February 18

Nasir al-Din al-Tusi was a leading Persian scholar active in the 13th century. He made groundbreaking contributions to trigonometry and spherical geometry. As director of the Maragheh observatory, he oversaw one of the most advanced astronomical research centers of the medieval world. His ethical treatise 'Akhlaq-i Nasiri' became a cornerstone in Islamic moral philosophy. Al-Tusi also wrote commentaries on Aristotle and played a key role in transmitting Greek philosophy to the Islamic world. His writings on theology, mathematics, and astronomy shaped intellectual life across the Middle East and later Europe.

Ibn Hajar al-Asqalani was an eminent Egyptian scholar born in 1372. He mastered the sciences of hadith and served as the leading muhaddith in Mamluk Cairo. His commentary 'Fath al-Bari' on Sahih al-Bukhari is still regarded as the definitive work on hadith interpretation. He held prestigious teaching and judicial positions, shaping the study of Islamic law and hadith for generations. A prolific author, he wrote extensively on jurisprudence, biography, and theology. His meticulous scholarship earned him the title Shaykh al-Islam before his death in 1448.

Bahāʾ al-dīn al-ʿĀmilī was born in 1547 in Jabal Amel (modern Lebanon). He established the Isfahan School, blending Islamic theology with philosophy and mysticism. His prolific writings cover logic, metaphysics, ethics, and astronomy. Al-ʿĀmilī served as Shaykh al-Islam at the Safavid court in Isfahan. He is also celebrated for his Persian and Arabic poetry. His intellectual legacy influenced Islamic thought for centuries after his death in 1621.

Isaac Casaubon was born in Geneva in 1559 into a family of Huguenot refugees. He gained fame for his meticulous philological work on ancient authors like Homer and Lucretius. Casaubon taught in France and England, earning the patronage of King James I. His scholarship laid the foundations for modern textual criticism. He also studied ancient inscriptions and contributed to the study of early Christian writings. Casaubon's erudition made him one of the leading humanists of his age before dying in 1614.

Francesco Redi was born in 1626 in Arezzo and became one of the pioneers of experimental biology. As a court physician to the Medici grand dukes, he conducted experiments with meat and insects to demonstrate that maggots arise from eggs, not spontaneous generation, detailed in his magnum opus 'Esperienze intorno alla generazione degli insetti'. Redi also made early contributions to parasitology by describing parasitic worms in detail. His work laid foundations for modern experimental methodology in biology. He published studies on the physiology of respiration and the circulation of blood. Redi died in 1697, leaving a lasting impact on scientific thought.

Alessandro Volta was born in Como in 1745 and became a professor of physics renowned for his pioneering studies in electricity. In 1800, he built the first electrochemical battery, known as the Voltaic pile, which provided the first continuous electric current. Volta's investigations into methane and the invention of the electrophorus furthered understanding of gases and electrostatics. His work led Napoleon Bonaparte to name him a senator and count. The SI unit of electric potential, the volt, honors his legacy. Volta published extensively on electricity and gas chemistry, influencing scientists across Europe. He died in 1827, leaving an enduring scientific legacy.

Born in 1838 in Brno, then Austria-Hungary, Ernst Mach conducted pioneering research on supersonic motion and shock waves, leading to the concept of the Mach number. He made major contributions to the study of optics and acoustics, including the optical illusion known as Mach bands. Mach's critical analysis of Newtonian mechanics laid groundwork for the philosophy of empiricism and logical positivism. He held professorships in Prague and Vienna and wrote influential works on the history and theory of science. Mach's ideas impacted scientists like Einstein and philosophers of the Vienna Circle. He died in 1916, remembered as a key figure in both experimental physics and the philosophy of knowledge.

Jean Jules Jusserand (1855–1932) was a French historian, author, and diplomat renowned for his tenure as French Ambassador to the United States from 1902 to 1924. Educated in literature and history, he published influential works on Franco-British and Franco-American relations. As ambassador, he fostered political and cultural ties between the two nations and advocated for U.S. support during World War I. After his ambassadorship, he represented France at the Paris Peace Conference of 1919. His scholarly insight and diplomatic skill left a lasting impact on early 20th century international affairs.

Harry Brearley (1871–1948) was an English metallurgist who discovered stainless steel while researching erosion-resistant alloys for gun barrels in Sheffield. His identification of a chromium-rich steel alloy led to the development of rust-proof steel, transforming industries ranging from cutlery and medical instruments to architecture. Brearley's invention triggered the growth of stainless steel manufacturing and established Sheffield as a center for metallurgical innovation. He later founded a research laboratory to further alloy development. His work laid the foundation for modern materials engineering.

Li Linsi was a distinguished educator at National Tsinghua University and a trusted diplomatic advisor to Chiang Kai-shek. He played a pivotal role in establishing scholarships and exchange programs that connected Chinese students with Western institutions. During World War II, Li spearheaded humanitarian initiatives to support scholars displaced by conflict. His insights into education policy and international relations shaped modern Chinese academic reforms. Nominated for the Nobel Peace Prize, he advocated for global understanding through dialogue and scholarship. Li's legacy lives on in the enduring partnerships between Chinese and international educational communities.

Arthur Bryant was a renowned English historian and journalist noted for his engaging narrative style. He served as chief leader writer for The Times and authored influential histories such as Praise of England. Bryant's biographies of figures like Edward II and Oliver Cromwell combined meticulous research with accessible prose. He was appointed to the Order of Merit in recognition of his outstanding contributions to literature and history. Bryant's interpretations of monarchy and empire shaped public understanding of Britain's past. His career spanned journalism, biography, and historical commentary, making him a key voice in 20th-century British letters.

Hans Asperger was an Austrian pediatrician who first described a pattern of social and communication difficulties in children with normal intelligence. As director of the Children's Clinic at the University of Vienna, he conducted groundbreaking studies in the 1940s that laid the foundation for Asperger's syndrome. His seminal paper introduced the term 'autistic psychopathy' and advocated for compassionate, individualized care. After World War II, Asperger continued teaching medical students and influencing pediatric psychiatry across Europe. Although debates over his actions during the Nazi era have clouded aspects of his legacy, his clinical observations remain central to autism research. Asperger's work fundamentally changed the understanding and diagnosis of autism spectrum disorders.