In his 1916 review paper on general relativity, Einstein made the often-quoted oracular remark that all physical measurements amount to a determination of coincidences, like the coincidence of a pointer with a mark on a scale. This argument, which was meant to express the requirement of general covariance, immediately gained great resonance. Philosophers such as Schlick found that it expressed the novelty of general relativity, but the mathematician Kretschmann deemed it as trivial and valid in all spacetime theories. With the (...) relevant exception of the physicists of Leiden (Ehrenfest, Lorentz, de Sitter, and Nordström), who were in epistolary contact with Einstein, the motivations behind the point-coincidence remark were not fully understood. Only at the turn of the 1960s did Bergmann (Einstein’s former assistant in Princeton) start to use the term ‘coincidence’ in a way that was much closer to Einstein’s intentions. In the 1980s, Stachel, projecting Bergmann’s analysis onto his historical work on Einstein’s correspondence, was able to show that what he started to call ‘the point-coincidence argument’ was nothing but Einstein’s answer to the infamous ‘hole argument’. The latter has enjoyed enormous popularity in the following decades, reshaping the philosophical debate on spacetime theories. The point-coincidence argument did not receive comparable attention. By reconstructing the history of the argument and its reception, this paper argues that this disparity of treatment is not justified. This paper will also show that the notion that only coincidences are observable in physics marks every critical step of Einstein’s struggle with the meaning of coordinates in physics. (shrink)

The aim of the paper is to demonstratethat Special Relativity and the Early Quantum Theory were created within the same programme of statisticalmechanics, thermodynamics and maxwellianelectrodynamics reconciliation. I shall try to explainwhy classical mechanics and classicalelectrodynamics were ``refuted'''' almost simultaneouslyor, in more suitable terms for the present congress,why did the quantum revolution and the relativisticone both took place at the beginning of the 20-thcentury. I shall argue that the quantum andrelativistic revolutions were simultaneous since theyhad a common origin -- the (...) clash between thefundamental theories of the second half of the 19-thcentury that constituted the ``body'''' of ClassicalPhysics. The revolution''s most dramatic pointwas Einstein''s 1905 photon paper that laid thefoundations of both Special Relativity and OldQuantum Theory. Hence the dialectic of the oldtheories is crucial for theory change. Modern physicsbegan with Einstein''s reconciliation ofelectrodynamics, mechanics and thermodynamics in 1905and his unification of Special Relativity andNewtonian Theory of Gravity. Or, in a more generalsocial context: progressive scientific change can bedescribed not in Weberian terms of zweckrationalaction forcing out all the other forms of action onlybut in terms of Habermas''s communicative rationalityencouraging the establishment of mutual understandingbetween the various scientific communities also.Einstein''s programme constituted a progressive stepwith respect to its rivals not because it couldexplain more ``facts'''' or was more ``mathematical''''. Itwas better than its rivals because it constituted abasis of communication and interpenetration betweenthree main paradigms of 19-th century physics. Ofcourse in the long run it resulted in empiricalsuccesses. (shrink)