Letting Go Of The Reality Ether
    By Johannes Koelman | December 19th 2011 06:52 PM | 49 comments | Print | E-mail | Track Comments
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    I am a Dutchman, currently living in India. Following a PhD in theoretical physics (spin-polarized quantum systems*) I entered a Global Fortune


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    In the previous blog post we familiarized ourselves with a most remarkable device. A device resulting from 20th century science: Albert's chest of drawers. This chest, although presented as a gedanken gadget, is real in the sense that devices with the same characteristics have been built, although none of these take the actual shape of a chest of drawers. In fact, the devices built so far are way smaller in size. They are based not on drawers, but on photons or sub-microscopic particles.

    While scaled-down, their behavior is exactly like that displayed by Albert's chest of drawers. A behavior predicted by the laws of quantum mechanics. So from a quantum theoretical point of view, the behavior of devices like Albert's chest is rather dull and unremarkable. Yet, for us human beings, whose view on reality is biased by sensory perceptions limited to classical physics situations, these devices are weird. For some of us they are weird  beyond belief, for everyone else they are weird enough to force you to redefine your view on reality. 

    In this follow-up post we are going to dive deeper into these matters. You should be able to read and understand this blog post without any knowledge of quantum theory, and without reading the previous post on this subject. I will start by recapping the key features of Albert's drawers. Next, we will discuss some choices of worldview that are compatible with the existence of this remarkable piece of furniture. These are the possible choices that I could come up with. I am keen to hear which choice is yours. And maybe you can offer a choice not listed by me. Let's see where we get.

    Albert's Chest

    Albert's chest, although most spooky when revealing its contents, appears rather unremarkable and featureless from the outside. Three rows, each consisting of three drawers, makes up this piece of furniture. Whenever Albert pulls open a drawer, he is presented with a number of socks. Once a drawer is open, Albert can not open just any remaining drawer. Each drawer opened blocks from opening all drawers not in the same row and all drawers not in the same column. This effectively restricts Albert, each morning when he inspects the chest in search for fresh socks, to the opening of three drawers configured in a horizontal row or in a vertical column. Only the next morning, after his housekeeper is done refilling the chest and resetting the drawers, can Albert again make a new choice of three drawers to open.

    Initially, out of habit, Albert always opens a horizontal row of drawers. He does this without giving much thought to which of the three rows to open. After a few days, he starts noticing a pattern. Whichever row he opens, the three open drawers always contained a total even number of socks. Many days pass by, and Albert never discovers a row not containing an even number. That makes sense: each row containing an even number of socks tells Albert that each morning the chest must be filled with an even number of socks. An observation comfortably compatible with the notion that socks come in pairs.

    One morning, Albert decides to deviate from his fixed ritual, and opens a vertical column of drawers: the three leftmost drawers. Interestingly, this time he observes an odd number of socks distributed over the three opened drawers. The next day, he opens the same leftmost column of drawers, and again observed an odd number of socks. This raises Albert's interest. There must be a correlation between the leftmost drawers of the different rows. The next few mornings Albert checks the same column of drawers, and indeed each time observes an odd number of socks.

    Albert gets curious about the other columns. What correlation will they reveal? The next day he opens the middle column. Again an odd number of socks. The next few days he again checks the middle column. Each time he observes an odd number of socks. 

    Albert is a clever guy, and he now realizes he can predict with certainty that the rightmost column of drawers must behave differently from the two columns already inspected. The rightmost drawers for sure must be correlated such that the socks in them add up to an even number. This is obvious as an odd number of socks in the rightmost drawers, added to the number of socks in the middle column (observed to be odd) and the leftmost column (also observed to be odd) would result in an odd total number of socks in the chest. A contradiction, as he had already observed, based on horizontal drawer openings, that the total number of socks in the chest is always even.

    The next morning he eagerly opens the three rightmost drawers. To his astonishment he observes an odd number of socks. 

