An argument against super-determinism

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Discussion Overview

The discussion centers around arguments against the super-deterministic interpretation of quantum mechanics (QM), particularly in the context of Bell experiments involving entangled photons and the implications of measurement settings based on irrational numbers. Participants explore the feasibility of super-deterministic theories in explaining quantum statistics and the nature of causation in such frameworks.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • One participant suggests that using the digits of irrational numbers to set polarizer angles in a Bell experiment raises questions about how super-determinism could account for the resulting quantum statistics.
  • Another participant argues that in a super-deterministic theory, the choice of measurement settings cannot be independent of the measurement results, as initial conditions would dictate both.
  • There is a contention regarding whether super-determinism can be classified strictly as a local hidden variable theory, with some asserting it is a subset while others argue it could encompass broader causal mechanisms.
  • Participants discuss the implications of super-determinism potentially being nonlocal, questioning its necessity and role if nonlocality is allowed.
  • One participant expresses uncertainty about the motivations behind super-determinism, indicating a lack of advocacy for the theory.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the classification of super-determinism as a local hidden variable theory and the implications of measurement settings being influenced by initial conditions. The discussion remains unresolved with multiple competing views presented.

Contextual Notes

Participants acknowledge that their arguments may lack rigor and that the discussion involves complex interpretations of quantum mechanics and the nature of causation, which are not fully settled.

MichPod
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TL;DR
Trying to disprove superdeterministic interpretation
I think I have something which can make an argument against superdeterministic interpretation of QM. Not that I am keen of disproving it, but I think that arguments even against some fringe ideas may have non-zero value and are anyway entertaining. I'll be glad to see feedbacks/review for whether this may be considered as a refutation of superdeterminism. I am sure this is not raised for the first time, i.e. my idea is not original, but I could not find it to be mentioned in available sources with either positive or negative attitude, nor with resolution.

Suppose that in the Bell Experiment (putting polarizers against two entrangled photons) we choose the angle of the photon polarizers on both directions based on the digits of decimal representation of two irrational numbers, let it be ##\pi## or ##e## or, say, ##\sqrt 2##. So we make a choice (may be a super-determined choice, if we believe superdeterminism is an option) that on the one end we use the sequence of digits of ##\pi## and on the other end, say, of the ##\sqrt 2##. Then, is it feasible that any super-deterministic local hidden variable theory could explain how the quantum statistics arises in such an experiment? Say, the digits of the irrational numbers are produced by 2 microcomputers staying each one near each polarizer correspondingly. But how the photons will know from any hidden variables of the environment, what are these digits on both sides? The information about the angles of both polarizers should be accessible per photons on the both sides of the experimental device via the hidden variables, either carried by them or found in the environment locally, but how could it ever be possible in such a case? I do understand this argument may lack rigor, i.e. by itself it is not a refutation. But how can it be satisfactory addressed by any possible superdeterministic interpretation?
 
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MichPod said:
Suppose that in the Bell Experiment (putting polarizers against two entrangled photons) we choose the angle of the photon polarizers on both directions based on the digits of decimal representation of two irrational numbers

In a superdeterministic theory, you can't "suppose" this independently of the measurement results. A superdeterministic theory would say that if you set things up this way, it's because the carefully chosen initial conditions of the universe determined that you would set things up this way, and set things up so that, even though you set things up this way, you would still obtain measurement results that were consistent with the predictions of QM.

MichPod said:
is it feasible that any super-deterministic local hidden variable theory could explain how the quantum statistics arises in such an experiment?

Note my strikethrough above. If you have specified that a theory is superdeterministic, you can't also specify that it's a local hidden variable theory. It might be, but you can't specify that, because it also might not be; you have no way of knowing unless you actually have a specific superdeterministic theory that you can look at.

With the strikethrough applied, my answer to this question is yes; see above.
 
PeterDonis said:
In a superdeterministic theory, you can't "suppose" this independently of the measurement results.

They are not independent and I do not suppose they are. Measurements of two entangled particles are correlated.

PeterDonis said:
A superdeterministic theory would say that if you set things up this way, it's because the carefully chosen initial conditions of the universe determined that you would set things up this way, and set things up so that, even though you set things up this way, you would still obtain measurement results that were consistent with the predictions of QM.

Yes. So let's say that "carefully chosen initial conditions of the universe" caused that I'll put a ##\pi## digits generator on the one side and ##\sqrt 2## digits generator on the other side. Or vice versa. Or may be ##e## on one side and ##\sqrt 10## on the other. No problem with that.
PeterDonis said:
Note my strikethrough above. If you have specified that a theory is superdeterministic, you can't also specify that it's a local hidden variable theory. It might be, but you can't specify that, because it also might not be; you have no way of knowing unless you actually have a specific superdeterministic theory that you can look at.

