December 21

Hincmar (806–882) served as the Archbishop of Reims and advisor to Carolingian kings. He played a central role in political and ecclesiastical affairs under Louis the Pious and Charles the Bald. Hincmar was a skilled speaker and author, producing theological works and canonical collections. He intervened in major controversies such as the deposition of bishops and monastic reform. As a historian, he compiled annals that provide valuable insights into 9th-century Frankish history. His legal and doctrinal writings influenced the medieval church for centuries.

James Parkinson practiced medicine in London and conducted research on neurological disorders. In 1817, he published 'An Essay on the Shaking Palsy', providing the first comprehensive description of Parkinson's disease. He was also an avid geologist and fossil collector, contributing to early paleontological studies. Parkinson's multidisciplinary interests extended to political activism and social reform. His work laid the foundation for modern neurology and medical understanding of movement disorders.

Born in 1809, Friedrich August von Quenstedt was a pioneering German geologist. He specialized in the study of Jurassic strata and ammonite fossils. Quenstedt authored influential works on paleontology and stratigraphy. His detailed descriptions and classification methods advanced the understanding of Mesozoic life. He served as a professor at the University of Tübingen, inspiring future scientists. Quenstedt's name remains associated with important fossil taxa and geological formations. He died in 1889 after a lifetime dedicated to earth sciences.

Knud Rasmussen was born in 1879 in Jakobshavn, Greenland. A pioneering anthropologist, he documented Inuit culture and traditions. Rasmussen led the famous Thule Expeditions across the Arctic. Fluent in Inuit languages, he collected oral histories and legends. His work bridged Western science and indigenous knowledge. Rasmussen published influential accounts of Arctic life and exploration. He died in 1933, leaving a rich legacy in anthropology and polar research.

Władysław Witwicki was born in 1878 in Kharkiv and studied medicine and philosophy before becoming a pioneering psychologist in Poland. He translated key philosophical and psychological works by Plato, Descartes, and Freud into Polish, making these ideas accessible to his countrymen. Witwicki published influential studies on aesthetics, human perception, and the history of art, blending scholarly rigor with creative insight. An accomplished painter and sculptor, he exhibited his works in Warsaw and contributed original designs to the Polish decorative arts. He also researched and taught the history of literature and art, fostering a deeper appreciation of Poland’s cultural heritage. His interdisciplinary legacy continues to inspire psychologists, philosophers, and artists alike.

Born in 1907 in The Hague, Netherlands. He studied ethology under Konrad Lorenz and developed pioneering methods for observing animal behavior. In 1973, he shared the Nobel Prize in Physiology or Medicine for his discoveries on animal instinct. He introduced the framework known as "Tinbergen's four questions" to explain behavior analysis. Tinbergen served as a professor at Oxford University and authored key works like "The Study of Instinct." His research remains foundational in behavioral biology and psychology.

Autar Singh Paintal was born in 1925 in Punjab and earned his medical degree in India before completing doctoral studies at Cambridge. He pioneered electrophysiological techniques to identify and classify sensory receptors in the cardiovascular and respiratory systems. His work on chemoreceptors and mechanoreceptors laid the foundation for modern neurophysiology. Paintal served as Director of the Indian Institute of Physiology and Allied Sciences and held fellowships in international scientific societies. He authored over 200 research papers and mentored generations of scientists, earning prestigious awards for his contributions to medical research.

Edwin G. Krebs was born in 1918 and received his doctorate in biochemistry before joining the University of Washington faculty. Alongside Edmond Fischer, he uncovered the mechanism of reversible protein phosphorylation, a fundamental process regulating cell signaling. This breakthrough, recognized with the 1992 Nobel Prize in Physiology or Medicine, revolutionized understanding of cellular regulation and disease pathways. Krebs’s research influenced cancer studies and drug development. He authored numerous publications, mentored many scientists, and received multiple honors, shaping modern biochemistry.

Born in 1937 in Boston, McCandless graduated from the United States Naval Academy and became a naval aviator. He was selected by NASA in 1966 and flew on the historic STS-41-B mission in 1984. During this flight, he conducted the first untethered spacewalk, floating freely in space with the Manned Maneuvering Unit. This groundbreaking achievement advanced human capability for on-orbit operations. After retiring from NASA, he continued contributing to space exploration and naval aviation. He died in 2017, remembered as a trailblazer in extravehicular activity.

Born in 1938, Palmer studied engineering at Imperial College London before joining the oil industry. He developed pioneering techniques for the design and construction of deepwater pipelines. His leadership at major engineering firms set new standards for safety and efficiency in offshore projects. Palmer's research was recognized with honors from professional societies and academic institutions. He mentored a generation of engineers and contributed to sustainable energy practices. He passed away in 2019, leaving a transformative legacy in subsea engineering.