Why is superdeterminism not the universally accepted explanation of nonlocality?

[zonde]

Bah! I had hoped you will have seen problem the so called "DrChinese challenge" by now. You keep saying:

- give me a dataset with values for simultaneous polarization outcomes at 0, 120 and 240 degrees.

Don't you yet understand that "dataset with simultaneous outcomes" implies an experiment is being performed. Previously I asked you to describe the experiment and I will give you the dataset but you never described the experiment because you can not and nobody can because THERE CAN NEVER BE AN EXPERIMENT WHICH SIMULTANEOUSLY MEASURES TWO PHOTONS AT 3 ANGLES (yes I'm shouting this time).

Therefore failure of anybody to provide your purported dataset is not due to anything other than the fact that the request is nonsensical.

Under local realism cloning of entangled pair is completely valid operation. From that follows that "DrChinese challenge" is applicable to LR models.

While I am proponent of local realism I side with DrChinese in this. Have to say that you can have constructive discussions with DrChinese and I am grateful to him as discussions with him have shaped a lot my own understanding about entanglement problem.

 

[zonde]

I don't normally get involved in these discussions, because ultimately I don't think they are very interesting.
However, I thought I'd add my (usual) comment about experimental QM.

Whereas nearly all "conceptual" (and many practical) experiments are done using light, there are lots of examples of QM experiments that do NOT involve light, angular momentum, polarization, photon detectors etc.

People have performed experiments that are formally exactly analogues to the early (optical) tests of Bell's inequalities. We will probably see the first demonstrations in my own field pretty soon (solid-state QIP, which has nothing to do with optics but the QM formalism is obviously the same)
Hence, any attempt to explain away Bell type experiments by saying that that results are due to the fact we do not understand a specific technical detail of Aspect's original experiments is ultimately futile.

Moreover, note also that we are nowadays often -in practical- terms more concerned about OTHER inequalities that for one reason or another are better to test experimentally. A good example are tests of Legget-type inequalities which can used to test whether or not QM is local.

Can you give one good reason why your position is not subject to confirmation bias?

 

[zonde]

Argh! ThomasT, I told you, the argument does not assume it, it proves it.

I would like to see this. Hmm, my guess would be that you are assuming perfect (anti-)correlations for matching measurement settings.

 

[lugita15]

I would like to see this. Hmm, my guess would be that you are assuming perfect (anti-)correlations for matching measurement settings.

You're right, I am assuming that. But that's a harmless assumption to make. Perfect correlations for matching measurement settings is a consequence of quantum mechanics, so surely if a local realist theory wanted to match the predictions of QM then it would have to have perfect correlations for matching measurement settings. I highly doubt this is what ThomasT is disputing.

(You can, of course, be the fringe type of local realist who has a theory making predictions contrary to QM, but who believes that the only reason the experiments have proven QM right is that they're subject to various flaws, loopholes, and systematic biases. But as Bell tests become more sophisticated, that becomes an increasingly untenable positon, arguably even more so than superdeterminism.)

 

[lugita15]

I didn't get that. How does it prove it?

The whole point of the entire proof is to show that the correlation is linear, but if you want the step that directly leads to it, look at 11: "So 75% of the time, P(-30)=P(0), and 75% of the time P(0)=P(30), so there's no way that P(-30)≠P(30) 75% of the time." But this is pretty much an indisputable step, because it's just math, not physics: if A has a 25% chance of occurring, and B has a 25% chance of occurring, then the probability that at least one of them occurs is at most 50%. It's definitely not possible for A to have a 25% chance of occurring, B to have a 25% chance of occurrring, but a 75% chance that at least one of them occurs.

Presumably you don't disagree with the straightforward math of step 11, so if you reject the conclusion that local realism implies linear correlation you must reject one of the earlier steps.