    The next few mornings he checks the same rightmost column. Each attempt reveals an odd number of socks. Albert realizes something must have gone wrong. Maybe his housekeeper coincidently changed from filling the chest with an even number of socks to filling it with an odd number of socks, just at the time he switched over from opening horizontal rows to vertical columns?The next morning Albert again opens a horizontal row. An even number of socks stares him in the face. He starts randomly switching between horizontal rows and vertical columns. Horizontal rows always deliver even numbers, vertical columns deliver odd numbers.

    This drives Albert crazy. What is happening? What on earth can explain these observations? The results he is obtaining are logically impossible. "At any given morning if I would open three rows", Albert reasons, "I would end up with an even number of socks."
    "But would I open three columns, I would end up with an odd number of socks."
    "Yet in both cases I would have opened the same nine drawers. This is absolutely impossible!"

    Living With Albert's Chest

    Being presented with Albert's chest, how do you incorporate its remarkable behavior in your views on physical reality? How would you put Albert at ease? I offer you five choices. What choice is yours? I don't claim completeness of the list. In case your choice isn't listed, I am most interested to hear the reasoning that allows you to live with Albert's chest.   

    1) Deny Its Existence
    I will refer to this position as the 'Bill O'Reilly position'. This position is easy to maintain. Just tell these physicists to bugger of.  You don't want to hear their crap and all that quantum nonsense. Quantum theory explaining this fantasy chest of drawers. C'mon, get real. And don't start again with your fairy tales how quantum theory has been tested to eleven decimal places, how it explains all of chemistry, and it has enabled my smartphone. If quantum theory was so damn capable, deliver me a hoover board! 

    Needless to say this position is not very popular with physicists. Yet to a sizable portion of human population this will be a comfortable position. If you don't take this position, you have to find an alternate position that allows you to explain to Albert his observations. No easy task!  

    2) Accept Non-Local Socks
    This position, labelled the 'Deepak Chopra position', is popular in the pop-science literature. Much less so amongst physicists. To come to terms with Albert's chest of drawers, this position allows for non-locality effects, such as socks jumping instantaneously from one drawer into the other at the very moment you open a drawer. Great possibilities await us if this position is correct. "Beam me up, Scotty!"

    Advocates of this position often use more nebulous terms to describe the magic that happens the very moment you open a drawer. You might hear phrases like "Sock potential crystalizes into socks when you open the drawer." Don't let this terminology fool you: something needs to happen faster than light (or should I say 'neutrino') speed, for you to always find the right (even or odd) number of socks in the drawer.  

    You guessed it, physicists are not very fond of superluminal effects and for them that pretty much rules out a 'Deepak Chopra position'. 

    3) Embrace Precognition
    What if Albert's housekeeper can look in the future and predict if Albert will open a row or a column of drawers? With that knowledge she can prepare the drawers accordingly. This 'Nostradamus position' is ironclad. That is: provided everyone who ever operated a chest like Albert's has precognition capabilities and is keen on playing tricks on the opener of the drawers. Yet, none of the researchers who created and operated their own version of Albert's chest would keep a straight when you asked them if their experiments succeeded because of their own precognition capabilities. They would point out that even if they could predict future actions, they would be incapable of preparing their submicroscopic chest accordingly. Their quantum versions of Albert's chest operates by always preparing it in the same way. 

    Of all potential positions, this 'Nostradamus position' is probably the one least popular under physicists. 

    4) Deny Free Will
    This 'Laplace position' starts from the assertion that both Albert as well as his housekeeper are sophisticated, yet deterministic machines.  Many physicists will agree to this statement. 'Laplace position' advocates point out that the course of action of these machines is encoded in the big bang, and for reasons unknown to us, each time they prepare and subsequently open the chest, Albert's and his housekeeper's actions are correlated such that even rows and odd columns result.

    This position takes the sting out of Albert's chest of drawers, but leaves unexplained why rows always come out as even, and columns as odd.  

    5) Avoid The "Would Have Happened If" Fallacy
    Pictures made along the road not taken, don't exist. This summarizes the 'Bohr position' that forms a key element in the Copenhagen interpretation of quantum mechanics. It tells us that any reasoning that includes the outcomes of observations "that could have been made if things would have been different" is suspect. Such reasoning might be convenient in everyday life, it is fundamentally flawed when applied to systems in which quantum effects are prominent. For such systems, the assumption of a reality being associated with observations not made can not be maintained. Observations not made don't exist. Period. 

