Scientific article
Open access

The Problem of Measurement in Quantum Mechanics

Published inHelvetica physica acta, vol. 37, no. 4-5, p. 293-316
Publication date1964

This is a new analysis of the measuring process for non-relativistic quantum mechanical systems, in order to clarify the well-known difficulties in the interpretation of this process. The rules of quantum mechanics prescribe two apparently different and unrelated changes of the state of a system under the measuring process. It is shown that the two ways of the change of state vectors can be understood without introducing von Neumann's 'ultimate observer' and without abandoning the linear law of the time evolution of states. Consciousness or even the macroscopic nature of the measuring device is not an essential requirement for a measurement. What is required is only a 'classical' property already present in certain microsystems. For such a classical system the states fall into classes of equivalent states which cannot be distinguished by any observation on the system. It is shown that the two states obtained in the measuring process are in the same equivalence class. Thus the problem concerning this strange duality which has haunted quantum mechanics from the beginning dissolves into a pseudoproblem.

Citation (ISO format)
JAUCH, Joseph-Maria. The Problem of Measurement in Quantum Mechanics. In: Helvetica physica acta, 1964, vol. 37, n° 4-5, p. 293–316. doi: 10.5169/seals-113486
Main files (1)
Article (Published version)
ISSN of the journal0018-0238

Technical informations

Creation07/20/2022 12:33:00 PM
First validation07/20/2022 12:33:00 PM
Update time03/16/2023 7:00:49 AM
Status update03/16/2023 7:00:48 AM
Last indexation01/17/2024 9:01:47 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack