May 15

Born in 1720 in Selmecbánya, Hungary, Hell joined the Society of Jesus and pursued studies in astronomy. He became director of the Vienna Observatory, where he published annual ephemerides used by navigators. In 1761, Hell led a scientific expedition to Vardø, Norway, to observe the transit of Venus and improve measurements of the solar system. His detailed observations and calculations contributed to more accurate determinations of the Earth-Sun distance. After his return, Hell published his findings, though they faced controversy over publication delays. He died in 1792, remembered as a key figure in 18th-century astronomical research.

Born in 1841 in Plainfield, Connecticut, Dutton graduated from West Point and served as a Union engineer during the Civil War. After the war, he joined the U.S. Geological Survey to explore the Colorado Plateau. Dutton produced the first comprehensive report on the Grand Canyon's geology, including detailed mapping and analysis of its rock layers. He introduced the concept of 'isostasy' to explain mountain uplift and crustal balance. His publications, such as the 'Tertiary History of the Grand Canyon District', set new standards for geological research. Dutton's fieldwork and writings influenced generations of geologists. Later in life, he taught at military academies and continued his research on tectonics. He died in 1912, recognized as a foundational figure in American geology.

Born in 1845 in Ukraine, Metchnikoff studied natural sciences at the University of Odessa before joining Louis Pasteur's laboratory in Paris. There he observed phagocytic cells engulfing pathogens, leading to his groundbreaking theory of cellular immunity. He coined the term 'phagocytosis' to describe this process and demonstrated its role in host defense. In 1908, Metchnikoff was awarded the Nobel Prize in Physiology or Medicine jointly with Paul Ehrlich. As director of the Institut Pasteur's microbiology department, he conducted research on aging and host-microbe interactions. He promoted the concept of probiotics and explored the relationship between gut flora and health. Metchnikoff's work laid the foundations for the study of innate immunity and inflammation. He died in 1916, leaving a lasting legacy in zoology, microbiology, and immunology.

Carl Wernicke (1848–1905) was a German physician and neuropathologist who made groundbreaking contributions to brain science. He is best known for identifying a region in the posterior part of the superior temporal gyrus—later named Wernicke’s area—that is critical for understanding spoken and written language. His work on aphasia led to the first classification of language disorders, distinguishing them from motor speech impairments. Wernicke served as a professor and head of pathology at several universities, where he continued his research on brain anatomy and function. His findings laid the foundation for modern neurology and cognitive neuroscience.

Ioannis Psycharis (1854–1929), also known as Jean Psychari, was a pioneering philologist who championed the demotic (vernacular) form of the Greek language. Born in Ukraine to Greek parents and educated in France, he authored the influential work "My Journey: Literary, Social and Political" which argued for linguistic reform and cultural revival. His theories sparked passionate debates and helped shape the emergence of Modern Greek. Psycharis also wrote essays and literary works in both Greek and French, blending scholarly research with accessible prose. He taught philology in Paris and became a leading figure in European linguistic circles before his death in 1929.

Williamina Paton Stevens Fleming (1857–1911) was a pioneering astronomer who worked at the Harvard College Observatory. Hired initially as a housekeeper, she became one of the first women to catalogue stars and organize stellar spectra. Fleming devised a system for classifying stars based on their hydrogen line strengths, paving the way for the Henry Draper Catalogue. She discovered the Horsehead Nebula (Barnard 33) and over 10 novae and thousands of stars still studied today. Fleming’s career broke gender barriers in science and inspired future generations of women astronomers.

Pierre Curie (1859–1906) was a French physicist and professor who made seminal contributions to the study of crystallography and magnetism. Alongside his wife Marie Curie, he discovered the phenomenon of radioactivity, earning them the Nobel Prize in Physics in 1903. Curie also conducted pioneering investigations into piezoelectricity, describing how certain crystals generate electric charge under mechanical stress. He served as a lecturer at the École Normale Supérieure and the Sorbonne, influencing a generation of physicists. Curie’s untimely death in a street accident cut short a brilliant career, but his research laid crucial groundwork for modern nuclear science.

Fritz Feigl (1891–1971) was a pioneering chemist who developed innovative methods in spot and paper chromatography. After emigrating from Austria to Brazil in the 1930s, he established a world-renowned school of analytical chemistry at the University of São Paulo. Feigl's 'spot tests' provided simple, rapid techniques for detecting chemical substances, revolutionizing qualitative analysis. He authored the seminal multivolume work 'Spot Tests in Organic Analysis', which became a standard reference. Feigl's contributions extended to forensic and industrial applications, impacting public health and environmental analysis. His legacy endures in laboratories worldwide through the methods and principles he devised.

Born in 1900, Ida Rhodes earned her degree in mathematics and began her career teaching at Columbia University. In the 1940s, she joined the mathematical tabulation division at Remington Rand, where she became one of the first programmers. Rhodes helped develop early compiler concepts and contributed to groundbreaking languages such as MATH-MATIC and FLOW-MATIC. She advocated for the use of computers in scientific research and mentored young women entering the field. Her work laid foundations for modern programming and she continued to influence computing until her death in 1986.

Born in Dresden in 1903, Maria Reiche studied mathematics at the University of Leipzig. Moving to Peru in 1932, she dedicated her life to surveying and interpreting the ancient Nazca geoglyphs. Her meticulous measurements and aerial mapping unveiled the stunning scale and precision of the lines. Reiche advocated for the preservation of this archaeological wonder, helping secure UNESCO World Heritage status in 1994. Known as the "Lady of the Lines," she wrote seminal works on the subject and lectured internationally. Her passion and perseverance transformed a local curiosity into a celebrated global treasure.

Born in Germany in 1911, Herta Oberheuser pursued a career in medicine and became one of the few female physicians in her era. During World War II, she was assigned to Ravensbrück concentration camp where she conducted medical procedures and experiments on prisoners. After the war, Oberheuser was the only female defendant in the Ravensbrück Trials and was convicted of crimes against humanity. She was sentenced to two decades in prison, though she was released in 1952 amid public debate. Following her release, she returned to private medical practice in West Germany. Her case remains one of the most notorious examples of the abuse of medical authority in wartime.

Paul Samuelson was born in Gary, Indiana in 1915 and became a pioneering figure in modern economics. He was the first American to receive the Nobel Prize in Economic Sciences in 1970 for raising the level of scientific analysis in economic theory. Samuelson's textbook 'Economics: An Introductory Analysis' became one of the best-selling economics texts of all time. He contributed foundational work in areas such as welfare economics, public goods, and the theory of dynamic markets. Samuelson served on the faculty of the Massachusetts Institute of Technology for over four decades, mentoring generations of economists. His influence extends through his extensive publication record and his role in shaping economic education worldwide.