Why is superdeterminism not the universally accepted explanation of nonlocality?

[jadrian]

Any deterministic theory has causality. But if you have some arbitrary deterministic theory and some arbitrary initial conditions, chances are you won't get the nonlocal correlations necessary to match the results of Bell tests. It's only if you have very specific initial conditions, conditions where the initial state of each particle is set based on the initial states of all other particles, that you get the right kind of nonlocal correlations. That's what makes superdeterminism conspiratorial.

Let me repeat, that does not mean superdeterminism is ruled out, it just means there are hurdles that any superdeterministic theory has got to face.

there is no conspiracy. c is pretty quick. there's no reason why you would need every particle to be causally strung together in the beginning. anything within a lightcone will be causally "connected" very quickly if it wasnt from the start. info spreads and infects through every event very quickly it like i said the cue ball and 8 ball alone will not know how they ended up in their future state. but think of the other balls as all the particles in the universe. each ball doesn't have a conpiratorial copy of what the cue ball did. they only know their own finite amount of info. but if you add up all their info, you will know where both the cue ball and 8 ball are

 

[jadrian]

No, there isn't, but there is something conspiratorial about a particle behaving in just the right way based on the information it has about what other particles are going to do at just the right time and place. Again, particles interacting and transferring information is not regarded as a conspiracy. It's a conspiracy if their interaction induced some very special behavior on their part which leads to a Bell-type nonlocal correlation.

i still have no idea why you say conspiratorial. say historically interacted instead of conspiracy.

bells nonlocal correlations... come up with a billion of them... they are a non issue because they don't violate relativity and are therefore predetermined

 

[jadrian]

To repeat, in order to have Bell-type nonlocal correlations between A and D in a local deterministic theory, we need A and D not only to have interacted in the past, but to have interacted in just the right way so that they would get the right "conspiratorial" initial conditions so that they would display the right kind of nonlocal correlations years later.

just the right way... you make it sound so special... its just causality... determinism does not have to be local, because nonlocality doesn't violate relativity.

 

[jadrian]

Off topic, but Einstein definitely did not find the new radical notions of space and time he came up with intuitive. He was led to SR because he saw that the electrodynamics of moving bodies seemed to possesses a greater degree of symmetry than their conventional description gave them credit for, and so he tried to redo the laws of kinematics so that Maxwell's equations could be shown to conform with the principle of relativity.

then why would he say things say things such as "your math is correct, but your physics is abominable"... einstein was a thinker no doubt about that. he's was the living representation of occams razor. he always believed the laws of nature should be elegant.

and gr owns qm in terms advancing our understanding of our world.

 

[jadrian]

There's no way to know or demonstrate that information, or anything else, is instantaneously transferred from a to b. In fact, instantaneous propagation is a contradiction in terms. If a and b are changing instantaneously, then they're changing simultaneously. And there's nothing in our observations of our world, our universe, that suggests that simultaneous, spacelike separated, changes in a and b imply a causal relationship, or any sort of communication, between a and b. Rather, what this does imply is that a and b are part of a larger system, or that a and b have something in common due to a common cause.

Wrt some formulations (eg., inferred wrt standard QM and explicit wrt dBB interpretation) a and b can be said to change, or are explicitly encoded as changing, simultaneously. So, if one wants to give this some sort of pseudo mechanical meaning, then one might say that information is being instantaneously transferred between a and b. But this isn't really mechanics. It's just an assumption that can't be verified or falsified. Ie., a physically meaningless statement.

That's news to me. I would say that observations indicate that our universe behaves contrary to the notion of block time. That is, it's evolving and transitory. But that certain theoretical constructs/eventualities suggest block time. And, afaik, the theoretical stuff that suggests block time (or that contradicts observation) is more or less routinely disregarded/discarded.

Because it's unwarranted wrt extant observation and mainstream interpretation of theory.

Your title asks why superdeterminsim isn't universally accepted. My guess is that it's because superdeterminism doesn't refer to anything other than determinism. Determinism might not be universally accepted, but I think it's the predominant assumption and starting point wrt virtually all of the physical sciences.

Why not? Are you saying that the assumption of determinism implies action at a distance? Or superluminal propagations?

Ok. So far this is just determinism.

You've arbitrarily assumed a starting point (ie., initial conditions) that isn't influenced by past events. But we can just as well assume that wrt whatever you want to assume as a starting point there are antecedent events, ie., some prior history/conditions.

