Before anything, I'm sorry for being an outsider coming to opine about your field. This is almost always a stupid decision, but I do have a good justification for this case. I've been reading about superdeterminism and it bothered me that most of you treat it as a joke. Well, before anything, I think at this point in history we should've already learned the lesson: ridiculous sounding ideas often end up becoming standards science, and that form of idealogical bullying should never exist. But, if at least the arguments were convincing, one could make an excuse for the author. Except not, his arguments sound just like someone with total lack of understanding of idea who rants against it just because he doesn't like it. "Superdeterminism would mean nature is sending magic agents to control our brains and conspire against us!" Is this even serious?

Yes, as a computer scientist I do think superdeterminism is the most natural approach to how the universe works. On my view the idea of "free will" - as in, something coming from outside the universe, interacting with the information stored in our brain and determining what we do physically - is the sketchy approach, not the opposite. I do think true randomness is the one that requires a lot of magical intervention, while superdeterminism is much more solid. And I even think recent insights support it without need for any "magical agents". But that is not the reason I'm mad - after all, I'm an outsider and my views doesn't matter a dime. It is because such an important idea with huge implications is regarded as a joke and not even considered just for matters of taste, with no actual proof or evidence of the case. And this is something I do have the right to complain, regardless of the field.

So, please, could anyone justify this prejudice?

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    $\begingroup$ Is this better suited for Philosophy.SE? $\endgroup$ Commented Apr 4, 2014 at 6:02
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    $\begingroup$ Luboš Motl is someone I have enormous respect for (just look at his answers on this forum!) but he has a rather sharp tongue and I suspect many physicists would take a more moderate tone. Experimental tests of Bell's inequalities have convinced most of us that hidden variable theories are unlikely, however that hasn't stopped people looking for loopholes. And good luck to them. It's a relatively small part of the science budget to pay some theorists to have a go at it and I don't begrudge them the opportunity. $\endgroup$ Commented Apr 4, 2014 at 6:38
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    $\begingroup$ See? "Loopholes". Even you disrespect it, even though you probably didn't notice nor mean to. That is what I'm talking about, it is like it is something so obvious to physicists that you don't even question it. On my view Bell's results relies on the presumption of the existence of "free will", which is a completely shady and unexplained concept. What is that "free will", where it does come from and how does it affect the physical world? How could a conclusion that depends on magical, unexplained concepts have convinced so many physicists ? $\endgroup$
    – MaiaVictor
    Commented Apr 4, 2014 at 8:20
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    $\begingroup$ Related: philosophy.stackexchange.com/q/9511/3164 $\endgroup$
    – Řídící
    Commented Apr 4, 2014 at 8:52
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    $\begingroup$ "ridiculous sounding ideas often end up becoming standards of science" Not true, you're cherry-picking. You're familiar with the ridiculous ideas that made it; a far, far deal more did fail horribly. $\endgroup$
    – Nick Gotch
    Commented Apr 4, 2014 at 15:02

6 Answers 6


First of all, "loopholes" is no disrespect. It's standard nomenclature. Given a law, a "loophole" is a way to circumvent it. Bell's inequalities, in their mathematical formulation, are laws that prevent superdeterminism, so if we believe it should exist, we have to find loopholes in the assumptions. It might be that the loophole is so big that the whole law becomes nonsense, but till now, nobody has found one - except the free will.

Except for a few really outspoken critics, I don't think that people regard superdeterminism as a "joke". If you are interested, here is a good summary about what is known by a computer scientist: http://www.scottaaronson.com/democritus/lec18.html It also tells you that for Bell's inequalities, the concept of "free will" is actually not "murky" but very clear: The detector settings must not be completely predetermined by the history of the universe. You can accept that assumption to be true or not.

In the end, of course, it means you have to decide: Is everything in the universe predetermined, or are there any choices possible that are not fully predetermined by the state of the universe? If the latter exists, you can't have superdeterminism. That's what Bell tells us. So let's assume we have superdeterminism. And then? Nothing. It doesn't give you any new predictions and despite that, it actually tells you that what you are doing is futile anyway, because your experiments don't fulfill the basic requirements we pose about experiments (reproducibility, parameters can be freely set, etc.), so in principle, you could stop right there. Then again, you won't stop, because you're predetermined not to.

Thus superdeterminism is a stance in philosophy not science in its modern form (and this question is not physics, but philosophy) - and many physicists/mathematicians strongly reject philosophy in science, they just don't get anything out of it. So, physicists don't treat superdeterminism as a joke, it's just not a position they feel comfortable with and since it doesn't predict anything anyway, they can just take a different position or none at all.

