It is hypothesized that de Broglie’s ‘matter waves’ provide a dynamical basis for Minkowski spacetime in an antisubstantivalist or relational account. The relativity of simultaneity is seen as an effect of the de Broglie oscillation together with a basic relativity postulate, while the dispersion relation from finite rest mass gives rise to the differentiation of spatial and temporal axes. Thus spacetime is seen as not fundamental, but rather as emergent from the quantum level. A result by Solov’ev which demonstrates that (...) time is not an applicable concept at the quantum level is adduced in support of this claim. Finally, it is noted that de Broglie waves can be seen as the “bridge of becoming” discussed by ( 2005 ). (shrink)
A recent ontological variant of Cramer’s Transactional Interpretation, called “Possibilist Transactional Interpretation” or PTI, is extended to the relativistic domain. The present interpretation clarifies the concept of ‘absorption,’ which plays a crucial role in TI (and in PTI). In particular, in the relativistic domain, coupling amplitudes between fields are interpreted as amplitudes for the generation of confirmation waves (CW) by a potential absorber in response to offer waves (OW), whereas in the nonrelativistic context CW are taken as generated with certainty. (...) It is pointed out that solving the measurement problem requires venturing into the relativistic domain in which emissions and absorptions take place; nonrelativistic quantum mechanics only applies to quanta considered as ‘already in existence’ (i.e., ‘free quanta’), and therefore cannot fully account for the phenomenon of measurement, in which quanta are tied to sources and sinks. (shrink)
It is argued that the Heisenberg picture of standard quantum mechanics does not save Einstein locality as claimed in Deutsch and Hayden (Proc. R. Soc. Lond. A 456, 1759–1774, 2000). In particular, the EPR-type correlations that the authors obtain by comparing two qubits in a local manner are shown to exist before that comparison. In view of this result, the local comparison argument would appear to be ineffective in supporting their locality claim.
Cramer's Transactional Interpretation (TI) is applied to the ``Quantum Liar Experiment'' (QLE). It is shown how some apparently paradoxical features can be explained naturally, albeit nonlocally (since TI is an explicitly nonlocal interpretation). At the same time, it is proposed that in order to preserve the elegance and economy of the interpretation, it may be necessary to consider offer and confirmation waves as propagating in a ``higher space'' of possibilities.
The attractive feature of the Everett approach is its admirable spirit of approaching the quantum puzzle with a Zen-like "beginner’s mind" in order to try to envision what the pure formalism might be saying about quantum reality, even if that journey leads to a strange place. It is argued that the transactional interpretation of quantum mechanics (TI), appropriately interpreted, shares the same motivation and achieves much more, with far fewer conceptual perplexities, by taking into account heretofore overlooked features of the (...) quantum formalism itself (i.e. advanced states). In particular, TI does not need to talk about brain states, consciousness, or observers (rational or otherwise). In its possibilist variant (“PTI”), it shares the realist virtues of treating state vector branches as genuine dynamical entities, without having to explain how or why all of their associated outcomes actually happen (they don’t), how to account for a plenitude of counterpart observers in some coherent notion of trans-temporal identity of the bifurcating observers (observers don’t bifurcate in TI), nor how the certainty of all outcomes could be consistent with any coherent theory of probability, let alone the Born probability (the Born probability emerges naturally in TI). In short, TI is precisely the one-world interpretation Kent is looking for in his (2010). (shrink)
Tim Maudlin's argument for the inconsistency of Cramer's Transactional Interpretation (TI) of quantum theory has been considered in some detail by Joseph Berkovitz, who has provided a possible solution to this challenge at the cost of a significant empirical lacuna on the part of TI. The present paper proposes an alternative solution in which Maudlin's charge of inconsistency is evaded but at no cost of empirical content on the part of TI. However, Maudlin's argument is taken as ruling out Cramer's (...) heuristic "pseudotime" explanation of the realization of one transaction out of many. (shrink)
Tim Maudlin’s argument for the inconsistency of Cramer’s Transactional Interpretation (TI) of quantum theory has been considered in some detail by Joseph Berkovitz, who has provided a possible solution to this challenge at the cost of a significant empirical lacuna on the part of TI. The present paper proposes an alternative solution in which Maudlin’s charge of inconsistency is evaded but at no cost of empirical content on the part of TI. However, Maudlin’s argument is taken as ruling out Cramer’s (...) heuristic “pseudotime” explanation of the realization of one transaction out of many. (shrink)
A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to a ``which-way'' measurement indicating which slit a particle goes through, an interference pattern exists. It has been claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation accomodates the result. It is shown that the Afshar experiment is isomorphic in key respects to a a spin one-half particle prepared as ``spin up (...) along x'' and post-selected in a specific state of spin along z. It is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. (shrink)
A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to what appears to be a ``which-way'' measurement, an interference pattern exists. Afshar has claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation easily accomodates the result. It is also shown that the Afshar experiment is isomorphic in key respects to a spin one-half particle prepared as ``spin up along x'' and (...) post-selected in a specific state of spin along z. The terminology ``which way'' or ``which-slit'' is critiqued; it is argued that this usage by both Afshar and his critics is misleading and has contributed to confusion surrounding the interpretation of the experiment. Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. In addition, some new inferences about the interpretation of delayed choice experiments are drawn from the analysis. (shrink)
ABSTRACT: A relation is obtained between weak values of quantum observables and the consistency criterion for histories of quantum events. It is shown that ``strange'' weak values for projection operators (such as values less than zero) always correspond to inconsistent families of histories. It is argued that using the ABL rule to obtain probabilities for counterfactual measurements corresponding to those strange weak values gives inconsistent results. This problem is shown to be remedied by using the conditional weight, or pseudo-probability, obtained (...) from the multiple-time application of Luders' Rule. It is argued that an assumption of reverse causality (a form of time symmetry) implies that weak values obtain, in a restricted sense, at the time of the weak measurement as well as at the time of post-selection. Finally, it is argued that weak values are more appropriately characterised as multiple-time amplitudes than expectation values, and as such can have little to say about counterfactual questions. (shrink)
The "N-box experiment" is a much-discussed thought experiment in quantum mechanics. It is claimed by some authors that a single particle prepared in a superposition of N+1 box locations and which is subject to a final "post-selection" measurement corresponding to a different superposition can be said to have occupied "with certainty" N boxes during the intervening time. However, others have argued that under closer inspection, this surprising claim fails to hold. Aharonov and Vaidman have continued their advocacy of the claim (...) in question by proposing a variation on the N-box experiment, in which the boxes are replaced by shutters and the pre- and post-selected particle is entangled with a photon. These authors argue that the resulting "N-shutter experiment" strengthens their original claim regarding the N-box experiment. It is argued in this article that the apparently surprising features of this variation are no more robust than those of the N-box experiment and that it is not accurate to say that the particle is "with certainty" in all N shutters at any given time. [Enlarge Image]. (shrink)
It is proposed that the recent controversy over "time-symmetric quantum counterfactuals" (TSQCs), based on the Aharonov-Bergmann-Lebowitz Rule for measurements of pre- and post-selected systems, can be clarified by taking TSQCs to be counterfactuals with a specific type of compound antecedent. In that case, inconsistency proofs such as that of Sharp and Shanks (1993) are not applicable, and the main issue becomes not whether such statements are true, but whether they are nontrivial. The latter question is addressed and answered in the (...) negative. Thus it is concluded that TSQCs, understood as counterfactuals with a compound antecedent, are true but only trivially so, and provide no new contingent information about specific quantum systems (except in special cases already identified in literature). (shrink)