So, as far as I can tell, superdeterminism is a superfluous term, which actually just refers to determinism.

thats the way i feel. there doesn't need any super conspiracy to allow determinism

 

[Delta Kilo]

bells nonlocal correlations... come up with a billion of them... they are a non issue because they don't violate relativity and are therefore predetermined

Let's say I decided to run Bell test and choose settings for A based on the address book of Acapulco. For the test to produce the results it does while maintaining local realism, something in the past would have to causally influence both the source of entangled photons in the lab and the early settlers of Acapulco in such a way as to establish a very specific relationship between the two. Just having a causal link is not sufficient, it would have to be a very specific 1-to-1 correspondence. Do you have a theory to explain it?

 

[jadrian]

Yes, I reread your reply. I still don't understand what differentiates superdeterminism from determinism. I think Demystifier also tried to explain it one time to me. That didn't do it for me either. Or what Bell or 't Hooft have to say about it. I mean, it just isn't clear to me what the word superdeterminism refers to that's different from what the word determinism refers to.

i agree.
and demystifyers explanation can simply be explained by causality. if that's not enough ill call it supercausality.

below is the explanation that demystifyer tried to explain supdet vs determinism.Originally Posted by ThomasT View Post

In an optical Bell test involving photons entangled in polarization, what does t=0 refer to? The time of emission of an entangled pair? What are the hidden variables? The polarizations of the paired (entangled) photons?

The time t=0 is some hypothetical time in the past when all of the particles in your system, or worse yet all the particles in the universe, communicated with each other and set the initial values of their hidden variables. This include the particles, or the ancestors of the particles, which will eventually end up in the brain of the experimenter, or whatever device he uses to choose the polarizer setting. It also includes the photons, or the ancestors of the photons, which will be measured in the Bell test. Presumably t=0 occurred long before the emission of your entangled pair, because it had to be a time when all of the particles were within a small distance of each other, so that they could communicate without FTL signals (otherwise we would have a nonlocal realist theory).

As to what the hidden variables are, they need to come in two kinds:
1. The particles whose descendants will be the photons in the Bell test will need to have information about whether a photon should go through or not when it encounters the polarizer, knowing in advance what the angle will be.
2. The particles whose descendants will (for instance) be in the brain of the experimenter need to have information about which setting the polarizer should be set to, knowing in advance whether the photon will go through or not.
Originally Posted by ThomasT View Post

But didn't Demystifier indicate, or at least suggest, that the predictions of local superdeterministic models (as opposed to the predictions of local deterministic models) agree with QM? That is, aren't local superdeterministic models enhanced in some way so as to predict (correctly) results that local deterministic models can't? This is what I'm asking about. What makes a model of a particular experimental preparation superdeterministic as opposed to merely deterministic?

Yes, a local superdeterminist model would make the same predictions as quantum mechanics. In a standard local realist model, Bell's inequality would be satisfied, whereas in quantum mechanics it is violated. In a superdeterminist model, the particles would set their initial conditions, knowing in advance what the polarizer settings will be, in order to make Bell's inequality appear violated. In other words, they are conspiring in order to make local determinism seem false when it is really true.

 

[DrChinese]

He posted a question and you replied, immediately equating his (perfectly legitimate) line of thought with religious belief.

Of course, you did answer the question, ...

This was from post 48, so 140 posts later:

I think jadrian has quite proven me correct about it taking on a religious fervor. And I really didn't need to be clairvoyant to see this coming.

 

[jadrian]

Yes, and to drive home to jadrian a point I keep making: A and D could NEVER have interacted in the past because they NEVER existed in a common light cone. They were "born" too far apart! So now you have to modify the physics so that the lasers that created them (which are pulse matched) must contain the information needed to yield the correlations. But that means it is the pulse that does this (since other lasers won't be able to do this). The pulse doesn't contain enough information to cause that to happen. So now you need even more ad hoc hypotheses to make it all work out.

And this is just one setup.

how are a and d not in a common light cone for this experiment to be theoretically carried out? that would violate relativity. and you can't prove that nonlocal interactions could take place outside lightcones even if you want to violate relativity. exercise possibility of lightcones existing before the big bang or perhaps our big bang and we might be in an infinitely large lightcone. a and d never had to interact in the past. what makes you think causality didnt govern the singularity?

 

[jadrian]

To explain such a correlation requires not just that the photons interacted some time in the past, but it also requires that some time in the past the photons interacted with whatever is controlling the polarizer setting (and that could be anything: neurons in the brains of the experimenters, coin flips, dice rolls, the weather in Houston... a wacky experimenter can set the polarizer angles based on just about anything)

thats simply determinism

 

[jadrian]

There is not a scintilla of evidence this is so. Do you not see that you are making up the physics as you go along? This is why I refer to superdeterminism as "ad hoc".