    This all may sound trivial, but most (if not all) sensible people would agree to the reasoning that if each row in Albert's chest of drawers always results in an even pair of socks, then the full drawer must always contain an even number of socks. Yet, according to the Bohr position this reasoning is fundamentally flawed, given that one can open only one row at a time. As soon as one rejects such reasoning, Albert's chest is no longer enigmatic. 

    Excess Baggage

    As mentioned above: I am interested to hear from you how you manage to live with Albert's chest of drawers. How would you explain to Albert the behavior of his chest of drawers? Have you taken up one of the five positions listed? Are you an O'Reilly, a Chopra, a Nostradamus, a Laplace, or a Bohr? Or did you identify your own unique position? 

    Let me offer you my view. A view that will not come as a surprise to you.

    O'Reilly, Chopra and Nostradamus are 'not my thing'. Also the Laplace position does not provide a viable alternative to me, as it leaves too much to be explained. I see no other choice than to take up the 'Bohr position'. This position is sometimes referred to as an anti-realism position. However, such is a misnomer. The Bohr position does accept a reality, albeit a minimalistic reality that does not extend beyond observations made. This does not cause any problems, as nowhere in physics do we need an extended reality 'underneath the observations'. Assuming such a reality to be 'out there', creates excess baggage. Nature provides us with hard experimental evidence of its dislike for excess baggage. One piece of excess baggage, the luminiferous ether got eliminated from our worldview thanks to Einstein. Another piece of excess baggage, a reality underneath observations, got eliminated despite Einstein. 

    Nature economizes on her baggage. It has eliminated all elements of reality not strictly necessary, but at the same time has provided us with enough to chew on. Or, as Einstein would have put it: "Frugal is the Lord, but malicious He is not."

    What other excess baggage might we be carrying? What else should we let go to make progress in our understanding of the universe?


    The Bohr position still gives no insight into why rows would be even and columns odd. Indeed it seems to me to leave as much unexplained as the Laplace position.

    Johannes Koelman
    The Bohr position allows for Albert's housekeeper to decide how to prepare the chest. Apparently she does such that even rows and odd columns result. 
    The Laplace position leaves no room for any choice, and therefore begs the question why on each attempt do rows come out even, and columns come out odd? Why are these outcomes not more random?

    Thought provoking entry as usual! I'm not sure yet if my personal interpretation is covered here or not, I'll try and post it later on if I still believe it's useful to the conversation.

    However, as a preliminary comment, your reply here confuses me... what do you mean by Albert's housekeeper "deciding how to prepare the chest?"
    Doesn't that once again assume there is a real configuration of the whole chest that yields the results measured by Albert?

    Perhaps it would be helpful to extend the analogy in order to explain what was done to the chest in the first place in order to get this behavior? (or what was done in the lab in order to construct this kind of system?)

    I mean clearly if Albert is unable to perform measurements of all drawers at once, then his housekeeper should follow the same restriction, no? Isn't assuming "she filled the chest" (in the conventional meaning of the word) the same as assuming that the contents of all drawers can be known simultaneously? or at the very least the contents of the complete chest can be known at a given moment by the housekeeper?