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    $\begingroup$ Very insightful, thank you! You got many things, so let me start with the "science invalidation" argument. You say that science would be invalidated if our decisions are pre-determined? That doesn't make sense. How so? Not having true free-will doesn't mean we don't percept free will locally. We do think we have it because we don't have enough information to predict our own actions. It works the same as pseudo-random numbers. They may look completely random for a humanbeing, but they are completely pre-determined. $\endgroup$
    – MaiaVictor
    Commented Apr 4, 2014 at 9:22
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    $\begingroup$ So, considering science is just a mean for humans to gather information about the universe, it does not matter that, globally, everything is pre-determined. As long as, for us, it looks like we have free will, then, for our own models, science is completely valid. $\endgroup$
    – MaiaVictor
    Commented Apr 4, 2014 at 9:25
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    $\begingroup$ If superdeterminism is the reality, we may never know. But if we can't find out, it's futile to muse about it outside philosophy. Basically, you just propose a different ontic model (which people don't like, because they like to think they can find out everything), but whose truth cannot be probed. I'd really go to the philosophers with this, they can tell you more about the differences between epistemology and ontology and how this might be important with your question, my knowledge there is pretty shaky! $\endgroup$
    – Martin
    Commented Apr 4, 2014 at 10:09
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    $\begingroup$ If it isn't, at least in principle, testable and refutable... it isn't science. Superdeterminism, like many philosophical/religious questions, simply doesn't occupy the space of questions that science is set up to handle. From this point of view, a difference that makes no difference really is no difference, and if there's no difference between yes and no then the only possible answer is "mu" -- your question is not a question. $\endgroup$
    – keshlam
    Commented Apr 4, 2014 at 15:47
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    $\begingroup$ @Martin Never say never $\endgroup$
    – Izkata
    Commented Apr 4, 2014 at 16:10

You say "ridiculous sounding ideas often end up becoming standards science" - but take into account that "ridiculous sounding ideas" much more often, by a large factor, end up becoming no science at all.

I agree that "that form of idealogical bullying should never exist" - except that it's not ideological, but just a practical matter of deciding which claims to spend time on understanding and possibly verifying.

When you ask scientists for "actual proof or evidence of the case" - it prove, that some new, and fairly unusual theory is invalid, you ask people to do a lot of work - but why should they do this work?

They would be interested to do this work - without even asking them - if someone provides some kind of evidence convinces them that there is a chance the new idea is at least useful enough to spend time on.
That's all.

I think “Extraordinary claims require extraordinary evidence” (Carl Sagan) applies perfectly to that.

  • $\begingroup$ Note I did not refer to the ideas you cited, and not even to physics for that matter. So it would equally apply to theories like "free energy" or "God". $\endgroup$ Commented Apr 4, 2014 at 8:50
  • $\begingroup$ OK, I actually agree with most of what you said. But about the problem itself. Do you see how bell's results prove that the world is inherently random by assuming thoughts are be random? It proves something by assuming it. I am the only who sees the absurdity on it? Or maybe I'm completely missing something else? $\endgroup$
    – MaiaVictor
    Commented Apr 4, 2014 at 8:58
  • $\begingroup$ Oh, looking the question from the perspective of a scientist, I did not, and do not intend to read about the problem itself. Sure, proving something based on the assumption it is true is an error. The first step to sort out this kind of problem when publishing something it the peer review; Was the paper/publication in question peer reviewed? $\endgroup$ Commented Apr 4, 2014 at 9:06

The real issue here is obscured by inane terminology and bad thinking.

The real issue is, what sort of "locally deterministic theory" could reproduce the experimentally successful predictions of quantum mechanics? Locality here means, not just that causal influences have to pass through space (rather than acting instantly at a distance), but that they don't go faster than light.

The key discovery of John Bell, immortalized in his theorem, is that there are experiments in which quantum mechanics predicts that there are correlations of a sort which cannot be produced by a locally deterministic theory.

The basic paradigm is that two particles are produced at a point, and move apart in opposite directions towards two rotatable filters. There are particle detectors on the far side of both filters. The probability that the particle will get through the filter depends on the filter's angle of orientation. The orientation of the filter is set while the particles are in flight, when they are too far apart for a light-speed influence to connect them. Yet whether they get through the filters or not, is highly correlated in a way that can't be produced by a locally deterministic theory with a light-speed limit. For more, see "Bell's theorem".

Bell's theorem is about probabilities. It is not literally impossible for a locally deterministic physics to reproduce the right results, but it would have to be an endless long-running coincidence, as if cosmic rays kept arriving from the other side of the universe in order to block the particles from getting through with the required frequency.

