Conflict in Quantum Physics

David John Baker

The phenomenon of broken spacetime symmetry in the quantum theory of infinite systems seems to point toward an unorthodox ontology. The standard conception of the physical meaning of these symmetries, as changes in coordinates, conflicts with the apparent physical inequivalence of symmetry-related states. I argue that this apparent conflict is an artifact of a subtle error in the extant account of physical equivalence due to Halvorson and Clifton.

Benjamin Z. Gal-Or

Benjamin Z. Gal-Or

Mendel Sachs

In this book, important conceptual developments of the two major revolutions of modern physics - the quantum and relativity theories - are presented in a nonmathematical, dialectical form of dialogue. The implications of conflicting philosophical attitudes of these revolutions in physics and applications to topics such as cosmology/astrophysics and high energy physics are emphasized. It is argued that for any substantial progress in our understanding of 21st century physics, it will be necessary to resolve these 20th century conflicts. These richly rewarding dialogues provide a starting point

Shan Gao

According to Penrose, the fundamental conflict between the superposition principle of quantum mechanics and the principle of general covariance of general relativity entails the existence of wavefunction collapse, e.g. a quantum superposition of two different space-time geometries will collapse to one of them due to the ill-definedness of the time-translation operator for the superposition. In this paper, we argue that Penrose's conjecture on gravity's role in wavefunction collapse is debatable. First of all, it is still a controversial issue what the exact nature of the conflict is and how to resolve it. Secondly, Penrose's argument by analogy is too weak to establish a necessary connection between wavefunction collapse and the conflict as understood by him. Thirdly, the conflict does not necessarily lead to wavefunction collapse. For the conflict or the problem of ill-definedness for a superposition of different space-time geometries also needs to be solved before the collapse of the superposition finishes, and once the conflict has been resolved, the wavefunction collapse will lose its physical basis relating to the conflict. In addition, we argue that Penrose's suggestions for the collapse time formula and the preferred basis are also problematic.

Armin Uhlmann