February 24

Johann Weyer studied medicine at the University of Cologne and was influenced by the works of Paracelsus. In 1563, he published "De Praestigiis Daemonum", challenging the prevailing belief in witchcraft and demon possession. He argued that many accused witches suffered from mental illness, pioneering a humane perspective toward the mentally ill. His work spurred debate across Europe and contributed to a gradual decline in witch trials. Besides his medical treatises, Weyer wrote on astrology and alchemy, leaving a varied intellectual legacy. He died in 1588, remembered as a compassionate scholar ahead of his time.

Georg Christoph Lichtenberg was appointed professor of experimental physics at the University of Göttingen in 1776. He discovered the branching electrical discharge patterns now known as Lichtenberg figures. His notebooks, filled with sharp and witty aphorisms, influenced European literary circles. A pioneer of public lectures, he made science accessible through clear demonstrations and engaging commentary. His interdisciplinary work bridged science and literature, marking him as a leading mind of the German Enlightenment.

Henry Cavendish identified hydrogen, which he called inflammable air, and studied its properties. His precise measurements led to an experiment determining the density of the Earth. A reclusive figure, he published little, leaving many discoveries in unpublished manuscripts. Cavendish's rigorous methods influenced the development of modern chemistry and physics. His work on gases and electricity established him as one of the most meticulous scientists of his age.

Étienne-Louis Malus observed that light reflected from certain surfaces became polarized, laying foundations for optical physics. He formulated Malus's law, which quantifies the intensity of polarized light through polarizing filters. As a military engineer under Napoleon, he applied his mathematical expertise to artillery and fortifications. His work in crystallography and wave theory advanced understanding of physical phenomena. Malus's discoveries remain fundamental to optics and photonics in science and technology.

Robert Fulton demonstrated commercial steam navigation with his steamboat Clermont on the Hudson River in 1807. He designed the Nautilus, the first practical submarine, which he presented in France in 1800. Originally a painter and inventor, Fulton secured government contracts for naval torpedoes. His innovations revolutionized maritime transport and laid the groundwork for the steamboat industry. Fulton's work accelerated economic growth and reshaped early 19th-century engineering practices.

Nikolai Lobachevsky challenged Euclidean geometry by developing a consistent hyperbolic geometry now known as Lobachevskian geometry. As rector of Kazan University, he modernized mathematical education and published influential geometry texts. His work anticipated key concepts in differential geometry and later supported Einstein's theory of general relativity. Despite limited contemporary recognition, his theories revolutionized mathematics and our understanding of space. Lobachevsky's legacy endures through his publications and the continued study of non-Euclidean geometries.

Born in 1842 in Istanbul, Osman Hamdi Bey studied art in Paris before returning to the Ottoman Empire. He was appointed curator of the Imperial Ottoman Museum and went on to establish the Istanbul Archaeology Museum, introducing scientific methods to excavations. His Orientalist paintings, including The Tortoise Trainer, are celebrated for their rich detail and cultural insight. As an archaeologist, he fought against antiquities smuggling and laid foundations for modern heritage law in Turkey. Bey's dual legacy as an artist and scholar continues to influence both museum practice and Ottoman art history to this day.

Born in 1850 near Stuttgart, von Ihering earned his doctorate in zoology before moving to Brazil in 1880. He became director of the Museu Paulista in São Paulo, organizing extensive expeditions into the country's interior. Von Ihering published foundational studies on mammals, reptiles, and insects, greatly enhancing scientific understanding of Brazilian biodiversity. He founded the Revista do Museu Paulista to share research and mentored many young Brazilian naturalists. His work laid the groundwork for modern zoological studies in South America. Von Ihering died in 1930, remembered for his dedication to exploration and museum curation.

Margaret Leech (1895-1974) was a pioneering American historian and author. She received the Pulitzer Prize for History in 1942 for Reveille in Washington and again in 1960 for In the Days of McKinley. Her narrative style brought to life the political and social currents of the United States during the Civil War and the McKinley era. Educated at Barnard College, she combined rigorous scholarship with engaging storytelling. Leech's works remain influential for their vivid character studies and meticulous research. She broke barriers as one of the first women to win multiple Pulitzers in history.

Claude Shannon (1916-2001) was an American mathematician, electrical engineer, and cryptographer whose pioneering work established the field of information theory. His landmark 1948 paper, 'A Mathematical Theory of Communication,' introduced the concept of information entropy and revolutionized digital communication. Shannon also made significant contributions to cryptography, switching circuits, and artificial intelligence. A professor at MIT, he received the National Medal of Science and numerous other honors for his innovative research. Shannon's theories underpin modern computing, telecommunications, and data compression technologies.

Educated at University College London, he joined the faculty at the Royal Free Hospital and later at the University of Oxford. Wrong’s work on renal tubular transport mechanisms advanced the understanding of electrolyte balance in the kidneys. He identified several hereditary kidney diseases, including Dent disease and other tubular disorders, improving diagnostic criteria. The Oliver Wrong Medal and Prize at the British Renal Society commemorates his contributions. He authored key textbooks and mentored many leading nephrologists, shaping modern clinical practices in nephrology.

Katherine Johnson was an American mathematician whose calculations were critical to the success of NASA's early human spaceflight missions. Born in 1918, she joined the National Advisory Committee for Aeronautics in 1953, which later became NASA. Johnson co-authored reports on orbital mechanics that enabled Alan Shepard's flight and John Glenn's orbit around the Earth. Her precise work ensured the safe re-entry and landing of astronauts during the Mercury and Apollo programs. Throughout her career, she broke racial and gender barriers in a segregated workforce. In 2015, President Barack Obama awarded her the Presidential Medal of Freedom. Her story brought attention to the contributions of African-American women in science and has been widely celebrated.