Quantum heterodoxy: realism at the Planck length
type: Item
instance of: scholarly article
title: Quantum heterodoxy: realism at the Planck length
zbMATH Open document ID: 1038.81005
DOI: 10.1023/A:1025355511088
author: Adrian Heathcote
published in: Science \& Education
publication date: 2003-09-25T00:00:00Z
review text: This paper has overtly philosophical aims -- realism is to be defended from the idealism prevalent in understanding and teaching quantum mechanics. Philosophical arguments open and close the paper, with a much more interesting discussion of quantum theory in-between. The measurement problem is the central theme. Conceptual and formal issues are presented initially in a clear and lively manner. The representation of pure and mixed states in Hilbert space is discussed, along with an interesting discussion of ``negative-outcome measurements'', measurements that fail to find an observable's value within a certain subset. He makes the point that these, like ``positive'' measurements, result in a change in quantum state that will be confirmed if the measurement is repeated. He notes that ``exotic'' wave functions with ``holes'' result from such measurements and that it becomes harder to argue that these changes in state result from physical interactions with measurement instruments. The projection operators associated with observable operators are considered the key to understanding measurement. He argues that proper understanding of these projections leads to a far more pathological version of the uncertainty relations than is usually accepted. From the Paley-Wiener theorem he concludes for example that: ``If the position wave function is localised, even if the area of its localisation is extremely large -- the momentum wave function is infinitely unlocalised.'' (his stress, p. 518). This leads to a distinction between ``pointwise location'' and having ``particle-like properties'', and discussion of the need to distinguish carefully between features of probabilities and of the systems they describe. The lack of a unique decomposition of mixtures into pure states makes an ``ignorance interpretation'' of mixed states untenable, and the violation of Bell's inequalities is considered ``empirical confirmation'' of this. In the final section the clarity and care of earlier dis…
Mathematics Subject Classification ID: 81P05
Mathematics Subject Classification ID: 81P15
zbMATH DE Number: 1985824
zbMATH Keywords: Realsim
zbMATH Keywords: Idealism
zbMATH Keywords: Quantum measurement
MaRDI profile type: Publication
description: scientific article; zbMATH DE number 1985824