The RR Lyrae Population of the Solar Neighbourhood. Proefschrift ter Verkrijging van de Graad van Doctor in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit to Leiden...

Amsterdam: University of Leiden, 1977. Perfect bound, original red wrappers printed in black. Charts and graphs within the text. Wrappers a little creased and rubbed, tears to the spine repaired with clear tape, head of spine bumped also affecting the contents. Good condition. The PhD thesis of University of Leiden astronomer Jan Lub, who specialises in "the molecular interstellar medium, galaxy centers, star formation and dwarf galaxies & Magellanic Clouds". The RR Lyrae are periodic variable stars that are commonly found in globular clusters and are used as standard candles to determine distances. This copy from the library of Allan R. Sandage (without ownership marks), who determined the first reasonably accurate values for the Hubble Constant and the age of the universe and "was probably (rightly) the greatest and most influential observational astronomer of the last half-century" (NY Times obituary, November 17, 2010). After serving in the Navy he finished his physics degree at the University of Illinois, then became a graduate student at Caltech, where he "learned the nuts and bolts of observing with big telescopes [at the Mount Wilson Observatory] from the founders of modern cosmology, Hubble; Walter Baade, who became his thesis adviser, and Milton Humason, a former mule driver who had become Hubble's right-hand man" (NY Times). "For his doctoral thesis he studied the stars in the globular cluster Messier 3 and the RR Lyrae variable stars it contains. Refinements in the accuracy of the distances to variable stars became a recurring theme of his work, as these were the first step in determining the ladder of distances through which the true scale of the universe was measured" (Guardian obituary, December 9, 2010). Sandage's first major contribution was the 1961 paper, "The Ability of the 200-inch Telescope to Discriminate Between Selected World Models", which "may well have been 'the most influential paper ever written in any field even close to cosmology'... It was to set the direction of observational cosmology for 40 years, ruling out the Steady State and the Big Crunch and culminating in the surprise discovery in 1998 that the expansion is not slowing down at all but speeding up" (NY Times). Next, by investigating the motion of old stars in the Milky Way, he and two co-authors showed in 1962 "that that the Milky Way formed from the collapse of a primordial gas cloud probably some 10 billion years ago. That paper still forms the basis of science's understanding of where the galaxy came from" (NY Times). He continually revised the estimate of Hubble's constant, the speed at which the universe is expanding. "By 1975 the value, they said, was all the way down to 50, corresponding to an age of as much as 20 billion years, comfortably larger than the ages of galaxies and globular clusters. This allowed them to conclude that the universe was not slowing down enough for gravity to reverse the expansion into a Big Crunch. That was in happy agreement with astronomers who had found that there was not enough matter in the universe to generate the necessary gravity" (NY Times).