 

[ThomasT]

The whole point of the entire proof is to show that the correlation is linear, but if you want the step that directly leads to it, look at 11: "So 75% of the time, P(-30)=P(0), and 75% of the time P(0)=P(30), so there's no way that P(-30)≠P(30) 75% of the time." But this is pretty much an indisputable step, because it's just math, not physics: if A has a 25% chance of occurring, and B has a 25% chance of occurring, then the probability that at least one of them occurs is at most 50%. It's definitely not possible for A to have a 25% chance of occurring, B to have a 25% chance of occurrring, but a 75% chance that at least one of them occurs.

Presumably you don't disagree with the straightforward math of step 11, so if you reject the conclusion that local realism implies linear correlation you must reject one of the earlier steps.

I don't understand your notation. For example, what does this mean? "So 75% of the time, P(-30)=P(0), and 75% of the time P(0)=P(30), so there's no way that P(-30)≠P(30) 75% of the time." I'm assuming that P(-30) refers to the probability of coincidental detection while keeping the setting of the A polarizer vertical and offsetting B, to the left, 30 degrees. And that P(30) refers to the probability of coincidental detection while keeping the setting of A vertical and offsetting B, to the right, 30 degrees. If so, then what? I don't get what "75% of the time, P(-30)=P(0)" is supposed to mean. Or what "75% of the time P(0)=P(30)" is supposed to mean.

Do you just mean that the probability of coincidental detection at θ=30 degrees is .75?

I think that's what you mean, so let's go with that. But wait, where did that come from? The polarizers were actually set that way, and you noted the result? Right?

Ok, so we have a probability of coincidental detection at θ=30 of .75 .

Then we set A 30 degrees to the left and B 30 degrees to the right, so now we have a θ of 60 degrees.

So now do we do some runs to see what the rate of coincidental detection at θ=60 degrees is, or do we first assume something about what that rate should be? And if we assume something about what that rate should be, then what's that assumption based on?

 

[lugita15]

ThomasT, I define P(θ) in step 2: "A local realist would say that the photon doesn't just randomly go through or not go through the detector oriented at an angle θ; he would say that each unpolarized photon has its own function P(θ) which is guiding it's behavior: it goes through if P(θ)=1 and it doesn't go through it P(θ)=0."

Let's get right to the heart of the matter. If P(-30)=P(0) and P(0)=P(30), then P(-30) must equal P(30). Thus if P(-30) does not equal P(30), either P(-30)≠P(0) or P(0)≠P(30) (or both). Since there is a 25% error rate whenever there is a thirty degree seperation, we know that the probabilities that P(-30)≠P(0) is 25%, and the probability that P(0)≠P(30) is 25%, and the probability that at least one of these two statements is true is at most 25%+25%=50%. This is not a physical assumption or constraint, it's just math. If event A happens 25% of the time and event B happens 25% of the time, then it's guaranteed that at least 50% of the time neither one of them occurs. If taxis are available in New York City a quarter of the time, and buses are available a quarter of the time, then you know that transportation is available at most 50% of the time. I hope you don't dispute this.

 

[ThomasT]

Since there is a 25% error rate whenever there is a thirty degree seperation, we know that the probabilities that P(-30)≠P(0) is 25%, and the probability that P(0)≠P(30) is 25%, and the probability that at least one of these two statements is true is at most 25%+25%=50%.

That assumes that there's a linear correlation between θ and rate of coincidental detection. But the historically observed and documented behavior of light suggests otherwise. So, where did this assumption come from?

 

[lugita15]

That assumes that there's a linear correlation between θ and rate of coincidental detection. But the historically observed and documented behavior of light suggests otherwise. So, where did this assumption come from?

In step 11 we're not making any assumptions about physics, we're just doing math. If the probability of A is 25% and the probability of B is 25%, then the probability of "A or B" is at most 50%, regardlesss of what A and B are and whether they have anything to do with each other. (Note that "A or B" means at least one of them is true.) That is just a simple mathematical fact. In this case, A is "P(-30)≠P(0)" and B is "P(0)≠P(30)".

