Herman Zanstra

Vocation

Traits

Frisian/Dutch astronomer. His father Auke Willems Zandstra (7 March 1845, Akkrum - 17 January 1918, Heerenveen) was a watchmaker. On 30 December 1969 he married Geertje Reitsma (6 February 1854, Dokkum - 23 June 1880, Heerenveen), the daugther of Ebe Hendriks Reitsma and Aaltje Geerts. After her death, he married on 12 January 1882 Greetje's half-sister Tietje Reitsma (8 March 1854, Dokkum - 29 March 1932, Heerenveen) the daugther of Ebe Hendriks Reitsma and his second wife Gaatske Donga. In 1917 he graduated with an Engineer's degree in chemical engineering from the Delft Institute of Technology. While working in Delft for four years, the last two as a high school teacher, he wrote a highly theoretical and mathematical paper on relative motion which he sent to William Francis Gray Swann. Swann, then offered him to earn a Ph.D. degree in theoretical physics with him at the University of Minnesota at Minneapolis, which he did in two years time by expanding on his dissertation: A Study of Relative Motion in Connection with Classical Mechanics( 1923). After another year with Swann, now in Chicago, and a year at various labs in the Netherlands and with Pauli and Baade in Germany and two months at Niels Bohr's lab in Copenhagen, he became a postdoc at Caltech. Here he wrote a famous paper, An Application of the Quantum Theory to the Luminosity of Diffuse Nebulae, which for the first time provided a quantitative method (the "Zanstra method") for understanding the luminosity of nebulas and comets. He called his spectrographic method: "space research at low cost". After teaching briefly at the University of Washington he went to London and eventually to the University of Amsterdam. World War II left him stranded in South Africa, and he therefore took up a teaching position in Durban, but returned to Europe after the war. In 1949 he became member of the Royal Netherlands Academy of Arts and Sciences. Zanstra had interest in philosophy and religion. In his book The construction of reality : lectures on the philosophy of science, theory of knowledge and the relation between body, mind and personality (1962), he wrote about his experiences with automatic handwriting and other metaphysical aspects of life. From 1962-1971 he held lectures for the Studievereniging voor Psychical Research at Haarlem. October 1961 he won the Gold Medal of the Royal Astronomical Society for his work on gaseous nebula. He died 2 October 1894 in Haarlem. His crematation was visited by Koelbloed, Houtgast, Oort and the ex PM Schermerhorn. The lunar crater Zanstra and the Asteroid 2945 Zanstra are named after him. Link to Wikipedia