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According to scientific realism, the aim of science is to discover the truth about both observable and unobservable aspects of the mind-independent, objective reality, which we inhabit. It has been objected by Putnam and others that such a metaphysically realist position presupposes a God’s Eye point of view, of which no coherent sense can be made. In this paper, I will argue for two claims. First, scientific realism does not require the adoption of a God’s Eye point of view. Instead, scientific realism is a hypothesis about the relationship between scientific theory and reality which may be proposed from within our human perspective. Second, even if scientific realism did require a God’s Eye point of view, this would not necessarily be to the detriment of realism. For it is possible to develop an intelligible external perspective on h...
The paradoxes of the EPR experiment with two particles are shown to originate in the implicit assumption that the particles are always located in the classical space. There exists a substitute for this assumption that yields a new definition of reality and offers a resolution of the paradoxes.
This paper deals with a number of technical achievements that are instrumental for a dis-solution of the so-called "Hole Argument" in general relativity. Such achievements include: 1) the analysis of the "Hole" phenomenology in strict connection with the Hamiltonian treatment of the initial value problem. The work is carried through in metric gravity for the class of Christoudoulou-Klainermann space-times, in which the temporal evolution is ruled by the "weak" ADM energy; 2) a re-interpretation of "active" diffeomorphisms as "passive and metric-dependent" dynamical symmetries of Einstein's equations, a re-interpretation which enables to disclose their (up to now unknown) connection to gauge transformations on-shell; understanding such connection also enlightens the real content of the Hole Argument or, better, dis-solves it together wi...
Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the "reality" of particles posed by the possibility of inequivalent quantizations of a classical field theory, i.e., inequivalent representations of the algebra of observables of the field in terms of operators on a Hilbert space. The threat is that each representation embodies its own distinctive conception of what a particle is, and how a "particle" will respond to a suitably operated detector. Our main goal is to clarify the subtle relationship between inequivalent representations of a field theory and their associated particle concepts. We also have a particular interest in the Minkowski versus Rindler quantizations of a free Boson field, b...
In a recent paper in the British Journal for the Philosophy of Science, Kosso discussed the observational status of continuous symmetries of physics. While we are in broad agreement with his approach, we disagree with his analysis. In the discussion of the status of gauge symmetry, a set of examples offered by ’t Hooft has influenced several philosophers, including Kosso; in all cases the interpretation of the examples is mistaken. In this paper we present our preferred approach to the empirical significance of symmetries, re-analysing the cases of gauge symmetry and general covariance.
It is argued that awareness of the distinction between dynamical and variational symmetries is crucial to understanding the significance of Noether's 1918 work. Specific attention is paid, by way of a number of striking examples, to Noether's first theorem, which establishes a correlation between dynamical symmetries and conservation principles.
This paper concerns the scale related decoupling of the physics of breaking drops and considers the phenomenon from the point of view of both hydrodynamics and molecular dynamics at the nanolevel. It takes the shape of droplets at breakup to be an example of a genuinely emergent phenomenon---one whose explanation depends essentially on the phenomenological (non-fundamental) theory of Navier-Stokes. Certain conclusions about the nature of "fundamental" theory are drawn.
Mara Beller's book Quantum Dialogue: The Making of a Revolution is a book in history and historiography, which invites a philosophical reading. The book offers a new and quite radical approach in the philosophy of science, which Beller calls dialogism, and it demonstrates the application of this approach by studying cases in the history of physics. This paper reconstructs of some of the book's theses, in a way which emphasises its philosophical insights, and goes on to shows how philosophically far dialogism can take us. The example on which the paper focuses is the demarcation between science and non-science.
I maintain that quantum mechanics is fundamentally about a system of N particles evolving in three-dimensional space, not the wave function evolving in 3N-dimensional space.
Uncertainty about the actual orientation of the measurement device has been claimed to open a loophole for hidden variable models of quantum mechanics. In this paper I describe the statistics of inaccurate spin measurements by unsharp spin observables. A no-go theorem for hidden variable models of the inaccurate measurement statistics follows: There is a finite set of directions for which not all results of inaccurate spin measurements can be predetermined in a non-contextual way. In contrast to an earlier theorem [Breuer, Phys. Rev. Lett. 88(2002), 240402] this result does not rely on the assigment of approximate truth values, and it holds under weaker assumptions on the measurement inaccuracy.