Please note that photons A and D only exist for a short period of time, and have never been in contact with each others' light cones. Yet they are entangled. That entanglement can be made to occur AFTER they cease to exist. (Yes you read this correctly.)

See page 5 especially:
http://arxiv.org/abs/quant-ph/0201134

So none of that is contemplated by your version of superdeterminism. Since by your definition, causes must precede effects. Obviously, if I choose to entangle particles that no longer exist, then I am changing the past (which I am in quantum terms).

And if I am correct, in that you are creating an ad hoc theory, I am sure a modification will be forthcoming in an attempt to keep the idea going. Or perhaps you will say uncle, and realize that some additional research on quantum theory would be beneficial to you. There is a lot of fascinating stuff out there!

By the way, we have all been down similar roads at one point or another. No one is picking on you, and we are not foolishly pro free will. I really don't care if there is free will or not, I still have to make the same decisions every morning either way.

a and d interacting outside each others light cones... still waiting for the result on that experiment. if d could alter the future of a, than that violates relativity. how many times have i said that.

 

[jadrian]

, I am sure a modification will be forthcoming in an attempt to keep the idea going. Or perhaps you will say uncle, and realize that some additional research on quantum theory would be beneficial to you.
I really don't care if there is free will or not, I still have to make the same decisions every morning either way.

you believe free will is possible, and you are telling me to cry uncle? haha bias much?

but tell me how you can effect the past through entangled photons that no longer exist. id like to try it.

 

[jadrian]

That characterization of delayed choice experiments is a controversial one that's not agreed on by everyone. In fact, I think there was an old thread where Demystifier set out to show that almost no major interpretation of quantum mechanics would actually interpret delayed choice as changing the past. But yes, I agree that delayed choice poses some thorny issues for deterministic theories.

choice has no meaning. but what is this delayed thing you are speaking of

 

[jadrian]

Maybe we should consider another point of view on the "conspiracy".

I'm not sure, if this wording is really a good choice. Seemingly very special initial conditions in other areas are well-known, consider the problem of finetuning. So maybe the "conspiracy" is analogous to the situation there.

If the universe started in a very dense state, it seems probable, that all particles are correlated. And since quantum mechanics is necessary to explain the stability of atoms, the special choice of initial conditions could be explainable by the anthropic principle: a world with only classical correlations would not support life.

did you not read my annihilation of the idea of choice and free will that appears to have pissed off 2 free willers in this thread? support life? didnt i clearly define that you cannot from any perspective distinguish ourselves from any laboratory chemical reaction

 

[DrChinese]

a and d interacting outside each others light cones... still waiting for the result on that experiment. if d could alter the future of a, than that violates relativity. how many times have i said that.

I will try to explain, where a=Alice, b=Bob, c=Chris, d=Dale.

Alice and Bob are created in Venice at 10am precisely. Chris and Dale are created in New York precisely (it's just an analogy of an experiment that has actually already been performed and which I referenced earlier)). The polarization of Alice and Dale are immediately checked and they both cease to exist. They never existed in a common region of space time because they were both too far apart.

Bob and Chris are sent to our space station on Mars, where they arrive about 10:03. There, an experimenter decides to entangle them or not. After deciding to entangle, we now have the situation where Alice and Dale were entangled after they were detected, and they never existed in a common area of space time.

Now of course all of the remaining apparati/observers involved were in causal contact with each other previously, no argument about that. What I want to know is by what specific mechanism is it possible for the laser that created Alice and the laser that created Dale supposed to know how to impart a different future result for each, all the while knowing which photons will later be entangled and which ones will not.

If you understand how a laser works you will understand that there is no known distinguishing factor for one photon as compared to another. They are all 100% identical, even as to polarization.

Or maybe it isn't the laser, maybe it is the BBo crystal. But the same question then applies, how does a crystal make it do one thing versus another? By definition, the inputs are identical and the crystal has no active component which is dynamic (changes). So why one result versus another?

So the question is about the mechanism. Where is it? How does it interact with known particles? Maybe we could probe it if you told us what to look for! I think once you go through this exercise a few times, you will realize the stretch you are making. Or you can simply skip my critique and continue to hold onto your (near religious) beliefs, and prove me right as I have said.

 

[jadrian]

I referred to it in the quantum sense of temporal order, just as you might refer to quantum non-locality. Quantum non-locality is not the same as having physically non-local forces. Of course there are interpretations, such as Bohmiam which we already mentioned, that do not involve retrocausality and in fact are deterministic.