The point is that the filter orientations can be set according to any rule, the probabilities of getting through at the different ends are both highly correlated with each other and depend on what the orientations actually are, and the filter orientations can be "chosen" in such a way that no lightspeed causal influence can connect them. So the hypothetical causal influence that determines whether the particles get through, would have to "know" what the orientations were in advance. And since the orientations could be chosen e.g. according to the digits of pi, or the letters of "Moby Dick", or the behaviors of rats in a maze, you would have to suppose that this sequence of information was programmed into the outside causal influence (like the cosmic rays) in advance.

That is the idea that is "regarded as a joke". But here is where the inane terminology and the bad thinking enter to confuse the issue.

Bell posed his scenario in terms of experimenters choosing the filter orientations. He said a loophole might exist, if the experimenters' own choices are not free, and he called this "superdeterminism", as if ordinary determinism was just about experiments and not also the people who make them.

In any case, this offers no improvement in terms of probability. Before, we had cosmic rays with "Moby Dick" pre-programmed into them. Here, we have (presumably) mysterious influences which would prevent experimenters from conducting the "Moby Dick" version of the experiment. It's just as silly, and in any case, Bell-type experiments have now been done many times, so the improbable thing has come to pass. (It would be interesting to have a lower bound on just how improbable the outcomes of all the world's EPR experiments would be by now, assuming local determinism.)

So, although there actually is a prejudice against determinism among many people brought up on quantum mechanics, and although many people have a philosophical prejudice in favor of free will, neither of those really has anything to do with the issue here. The core issue is the fact that locally deterministic theories can only produce Bell correlations by coincidence, and that has a probability approaching zero as the experiments keep getting repeated and the predictions confirmed. If you want determinism in subquantum physics, you need nonlocality (Bohmian mechanics), causality backwards in time (various "interpretations"), perhaps some form of emergent space (with an underlying causal network that is nonlocal)...

This paper is a more accurate and scholarly expression, using a contemporary form of causal analysis, of what I am trying to say. When I say it needs cosmic rays pre-programmed with Moby Dick... that's an example of what they call "fine-tuning". The local causal influences responsible for producing nonlocal Bell correlations would have to be tuned in advance to produce the required effects.

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    $\begingroup$ Yes, I understand all that you are saying. I think the problem is that there is such a ingrained concept of flow of time in our brains. The orientations could be defined in function of whatever we want, it doesn't make it any absurd. Maybe if, instead of a static time, you think that the decision of modifying it alters something in the past, then it will sound less magical. This way it is not like the universe understands that we are orienting the filters in function of moby dick's characters. It is just that we affect the past after making such a decision. $\endgroup$
    – MaiaVictor
    Commented Apr 4, 2014 at 22:48

Why is superdeterminism generally regarded as a joke?

My personal (somewhat facetious) answer to that would be because people lack imagination. I don't think of superdeterminism in terms of conspiracies, but rather retrocausality, and do not find it ridiculous if phrased this way.

Basically, I don't believe there's really something like a physically significant arrow of time - just an arrow of perception of time. Reality doesn't care how we subjectively experience time as somehow flowing from one moment to the next.

Some anecdotal evidence for this: First, relativistic theories are reparametrization-invariant - there isn't really a preferred notion of time. Then, there's the idea due to Stueckelberg and Feynman that anti-particles are basically just particles propagating backwards in time, or the time-symmetric reformulation of electrodynamics. Also, there's the fact that in general relativity, we need to solve for a consistent space-time (which takes future 'boundary conditions' into account), with the aggravation that space-time might possibly have a non-trivial topology at the quantum level.

This is also the basic idea behind the (somewhat naive) transactional interpretation of quantum mechanics.


I think you are prejudiced yourself if you say 'I do think superdeterminism is the most natural approach to how the universe works'. This is not meant as criticism, I just want to say that your mind is shaped by the world you perceive, and that world looks deterministic.

Quantum mechanics and its randomness represent a different view on the (microscopic) world, and it does look unnatural to a mind that is shaped by the behavior of the (macroscopic) world. When I studied physics, it took me years to get some intuitive understanding of the quantum mechanical world, because it contradicted my intuitive understanding of the world of classical physics in so many ways.

Personally, I am glad about the randomness in quantum mechanics, because to me it seems that it negates determinism and makes free will possible.

