A measured spin is still a Qbit

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  • Thread starter Thread starter Gary Venter
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    Uncertainty principle
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Discussion Overview

The discussion centers on the nature of quantum bits (Qbits) and the implications of measurement in quantum mechanics, particularly regarding the interpretation of spin measurements and probabilities. It touches on conceptual and technical aspects of quantum measurement and the physical properties of measurement devices.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant suggests that a Qbit with a very low probability of being in the up state (1 - (10^-75)) can still yield an up reading, indicating that a reading of up does not imply absolute certainty in the probability.
  • It is noted that the spin detector, being a physical device, introduces uncertainty and is not a perfect mathematical construct, which may affect the interpretation of the measurement results.
  • Another participant expresses confusion regarding the clarity and coherence of the initial statement about Qbits and measurements.
  • A further comment references the importance of word order and clarity in communication, highlighting the challenges in conveying complex ideas effectively.

Areas of Agreement / Disagreement

The discussion reflects a lack of consensus, with some participants questioning the clarity of the arguments presented and others attempting to articulate complex ideas about quantum measurement without reaching a definitive agreement.

Contextual Notes

There are indications of missing assumptions regarding the interpretation of probabilities in quantum mechanics and the physical characteristics of measurement devices, which remain unresolved.

Gary Venter
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TL;DR
A Qbit with up probability 1 - (10^-75) would most likely still produce a reading of up, and an up reading does not mean that the up probability is 1.0 to billions of decimal places.
A Qbit with up probability 1 - (10^-75) would most likely still produce a reading of up, so an up reading does not mean that the up probability is 1.0 to millions of decimal places.

The spin detector is a physical device made of atoms. None of its surfaces are pure mathematical planes or lines. Just because it has oriented a particle in the x-direction in a way to produce a reading of up does not mean that it is oriented exactly in that direction with zero uncertainty or has stopped having Qbit spin.
 
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Those are words. What they mean put together like this I cannot fathom.
 
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As Monty Python said "It's not just the total number of words. Getting them in the right order is almost as important."
 
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