April 29

Born in 1517, Cooper held various academic and clerical posts before being appointed Bishop of Lincoln by Queen Mary I. He compiled the Thesaurus Linguae Romanae et Britannicae, one of the first comprehensive English–Latin dictionaries. Cooper's translations and theological works reflected the intellectual currents of Tudor England. He served as a royal chaplain and supported the Marian restoration of Catholicism. Later, he continued his scholarship under Elizabeth I despite religious shifts. His pioneering lexicographical work laid the groundwork for future English dictionaries. Thomas Cooper died on April 29, 1594, leaving a lasting academic legacy.

Born in 1694 near Stockholm, Georg Brandt was educated in medicine and chemistry. He investigated the mineral smalt and isolated a previously unknown metal, which he named cobalt. Brandt's work challenged alchemical traditions and applied rigorous experimental methods. He served as a court chemist and physician to the Swedish royal family. Brandt published treatises on mineralogy and analytic chemistry, influencing scientific classification. His discovery of cobalt marked a milestone in inorganic chemistry. Georg Brandt died on April 29, 1768, remembered for his precise research and scholarly contributions.

Born in 1756 in County Wexford, William Babington studied medicine in Dublin and London. He became a respected physician and fellow of the Royal College of Physicians. Babington's 1799 publication, A System of Mineralogy, introduced a systematic approach to classifying minerals by chemical composition. He established the mineral babingtonite, which was named in his honor. Babington served as president of the Medico-Chirurgical Society and contributed to the Geological Society of London. His dual expertise bridged medicine and geology, reflecting the interdisciplinary spirit of his era. William Babington died on April 29, 1833, remembered for his influential scientific works.

Paul Du Chaillu (1835–1903) was a pioneering explorer, anthropologist, and zoologist. He gained fame in the 1860s for his expeditions in equatorial Africa, where he provided the first scientifically documented accounts of gorillas and the Pygmy peoples. Du Chaillu's detailed observations and specimens challenged European understanding of African wildlife and cultures. He published several influential works based on his journeys, blending scientific rigor with captivating storytelling. His contributions expanded knowledge of primate behavior and human diversity, inspiring subsequent generations of naturalists and explorers. Despite initial skepticism, his findings were eventually validated, securing his place in the history of anthropology and zoology.

Jørgen Pedersen Gram (1850–1916) was a Danish mathematician whose work laid foundations in linear algebra and probability theory. He introduced the Gram determinant (now known as the Gram matrix) in the context of bilinear forms. His research on discrete distributions led to what is now called the Gram–Charlier series in statistical theory. Gram published pioneering texts in mathematics and served as a professor, influencing both peers and students. His contributions continue to underpin modern developments in mathematics, signal processing, and data analysis. Gram's elegant combination of theoretical insight and practical applications marked him as a leading scholar of his time.

Ernest Fox Nichols (1869–1924) was an American physicist and academic leader. He earned acclaim for his precision experiments measuring radiation pressure, confirming Maxwell's theoretical predictions. Nichols held professorships in physics at several universities before becoming president of Dartmouth College. Under his leadership, Dartmouth expanded its academic programs and campus facilities. Nichols was active in scientific societies, promoting collaboration among researchers in the United States. His blend of scholarly achievement and administrative skill helped shape American higher education in the early 20th century.

Irving Fisher was born in 1867 in Saugerties, New York, and became one of the most influential economists of his era. A professor at Yale University, he formulated the Fisher equation linking nominal interest rates, real rates, and inflation. Fisher also developed the concept of the consumer price index and advanced the theory of index numbers. He applied mathematical rigor to economic analysis, influencing modern macroeconomics and monetary theory. Despite financial setbacks during the Great Depression, his theoretical innovations endured. Fisher died in 1947, leaving a profound legacy in economic thought and statistical methods.

William Eccles was an English physicist and engineer whose research advanced early radio and electronic technology. Born in 1875, he conducted foundational work on electrolytic detectors and gas-filled tubes that improved signal detection. He co-invented the Eccles–Jordan multivibrator circuit, a precursor to digital electronic switches. Throughout his career, he published influential papers on electromagnetic theory and lectured at leading academic institutions. Eccles also served as President of the Physical Society, mentoring a new generation of scientists. His textbooks and articles shaped the study of electronics for decades. He died in 1966, leaving a lasting impact on modern communication and computing.

Born in 1936, Arthur B. C. Walker Jr. became a distinguished professor of physics at Stanford University. He developed groundbreaking instruments for observing the Sun’s atmosphere in ultraviolet wavelengths. Walker's solar telescopes aboard NASA missions captured unprecedented images of solar flares and coronal mass ejections. He mentored generations of students and championed diversity in the sciences as one of Stanford’s first African-American faculty. Walker published influential papers and shaped space science policy debates throughout his career. His legacy continues through the Walker Solar Telescope and the many scientists he inspired.

Louis Leithold was an American mathematician renowned for his dynamic teaching style and authorship of 'The Calculus'. He revolutionized calculus education with clear explanations and innovative pedagogy. Leithold taught for many years at the University of Southern California and College of the Canyons. His textbook became a standard reference, widely adopted by high schools and universities. He was celebrated for making complex concepts accessible to students. Leithold's impact on mathematics education continues through decades of successful learners.

John Kenneth Galbraith was one of the most influential economists of the 20th century. He authored best-selling books such as 'The Affluent Society' and 'The New Industrial State'. Galbraith served as the U.S. Ambassador to India from 1961 to 1963 under President Kennedy. He held professorships at Harvard University and was known for his sharp critiques of conventional economic theory. Galbraith's work bridged academic research and public policy, shaping debates on wealth and inequality. His writings and diplomatic service left a lasting imprint on both economics and international relations.

Albert Hofmann was a pioneering Swiss chemist who first synthesized LSD in 1938. In 1943, he discovered its powerful psychoactive effects, leading to widespread interest and research. Hofmann authored the classic book 'LSD: My Problem Child', detailing his experiences and insights. Throughout his long career, he explored the value of natural psychoactive substances and their potential therapeutic uses. He remained active in research and lecturing well into his later years, living past his 100th birthday. Hofmann's work continues to influence pharmacology, psychiatry, and the study of consciousness.