As I said, once you've gotten down to step 11 there is no room for argument left, it's just math. If you want to dispute the reasoning you'll have to find an earlier step you disagree with.

 

[Demystifier]

Lugita15, I would like to see your response to my post #127.

 

[jadrian]

By the way i think you should be focusing more on simply c and d which i presume are next to the measurement devices and thus are far apart so they are the "conspirators", because they causally effect the outcome of the measurements by bumping the measurement device into whatever angle. either way a and d or c and d doesn't matter which you consider to be conspiring. There should be nothing conspiratorial about particle d being able to affect particle c and therefore effect a because in the history of the universe, the 10^10^MILLION (who can say how many?) interactions that have taken place, through causality and info exchange, HAVE PREDETERMINED that particle d was going to effect c and therefore a. you say a and d seemingly have nothing to do with each other. THEY HAVE EVERYTHING TO DO WITH EACHOTHER! Simple logical determinism would lead you to the conclusion that d had causal effects on perhaps everything in the universe which ultimately led to the causal outcome of the measurement of a. Not only that but particle d,d1,d2,d3 d infinity not only via cause-effect cause-effect cause-effect...eventually caused c to affect the measurement device for a, but d, d1, d2... caused the experimenters to make the experiment take place in the first place.

i don't believe faster than light info transfer will be an issue here as it is not an issue with normal entanglement, because info transferred at the speed of light will always beat instantaneous info transfer to the punch. Sending light in opposite directions i suspect would be solvable by relativity to give the same conclusion.

dont think of it not particles all knowing about each other, think of it as historical interactions in the universe as spreading a virus to every particle in the entire universe.

its not that every particle knows everything about every other particle. it only knows what has happened to it in the past. but the addition of all current states of particles which are in their current state because of their continuous past history traced back in time will give you the full information in the universe, and having this information, you would be able to predict it. and if you could predict it, that would mean it must be deterministic as a whole. so although we cannot predict the future, and the future isn't predictable, que sera' sera'.

let me clarify this a little bit. the "conspiracy" is simply the result of the history of the causal interactions of ALL the stuff in the universe. the affect of d on a is not just a relationship between of d and a. it is a result of d and a being the part of the sum of everything in the universe. d and a alone would not be able to affect each other if isolated from the history of all interactions in the universes past. it requires all the information in the universe to result in determinism. there is nothing super about it.

if determinism only is effective within lightcones, in which case if outside each others lightcones, a and d could not affect each other just as future events cannot effect the past, as lightcones expand at the speed of light, if there were particle a that had not yet interacted with other particles d1 d2 d-infinity, (i stated before that this should be impossible under a causally governed universe) in this hypothetical case it would be not practically, but THEORETICALLY impossible to do such an experiment or have such nonlocal effects even without an experiment. also, along with photons a and b traveling in opposite directions, so too will plenty of other EFFECTUAL information be propagated to a and d from particles locally and causally effecting the photon source, so it would make a and d effectively the same as being locally deterministic. it would be determined tho in the universe that the lightcones would eventually expand to make a and d react causally therefore deterministically.

 

[lugita15]

Lugita15, I would like to see your response to my post #127.

Oh, I agree wholeheartedly that all of the theories listed in your blog post are viable alternatives (with the exception of Joy Christian), and that they are each in one way or another local, and even that some of them are in one way or another realistic or deterministic. But I think the only alternative out of your list that deserves the appelation "local determinism" is superdeterminism, because it is the only when where the real future states of real particles in our 3-dimensional universe are determined by the real past states and real local interactions of real particlces (whew, I think I put enough qualifications). But yes, there are several viewpoints that someone like backwards causation where some pedant could make the argument that we have a local determinist theory.

Still, it's a worthwhile task to show that local realism (unless it's superdeterministic) using the conventional definiton cannot reproduce the predictions of quantum mechanics.

 

[Demystifier]

Thanks lugita!

