Understanding Faithful Measurement in Quantum Mechanics

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Discussion Overview

The discussion centers on the concept of "faithful measurement" in Quantum Mechanics, particularly in relation to the Kochen-Specker Theorem. Participants explore the definition and implications of faithful measurement within the context of quantum theory and its interpretations.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant seeks clarification on the meaning of "faithful measurement" as encountered in the Kochen-Specker Theorem.
  • Another participant references a Wikipedia entry, suggesting that faithful measurement implies a deterministic relationship between a subquantum element and the observable value, but questions the relevance of this concept to mainstream interpretations of Quantum Mechanics.
  • A subsequent post reiterates the definition from the Wikipedia source but expresses confusion about the precise meaning of faithful measurement.
  • One participant offers a definition, stating that faithful measurement refers to the measurement being the result of a specific (non-stochastic) function of some observable.

Areas of Agreement / Disagreement

Participants express differing interpretations of faithful measurement, with some questioning its relevance to Quantum Mechanics and others attempting to define it technically. The discussion remains unresolved regarding a consensus on the definition and implications of faithful measurement.

Contextual Notes

There are limitations in the discussion regarding the assumptions underlying the definitions of faithful measurement and the interpretations of the Kochen-Specker Theorem. The dependence on specific interpretations of Quantum Mechanics is also noted.

omidaut
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What is ''faithful measurement'' in Quantum Mechanics exactly. I have seen this expression in Kochen-Specker Theorem.
 
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To quote wiki (http://en.wikipedia.org/wiki/Kochen–Specker_theorem:
For such more general theories the KS theorem is applicable only if the measurement is assumed to be a faithful one, in the sense that there is a deterministic relation between a subquantum element of physical reality and the value of the observable found on measurement.
In this case "subquantum element" is a supposed "hidden value".
Since KS argues against hidden values and hidden values are not how most physicists interpret QM, it's probably not correct to say that "faithful measurement" is part of QM - only as part of the study of QM.
 
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It simply means that the measurement is the result of a specific (non-stochastic) function of some observable.
 
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