The year 2016 marks not only the 100th birthday of Einstein’s first comprehensive review paper of the general theory of relativity and his first (faulty) prediction of gravitational wave solutions . The year also marks the 100th anniversary of Ernst Mach’s death. Many may know the name only because of Mach’s scale of faster-than-sound velocities (Mach 1, Mach 2, Mach 3…). But Mach was also a historian and philosopher of science who had a decisive influence on Einstein’s way of thinking about physics.
Mach’s influential book, “The Science of Mechanics; a critical and historical exposition of its principles”, helped his appointment to a specially created chair in “the history and philosophy of the inductive sciences” at the University of Vienna in 1895. Mach combined careful and critical historical work on the development of physics with deep reflections on its conceptual foundations. As Don Howard recently pointed out at the 2016 Vienna Conference celebrating Mach, around 1900, every literate German-speaking reader of Mach would have recognized the book’s subtitle as an allusion to the method (not the content) of biblical hermeneutics: the aim was not just to use and summarize the science of mechanics but also to interpret it while studying its history, and to uncover its truly fundamental principles.
While working as a patent clerk in Bern, Einstein studied Mach’s history of mechanics with his reading group – the self-mockingly named Olympia Academy. Doing so was an eye-opener; he was particularly impressed with Mach’s criticism of Newton’s concept of absolute space. Mach sided with Leibniz against Newton, arguing that the motion of a body was to be defined only relative to other bodies, rather than with respect to absolute space. Equally important for Einstein was Mach’s idea that whether a body moves free of forces or not was also a relative matter. This provided a strong impetus for generalizing the relativity principle from inertial motion to all kinds of motion --- thus, for the general principle of the relativity of motion that Einstein used in the construction of the general theory of relativity. Indeed, in 1918 Einstein remarked that up until then (i.e. up until three years after the formal completion of the theory) he had not carefully distinguished between what he now called Mach’s principle on the one hand, and the relativity principle on the other. In the next post of this series, we will see how Einstein came to disentangle these principles, and how he fought hard to keep Mach’s principle as one of the fundamental pillars of relativity theory even after the principle came under pressure by work on solutions of Einstein’s gravitational-inertial field equations.
On February 16, 2016, the Division of the Humanities and Social Sciences and the Einstein Papers Project opened an exhibition of Einstein manuscripts, calculations, letters, books, and photographs from the Albert Einstein Archives at the Hebrew University in Jerusalem. The exhibit runs February 16-23 in Dabney Lounge, after which time it will be moved to the Einstein Papers Project February 24-March 9 (10am to 4pm M-F). (pdf)
On Thursday March 10, 2016, Prof. Jürgen Renn, Director, Max-Planck Institute for the History of Science, Berlin, will deliver the 6th Biennial Bacon Award Public Lecture on "The Genesis and Transformation of General Relativity" at 4pm in Baxter Hall, Caltech. The lecture will be the opening event of GENERAL RELATIVITY AT ONE HUNDRED: THE 6th BIENNIAL BACON CONFERENCE. 3-4-16
Gravitational waves do exist, as has been announced today with great joy by the scientists of the LIGO collaboration, after more than two decades of intensive experimental work. Collaborative work on the historiography of 20th century physics by the Einstein Papers Project at Caltech, the Hebrew University of Jerusalem, and the Max Planck Institute for the History of Science carried out over many years has recently shown that the prediction of gravitational waves emerged almost exactly 100 years ago, in mid-February 1916, from an exchange of letters between Albert Einstein and the astronomer Karl Schwarzschild. See the full story here.
On February 4, 2016, the Association of American Publishers conferred the 2016 AWARD FOR EXCELLENCE IN PHYSICAL SCIENCES & MATHEMATICS and the 2016 AWARD FOR BEST IN PHYSICAL SCIENCES & MATHEMATICS/EPRODUCT to Princeton University Press for our Digital Edition of The Collected Papers of Albert Einstein.
Einstein's Legacy: An Origins Project Panel took place on 22 February 2016 at Arizona State University. Frank Wilczek, Kip Thorne, and Diana K. Buchwald joined Lawrence Krauss in discussing insights into Einstein and his most famous work, exciting developments in physics, and what we can expect in the next 100 years from this groundbreaking theory. 2-11-16
On February 3, 2016, Diana K. Buchwald and Jürgen Renn presented highlights in the history of general relativity at a celebratory dinner for Caltech Associates at the Athenaeum Faculty Club. 2-4-16