 

[jadrian]

let me clarify this a little bit. the "conspiracy" is simply the result of the history of the causal interactions of ALL the stuff in the universe. it is a result of d and a being the part of the sum of everything in the universe. d and a alone would not be able to affect each other if isolated from the history of all interactions in the universes past. it requires all the information in the universe to result in determinism. there is nothing super about it.

if determinism only is effective within lightcones, in which case if outside each others lightcones, a and d could not affect each other just as future events cannot effect the past, as lightcones expand at the speed of light, if there were particle a that had not yet interacted with other particles d1 d2 d-infinity, (i stated before that this should be impossible under a causally governed universe) in this hypothetical case it would be not practically, but THEORETICALLY impossible to do such an experiment or have such nonlocal effects even without an experiment. also, along with photons a and b traveling in opposite directions, so too will plenty of other EFFECTUAL information be propagated to a and d from particles locally and causally effecting the photon source, so it would make a and d effectively the same as being locally deterministic. it would be determined tho in the universe that the lightcones would eventually expand to make a and d react causally therefore deterministically.

but outside our lightcone they will have their own lightcone, in which their determinism will eventually mesh precicely with our determinism leading to the same result that the future of everything is predetermined.

 

[Delta Kilo]

Wouldn't retro-casuality have exactly the same outward appearance as superdeterminism to us? It is certainly more economical (in occam sense) - the 'conspiracy' in each case only has to go back in time as far as needed to achieve correct outcomes as opposed to setting it all up just before big bang. Also laws of physics are time-symmetrical already (:those that counts anyway:).

 

[DrChinese]

if determinism only is effective within lightcones, in which case if outside each others lightcones, a and d could not affect each other just as future events cannot effect the past, as lightcones expand at the speed of light, if there were particle a that had not yet interacted with other particles d1 d2 d-infinity, (i stated before that this should be impossible under a causally governed universe) in this hypothetical case it would be not practically, but THEORETICALLY impossible to do such an experiment or have such nonlocal effects even without an experiment. also, along with photons a and b traveling in opposite directions, so too will plenty of other EFFECTUAL information be propagated to a and d from particles locally and causally effecting the photon source, so it would make a and d effectively the same as being locally deterministic. it would be determined tho in the universe that the lightcones would eventually expand to make a and d react causally therefore deterministically.

Not sure what most of this means, but would like to remind you that a and d have never existed within a common light cone. They were "born" separated and remain separated their entire existence. Yet they were made to be entangled, displaying correlations characteristic of twins. Yet other photons from the same laser sources at the same time, those not made to be entangled, show no such relationship. Further, the decision to entangle is made AFTER the photons are detected and their existence has ended.

And you are trying to say that local deterministic systems naturally display this behavior. You might want to rethink that. Clearly, you need something "super" to explain this. Because your explanation above doesn't explain why some photons show the correlations and others don't. Following your concepts, all of them should evidence Bell state statistics.

 

[lugita15]

And you are trying to say that local deterministic systems naturally display this behavior. You might want to rethink that. Clearly, you need something "super" to explain this. Because your explanation above doesn't explain why some photons show the correlations and others don't. Following your concepts, all of them should evidence Bell state statistics.

DrChinese, you're not a very good conspiracy theorist. Clearly the particles are always entangled with each other, but never display this entanglement unless they know that quantum mechanics would consider them to be entangled, in which case they would each try to act in exactly the right way so that everyone is fooled into thinking quantum mechanics is right. Theories are so easy to make when you abandon things like Occam's razor.

 

[DrChinese]

DrChinese, you're not a very good conspiracy theorist. Clearly the particles are always entangled with each other, but never display this entanglement unless they know that quantum mechanics would consider them to be entangled, in which case they would each try to act in exactly the right way so that everyone is fooled into thinking quantum mechanics is right. Theories are so easy to make when you abandon things like Occam's razor.

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...

 

[zonde]

You're right, I am assuming that. But that's a harmless assumption to make.

