Online research in philosophy

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.

A study of the published and unpublished parts of Ernst Mach's last notebook (1910–14) suggests that Max Planck's attack (1908–11) provoked Mach into opposing ‘The Church of Physics’ more strongly than previously realized. Shortly after Mach threatened to leave the discipline if belief in atoms were required. Albert Einstein tried to persuade him to accept atomism (September 1910). Mach declined to mention Einstein again in his publications and increasingly criticized ‘The Church of Physics’. Evidence that Mach opposed relativity theory and the absence of evidence that he favored it is pointed out. It is suggested that Mach's alleged ‘friendly interest’ in Einstein's work in early 1914 may have been stimulated by the hope that the young genius might develop a continuum or field theory to refute Planck's discontinuity physics. The paper concludes with suggestions on how philosophers who defend Mach's non-realism such as Gereon Wolters and Paul Feyerabend might be better off switching to a realist epistemology more compatible with rationally-held science, religion, and common sense.