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    $\begingroup$ Is it the last sentence that lead to the downvotes? Downvoters please say why you downvote otherwise no-one learns anything. I don't agree with the last sentence either, but aside from that this is a very good answer to the OP's question, so +1 $\endgroup$ Commented Apr 5, 2014 at 7:39
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    $\begingroup$ So why don't you agree with the last sentence? $\endgroup$
    – FelixM
    Commented Apr 6, 2014 at 14:40
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    $\begingroup$ People disagree with the last sentence because randomness is not freedom - people who think free will is nonsensical upon close inspection think you either choose because of causes or you choose randomly, and neither of those is intuitive "free will". Randomness actually gives us less power over our choices because at least when they're deterministic our mind can be part of the feedback loop that makes up the causes, but randomness takes no feedback. It only feels intuitively freeing as an "out" if your intuition is that a lack of free will is constraining, but it is merely explanatory. $\endgroup$
    – mtraceur
    Commented Apr 19, 2020 at 15:28

Ideas shouldn't be treated as jokes but superdeterminism is false: it is incompatible with the best available theory of knowledge.

First, a digression on the theory of knowledge. Any instance of adaptive complexity has to be explained. For example, as Paley noted, if you find a watch and notice that its parts fit together in such a way that they accurately tell time and that a small change in the arrangements of the parts would destroy its ability to tell time, then some process must have set it up to do that. The information required to set up such a system is knowledge. Philosophers often think of knowledge as being something a person believes but adaptive complexity in an artefact like a watch or the wing of a bird or whatever all require explanation and the explanation has to be pretty similar in each case because what requires explanation is pretty similar. Namely, whatever set up the system has to have started out without that information and then created it. Since it didn't start out with the knowledge, it can't just magically produce the right answer in a single leap, rather it has to produce variations on its current information and then selected among those variations. There has to be some medium in which the information is stored and can be easily accessed, read and used to produce things like watches or butterfly wings or whatever. In the case of artefacts that humans make, the information can be stored in books, computer programs and so on. In the case of biological evolution, the information is stored in genes. But any such information has to be stored somewhere.

If superdeterminism was true then there would have to be some system that can mess about with the human brain in such a way as to gives people specific ideas. It would not be enough to make random changes because such changes would not produce the idea of making a specific measurement. A random change might produce an epileptic fit or brain damage or the brain might just ignore it depending on the kind of change but it won't produce a specific idea. So where is this system? Where does it store the information required to manipulate human experimenters? How did it create that knowledge without anybody noticing?

And suppose that such a system existed and that it had somehow concealed itself from us. Why would it do that when it could cooperate for mutual benefit? Even if it has a much greater information storage capacity or processing speed or whatever, surely it can figure comparative advantage or at least read about it in economics books? Comparative advantage means you should do what you're best at and leave other people to do stuff you're not so good at. So if it can do numerical integration in fifty dimensions without breaking a sweat and it had a reason to do so it could contract out less urgent stuff to humans.

Finally, I think the problem physicists have with quantum mechanics is largely that they fail to take it seriously as a description of how the world works. For example, quantum mechanics is a local theory and the non-locality is a result of trying to force it into a classical shape, see



  • $\begingroup$ " it is incompatible with the best available theory of knowledge. " No. Determinism, technically, is unfalsifiable and cannot be incompatible with any experimental result. (Even apparently random results could be in principle be pre-scripted - the Creator may have pre-scripted every quantum collapse). Unable to downvote as I lack rep. $\endgroup$
    – Ben
    Commented Apr 4, 2014 at 12:36
  • $\begingroup$ There are two problems with your comment. First, I didn't say determinism is false, I said superdeterminism is false. Determinism and superdeterminism are not the same. Superdeterminism claims that somehow an experimental apparatus is correlated with the tests we are going to do. Second, the theory of knowledge is not experimentally testable (see "Logic of Scientific Discovery" by Karl Popper, Chapter 2) so an idea could be incompatible with it and also not be experimentally testable. $\endgroup$
    – alanf
    Commented Apr 4, 2014 at 13:13
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    $\begingroup$ Firstly superdeterminism is determinism of the whole universe including the experimenter. That's the normal use of the word determinism, the super is superfluous. If you want to exclude the experimenter the word is dualism. Secondly your argument why determinism conflicts with the theory of knowledge makes no sense. Nobody says determinism has to be random. $\endgroup$
    – Ben
    Commented Apr 4, 2014 at 14:09
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    $\begingroup$ Superdeterminism is a stronger position than determinism of the whole universe. Superdeterminism specifically states that the experimental apparatus will be correlated in a specific way with the experiment you decide to do: this is required to explain the results of EPR experiments. I didn't say determinism or superdeterminism has to be random: I don't know where you got that idea. $\endgroup$
    – alanf
    Commented Apr 4, 2014 at 14:16

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