The main focus of this book is on the interconnection of two unorthodox scientific ideas, the varying-gravity hypothesis and the expanding-earth hypothesis. As such, it provides a fascinating insight into a nearly forgotten chapter in both the history of cosmology and the history of the earth sciences.

The hypothesis that the force of gravity decreases over cosmic time was first proposed by Paul Dirac in 1937. In this book the author examines in detail the historical development of Dirac's hypothesis and its consequences for the structure and history of the earth, the most important of which was that the earth must have been smaller in the past.

Demonstrates the close and fascinating connection between the earth sciences and cosmological theory as seen in parts of the twentieth century Details from a historical perspective the hypothesis that gravitational force varies in time, an alternative to Einstein's theory of general relativity Presents for the first time a full history of the varying-gravity hypothesis, integrating aspects of cosmology, geology and astronomy Discusses the broader philosophical significance of the development of the varying-gravity hypothesis

Autorentext
After graduation from the University of Copenhagen in Physics and Chemistry, and a period as teacher in gymnasium schools, Helge Kragh became Associate Professor at Cornell University, Departments of History and Physics. Later, he took positions as Curator at the Steno Museum for Science and Medicine and Professor of the History of Science at the University of Oslo, Norway. Since 1997, he has been Professor of the History of Science and Technology, University of Aarhus, Denmark. He is a Member of the Royal Danish Academy of Science, the International Academy for the History of Science, and of the European Academy of Science. He was President of the European Society for the History of Science (2008-10).

Inhalt
Preface.- 1.Introductory Issues.- 2.Varying Gravity.- 3.The Expanding Earth.- 4.After Plate Tectonics.- Bibliography.- Index.