Superdeterminist
Enlightened
- Apr 5, 2020
- 1,877
Let us talk physics. Specifically: Superdeterminism. The name 'Superdeterminism' is misleading because really it's identical to determinism. Superdeterminism is a property of a class of theories. This property is the violation of a Bell-theoretic assumption known as statistical independence.
Bell's theorem, a central pillar of today's quantum mechanics, tells us that no local hidden variables theories can reproduce experimental observations, and its starting assumption of statistical independence is the assumption that the local hidden variables aren't correlated with measurement settings. The assumption of statistical independence is sometimes also called the 'free will' assumption, because it stipulates that experimenter choices are free from the influence of the hidden variables. By calling this assumption into question, we may find ways to model observed correlations via local hidden variables.
What are hidden variables? These are simply any physical variables which are not described in quantum mechanics. They are not necessarily unobservable (ideally they are observable, of course). Thus the 'hidden' in hidden variables is misleading, and the alternative name 'additional variables' has been proposed instead.
What's the motivation for all of this? Currently the prevailing regime in physics is quantum mechanics. But quantum mechanics is incomplete for several reasons, most notably the measurement problem: there is no description of the measurement process under QM, the narrative is that "we observe and the wave function instantly collapses into an eigenstate (a definite state)". You can see how this is sorely lacking - it doesn't explain how observation works or why we observe the states we observe out of all the possibilities in the initial wave function.
To avoid this problem, physicists proposed that the measurement process ISN'T a physical process...but this is inadequate. If it is not a physical process, then what is it? A...non-physical process? This evasive manoeuvre fails to explain how we observe definite states from the probability waves calculated in QM.
There have been attempts to physicalise the measurement process (e.g. pilot wave theory), however under the quantum mechanical formalism, this process must be nonlocal. Nonlocality means violation of relativity. This is tension between QM and relativity shows that one of them needs to be modified. While nonlocality (the idea that objects can affect other objects far away from them instantly) is not necessarily false, it certainly is unintuitive.
But back to Superdeterminism. Superdeterministic theories offer a way to describe the measurement process in a local manner by way of local hidden variables, thus preserving consistency with relativity. There are currently 3 main Superdeterministic theory candidates: Hossenfelder's 'Degree's of Freedom' model, Palmer's Invariant Set Theory, and T' Hooft's Cellular Automaton Interpretation. See this talk for a discussion involving all three individuals.
So to recap: Superdeterministic theories challenge Bell's theorem by questioning its assumption of statistical independence. If correct, this would mean Bell's theorem is incorrect, and so local hidden variables are no longer ruled out to explain quantum mechanical phenomena in a local manner, and to describe the measurement process. A superdeterministic theory would NOT falsify quantum mechanics, but would be a more fundamental theory underlying quantum mechanics. The apparent nonlocality of quantum mechanics would be falsified, revealed to be only an illusion arising due to the oversight of hidden variables.
Einstein was a (super)determinist, believing that "god does not play dice", suggesting that hidden variables were at play in his 1935 EPR paper. I'm very much inclined to agree with him, since I can't grasp how pure probabilities could or would be the most fundamental aspect of reality, as quantum mechanics suggests. How do you get a result from just a probability? You seem to require a definite mechanism, not just a probability. It surely doesn't suffice to say that "we observed this outcome because it was the most probable". Anyway, the actual outcome isn't always the most probable one, as we all know.
For the best description of Superdeterminism, I would recommend this paper: https://www.frontiersin.org/articles/10.3389/fphy.2020.00139/full. It is technical in some parts, but the general theme can be understood with little to no technical knowledge.
I apologise for this very long-winded post, but I am excited by this attempt to move beyond the mere probabilities of quantum mechanics into a more ambitious and definite explanation for reality. My deep frustration with existence and suffering is really what motivates this interest, fundamentally. I feel that physics should, in the end, provide closure on all of our experiences in life, especially those most terrible ones over which we cry out "why?"...I hope I've ignited (or refreshed any existing) interest you may have had on this topic, and wonder about your thoughts on this, or any related subject.
