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Check out "superdeterminism," first proposed by Bell (of Bell's inequality fame) himself and currently being vigorously pursued by Sabina Hossenfelder. There is

Check out "superdeterminism," first proposed by Bell (of Bell's inequality fame) himself and currently being vigorously pursued by Sabina Hossenfelder. There is no "collapse" per se according to this model and everything is really classical with hidden variables, and the entanglement comes because everything shared the same origin (the big bang). A very fascinating and in my opinion the best explanation, though it's extremely controversial and taboo because of its implications on free will (e.g., I see no mention of it at all in this article).

iainmerrick 4y ago
I have never fully understood that idea, even after reading Hossenfelder's posts about it. The idea that there's a "block universe" and everything is predetermined is comprehensible, sure; but what's the exact mechanism by which Bell's inequality is violated in experiments? Doesn't that require the universe to have been carefully set up to look as if it's acting in a weird non-local way, on an experiment-by-experiment basis? I assume I am just misunderstanding the idea, though. Any suggested reading material much appreciated!
- superposeur 4y ago
  Agreed — superdeterminism is not so much a theory as a theory-for-a-theory at this stage (a vague guess at the form such a theory might take). It is a sign of the much greater maturity of the physical collapse models that their parameters can be constrained by experiment. The ability to be constrained is a good sign, not a bad one. I love John Preskill’s standard nod to superdeterminism in his writings: without mentioning it by name he says “I leave it up to the reader to decide how seriously to take this possibility” (get it?)
  - naasking 4y ago
    I think the right way to look at it is that superdeterminism is an umbrella term for a class of theories that have a certain property. Like some interpretations of quantum mechanics are "psi-ontic", meaning the wave function is considered physically real (like many worlds), vs. "psi-epistemic" where the wave function is considered a reflection of our knowledge of reality (Copenhagen).
- naasking 4y ago
  We had a recent thread about an article from Tim Palmer who has a good take on this: https://news.ycombinator.com/item?id=33223391 https://news.ycombinator.com/item?id=33223391 The idea is that the natural laws are fractal, which when mapped out trace many state space configurations. But with a fractal there are always gaps in state space that remain no matter how much you zoom in or out; fractals preserve certain structural invariants at all scales. So the idea is that counterfactual reasoning sometimes fails in a fractal universe, because statistical independence no longer works as a general rule (your counterfactual could lie in one of those gaps). He first published this idea in 2009 under the name "invariant set postulate": https://en.wikipedia.org/wiki/Invariant_set_postulate https://en.wikipedia.org/wiki/Invariant_set_postulate His paper with Hossenfelder is also a good overview: https://www.frontiersin.org/articles/10.3389/fphy.2020.00139/full https://www.frontiersin.org/articles/10.3389/fphy.2020.00139... Superdeterminism gets an unnecessarily bad rap.
  - iainmerrick 4y ago
    Superdeterminism gets an unnecessarily bad rap. If determinism is true, don't you mean "necessarily"? :)
- pdonis 4y ago
  > Doesn't that require the universe to have been carefully set up to look as if it's acting in a weird non-local way, on an experiment-by-experiment basis? Yes. That is a big reason why most physicists do not favor superdeterminism.
  - geertj 4y ago
