Jump to ContentJump to Main Navigation
The Quantum CookbookMathematical Recipes for the Foundations for Quantum Mechanics$
Users without a subscription are not able to see the full content.

Jim Baggott

Print publication date: 2020

Print ISBN-13: 9780198827856

Published to Oxford Scholarship Online: January 2020

DOI: 10.1093/oso/9780198827856.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (www.oxfordscholarship.com). (c) Copyright Oxford University Press, 2020. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 03 June 2020

Von Neumann and the Problem of Quantum Measurement

Von Neumann and the Problem of Quantum Measurement

The ‘Collapse of the Wavefunction’

(p.219) 11 Von Neumann and the Problem of Quantum Measurement
The Quantum Cookbook

Jim Baggott

Oxford University Press

Heisenberg was an ‘anti-realist’. Although Bohr was infamously obscure in many of his writings, it seems that he adopted a generally anti-realist interpretation, too. As their debate became more bitter, in early June 1927 Pauli was called in to mediate. With Pauli’s help, they forged an uneasy consensus, which became known as the Copenhagen interpretation. Einstein didn’t like it at all, setting the stage for a great debate about the quantum representation of reality. Although von Neumann’s formalism broadly conforms to the Copenhagen interpretation, he saw no need to introduce an arbitrary split between the classical and quantum worlds. But eliminating the split poses the problem of quantum measurement: when scaled to classical dimensions, a superposition of different measurement outcomes appears contrary to our experience, exemplified by the famous paradox of Schrödinger’s cat. Von Neumann was obliged to break the infinite regress by postulating the ‘collapse of the wavefunction’.

Keywords:   Werner Heisenberg, Niels Bohr, Albert Einstein, John von Neumann, Copenhagen interpretation, quantum measurement, collapse of the wavefunction, projection postulate, Wigner’s friend, Schrödinger’s cat

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .