January 31

Jost Bürgi was born in Switzerland in 1552 and trained as a clockmaker, producing exceptionally accurate timepieces for European courts. He invented novel escapement mechanisms that improved the precision of astronomical instruments and clocks. Bürgi collaborated with leading astronomers, including Tycho Brahe and Johannes Kepler, providing essential observations and equipment. Independently of John Napier, he developed methods akin to logarithms to streamline complex calculations. His work on trigonometric tables and mechanical calculating devices influenced the advancement of mathematics and navigation. Bürgi's blend of craftsmanship and theoretical insight made him a pivotal figure in the Scientific Revolution.

John Cheyne was born in Edinburgh in 1777 and studied medicine at the University of Edinburgh. As a physician at the Meath Hospital in Dublin, he observed and documented fluctuating breathing patterns in patients, a condition now known as Cheyne–Stokes respiration. Cheyne's detailed clinical observations laid the groundwork for future research into cardiac and respiratory disorders. An accomplished author, he published works on obstetrics, mental health, and the history of medicine. Cheyne also delivered influential lectures on anatomy and physiology, shaping medical education in Ireland. His blend of clinical practice and scholarship earned him recognition among European medical circles. He died in 1836, leaving a lasting legacy in respiratory medicine.

Edwin Howard Armstrong (1890-1954) was an American electrical engineer and inventor credited with developing frequency modulation (FM) radio. A prodigious talent, he built his first regenerative circuit at age 19 while a Columbia University student. In the 1920s, Armstrong patented the superheterodyne receiver, a radio design still in use today. His major breakthrough came in 1933 with the introduction of FM broadcasting, offering listeners clearer sound free from static interference. Despite prolonged legal battles over patent rights, Armstrong's technology became the standard for high-fidelity radio. He also contributed to early radar systems during World War II. Armstrong's innovations laid the groundwork for modern communications.

Viktor Zhirmunsky (1891-1971) was a Soviet literary historian and linguist renowned for his work in comparative literature and folklore. He authored influential studies on Indo-European poetics and Slavic oral traditions. Zhirmunsky held academic positions at Leningrad and Moscow universities, mentoring a generation of scholars. He also served as an editor of the Literary Encyclopedia. His research bridged linguistic analysis and literary criticism, leaving a lasting impact on humanities scholarship.

Ragnar Frisch (1895-1973) was a Norwegian economist who co-received the first Nobel Prize in Economic Sciences in 1969. He is considered one of the founders of econometrics and introduced key statistical methods to economic analysis. Frisch served as a professor at the University of Oslo and led the Econometric Society as its first president. His work on demand analysis and macroeconomic modeling shaped modern economic theory. He remained active in research until his death and is celebrated as a pioneer in his field.

Eveline Du Bois-Reymond Marcus was a German-born zoologist who specialized in the taxonomy and anatomy of marine mollusks. Born in 1901, she worked closely with her husband, Ernst Marcus, publishing influential papers on gastropods and other invertebrates. After escaping Nazi Germany, the couple continued their research in Brazil, greatly enriching the knowledge of South American marine fauna. Her meticulous illustrations and descriptions remain references in malacology. Marcus was a professor and mentor, fostering generations of Brazilian biologists. Her contributions advanced the field of zoology and set high standards for integrative taxonomic research.

Born in Egypt in 1935, Rashad Khalifa earned a Ph.D. in biochemistry in the United States and became a university researcher. In 1974, he proposed the controversial Quran code theory, suggesting a mathematical structure based on the number 19. Khalifa translated the Quran into English, removing certain verses he considered later additions, and established the United Submitters International. His work sparked intense debate among Muslim scholars, leading to both followers and fierce opposition. He balanced careers in science and religious scholarship until his assassination in 1990. His theories continue to influence Quranic studies and discussions on textual integrity.