QM interpretations defined as eigenvalues?

In summary, Bill is asking a question about whether counterfactual definiteness must be dropped in order for a system to be in a superposition. He is told that all superposition is is pure states form a vector space, and there is no connection to counterfactual definiteness.
  • #1
entropy1
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And back again with a strange/odd layman question:

Actually, this remark of Jilang is a perfect illustration of what I am wondering about:
Jilang said:
Hi Markus, you have a choice that comes down to interpretation. If realism is your thing you have to abandon locality and vice-versa. QM says you cannot have both at the same time. I don't think one is less worrisome than the other!

It seems as if realism and locality are behaving like two eigenstates in a space of interpretations of QM. Most people seem to suggest that you must have either one or the other. However, does that make sense if both are possible? Could there be a space in which, depending on the set of measurements and/or experimental setup, there is a mixture of degrees to which two or more interpretations form an explanation of the experimental outcome? Most scientifically educated forum members seem to suggest interpretations are not the field of QM. If that is the case, please let me know. I am not asking this odd question because I suggest I have any anwer to anything. I have just been wondering about exactly this for a long time! It is an insight in my strange world of thought! o0) I hope someone can pinpoint where I am mistaking (probably everyone :wink: ). Thanks! :smile:

UPDATE: In fact, forget the notion of eigenvalues. Is it possible that certain experiments can be interpreted by a mixture of degrees of mutually exclusive interpretations? (I imagine aspects of the experimental setup determine the values of the degrees - so the experimental setup is part of the definition of the interpretation of the experiment and its outcomes. In other words: the experimental setup is the definition of the interpretation of it; that we can have different interpretations doesn't necessarily have to mean that interpretations can't be combined. I could rephrase this in: of which is realism or locality the property? :smile::nb) ).
 
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  • #2
entropy1 said:
of which is realism or locality the property? :smile::nb) ).
Of the interpretation.

so the experimental setup is part of the definition of the interpretation of the experiment and its outcomes. In other words: the experimental setup is the definition of the interpretation of it
No, setups are independent of interpretation.

The interpretation isn't a physical entity, so it doesn't make sense.

Also realist interpretations avoid superpositions of states, that's the point.
 
  • #3
entropy1 said:
In fact, forget the notion of eigenvalues. Is it possible that certain experiments can be interpreted by a mixture of degrees of mutually exclusive interpretations?.

As far as I can see, mixture of mutually exclusive interpretations is a non-sense statement like immovable object meets irresistible force. Mutually exclusive means they each exclude the other so you can't have a mixture. In QM, and physics in general you need to put some thought into what you say and not just put forth whatever word salid pops into your head which is what you seem to do.

As to how eigenvalues come into it, it comes from the very foundations of QM - see post 137:
https://www.physicsforums.com/threads/the-born-rule-in-many-worlds.763139/page-7

Thanks
Bill
 
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  • #4
ddd123 said:
Also realist interpretations avoid superpositions of states, that's the point.
I don't intend to take this discussion out of topic but I have a real quick question.
In order for a system to be in a superposition, does one have to drop counterfactual definiteness?
 
  • #5
quantumphysics11 said:
In order for a system to be in a superposition, does one have to drop counterfactual definiteness?

All superposition is is pure states form a vector space. It has nothing to do with CFD.

Thanks
Bill
 
  • #6
Quantum mechanics is a theory about the results of measurements. It says that the result of a measurement on a system will be one of the eigenvalues of the corresponding operator, with probabilities given by the rules of QM and the way the system was prepared. This is very much a black-box picture: You have a prepared state and an operator, you do some abstract math involving Hilbert spaces and inner products, and out pops a bunch of eigenvalues with probabilities attached to each one. But that's all that quantum mechanics does for you, which is why "shut up and calculate" is so often sound advice.

However, we humans generally hate black boxes. We cannot resist the temptation to make up stories form mental models about hypothetical machinery that might be operating inside the black box to make it produce the results that it does. Those stories mental models are called interpretations... and no, they are not formally part of quantum mechanics.

The analogy that "realism and locality are behaving like two eigenstates in a space of interpretations of QM" is quite unhelpful. The mathematical formalism is precise and rigorous; sloppy vague language about how it "behaves" loses the precision and rigor and gives us in return only misconceptions and incomplete understanding.

This thread is closed, as there is little point in carrying on a discussion based on this bogus analogy.
 
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1. What is the concept of "QM interpretations defined as eigenvalues" in quantum mechanics?

"QM interpretations defined as eigenvalues" refers to the mathematical framework used to interpret the results of quantum mechanics experiments. In this framework, observables (such as position, momentum, and energy) are represented by mathematical operators that have corresponding eigenvalues. These eigenvalues represent the possible outcomes of a measurement of that observable.

2. How do eigenvalues relate to quantum mechanics?

Eigenvalues play a crucial role in quantum mechanics as they represent the possible outcomes of a measurement of an observable. The corresponding eigenstates (eigenvectors) of these eigenvalues represent the states of a system in which the observable has a definite value. This relationship helps to explain the probabilistic nature of quantum mechanics and allows for the prediction of the outcomes of experiments.

3. What are the different interpretations of eigenvalues in quantum mechanics?

There are several interpretations of eigenvalues in quantum mechanics, including the Copenhagen interpretation, the many-worlds interpretation, and the pilot-wave theory. These interpretations differ in their understanding of the nature of quantum states and the role of measurement in determining outcomes.

4. How do eigenvalues affect the measurement process in quantum mechanics?

Eigenvalues play a crucial role in the measurement process in quantum mechanics. When a measurement is made on a quantum system, the state of the system is "collapsed" into one of its eigenstates, and the corresponding eigenvalue is observed as the outcome. The probabilities of obtaining each eigenvalue are determined by the system's wavefunction, which evolves according to the Schrödinger equation.

5. Can eigenvalues be used to explain quantum entanglement?

Eigenvalues are often used to explain quantum entanglement, which is the phenomenon where two or more particles become correlated in such a way that the state of one particle cannot be described independently of the other. In this framework, the entangled particles have a shared wavefunction, and their measured eigenvalues must be consistent with the entanglement relationship. However, there is ongoing debate and research regarding the role of eigenvalues in understanding and explaining quantum entanglement.

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