Herman Zanstra (November 3, 1894,Schoterland – October 2, 1972,Haarlem) was aDutchastronomer.
Zanstra was born nearHeerenveen inFriesland. In 1917 he graduated with anEngineer's degree inchemical engineering from theDelft Institute of Technology. While working inDelft 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 toWilliam Francis Gray Swann. Swann, then offered him to earn aPh.D. degree in theoretical physics with him at theUniversity of Minnesota atMinneapolis, which he did in two years time by expanding on his paper (dissertation:A Study of Relative Motion in Connection with Classical Mechanics, 1923). After another year with Swann, now inChicago, and a year at various labs in the Netherlands and Germany and two months atNiels Bohr's lab inCopenhagen, he became a postdoc atCaltech. 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 ofnebulas andcomets.
After teaching briefly at theUniversity of Washington he went to London and eventually to theUniversity of Amsterdam.World War II left him stranded inSouth Africa, and he therefore took up a teaching position inDurban, but returned to Europe after the war. In 1949 he became member of theRoyal Netherlands Academy of Arts and Sciences.[1]
He won theGold Medal of the Royal Astronomical Society in 1961.
The lunar craterZanstra is named after him,[2] as isAsteroid2945 Zanstra.[3]