The ArgumentBehind the dispute over the relative priority of theory and experiment lie conflicting philosophical images of the nature of scientific inquiry. One crucial image arose in the 1920s, when the logical positivists agitated for a “unity of science” that would ground all meaningful scientific activity on an observational foundation. Their goals and rhetoric dovetailed with the larger movements of architectural, literary, and philosophical modernism. Historians of science followed the positivists by tracking experimental science as the basis for scientific progress. (...) After World War II, historians and philosophers of science created an antipositivist movement, inverting the positivist idea that observation had epistemic priority. But this counter-movement retained the modernist aspiration to unity, now chaining observation to theory. Once again historians of science, following their philosophical colleagues, illustrated the new modernism with historical instances of observation dominated by theory.Either reductionist scheme, by privileging one activity over the other, dictates an overly constrictive periodization. We need a wider class of periodization models that will allow instrumentation, experimentation, and theory a partial autonomy without granting any one the sole legitimate narrative standpoint. Such a heterogeneous representation of historical traditions may, surprisingly, make better sense of the perceived coherence of activity across theoretical transitions than the monolithic modernist representation of science it displaces. (shrink)

The contributions of few contemporary scientists have been as far reaching in their effects as those of Nobel Laureate Werner Heisenberg.

I present philosophical reflections arising from a study of laboratory measurement methods in quantum physics. More specifically, I investigate three major methods of measuring kinetic energy, from the period during which quantum physics was developed and came to be widely accepted: magnetic deflection, electrostatic retardation, and material retardation. The historical material serves as a provocative focus at which many broader philosophical topics come together: the empirical testing of theories, the universal validity of physical laws, the interaction between theoretical and experimental (...) traditions, incommensurability, meaning and definition, realism and instrumentalism, the process of scientific change, and the unity of science. ;I begin the discussion by noting that the measurement methods in question were based on classical theory. Chapter 1 asks how the classical reasoning in measurements can be interpreted in quantum-mechanical terms, and concludes that only a "surface interpretation" is possible, since the classical methods involve many assumptions that conflict with quantum mechanics. Chapter 2 attempts to give a quantitative assessment of the inaccuracies that might result from using the "incorrect" classical theory in the design of measurement methods. Chapter 3 asks how we can know whether a measurement method is reliable, and investigates how different methods of measuring the same quantity can ground each other; this mutual grounding is also seen as a process of concept-formation. Chapter 4 argues that the customary quantum theories of measurement do not describe actual measurements well, and originate from an overly literal interpretation of the operator formalism of quantum mechanics. Chapter 5 examines how the classically reasoned measurement methods were incorporated into quantum physics; that history suggests a model of scientific development which can introduce fundamental changes while preserving much continuity with the old tradition. Chapter 6 develops a philosophical framework which allows a synthetic view of the concrete results presented in the earlier chapters: my work is an attempt to establish "conceptual coherence," creating and clarifying noncontradictory connections among the various conceptual activities that make up quantum physics. (shrink)