It is demonstrated that neither the arguments leading to inconsistencies in the description of quantum-mechanical measurement nor those “explaining” the process of measurement by means of thermodynamical statistics are valid. Instead, it is argued that the probability interpretation is compatible with an objective interpretation of the wave function.

Whilst a straightforward consequence of the formalism of non-relativistic quantum mechanics, the phenomenon of quantum teleportation has given rise to considerable puzzlement. In this paper, the teleportation protocol is reviewed and these puzzles dispelled. It is suggested that they arise from two primary sources: (1) the familiar error of hypostatizing an abstract noun (in this case, ‘information’) and (2) failure to differentiate interpretation dependent from interpretation independent features of quantum mechanics. A subsidiary source of error, the simulation fallacy, is also (...) identified. The resolution presented of the puzzles of teleportation illustrates the benefits of paying due attention to the logical status of ‘information’ as an abstract noun. Introduction The quantum teleportation protocol 2.1 Some information-theoretic aspects of teleportation 2.1.1 Preamble 2.1.2Application to teleportation The puzzles of teleportation Resolving (dissolving) the problem 4.1 The simulation fallacy The teleportation process under different interpretations 5.1 Collapse interpretations:Dirac/von Neumann, GRW 5.2 No collapse and no extra values: Everett 5.3 No collapse, but extra values: Bohm 5.3.1 A note on active information 5.4 Ensemble and statistical viewpoints Concluding remarks. (shrink)

in: Compendium of Quantum Physics, ed. by F. Weinert, K. Hentschel, D. Greenberger, and B. Falkenburg (Springer 2008).

The paper presents a revised view of quantum mechanics centered on the notion (“genuine fortuitousness”) that the click in a counter is a totally lawless event, which comes by itself. A crucial point is the distinction between events on the spacetime scene and the content of the symbolic algorism. A revised conception of matrix variables emerges, by which such a variable, as part of a whole, does not have a value, under any circumstance. This conception is at variance with that (...) of indeterminate variables. A matrix variable not having a value does not enter spacetime and is not a measurable quantity, but manifests itself by a click in a counter with the remarkable property of having an onset, a beginning, from which the click develops. The individual click with its immense complexity is unique and lawless, even beyond probability. The notion of probability only applies to clicks in low resolution, and the completeness of a probabilistic theory is thereby seen in a new perspective. The genuinely fortuitous click is not produced by the impact of a particle, nor caused by an event in the source prior to the click in the counter. Indeed, there are no particles on the spacetime scene. The theory is thereby liberated from notions, which go with particles having indeterminate variables, and which have given to quantum mechanics the image of an unfathomable theory. With no particle as intermediary, the connection between source and detector is non-local, as is the entire theory, which deals exclusively with distributions of clicks. The locality permeating quantum mechanics is a symbolic one. The wave function enters in the sole role of encoding the probability distributions of clicks. The quest to understand the occurrence of the click in terms of the evolution of the wave function loses its meaning. However, click distributions in low resolution can be analyzed in terms of the connection between click distributions for different sets of counters, as given by the wave function. With increasing resolution, the probabilities, and the wave function, gradually lose significance, whereby the onset remains beyond reach. Thus, the downward path from events on the spacetime scene does not extend beyond the onset. The notion that quantum mechanics deals with particles (or fields) is rooted in the historical evolution but appears unable to accomodate genuine fortuitousness. The latter concept is given its due place by fully accepting the abstract nature of the matrix variables. (shrink)