September 26

Gottfried von Hagenau was an Alsatian scholar active in the early 14th century. He held roles as a theologian, medical doctor, and poet, reflecting the interdisciplinary nature of medieval scholarship. His theological writings engaged with the scholastic debates of the High Middle Ages, while his medical practice served local communities across Alsace. As a poet, he crafted Latin verses that wove religious themes with classical influences. Gottfried's diverse works illustrate the rich intellectual life of medieval Europe.

Cecco d'Ascoli was an early polymath who compiled extensive knowledge in his famous didactic poem 'Acerba.' He combined astronomical observations, natural history, and philosophical discourse within a poetic framework. As a practicing physician, he served noble patrons and applied his understanding of medicine to clinical care. His outspoken views on astrology and critical thinking attracted scrutiny from church authorities. Tried for heresy, he was executed in 1327, cementing his reputation as a bold medieval thinker.

Antoine Parent (1666–1716) was a French mathematician who made significant advances in the study of curves and surfaces. A member of the French Academy of Sciences, he investigated properties of conic sections and offered early insights into differential geometry. Parent corresponded with leading scientists of his time, including Leibniz, and explored the foundations of calculus. His publications on the theory of curved surfaces influenced subsequent developments in mathematics. Parent’s work laid groundwork for later geometers and analysts.

Born in 1676, Benito Jerónimo Feijóo y Montenegro was a Benedictine monk and essayist considered Spain’s first Enlightenment thinker. He published ‘Teatro Crítico Universal,’ a series of essays challenging superstitions, blind traditions, and false learning. Feijóo advocated for the scientific method and empirical observation, bringing European Enlightenment ideas to the Iberian Peninsula. His work covered topics from natural philosophy to social reform, earning him both admirers and critics. He spent much of his life teaching in Oviedo and influencing future generations of Spanish intellectuals.

Jurij Vega was a prominent Slovene mathematician and physicist who advanced numerical methods in the 18th century. He published new logarithmic tables that became standard references for engineers and astronomers. In 1789, Vega achieved a record precision in calculating π, improving its value to 140 decimal places. His work on artillery trajectory and ballistics contributed to military physics. Vega’s studies in mathematics and natural philosophy earned him membership in several European academies. His legacy endures in the continued use of his mathematical tables well into the 19th century.

August Ferdinand Möbius was a pioneering German mathematician and astronomer in the 19th century. In 1858, he introduced the concept of the Möbius strip, a surface with only one side and one boundary. His work in projective geometry led to the Möbius transformation, fundamental in complex analysis. Möbius served as a professor at the University of Leipzig and mentored future scientists. He published influential textbooks on geometry and celestial mechanics. His discoveries remain central to modern mathematics, topology, and physics.

Hermann Grassmann was a groundbreaking German polymath whose work laid the foundation for modern vector spaces. His 1844 book 'Die Lineale Ausdehnungslehre' introduced the idea of n-dimensional spaces and vector addition. Grassmann’s algebraic methods anticipated later developments in multilinear algebra and exterior algebra. Although his ideas were initially overlooked, they were later recognized as essential to mathematical physics. He also published research on crystallography, linguistics, and theology, showcasing his diverse intellect. Grassmann’s concepts underpin much of contemporary geometry, physics, and engineering.

Born in 1885 in Koblenz, Germany, Hans Cloos studied geology at the University of Bonn. He became a leading authority on rock deformation and mountain-building processes. Cloos conducted field research in the Alps and contributed to the understanding of orogenic belts. His publications, including Problems of Petrology and Geodynamics, influenced geological sciences. As a professor at the University of Freiburg, he trained a generation of geologists. Cloos advocated for integrated approaches combining fieldwork, experimental geology, and theoretical models. He died in 1951, leaving a rich legacy in structural geology research.

Born in Warsaw in 1902, Lipman-Heilprin graduated in medicine in Germany before emigrating to Palestine. He established the neurology department at Hadassah Hospital, introducing advanced diagnostics and treatments. An academic at the Hebrew University, he trained a generation of Israeli neurologists and authored seminal papers. His research on cerebrovascular and spinal cord disorders earned international recognition for its clinical impact. He was admired for combining scientific rigor with compassionate patient care in a developing healthcare system. Lipman-Heilprin’s legacy endures in Israel’s thriving neurology programs and ongoing medical innovations.

Leopold Ružička (1887–1976) was a Croatian-Swiss chemist awarded the Nobel Prize in Chemistry in 1939 for his groundbreaking work on polymethylenes and higher terpenes. Born in Vukovar, he studied under Fritz Hofmann in Berlin before establishing his research career in Zurich. Ružička's investigations into the structure of natural compounds revolutionized organic chemistry and impacted pharmaceuticals and fragrances. He served as a professor at ETH Zurich and mentored numerous scientists. His legacy includes the Ružička reaction and a deeper understanding of molecular ring structures. He is regarded as one of the founders of modern stereochemistry.

Manne Siegbahn (1886–1978) was a Swedish physicist who received the Nobel Prize in Physics in 1924 for his pioneering work in X-ray spectroscopy. Educated at Uppsala University, he developed precise techniques to measure X-ray wavelengths, enhancing the understanding of atomic structure. He served as a professor and later as director of the Nobel Institute for Physics in Stockholm. His innovations laid the groundwork for modern spectral analysis in physics and chemistry. Siegbahn's legacy continued through his son Kai Siegbahn, who also won a Nobel Prize. He is remembered as a foundational figure in the field of spectroscopy.

He was born in 1912 in the Austrian town of Leoben and pursued studies in geology at the University of Graz. Tichy combined his scientific interests with a passion for storytelling, working as a journalist for Austrian publications while undertaking expeditions across the Andes and Himalayas. In 1953, he joined Hermann Buhl and Kurt Diemberger to achieve the first alpine-style ascent of Nanga Parbat, one of the world’s most formidable peaks. His account of the climb, published in several languages, remains a classic in mountaineering literature. Tichy’s unique blend of geological expertise and literary talent allowed him to capture both the physical challenges and the natural beauty of his expeditions. He continued to write and lecture about his adventures until his death in 1987, inspiring generations of climbers and scientists alike.