On the other hand, I consider any interpretation in which there are elements of time symmetry or block structure to be retrocausal. The point is, time exhibits a degree of freedom. Any way you look at it, in the experiment cited, the decision to entangle is made after the entangled pair is detected. So whatever you choose to call that, it isn't viable under superdeterminism UNLESS jadrian postulates ever more and more new and exotic features to our universe. Which is I think what we are both saying, the ad hoc nature of the theory never ceases to grow.

you seem to have blindly excepted everything in qm, randomness etc, without evver questioning it. you apparently learn from the top down, like a chemist, while i prefer to start at the rock bottom, so ill stick to the einstein line(i know he was wrong in this case, but proving einsteins apprach to science).. "your math is correct, but your physics is abominable"

 

[DrChinese]

If the universe started in a very dense state, it seems probable, that all particles are correlated.

This is inaccurate. The entire universe might be ENTANGLED, but that would NOT make particles properties CORRELATED at all. This is easy to see if you have as few as 4 to 8 particles. There is no correlation at all between any 2 randomly selected. The entangled statistics apply to the group as a whole and constrains the observable permutations but does not say anything about small subsets.

 

[jadrian]

I will try to explain, where a=Alice, b=Bob, c=Chris, d=Dale.

Alice and Bob are created in Venice at 10am precisely. Chris and Dale are created in New York precisely (it's just an analogy of an experiment that has actually already been performed and which I referenced earlier)). The polarization of Alice and Dale are immediately checked and they both cease to exist. They never existed in a common region of space time because they were both too far apart.

Bob and Chris are sent to our space station on Mars, where they arrive about 10:03. There, an experimenter decides to entangle them or not. After deciding to entangle, we now have the situation where Alice and Dale were entangled after they were detected, and they never existed in a common area of space time.

Now of course all of the remaining apparati/observers involved were in causal contact with each other previously, no argument about that. What I want to know is by what specific mechanism is it possible for the laser that created Alice and the laser that created Dale supposed to know how to impart a different future result for each, all the while knowing which photons will later be entangled and which ones will not.

If you understand how a laser works you will understand that there is no known distinguishing factor for one photon as compared to another. They are all 100% identical, even as to polarization.

Or maybe it isn't the laser, maybe it is the BBo crystal. But the same question then applies, how does a crystal make it do one thing versus another? By definition, the inputs are identical and the crystal has no active component which is dynamic (changes). So why one result versus another?

So the question is about the mechanism. Where is it? How does it interact with known particles? Maybe we could probe it if you told us what to look for! I think once you go through this exercise a few times, you will realize the stretch you are making. Or you can simply skip my critique and continue to hold onto your (near religious) beliefs, and prove me right as I have said.

your post doesn't make much sense to me in regards to the identical photons producing different futures. ether way, you are talking talking about entangling photons which no longer exist, that's sounds cool/ridiculous. and at 1005, scatch your head and ask how could anything that had just occurred in the last 5 min, have occurred differently than it just did?

and near religious haha. your the one clinging to the defintetively falsified idea that you are alive and have free will haha

 

[jadrian]

plus it seems to assume implied randomness, something you seem to have just accepted when learning qm, along with free will, the idea that you are alive, santa clause etc without the full implications of randomness hitting you.

if you could clarify what you mean by different futures that would be nice

 

[jadrian]

No, you must now add physics which explains the experimenter's choice of measurement directions as being part of everything, i.e. themselves part of the initial conditions AND causally connected to the results themselves. We don't have anything in current theory that does that. So you have to make it up as you go along.

.

are you saying you don't believe the experimenters actions and measurement directions are part of everything?

 

[jadrian]

haha omg

 

[jadrian]

also if these entangled photons no longer exist in the present, how do they affect anything? and if they did have the ability to affect the past, would it not be possible for them to disrupt the experiment and prevent the experiment from happening, negating their own creation? paradox?

 

[jadrian]

Yes, "the Universe cheats" is actually a pretty good description of superdeterminismBell's theorem implies that any local deterministic theory which reproduces the predictions of quantum mechanics must be superdeterministic. But you can have a nonlocal deterministic theory like Bohmian mechanics, and that need not be superdeterministic. But you're right that Bell's theorem does not disprove superdeterminism.
Science does not accept all theories until they are rejected by experiments. In science we do not accept claims unless we have good experimental reason to do so. Currently we have a nondeterministic theory, quantum mechanics, which is extremely accurate in its predictions. Thus the burden of proof is on the determinist to demonstrate his thesis, not on the scientific community to disprove it.

define accuracy or precision for that matter. what we may think of as precise may be grossly imprecise compared to absolute predictive ability. 8 decimal places sounds accurate to us compared to our everyday measurements, just as cosmological decades are something our minds are not tuned to percieving.