Linear relationship between θ and correlation level follows directly from that assumption.
So your statement that "the argument does not assume it, it proves it." ... well, I wouldn't say it's very truthful.

Perfect correlations for matching measurement settings is a consequence of quantum mechanics, so surely if a local realist theory wanted to match the predictions of QM then it would have to have perfect correlations for matching measurement settings. I highly doubt this is what ThomasT is disputing.

Local realistic theory can not reproduce all predictions of QM.

But local realistic theory can try to reproduce QM predictions in domain where they are experimentally verified. And that domain does not include (something close to) perfect correlations for matching measurement settings.

What I think ThomasT is disputing is that given Malus law it is very unreasonable conclusion that there is linear relationship between θ and correlation level.

(You can, of course, be the fringe type of local realist who has a theory making predictions contrary to QM, but who believes that the only reason the experiments have proven QM right is that they're subject to various flaws, loopholes, and systematic biases. But as Bell tests become more sophisticated, that becomes an increasingly untenable positon, arguably even more so than superdeterminism.)

No, I am a type of local realist who tries to make falsifiable local realistic explanations agreeing with QM in a domain where it is experimentally tested.

 

[lugita15]

Linear relationship between θ and correlation level follows directly from that assumption.

You're right, it's a fairly direct route from the assumption that there is perfect correlation at identical polarizer settings to the conclusion that the local realist must believe that the correlation is linear. But ThomasT does not agree with this fairly direct line of reasoning, so I'm trying to convince him that it works.

Local realistic theory can not reproduce all predictions of QM.

If I could persuade ThomasT of this, I'd be done.

But local realistic theory can try to reproduce QM predictions in domain where they are experimentally verified. And that domain does not include (something close to) perfect correlations for matching measurement settings.

But that just has to do with practical experimental limitations. The point I'm arguing with him about is whether someone can believe that all the predictions of quantum mechanics are correct and still believe in (non-superdeterministic) local realism. I'm trying to show that the answer is no, because one experimental prediction of QM is perfect correlations at identical polarizer settings, from which the local realist is forced to believe in a linear correlation relationship, which is in contradiction with another experimental prediction of QM.

What I think ThomasT is disputing is that given Malus law it is very unreasonable conclusion that there is linear relationship between θ and correlation level.

I agree that this is the point of contention, but keep in mind that he thinks a local realist can believe in the nonlinear correlation given by Malus' law, while at the same time also believing that there is perfect correlation at identical settings. I hope you agree that he's wrong on this point.

No, I am a type of local realist who tries to make falsifiable local realistic explanations agreeing with QM in a domain where it is experimentally tested.

Out of curiosity, which experimental loophole of Bell tests do you cling onto? Detector efficiency, communication, freedom of choice, or something else?

 

[jadrian]

Wouldn't retro-casuality have exactly the same outward appearance as superdeterminism to us? It is certainly more economical (in occam sense) - the 'conspiracy' in each case only has to go back in time as far as needed to achieve correct outcomes as opposed to setting it all up just before big bang. Also laws of physics are time-symmetrical already (:those that counts anyway:).

exactly. it shouldn't be called super determinism. it should be called universal causality. if I am the first with this this then i claim it. adrians universal causality

 

[jadrian]

You're right, I am assuming that. But that's a harmless assumption to make. Perfect correlations for matching measurement settings is a consequence of quantum mechanics, so surely if a local realist theory wanted to match the predictions of QM then it would have to have perfect correlations for matching measurement settings. I highly doubt this is what ThomasT is disputing.

(You can, of course, be the fringe type of local realist who has a theory making predictions contrary to QM, but who believes that the only reason the experiments have proven QM right is that they're subject to various flaws, loopholes, and systematic biases. But as Bell tests become more sophisticated, that becomes an increasingly untenable positon, arguably even more so than superdeterminism.)

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

 

[jadrian]

OK, let me give you an example of why you need special initial conditions.