For my understanding, a superdeterministric theory is a kind of a "local hidden variable" theory by definition. I.e. superdeterministic theories are a subset in hidden variable theories. It's just a special sort of hidden variables which are "orchestrated" in a way to reproduce QM predictions. So each photon has its own hidden state + it might access the hidden state of the vacuum (whether it exists) along its trajectory + the hidden state of the polarizer, and in the end that should "help" the photon to decide whether it passes the polarizer or is absorbed on it.
 
MichPod said:
They are not independent

I'm not talking about the measurement results being independent of each other. I'm talking about the measurement results being independent of whatever process you say is determining the measurement settings. If superdeterminism is true, it is simply impossible to make the process that chooses the measurement settings independent of the measurement results, since superdeterminism by definition asserts that the initial conditions of the universe are carefully chosen so that those things are not independent.

MichPod said:
let's say that "carefully chosen initial conditions of the universe" caused that I'll put a ##\pi## digits generator on the one side and ##\sqrt{2}## digits generator on the other side. Or vice versa. Or may be ##e## on one side and ##\sqrt{10}## on the other.

Yes.

MichPod said:
For my understanding, a superdeterministric theory is a kind of a "local hidden variable" theory by definition.

No, it isn't. Superdeterminism simply says that however the carefully chosen initial conditions of the universe cause you to set up the measurement settings, those carefully chosen initial conditions of the universe also cause the measurement results to be consistent with QM. Superdeterminism says nothing specific at all about how all that causation comes about. It could be local hidden variables or it could be something else. Superdeterminism just asserts that, however it comes about, it ends up producing the results as described.
 
PeterDonis said:
No, it isn't. Superdeterminism simply says that however the carefully chosen initial conditions of the universe cause you to set up the measurement settings, those carefully chosen initial conditions of the universe also cause the measurement results to be consistent with QM. Superdeterminism says nothing specific at all about how all that causation comes about. It could be local hidden variables or it could be something else. Superdeterminism just asserts that, however it comes about, it ends up producing the results as described.

Well, if superdeteminism may be nonlocal, then why is it needed and what is its role? What problem should it resolve particularly if, say, we allow nonlocality?
 
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MichPod said:
if superdeteminism may be nonlocal, then why is it needed and what is its role? What problem should it resolve particularly if, say, we allow nonlocality?

I have no idea, since I'm not an advocate of superdeterminism. You would have to ask someone who is.
 
PeterDonis said:
I have no idea, since I'm not an advocate of superdeterminism. You would have to ask someone who is.
All advocates of superdeterminism assume that it is a local hidden variable theory. Otherwise it's pointless.
 
Yeah, it has to be a local hidden variable theory. Superdeterminism basically says that the entire universe is mechanistic and just proceeds mechanically from an initial state. This, by definition, requires local hidden variables so they can exert influences consistent with the speed of light being the universal speed limit. From what I can tell, such an experiment, if it was performed, would disprove the hidden variable theory, which would then leave the Copenhagen interpretation (the oldest and most plausible theory) as the only viable option! Of course, such an experiment would have to be performed, but once performed, it’s disproved. Fascinating stuff. Not to mention, the universe requires a starter to make a non-deterministic choice in order for time to start. (Von-Neumann paradox) So why would beings in the universe that followed have anything less than free will if we have the appearance of it? I hope someone does this experiment or one like it to finally put super-determinism (a dangerous theory which disallows Any justification of morality) to rest.
 
Envirobridge98 said:
From what I can tell, such an experiment, if it was performed, would disprove the hidden variable theory, which would then leave the Copenhagen interpretation (the oldest and most plausible theory) as the only viable option!
What experiment are you talking about here? We have a half-century of Bell-type experiments that show that no realistic local hidden variable theory can be right, but that certainly does not limit us to Copenhagen - any non-realistic and/or non-local interpretation will work, and there are many of these.

Superdeterminism is the suggestion that these experiments are all flawed in one particular way: There are events common to the past light cones of state preparation and both choices of measurement. If these events are sufficient to determine the state preparation and measurement choices then all three can be related without requiring any non-local faster-than-light influence. It is impossible to construct an experiment that does not include such a shared past so there no way of experimentally disproving the superdeterministic explanation - the best we can do is to point to the unbounded absurdities that appear when we apply it to modern Bell tests.
 
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