184 research outputs found

    Conventionality of Simultaneity and Reality

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    An important epistemological lesson can be learned from the impossibility to determine the one-way velocity of light and the immediate implication that simultaneity is conventional. The vicious circle -- to determine whether two distant events are simultaneous we need to know the one-way velocity of light between them, but to determine the one-way velocity of light we need to know that the two events are simultaneous -- is an indication of the need for a profound change of our view on reality

    On the Reality of Minkowski Space

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    Should physicists deal with the question of the reality of Minkowski space (or any relativistic spacetime)? It is argued that they should since this is a question about the dimensionality of the world at the macroscopic level and it is physics that should answer it.Comment: 3 pages; this is the published version of the pape

    Scattering problems for symmetric systems with dissipative boundary conditions

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    We study symmetric systems with dissipative boundary conditions. The solutions of the mixed problems for such systems are given by a contraction semigroup V(t)f=etGbf,t0V(t)f = e^{tG_b}f, t \geq 0. The solutions u(t,x)=V(t)fu(t, x) = V(t)f, where ff is an eigenfunction of the generator GbG_b with eigenvalue λ,λ<0,\lambda,\Re \lambda < 0, are called asymptotically disappearing (ADS). We prove that the wave operators are not complete if there exist (ADS). This is the case for Maxwell system with special boundary conditions in the exterior of the sphere. We obtain a representation of the scattering kernel and we examine the inverse back-scattering problem related to the leading term of the scattering kernel