In a deterministic theory, in order to predict the current behavior of any object, you need to know the initial conditions of the object, as well as the deterministic laws of the universe. In Newtonian mechanics, for example, you need to know the positions and velocities of all the particles at time t=0, and then F=ma will tell you the behavior of the particles at all later times.

Now let's consider what a local deterministic explanation of entanglement would look like. Let particles A and B be an entangled pair of photons, which are separated by a great distance and then sent through polarization detectors. We also have particles C and D: C tells the experimenter what angle he should set the polarizer that measures A, and D tells the experimenter how to set the polarizer that measures B. You can think of C and D as neurons in the brains of the experimenters if you like.

Now we find experimentally that the behavior of particle A through its measurement device is strongly correlated with the angle at which B's measurement device is set. And that angle is determined by particle D. So we have a correlation between the behavior of particles A and D.

But particles A and D are separated by such a large distance, so they cannot communicate with each other to coordinate their behavior (unless you have a nonlocal theory like Bohmian mechanics which allow undetectable faster-than-light signalling between particles). So a local determinist has to conclude that A and D are correlated not based on a current relationship between the present states of A and D, which would be impossible, but based on a past relationship of the initial states of A and D.

This is what we mean by special initial conditions: A and D seemingly have nothing to do with each other. After all, it is A and B that were in the entangled state, and yet somehow we have to conclude that the initial conditions of A and D had to be specially set so that a correlation between A and D would be observed in the future. And instead of just D, we can have a large number of particles D1, D2, D3,... which together determine the measurement setting, so the initial state of particle A had to have been set based on the initial states of all these particles. And in the real world, almost all particles in the universe are interacting in some way with almost all other particles, so really the setting of measurement device depends on almost everything in the universe, from which we conclude that the initial conditions of the whole universe were specially set so that the right kind of correlation would be displayed billions of years later between particle A and the measuring device.

This is why superdeterminism is called "conspiratorial". That doesn't mean it's wrong, it just has some issues which make it rather difficult to construct a viable superdeterministic theory, but let me repeat that some potential first steps toward such a theory have already been taken by a few people.

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?

this further seems proof that d and are within the lightcone of the distant past, in which case, the info about what d will do to affect a is predetermined. and nonlocal interactions can only occur within a lightcone or you violate relativity.

 

[jadrian]

also, has it been proven in a lab that time moves forward and isn't frozen or moving backwards? it seems like that is something our intuition has guided us to regard as truth. is there not enough intuition in the world to regard determinism as truth?

 

[jadrian]

Free will is not a necessary component of QM. So I certainly am not rejecting superdeterminism because of that. I reject superdeterminism as an explanation for Bell test results, and I do so for the reasons already stated.

Please bear in mind that there are no candidate superdeterministic theories to reject at this point, so it is a moot point in many ways. The reason I mention the amount of local information to be stored in every particle is because a candidate theory will end up postulating this (in some form or fashion) as a way to explain Bell test results. It is not necessary to assume free choice for measurement settings in any stage of the argument, but you must explain how (i.e. the exact mechanism, since we have no other reason to suspect it exists) the choice is propagated in a superdeterministic candidate.

Not so easy, I assure you. Which is again, the answer to your original question.

then why even call it superdeterminism. there is no conpiracy! its simply causality governed by relativity. call it universal causality. yes it is that easy.

 

[Delta Kilo]

exactly. it should be called super determinism. it should be called universal causality.

No, it is obviously different. superdeterminism does not by itself imply retro-causality. Instead some constraints are placed on the initial conditions which somehow pre-determine the outcomes of all Bell-type experiments (including experimenters' choices) in the future. These initial conditions then evolve forward in time according to laws of physics, causing all these pre-determined outcomes to eventuate.

And the other way around, retro-causality does not mean total super-determinism.

if I am the first with this this then i claim it. adrians universal causality

Too bad, you are at least 25 years late. See http://www.npl.washington.edu/npl/int_rep/tiqm/TI_toc.html. Although I personally don't like it, or rather don't see a point. It does not clarify what measurement apparatus is, where does preferred basis come from and what happens to Shroedinger's cat. It keeps all these thorny questions swept under the carpet.

