidential Medal of Freedom. A champion for gender equality, she tirelessly promoted opportunities for women in science and engineering.