    I am not so sure. In my understanding of the block universe, causality doesn't really exist, and the universe is simply a consistent solution with boundary conditions both at the beginning and at the end of time (as well as in space). The game of life is perhaps a nice analogy here. On the 2d grid of the game of life, a glider seems moving in a certain direction when time moves forward. But in the 3d grid, where time is the third dimension, a glider is just a static volume of space. The reason we experience time is that the evolution of the block universe does depend on the dimension you look at (e.g entropy generally increases in the positive time dimension), and because our consciousness is an emergent property of a self-sustaining structure within the block universe, it's plausible at least that we perceive movement in time different from movement in space. I realize this is very sloppy wording but I'm having trouble finding better words to describe my intuition here.
    - pdonis 4y ago
      > In my understanding of the block universe, causality doesn't really exist That's one way of interpreting it, but superdeterminism does not entail or require this. Superdeterminism can be formulated just fine for a universe that evolves in time from some initial state according to causal processes.
- kgwgk 4y ago
  > what's the exact mechanism by which Bell's inequality is violated in experiments? It’s not violated - it simply doesn’t apply because it’s predetermined that the measurements that are done work well together. The experimenters follow the script.
  - inwit 4y ago
    That a serious scientist can believe this leads me to consider the economic benefits of believing such nonsense, rather than prompting me to examine it further. Just total rubbish
    - kgwgk 4y ago
      We should be merciful with superdeterminists: they don't have a choice!
sebastialonso 4y ago
Is superdeterminism even falsifiable?
- naasking 4y ago
  Is Many-Worlds even falsifiable?
  - tshaddox 4y ago
    David Deutsch seems to think that a general intelligence running on a quantum computer ought to be able to observe itself existing in parallel worlds if many-worlds is true.
    - naasking 4y ago
      I'm skeptical that Deutsch actually meant that, but even smart people have crazy ideas.
      - tshaddox 4y ago
        He wrote a pretty well known article about it that as far as I can tell wasn’t written off-hand and hasn’t been retracted or disavowed. I’m pretty confident he meant it.
        ummonk 4y ago
        There has to be some misinterpretation going on here (or David Deutsch just hasn't thought this through). You can have a quantum computer in a superposition of states, but that isn't many worlds; to have many worlds, the computer has to interact with the outside world and split the outside world into a corresponding superposition of states. Such interaction with the outside world prevents a quantum computer from functioning - and it's precisely such information leakage to the outside world that is a major difficulty when trying to scale up quantum computers.
    - xwolfi 4y ago
AnIdiotOnTheNet 4y ago
Even without superdeterminism free will is a concept that only makes any sense in specific contexts. To say otherwise is to introduce God of the Gaps style woo.
- ffhhj 4y ago
  Free will is about choosing what binds us, as we can't choose being free of matter without becoming inmaterial.
tsimionescu 4y ago
> it's extremely controversial and taboo because of its implications on free will (e.g., I see no mention of it at all in this article). "True" free will is ruled out by all existing physical theories, so that's not why it's controversial. The bigger problem with superdeterminism is that it wants to explain physics without assuming statistical independence, even for far away events.
kgwgk 4y ago
> Check out "superdeterminism," first proposed by Bell (of Bell's inequality fame) himself “Proposed” - but as something that avoids the issue but it’s not worthy of much consideration. - I was going to ask whether it is still possible to maintain, in the light of experimental experience, the idea of a deterministic universe? You know, one of the ways of understanding this business is to say that the world is super-deterministic. That not only is inanimate nature deterministic, but we, the experimenters who imagine we can choose to do one experiment rather than another, are also determined. If so, the difficulty which this experimental result creates disappears. - Free will is an illusion - that gets us out of the crisis, does it? That's correct. In the analysis it is assumed that free will is genuine, and as a result of that one finds that the intervention of the experimenter at one point has to have consequences at a remote point, in a way that influences restricted by the finite velocity of light would not permit. If the experimenter is not free to make this intervention, if that also is determined in advance, the difficulty disappears.
