Concepts of Simultaneity: From Antiquity to Einstein and Beyond

Preface

Preface Quite a few notions in the physical sciences, such as “force” or “mass,” are used in everyday language before becoming rigorously defined scientific concepts or technical terms. Only one concept of this kind, however, played a critical role in initiating a new physical theory that has fundamentally changed all our conceptions of physical reality and for which the question of whether it has a factual or only a conventional status in this theory remains a matter of dispute. This unique notion is the concept of simultaneity of spatially separated events, and the theory that it initiated is Albert Einstein’s special theory of relativity. In fact, the first paragraph of the seminal paper of this theory, published by Einstein in 1905 and hailed as “possibly the most important scientific paper . . . written in the twentieth century,”1 carries the heading “§ 1. Definition of Simultaneity.”2 This monograph presents a comprehensive, coherent, critical, and completely documented analysis of the conceptual development of the notion of simultaneity from its earliest use in remote antiquity until its present status in modern physics. Some sections of the text are based on papers that I have read at scientific meetings or on lectures given at various times. They include (1) “Some Fundamental Problems in the Special Theory of Relativity,”3 a lecture presented in June 1978 at the International School of Physics Enrico Fermi in Varenna, Italy; (2) a series of lectures given in 1981 at the University of Otago in Dunedin, New Zealand; (3) “The Concept of Time,”4 an address delivered in August 1983 at Gakushuin University in Tokyo, Japan; (4) “The History of 1 R. W. Clark, Einstein: The Life and Times (New York: Avon Books, 1971), p. 116. 2 A. Einstein, “Zur Elektrodynamik bewegter Körper,” Annalen der Physik 17, 891–921 (1905). 3 In Toraldo di Francia, ed., Problems in the Foundations of Physics, Course 72 (Amsterdam: North-Holland, 1979), pp. 202–236. 4 In Gakushuin Daigaku 2, 1–35 (1984), in Japanese. x Preface the Concept of Distant Simultaneity,”5 a talk given in May 1985 at the University of Rome; (5) a lecture on the concept of simultaneity, delivered in October 1987 at the Department of Physics of the University of Bari, Italy; (6) a series of lectures on the history and philosophy of the concept of time, presented in June 1989 at the University of Konstanz, Germany; (7) and a seminar conducted on the philosophy of time in the winter semester 1989/90 at the University of Western Ontario in London, Ontario, Canada. I wish to thank Dr. Trevor Lipscombe, editor-in-chief of the Johns Hopkins University Press, for fruitful cooperation, and I thank an anonymous reader of the manuscript for useful comments. I also thank Nancy S. Wachter for her careful copyediting of the manuscript. 5In Rendiconti della Accademia delle Scienze 9, 169–184 (1985), in Italian. Concepts of Simultaneity This page intentionally left blank ...