How long does a quantum particle take to traverse a classically forbidden energy barrier? In other words, what is the correct expression for quantum tunnelling time? This seemingly simple question has inspired widespread debate in the physics literature. I argue that we should not expect the orthodox interpretation of quantum mechanics to provide a unique correct expression for quantum tunnelling time, because to do so it would have to provide a unique correct answer to a question whose assumptions are in (...) tension with its core interpretational commitments. I explain how this conclusion connects to time’s special status in quantum mechanics, the meaningfulness of classically inspired concepts in different interpretations of quantum mechanics, the prospect of constructing experimental tests to distinguish between different interpretations, and the status of weak measurement in resolving questions about the histories of subensembles. (shrink)

It is generally believed that two rival non-relativistic quantum theories, the realist interpretation of quantum mechanics and Bohmian mechanics, are empirically equivalent. In this paper, I use these two quantum theories to show that it is possible to offer a solution to underdetermination in some local cases, by specifying what counts as relevant empirical evidence in empirical equivalence and underdetermination. I argue for a _domain-sensitive_ approach to underdetermination. Domain sensitivity on theories’ predictions plays a role in determining whether two or (...) more theories are empirically equivalent and underdetermined. To support my argument for the denial of the empirical equivalence between Bohmian mechanics and the realist interpretation of quantum mechanics, I argue that they are not empirically equivalent when we consider their predictions for domains outside their application, using the relativistic domain as an example. (shrink)

Quantal penetration through a (stationary) one-dimensional potential barrier is considered as a time evolution of an initially prepared wave packet. The large-time asymptotics of the process is concerned. Locality of the potential imposes certain analytical properties of the interaction amplitudes in the energy representation. The results are presented in terms of development of the phase-space (Wigner's) quasi-distribution. The phase-space evolution kernel is constructed, and it is shown that in the presence of a positive potential no part of the distribution is (...) transported faster than the free particle. For the case of a small initial momentum uncertainty, the deformation of the coordinate density is considered, including a possible advance of its maximum, which would not mean any noncausal signal transport. (shrink)

This paper examines the epistemological significance of the present situation of underdetermination in quantum mechanics. After analyzing this underdetermination at three levels---formal, ontological, and methodological---the paper considers implications for a number of variants of the thesis of scientific realism in fundamental physics and reassesses Lakatos‘ characterization of progress in physical theory in light of the present situation. Next, this paper considers the implications of underdetermination for Weinberg’s ‘‘dream of a final theory.’’ Finally, the paper concludes by suggesting how one might (...) still think of realism and progress in fundamental physics despite the possibility of persistent underdetermination in quantum mechanics. (shrink)