whimsicalism 4y ago
> though it's extremely controversial and taboo because of its implications on free will Uhh, no. Essentially all existing physical theories are devastating for any non-compatabilist account of free will.
- skissane 4y ago
  I get the impression that physicists who advocate “superdeterminism” are ignorant of the philosophical literature on “determinism” - because from a philosophical viewpoint, there is nothing “super-“ about their position, it is just plain old “determinism”.
  - pilebunker7 4y ago
    Advocates of superdeterminism aren't always in favour of the term. Its most notable advocate, Hossenfelder, disapproves of the term, believing it to be misleading. She suggests the term 'implicate order' (crediting Bohm) be used instead.
- ummonk 4y ago
  Exactly. Even if you dispense with hard determinism and allow randomness in your theory, pure randomness is not really free will.
- alexvoda 4y ago
  Free will is also incoherent in any religion or philosophy presupposing a bi-omni deity (which itself is an incoherent notion). The point, that many ignore, however is that, free will does not matter. It is irrelevant. Regardless of whether one has free will or not, one still has to make choices and support the consequences of said choices. Lack of free will was never the get out of jail free card some fear it to be. If you bring in to the discussion sociology and psychology, free will makes even less sense.
drewrv 4y ago
I'm a fan of hers but I think many of her criticisms of string theory, multiverse stuff, etc, apply equally well to superdeterminisim. That being said, in her latest book she has a pretty strong argument against free will that does not require superdeterminisim so if that sounds interesting check it out.
EamonnMR 4y ago
The notion that a probabilistic world enables free will in a way that a deterministic one doesn't still confuses me. A coin I flip isn't exercising free will.
- dilap 4y ago
  Could free will be explained as super-physical phenomena that "haunts" the physical world, w/ choice manifest as which of the branching many worlds' paths consciousness "chooses" to experience? E.g., I am in some universe taking every possible action right now, but I'm only experiencing the actions which I "chose" to take.
  - The5thElephant 4y ago
    What is the point of such a theory besides trying to relieve us from the uncomfortable idea of many worlds? It is no better at explaining our perceived world than the simpler theory that consciousness exists across all these states and we aren't following some particular path through them. All states of conscious existence are being perceived and the perception of it being a coherent path through time is just an illusion created by memory and the similarity of adjacent states. Furthermore it still removes any actual willed choice of path within the context of our existence. I am not some meta-entity seeing all possible paths and choosing one for some unknown reason. That would be an existential alien "haunting" me and not "free will".
    - dilap 4y ago
      I am trying the reconcile the feeling of free-will we experience with its evident absence, per the theory. (Of course, you could also just say the feeling is an illusion.) I don't know if you can ever answer it one way or the other, because while consciousness certainly exists (again a fact I believe just because I feel it), it can't in any way influence the universe, at least per current theories of physics. On the other hand, if you're right that many-worlds is real and our consciousness persists in all of them, then we will, individually, come to realize that is the case, as find ourselves still alive, forever, ever more improbably (since, I think, the odds of dying would never be 1, so you'll always be alive in some lucky world).

