Francesco Lana Terzi

Francesco Lana Terzi, an Italian Jesuit scientist, died Feb. 22, 1687; his date of birth is unknown. Lana Terzi is best known for a book he published in 1670, Prodromo, and for a single illustration in that book, depicting an airship borne aloft by four evacuated copper spheres (first image). It is often said that he got the idea from Otto von Guericke’s Magdeburg experiments with evacuated copper spheres, and indeed he did, but not from von Guericke directly, since his book did not appear until 1672, after the Prodromo was published…

Louis Essen

Louis Essen, an English physicist, was born Sep. 6, 1908. Essen made two major contributions to physics, in two different fields, which is not as common as you might think, at least not in the twentieth century. In 1946, he developed a method of measuring the speed of...

Lewis Rutherfurd and Cleveland Abbe

On Oct. 13, 1884, the delegates to the International Meridian Conference in Washington D.C. voted to establish a Prime Meridian for navigation and time-keeping purposes. The delegates had been invited by President Chester A. Arthur (second image) to convene on Oct. 1...

Math, Myth, and the Measure of Maya Time

William Saturno, Assistant Professor of Archaeology at Boston University. Much has been made this year of the approaching “end-date” of the Maya calendar and its implications for our own society’s future. Keeping track of the passage of time was very important to the...