February 12

Dutch humanist scholar and professor of philosophy. He studied at the University of Leiden and became a leading intellectual of the Dutch Golden Age. He authored historical accounts of the Dutch Revolt and published Latin poetry celebrated for its elegance. He contributed important theological treatises and was a prominent figure in Amsterdam's intellectual circles. His writings influenced both historians and poets of his era.

A groundbreaking scientist in the study of entomology and comparative anatomy. He used early microscopes to observe and document the life cycles of insects, proving that maggots are fly larvae. His meticulous drawings and experiments laid the foundation for modern histology. He challenged prevailing theories by demonstrating physiological processes such as muscle contraction. His posthumous work 'Bybel der Natuure' (Bible of Nature) influenced future generations of biologists.

Educated in medicine and botany, he served as a professor at the University of Tübingen. In his seminal work 'De Sexu Plantarum Epistola', he provided experimental proof of plant sexual organs. He identified distinct male and female structures in plants, revolutionizing botanical science. His research laid the groundwork for modern plant physiology and taxonomy. He is remembered as one of the pioneers of experimental botany in the early 18th century.

Originally investigating seaweed ashes for alkali extraction, Courtois accidentally isolated a purple vapor that condensed into iodine. His discovery in 1811 opened a new field of halogen chemistry with widespread medical applications. Courtois's work earned recognition across Europe, influencing scientists like Gay-Lussac and Davy. As a professor at the École Polytechnique, he mentored students and advanced chemical analysis techniques. His identification of iodine's antiseptic properties paved the way for its use in surgery and antiseptics. Despite financial difficulties, his chemical contributions left a lasting impact on both science and public health.

Dulong studied at the École Polytechnique and became a professor at the Sorbonne, distinguishing himself in experimental physics. In 1819 he formulated the Dulong–Petit law with Alexis Thérèse Petit, establishing a key principle in thermodynamics. This law provided a predictable relation between atomic weight and specific heat, aiding chemical atomic weight determination. Dulong also conducted research on gas density, elasticity, and the properties of metals at cryogenic temperatures. His precise measurements and methodological rigor advanced the quantitative understanding of heat and matter. His contributions laid groundwork for later thermochemistry and physical chemistry developments.

Reichenbach began his career in the chemical industry, studying creosote, naphthalene, and glacial acetic acid. He is credited with pioneering the extraction of paraffin from mineral oils, revolutionizing the wax and lubrication industries. Beyond chemistry, Reichenbach explored phlogiston and metaphysical concepts, coining the idea of the 'Odic force'. His controversial theories on life forces influenced early spiritualist and hygienist movements. Reichenbach published extensively on natural sciences, blending empirical research with speculative philosophy. Though his Odic force theory was later discredited, his chemical innovations had lasting industrial impact.

Born in 1804, Heinrich Lenz studied physics at the University of Dorpat and later became a professor at the University of St. Petersburg. In 1834, he formulated Lenz's law, which describes the direction of induced electric currents. Lenz made significant contributions to the understanding of electromagnetic induction and thermodynamics. He published research on the conservation of energy in electrical processes and taught many students in Russia. His work laid foundational principles for electrical engineering and theoretical physics. Lenz remained a respected academic until his death in 1865.

Born in 1809 in Shrewsbury, Charles Darwin embarked on the HMS Beagle voyage in 1831, observing diverse species and geological formations around the world. Upon his return, he developed the theory of evolution by natural selection, publishing the book On the Origin of Species in 1859. Darwin’s meticulous observations and extensive correspondence with scientists and breeders advanced the study of variation and adaptation. He also wrote influential works on coral reefs, earthworms, and human evolution. Despite initial controversy, his ideas became the cornerstone of modern biology. Darwin continued to refine his theories until his death in 1882, leaving a profound scientific legacy.

Born in St. Petersburg in 1861, Lou Andreas-Salomé was a pioneering psychoanalyst. She studied philosophy and theology before meeting Friedrich Nietzsche and becoming his intellectual confidante. Salomé was among the first women practitioners of psychoanalysis and contributed to early theories of the human psyche. She wrote extensively on love, sexuality, and the psychology of religion, influencing contemporaries such as Rainer Maria Rilke. Her literary works include essays, novels, and autobiographical writings that blend philosophical insight with narrative flair. She maintained a lifelong commitment to women's intellectual independence and continued her work until her death in 1937.

He earned his Ph.D. in astronomy and began teaching at the University of New Mexico. He founded the Institute of Meteoritics, advancing the study of meteorite falls in the American Southwest. His work helped classify numerous meteorites and understand their origins. LaPaz published influential papers on planetary craters and impact processes. His research laid foundations for modern meteoritical science and planetary geology.

Born in Tacna, Basadre studied law and history at the National University of San Marcos. He authored the monumental Historia de la República del Perú, documenting Peru's political and social evolution from independence onward. Basadre served as Director of the National Library of Peru and co-founded the Peruvian Institute of History. His research and writings helped shape national identity and historical understanding in Peru. Remembered as the country's foremost historian, his legacy endures through his scholarly contributions.

Jacques Herbrand made significant advances in proof theory and formal logic at a young age. His work on what became known as Herbrand's theorem laid the groundwork for automated theorem proving. Despite his untimely death in a mountaineering accident, his publications profoundly influenced 20th-century logic and computer science. Herbrand's research bridged the gap between abstract mathematical concepts and practical methods for verifying proofs. Today, his legacy persists in logic, artificial intelligence, and theoretical computer science.