iainmerrick 4y ago

I have never fully understood that idea, even after reading Hossenfelder's posts about it. The idea that there's a "block universe" and everything is predetermined is comprehensible, sure; but what's the exact mechanism by which Bell's inequality is violated in experiments? Doesn't that require the universe to have been carefully set up to look as if it's acting in a weird non-local way, on an experiment-by-experiment basis? I assume I am just misunderstanding the idea, though. Any suggested reading material much appreciated!

superposeur 4y ago
Agreed — superdeterminism is not so much a theory as a theory-for-a-theory at this stage (a vague guess at the form such a theory might take). It is a sign of the much greater maturity of the physical collapse models that their parameters can be constrained by experiment. The ability to be constrained is a good sign, not a bad one. I love John Preskill’s standard nod to superdeterminism in his writings: without mentioning it by name he says “I leave it up to the reader to decide how seriously to take this possibility” (get it?)
- naasking 4y ago
  I think the right way to look at it is that superdeterminism is an umbrella term for a class of theories that have a certain property. Like some interpretations of quantum mechanics are "psi-ontic", meaning the wave function is considered physically real (like many worlds), vs. "psi-epistemic" where the wave function is considered a reflection of our knowledge of reality (Copenhagen).
naasking 4y ago
We had a recent thread about an article from Tim Palmer who has a good take on this: https://news.ycombinator.com/item?id=33223391 https://news.ycombinator.com/item?id=33223391 The idea is that the natural laws are fractal, which when mapped out trace many state space configurations. But with a fractal there are always gaps in state space that remain no matter how much you zoom in or out; fractals preserve certain structural invariants at all scales. So the idea is that counterfactual reasoning sometimes fails in a fractal universe, because statistical independence no longer works as a general rule (your counterfactual could lie in one of those gaps). He first published this idea in 2009 under the name "invariant set postulate": https://en.wikipedia.org/wiki/Invariant_set_postulate https://en.wikipedia.org/wiki/Invariant_set_postulate His paper with Hossenfelder is also a good overview: https://www.frontiersin.org/articles/10.3389/fphy.2020.00139/full https://www.frontiersin.org/articles/10.3389/fphy.2020.00139... Superdeterminism gets an unnecessarily bad rap.
- iainmerrick 4y ago
  Superdeterminism gets an unnecessarily bad rap. If determinism is true, don't you mean "necessarily"? :)
pdonis 4y ago
> Doesn't that require the universe to have been carefully set up to look as if it's acting in a weird non-local way, on an experiment-by-experiment basis? Yes. That is a big reason why most physicists do not favor superdeterminism.
- geertj 4y ago
  I am not so sure. In my understanding of the block universe, causality doesn't really exist, and the universe is simply a consistent solution with boundary conditions both at the beginning and at the end of time (as well as in space). The game of life is perhaps a nice analogy here. On the 2d grid of the game of life, a glider seems moving in a certain direction when time moves forward. But in the 3d grid, where time is the third dimension, a glider is just a static volume of space. The reason we experience time is that the evolution of the block universe does depend on the dimension you look at (e.g entropy generally increases in the positive time dimension), and because our consciousness is an emergent property of a self-sustaining structure within the block universe, it's plausible at least that we perceive movement in time different from movement in space. I realize this is very sloppy wording but I'm having trouble finding better words to describe my intuition here.
  - pdonis 4y ago
    > In my understanding of the block universe, causality doesn't really exist That's one way of interpreting it, but superdeterminism does not entail or require this. Superdeterminism can be formulated just fine for a universe that evolves in time from some initial state according to causal processes.
kgwgk 4y ago
> what's the exact mechanism by which Bell's inequality is violated in experiments? It’s not violated - it simply doesn’t apply because it’s predetermined that the measurements that are done work well together. The experimenters follow the script.
- inwit 4y ago
  That a serious scientist can believe this leads me to consider the economic benefits of believing such nonsense, rather than prompting me to examine it further. Just total rubbish
  - kgwgk 4y ago
    We should be merciful with superdeterminists: they don't have a choice!

sebastialonso 4y ago

Is superdeterminism even falsifiable?

naasking 4y ago
Is Many-Worlds even falsifiable?
- tshaddox 4y ago
  David Deutsch seems to think that a general intelligence running on a quantum computer ought to be able to observe itself existing in parallel worlds if many-worlds is true.
  - naasking 4y ago
    I'm skeptical that Deutsch actually meant that, but even smart people have crazy ideas.
    - tshaddox 4y ago
      He wrote a pretty well known article about it that as far as I can tell wasn’t written off-hand and hasn’t been retracted or disavowed. I’m pretty confident he meant it.
      - ummonk 4y ago
        There has to be some misinterpretation going on here (or David Deutsch just hasn't thought this through). You can have a quantum computer in a superposition of states, but that isn't many worlds; to have many worlds, the computer has to interact with the outside world and split the outside world into a corresponding superposition of states. Such interaction with the outside world prevents a quantum computer from functioning - and it's precisely such information leakage to the outside world that is a major difficulty when trying to scale up quantum computers.
  - xwolfi 4y ago

AnIdiotOnTheNet 4y ago

Even without superdeterminism free will is a concept that only makes any sense in specific contexts. To say otherwise is to introduce God of the Gaps style woo.

ffhhj 4y ago
Free will is about choosing what binds us, as we can't choose being free of matter without becoming inmaterial.

tsimionescu 4y ago

> it's extremely controversial and taboo because of its implications on free will (e.g., I see no mention of it at all in this article). "True" free will is ruled out by all existing physical theories, so that's not why it's controversial. The bigger problem with superdeterminism is that it wants to explain physics without assuming statistical independence, even for far away events.