Bell's theorem, a central pillar of today's quantum mechanics, tells us that no local hidden variables theories can reproduce experimental observations, and its starting assumption of statistical independence is the assumption that the local hidden variables aren't correlated with measurement settings. The assumption of statistical independence is sometimes also called the 'free will' assumption, because it stipulates that experimenter choices are free from the influence of the hidden variables. By calling this assumption into question, we may find ways to model observed correlations via local hidden variables.
What are hidden variables? These are simply any physical variables which are not described in quantum mechanics. They are not necessarily unobservable (ideally they are observable, of course). Thus the 'hidden' in hidden variables is misleading, and the alternative name 'additional variables' has been proposed instead.
What's the motivation for all of this? Currently the prevailing regime in physics is quantum mechanics. But quantum mechanics is incomplete for several reasons, most notably the measurement problem: there is no description of the measurement process under QM, the narrative is that "we observe and the wave function instantly collapses into an eigenstate (a definite state)". You can see how this is sorely lacking - it doesn't explain how observation works or why we observe the states we observe out of all the possibilities in the initial wave function.
To avoid this problem, physicists proposed that the measurement process ISN'T a physical process...but this is inadequate. If it is not a physical process, then what is it? A...non-physical process? This evasive manoeuvre fails to explain how we observe definite states from the probability waves calculated in QM.
There have been attempts to physicalise the measurement process (e.g. pilot wave theory), however under the quantum mechanical formalism, this process must be nonlocal. Nonlocality means violation of relativity. This is tension between QM and relativity shows that one of them needs to be modified. While nonlocality (the idea that objects can affect other objects far away from them instantly) is not necessarily false, it certainly is unintuitive.
But back to Superdeterminism. Superdeterministic theories offer a way to describe the measurement process in a local manner by way of local hidden variables, thus preserving consistency with relativity. There are currently 3 main Superdeterministic theory candidates: Hossenfelder's 'Degree's of Freedom' model, Palmer's Invariant Set Theory, and T' Hooft's Cellular Automaton Interpretation. See this talk for a discussion involving all three individuals.
So to recap: Superdeterministic theories challenge Bell's theorem by questioning its assumption of statistical independence. If correct, this would mean Bell's theorem is incorrect, and so local hidden variables are no longer ruled out to explain quantum mechanical phenomena in a local manner, and to describe the measurement process. A superdeterministic theory would NOT falsify quantum mechanics, but would be a more fundamental theory underlying quantum mechanics. The apparent nonlocality of quantum mechanics would be falsified, revealed to be only an illusion arising due to the oversight of hidden variables.
Einstein was a (super)determinist, believing that "god does not play dice", suggesting that hidden variables were at play in his 1935 EPR paper. I'm very much inclined to agree with him, since I can't grasp how pure probabilities could or would be the most fundamental aspect of reality, as quantum mechanics suggests. How do you get a result from just a probability? You seem to require a definite mechanism, not just a probability. It surely doesn't suffice to say that "we observed this outcome because it was the most probable". Anyway, the actual outcome isn't always the most probable one, as we all know.
For the best description of Superdeterminism, I would recommend this paper: https://www.frontiersin.org/articles/10.3389/fphy.2020.00139/full. It is technical in some parts, but the general theme can be understood with little to no technical knowledge.
I apologise for this very long-winded post, but I am excited by this attempt to move beyond the mere probabilities of quantum mechanics into a more ambitious and definite explanation for reality. My deep frustration with existence and suffering is really what motivates this interest, fundamentally. I feel that physics should, in the end, provide closure on all of our experiences in life, especially those most terrible ones over which we cry out "why?"...I hope I've ignited (or refreshed any existing) interest you may have had on this topic, and wonder about your thoughts on this, or any related subject.