 

[lugita15]

if you could match experimental settings, which you cant, then you wouldn't have correlations, youu would have the exact same result.

But having the exact same result just means 100% correlation. And what makes you think you can't exactly match polarizer settings?

 

[lugita15]

also with d could have this instantaneous effect on a as i could decide to shoot my self in the head or not depending on the angle, wouldn't this be faster than light info tranfer, violating relativity?

I think I told you earlier that the same theory of quantum mechanics which tells us about the nonlocality of entanglement also tells us that this nonlocality cannot be used by humans to transfer information faster than light. If you have an entangled pair of photons and you send each one through a polarizer oriented at the same angle, then each experimenter cannot find out on his own locally about the effect of the nonlocality. It's only by comparing the results of the two photons that we can see the nonlocal correlation. And one experimenter cannot find out the results the other experimenter found without communicating with him, and presumably that cannot be done faster than the speed of light.

 

[lugita15]

they don't have to interact in a special way, what makes you think that. we've already been through your abcd experiment and I've shown its irrellevant to universal causality leading to determinism without any special initial conditions. there is no conspiracy unless you NEGLECT the histories of the pool balls besides the cue ball and 8 ball as i described above

jadrian, just try to set up a scenario in which pool balls, just through the local interactions of hitting each other and without any special initial conditions, can produce the right kind of nonlocal correlation required to pass a Bell test. If you're successful, you can give Nobel laureate Gerard t'Hooft a run for his money, because all he's trying to do is create a local determinist theory WITH special initial conditions that agrees with QM, and he's finding it really difficult.

 

[lugita15]

just the right way... you make it sound so special... its just causality... determinism does not have to be local, because nonlocality doesn't violate relativity.

OK, if you're willing to have a nonlocal deterministic theory, then you don't need any conspiratorial elements like special initial conditions. You can be a Bohmian like Demystifier. Bohmians believe that there are nonlocal interactions between particles, but this do not violate relativity, because it can proven that these nonlocal interactions cannot be used by humans to transfer information faster than light. And generally Bohmians don't believe in free will, just like you.

 

[lugita15]

i agree.
and demystifyers explanation can simply be explained by causality. if that's not enough ill call it supercausality.

below is the explanation that demystifyer tried to explain supdet vs determinism.

For the record, the explanation of superdeterminism you're quoting is mine, not Demystifier's.

 

[jadrian]

I was trying (unsuccessfully it seems ) to force jadrian to realize that the laser source must be imparting the hidden (it is a conspiracy, so something should be hidden) information to the photon at the time it is created. But that the same laser source only imparts the correct information for perfect correlations to a small subset of photons, just those that some spacelike-separated robotic observer will eventually mark as being in a Bell state (and no others).

So that means the laser source ALSO knows enough about that robotic observer to know which ones will be seen to be entangled (since the robotic observer makes that decision at a later time).

Oh, and the laser source ALSO knows which direction the polarizers for a and d are set in. That, of course, so that the Bell relationship holds. Of course, those polarizers can be set by 2 more robotic observers using let's say, 2 different random algorithms. Which of course the laser source knows this too.

Of course, there are actually 2 separate laser sources which are phase locked together. So both knows what the other is going to do. On the other hand, the photons don't even need to exist at the same time any more than they need to exist in the same location, so that the appearance of entanglement crosses both space and time if we want to set it up that way.

And so, as you say, does the theory continue on without the benefit of Occam...

what is all this "the laser knows" the laser doesn't know anything. reality isn't what is. reality is what occurs. by the way i don't make all these assumptions. you do. my logic of nonlocality being fine within a lightcone seems pretty solid as it doesn't piss of einstein. youre repeated statements that a and d are outside each others lightcones violates relativity if the entanglement has effects on its local environment. occams on my side by a long way fyi.

 

[DrChinese]

if you could clarify what you mean by different futures that would be nice

There are many photons being created by each laser source. Some Alice/Dale pairs will be entangled, but some will not. Now the question is: how does the laser impart this distinction on the correct pairs and not any others? (The distinction being to act entangled and yield Bell state statistics.)

So 2 things need to be explained: a) how does the lasers know which photons to pair up as "acting entangled" (since the entangled state is not real in your book, just an illusion); and how does it mark them when they are otherwise identical to "not acting entangled" photons.

What is the mechanism or rule? A scientist will normally postulate one, and will then try to find ways to support that assumption or to disprove it. So this is what I am asking you to do. And for the Nth time, I don't know if there is free will or not, that is not an important issue for me and certainly doesn't color my perspective in any way.