kgwgk 4y ago

> Check out "superdeterminism," first proposed by Bell (of Bell's inequality fame) himself “Proposed” - but as something that avoids the issue but it’s not worthy of much consideration. - I was going to ask whether it is still possible to maintain, in the light of experimental experience, the idea of a deterministic universe? You know, one of the ways of understanding this business is to say that the world is super-deterministic. That not only is inanimate nature deterministic, but we, the experimenters who imagine we can choose to do one experiment rather than another, are also determined. If so, the difficulty which this experimental result creates disappears. - Free will is an illusion - that gets us out of the crisis, does it? That's correct. In the analysis it is assumed that free will is genuine, and as a result of that one finds that the intervention of the experimenter at one point has to have consequences at a remote point, in a way that influences restricted by the finite velocity of light would not permit. If the experimenter is not free to make this intervention, if that also is determined in advance, the difficulty disappears.

whimsicalism 4y ago

> though it's extremely controversial and taboo because of its implications on free will Uhh, no. Essentially all existing physical theories are devastating for any non-compatabilist account of free will.

skissane 4y ago
I get the impression that physicists who advocate “superdeterminism” are ignorant of the philosophical literature on “determinism” - because from a philosophical viewpoint, there is nothing “super-“ about their position, it is just plain old “determinism”.
- pilebunker7 4y ago
  Advocates of superdeterminism aren't always in favour of the term. Its most notable advocate, Hossenfelder, disapproves of the term, believing it to be misleading. She suggests the term 'implicate order' (crediting Bohm) be used instead.
ummonk 4y ago
Exactly. Even if you dispense with hard determinism and allow randomness in your theory, pure randomness is not really free will.
alexvoda 4y ago
Free will is also incoherent in any religion or philosophy presupposing a bi-omni deity (which itself is an incoherent notion). The point, that many ignore, however is that, free will does not matter. It is irrelevant. Regardless of whether one has free will or not, one still has to make choices and support the consequences of said choices. Lack of free will was never the get out of jail free card some fear it to be. If you bring in to the discussion sociology and psychology, free will makes even less sense.

drewrv 4y ago

I'm a fan of hers but I think many of her criticisms of string theory, multiverse stuff, etc, apply equally well to superdeterminisim. That being said, in her latest book she has a pretty strong argument against free will that does not require superdeterminisim so if that sounds interesting check it out.

EamonnMR 4y ago

The notion that a probabilistic world enables free will in a way that a deterministic one doesn't still confuses me. A coin I flip isn't exercising free will.

dilap 4y ago
Could free will be explained as super-physical phenomena that "haunts" the physical world, w/ choice manifest as which of the branching many worlds' paths consciousness "chooses" to experience? E.g., I am in some universe taking every possible action right now, but I'm only experiencing the actions which I "chose" to take.
- The5thElephant 4y ago
  What is the point of such a theory besides trying to relieve us from the uncomfortable idea of many worlds? It is no better at explaining our perceived world than the simpler theory that consciousness exists across all these states and we aren't following some particular path through them. All states of conscious existence are being perceived and the perception of it being a coherent path through time is just an illusion created by memory and the similarity of adjacent states. Furthermore it still removes any actual willed choice of path within the context of our existence. I am not some meta-entity seeing all possible paths and choosing one for some unknown reason. That would be an existential alien "haunting" me and not "free will".
  - dilap 4y ago
    I am trying the reconcile the feeling of free-will we experience with its evident absence, per the theory. (Of course, you could also just say the feeling is an illusion.) I don't know if you can ever answer it one way or the other, because while consciousness certainly exists (again a fact I believe just because I feel it), it can't in any way influence the universe, at least per current theories of physics. On the other hand, if you're right that many-worlds is real and our consciousness persists in all of them, then we will, individually, come to realize that is the case, as find ourselves still alive, forever, ever more improbably (since, I think, the odds of dying would never be 1, so you'll always be alive in some lucky world).