But then transactional interpretation does not hold a monopoly on advanced wave solutions. After all, MWI is sufficiently weird, those who accept it might as well go for broke and add retro-causality to the mix.

 

[jadrian]

That is just NOT true in any meaningful sense. A particle has only a few observable elements: momentum, position, mass, charge, spin, color, etc. It would be instructive to state specifically how you would know ANY information about the past interactions by knowing these. Suppose the spin is +1. What does that tell you? Or momentum is 1.63 (units ignored) in direction XYZ? Not much history to be gained from that!

No, you need there to be a rich hidden internal structure. One that contains the entire initial conditions of the universe, like DNA. And this DNA would need to be in every particle so they know how to react during Bell tests.

conservation of information. finiteness of information. your quote "what does that tell you" is ambiguous. you are trying to say that information can not adequately explain the universes deterministic evolution? are you serious? do you believe in true randomeness? in order for an electrons position to be truly random, you would have to assume it is moving at infinite speed!

and your dna analogy is completely imcompatable. dna is replicated. information is not.

consider a rack of pool balls getting struck by the cue ball.
now remove all the balls besides the cue ball and the 8 ball. assume the cue ball is particle d and the 8 ball is particle a. without the other balls measured positions on the table, you will not be able to know how the cue ball transferred its info into the 8 ball resulting in the cue ball and 8balls new locations. it requires ALL!, ALL! how many times do i have to say it? of the information of all the other balls location, how much they spun, etc.. to figure out how cause led to effect via determinism in this situation. you keep throwing these things at me as if they are a way around the law of conservation of information. seriously?

 

[DrChinese]

also, has it been proven in a lab that time moves forward and isn't frozen or moving backwards? it seems like that is something our intuition has guided us to regard as truth. is there not enough intuition in the world to regard determinism as truth?

Actually, there are QM interpretations in which time does not flow in the conventional sense. These are called "block world". I happen to be something of a fan of a particular one of these, called Relational Block World.

Relational Blockworld: A Path Integral Based Interpretation of Quantum Field Theory; W.M. Stuckey, Michael Silberstein, Timothy McDevitt (2009)

Although time does not flow, the future is a component in interactions and it is the total setup that is relevant. Although the authors do not call it a time symmetric model per se, I think it qualifies.

For those that are interested:

The above paper is advanced reading, but it is absolutely fascinating in this sense: It is a QM interpretation that makes predictions that are slightly DIFFERENT than standard QM. Incredibly, those predictions seem to account for experimental evidence in favor of an accelerating expansion of the universe WITHOUT adding otherwise new physics.

Easily the most ambitious program I have seen in the few years. So a tip of the hat to the authors, good luck! If anyone wants to discuss, we can start a new thread on that.

 

[jadrian]

Again, I am not claiming that A and D could never have interacted. I am saying that the interaction of A and D would have to have occurred in just the right way so that they would demonstrate nonlocal correlations of just the right kind. And by similar arguments, you would have to conclude that at the beginning of the universe all the particles interacted with each other to set just the right initial states for each particle, so that all the Bell tests which would be performed in the entire history of the universe would get just the right results. That's what's called a conspiracy.

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

 

[DrChinese]

conservation of information. finiteness of information... you keep throwing these things at me as if they are a way around the law of conservation of information. seriously?

Well, golly. Perhaps you can share this with us. What exactly is this law? Can you cite a reference? Does it have anything to do with entropy (which increases to the future, see 2nd law of thermodynamics)?

At any rate, you continue to throw out terms without understanding their meaning. At this point, I, lugita15. Delta Kilo and others have tried to help you with the physics involved. You seem to reject this in favor of speculation which lacks any basic background study or consideration. Your billiard ball example is typical, as it doesn't explain Bell test results and never will.

So good luck, and again I recommend you do some more study in the area.

 

[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?