Why did Einstein tirelessly study unified field theory for more than 30 years? In this book, the author argues that Einstein believed he could find a unified theory of all of nature's forces by repeating the methods he used when he formulated general relativity. The book discusses Einstein's route to the general theory of relativity, focusing on the philosophical lessons that he learnt. It then addresses his quest for a unified theory for electromagnetism and gravity, discussing in detail his efforts (...) with Kaluza-Klein and, surprisingly, the theory of spinors. From these perspectives, Einstein's critical stance towards the quantum theory comes to stand in a new light. This book will be of interest to physicists, historians and philosophers of science. (shrink)

It is demonstrated that Maxwellian electrodynamics was created as a result of the old pre-Maxwellian programmes’s reconciliation: the electrodynamics of Ampère–Weber, the wave theory of Young–Fresnel and Faraday’s programme. Maxwell’s programme finally superseded the Ampère–Weber one because it assimilated the ideas of the Ampère–Weber programme, as well as the presuppositions of the programmes of Young–Fresnel and Faraday. Maxwell’s victory became possible because the core of Maxwell’s unification strategy was formed by Kantian epistemology. Maxwell put forward as a basic synthetic principle (...) an idea that radically differed from that of rival approaches by its open, flexible and contra-ontological character. “Action at a distance”, “incompressible fluid”, “molecular vortices” were contrived analogies for Maxwell, capable only of directing the researcher to the “right” mathematical relations Kantian epistemology subsequently enabled Helmholtz and Hertz to arrive at a version of Maxwell’s theory that served as a heuristical basis for the discovery of radio waves. Finally, though neither of Einstein’s relativistic ideas came directly from Kant, they were made possible by the Kantian worldview that had permeated Einstein’s thinking. The Maxwellian revolution can be described in terms of Habermas’s communicative rationality encouraging the establishment of mutual understanding between the various scientific communities. Maxwell’s programme constituted a progressive step in respect to its rivals because it constituted a basis of communication and interpenetration between the main paradigms of 19th century physics. (shrink)

If you wish to learn from the theoretical physicist anything about the methods which he uses, I would give you the following piece of advice: Don't listen to his words, examine his achievements. For to the discoverer in that field, the constructions of his imagination appear so necessary and so natural that he is apt to treat them not as the creations of his thoughts but as given realities.

Universally recognized as bringing about a revolutionary transformation of the notions of space, time, and motion in physics, Einstein's theory of gravitation, known as "general relativity," was also a defining event for 20th century philosophy of science. During the decisive first ten years of the theory's existence, two main tendencies dominated its philosophical reception. This book is an extended argument that the path actually taken, which became logical empiricist philosophy of science, greatly contributed to the current impasse over realism, whereas (...) new possibilities are opened in revisiting and reviving the spirit of the more sophisticated tendency, a cluster of viewpoints broadly termed transcendental idealism, and furthering its articulation. It also emerges that Einstein, while paying lip service to the emerging philosophy of logical empiricism, ended up siding de facto with the latter tendency. Ryckman's work speaks to several groups, among them philosophers of science and historians of relativity. Equations are displayed as necessary, but Ryckman gives the non-mathematical reader enough background to understand their occurrence in the context of his wider philosophical project. (shrink)

In recounting his discovery of special relativity, Einstein recalled a debt to the philosophical writings of Hume and Mach. I review the path Einstein took to special relativity and urge that, at a critical juncture, he was aided decisively not by any specific doctrine of space and time, but by a general account of concepts that Einstein found in Hume and Mach’s writings. That account required that concepts, used to represent the physical, must be properly grounded in experience. In so (...) far as they extended beyond that grounding, they were fictional and to be abjured (Mach) or at best tolerated (Hume). Einstein drew a different moral. These fictional concepts revealed an arbitrariness in our physical theorizing and may still be introduced through freely chosen definitions, as long as these definitions do not commit us to false presumptions. After years of failed efforts to conform electrodynamics to the principle of relativity and with his frustration mounting, Einstein applied this account to the concept of simultaneity. The resulting definition of simultaneity provided the reconceptualization that solved the problem in electrodynamics and led directly to the special theory of relativity. (shrink)