September 23

John Loudon McAdam was a Scottish civil engineer who revolutionized road building in the early 19th century. He developed the macadam process, layering crushed stone for improved durability and drainage. As highway engineer for several British counties, he advocated for better infrastructure to support trade and travel. The term “macadamization” and later “tarmac” derive from his name and his techniques formed the basis of modern roads. McAdam’s innovations facilitated the Industrial Revolution and left a lasting legacy in civil engineering until his death in 1836.

Johann Franz Encke was born in 1791 and became director of the Berlin Observatory, where he conducted pioneering studies of comets and celestial mechanics. He determined the orbit of the comet later named Encke’s Comet, which orbits the Sun every 3.3 years. Encke contributed to geodetic surveys and collaborated on European longitude determinations. His precise astronomical tables improved navigation and understanding of the solar system. Honored with membership in the Royal Society and the Copley Medal, his legacy endures in the Encke Gap within Saturn’s rings and numerous astronomical journals.

Armand Hippolyte Louis Fizeau was born in 1819 and became a pioneering French physicist in optics and electromagnetism. In 1849, he conducted the first successful terrestrial measurement of the speed of light using a rotating cogwheel apparatus. Fizeau also demonstrated how a moving medium affects light propagation, a key result preceding relativity. He collaborated on early telegraph networks and explored the Doppler effect for light waves. His work earned him membership in the French Academy of Sciences and laid foundational concepts for modern experimental physics until his death in 1896.

Ellen Hayes was an influential 19th-century American mathematician and astronomer who taught at Wellesley College. She was one of the first women to hold a faculty position in mathematics and astronomy at a major U.S. university. Hayes conducted research in algebraic theory and contributed to popularizing advanced mathematics. She was also an ardent suffragist and lecturer, advocating for women's education and equal rights. In her later years, she engaged in mountaineering and remained active in scientific societies.

William Stewart Halsted was a leading figure in the development of modern surgery in the United States. As one of the founding professors of Johns Hopkins Hospital, he championed strict aseptic protocols and introduced the use of rubber gloves in the operating room. Halsted made groundbreaking contributions to anesthesia, local anesthesia techniques, and radical mastectomy for breast cancer. He also explored pioneering blood transfusion methods. Despite personal struggles with addiction, his innovations established the foundation for contemporary surgical standards and medical education.

Born in 1867 in Granbury, Texas, John Lomax became one of the first scholars to systematically document American folk music. Over several decades he traveled across the southern United States, recording work songs, ballads, and spirituals from rural communities. His publications, including "Cowboy Songs and Other Frontier Ballads," introduced traditional music to a wider audience and influenced future ethnomusicologists. Lomax taught at various institutions and helped establish the Archive of American Folk Song at the Library of Congress. His efforts laid the groundwork for folk music revivals and the study of cultural heritage.

Born in Glasgow in 1880, John Boyd Orr studied medicine and turned to animal nutrition research, eventually directing the Rowett Research Institute. He conducted groundbreaking studies on diet and health, demonstrating the importance of vitamins and minerals. In 1945, he became the first Director-General of the United Nations Food and Agriculture Organization, advocating for equitable food distribution. For his efforts to combat hunger worldwide, he was awarded the Nobel Peace Prize in 1949. Boyd Orr later served in the British House of Lords, championing social welfare and public health until his death in 1971.

Su Buqing obtained his doctorate in mathematics from the University of Paris and brought modern geometric methods to China. He served as a professor at Zhejiang University and held leadership positions in China’s mathematical community. Su made significant contributions to projective differential geometry, notably the Su–Weingarten equation. He was elected a member of the Chinese Academy of Sciences and mentored generations of mathematicians. His textbooks and research laid the foundation for further development in Chinese mathematical sciences.

Ramdhari Singh Dinkar (1908–1974) was a towering figure in modern Hindi poetry, known for his passionate and nationalistic verses. His powerful poems, such as 'Rashmirathi,' explored themes of heroism, freedom, and social justice. Dinkar served as a professor of Hindi literature and contributed to academic scholarship and critical essays. He also engaged in politics, serving as a member of the 1st Lok Sabha and advocating for cultural and linguistic causes. Awarded the Padma Bhushan in 1959, his legacy as the Rashtrakavi (National Poet) of India endures in textbooks and public memory. Dinkar’s work blended classical forms with contemporary concerns, inspiring generations of writers and activists.

Ghulam Mustafa Khan (1912–2005) was a distinguished scholar of Urdu language and literature from Pakistan. He served as a professor and chair of the Urdu department at the University of Karachi. Khan authored critical studies, anthologies, and historical texts on Urdu poetry and prose. His research emphasized linguistic analysis, folklore, and cultural heritage of South Asia. He was awarded the Sitara-i-Imtiaz and Pride of Performance for his contributions to literature and education. Khan’s mentorship shaped many leading writers and academics in the Urdu literary world.

Born in Pittsburgh, he earned his doctorate at the Carnegie Institute of Technology and joined the Massachusetts Institute of Technology as a researcher. At MIT, he pioneered neutron diffraction instruments that revealed the atomic structure of materials. In 1994, he shared the Nobel Prize in Physics for these groundbreaking contributions. His work opened new pathways in condensed matter physics, influencing research on magnetism, superconductivity, and molecular biology. Shull remained committed to teaching and mentoring students, leaving a lasting legacy in both academia and research.

Asima Chatterjee was the first woman to earn a Doctorate of Science from an Indian university in 1944. Her groundbreaking work led to the development of the anti-epileptic drug Ayush-56 and significant advances in alkaloid chemistry. Appointed professor at the University of Calcutta, she inspired generations of scientists, especially women. She was awarded the Padma Bhushan in 1958 and the Padma Vibhushan in 1975 for her scientific achievements. Chatterjee's research on natural products and medicinal chemistry had a profound and lasting impact on pharmaceutical science in India.