    Johannes Koelman
    ... what do you mean by Albert's housekeeper "deciding how to prepare the chest?"
    Doesn't that once again assume there is a real configuration of the whole chest that yields the results measured by Albert?
    There is a 'configuration' that describes the whole chest and that yields the results obtained by Albert, but it takes the shape of a superposition of 'sock amplitudes'. 
    Perhaps it would be helpful to extend the analogy in order to explain what was done to the chest in the first place in order to get this behavior? (or what was done in the lab in order to construct this kind of system?)
    Wish I knew how to create a simple and insightful analogy! The nice thing about focusing on the observation (and ignoring the details of the preparation) is that it allows me to convey the weirdness of quantum reality without requiring a single bit of quantum physics knowledge. As soon as the preparaton of the system enters the picture, we have to dive fully int quantum theory.
    Isn't assuming "she filled the chest"
    I hope I didn't anywhere write "filling the chest", as that would be wrong. She prepares the chest, but doesn't fill it (the latter action implying knowledge of the content of each drawer).
    Proposed solution to this drawer analogy:
    Assume the individual drawers are horizontally rectangular (2" tall by 3" wide by 2" deep).
    Assume Albert's vision is square (limited to 2" tall by 2" wide; unlimited depth).
    From the top of the cabinet, as he looks down, Albert can only see the contents of a 2 by 2 vertical column.
    From the side of the cabinet, as he looks across a row, Albert again sees a 2 by 2 horizontal column, this time appreciating the true width of the drawers, now seeing 1.5 times greater "depth of socks".
    There is now no problem that Albert can't see both at the same time.

    I think your wording of Bohr is perhaps overly strong. It comes down to the interpretation of "It tells us that any reasoning that includes the outcomes of observations "that could have been made if things would have been different" is suspect."

    Having opened the middle row and found an even number of socks, it's perfectly reasonable to believe that if you had opened the top row or the bottom row you would also have found an even number of socks.

    However it is not reasonable to then add those 3 even results together as that presumes that you could have opened all 3 rows at once which by the rules given you can't do.

    Johannes Koelman
    Adding the results of multiple rows is exactly "a reasoning that includes the outcomes of observations that could have been made if ...".
    I agree that it is reasonable to believe that had you opened another row instead of the row you opened, an even row would have resulted. However, the element of reality that you can associate with such 'would-if' expectation is only meaningful in the context of a 'reality' that didn't happen. 

    It is not reasonable to believe that had you been able to open another row next to the row you opened, that an even row would have resulted.
    Gerhard Adam
    Deny Free Will
    Seems like you're trying to force a philosophical position based on a naive determinism.
    Mundus vult decipi
    Johannes Koelman
    What determinism "more advanced than Laplace's" do you have in mind that would allow us to come to terms with Albert's chest?
    Gerhard Adam
    If you want to use Lapace's determinism to argue for a particular ordering of events in the world, then that's fine.  However, conflating it with "free will" is extending such a concept beyond the realm of anything reasonable and attempts to create a false dependency.  "Free will" has nothing to do with it.
    Mundus vult decipi

    I think Johannes is misunderstanding your use of the word "naive" and taking it to be the opposite of "advanced".  In philosophy, "naive" is the posh word for "common-sense" (non-modal, more-or-less direst etc). However, it's still reasonable to call naive determinism "anti-free-will" - not because free-will comes into the physics but because its non-existence is implied by inflexible determinism. The biggest danger is that it all adds to the public perception of physicists as crackpots :)  As a member of the public...

    By the way, "that sentence" had no mistakes :)

    Gerhard Adam
    By the way, "that sentence" had no mistakes :)
    That's part of the nuance isn't it?  It could be interpreted in several ways.
    Mundus vult decipi
    What of the David Deutsch position? How would 'many worlds' explain of the chest?

    Johannes Koelman

    How would 'many worlds' explain of the chest?

    It wouldn't. That is to say: despite the infinite multiplication of our universe (that's a mountain of excess baggage!) it wouldn't do any better than the Laplace determinism 'explanation'. 

    Consider this: maybe there are universes in which the housekeeper fills the chest such that all rows yield even numbers of socks and Albert opens a row, next to universes in which the housekeeper fills the chest such that all columns yield odd numbers of socks and Albert opens a column. But what heppened to the universes in which the housekeeper fills the chest such that all rows yield even numbers of socks and Albert opens a column?  
    That's an important point, Johannes. Many worlds does not explain the quantum behaviour, it merely eliminates the random element - which is the least of our worries.
    "Bohr reasoning" does not explain the relation between objective reality and observation, it rather "explains it away".
    The problem is not if there is a picture of the road not taken, but if it even makes sense to talk about the road itself.

    But if it doesn't, what is physics talking about? Bohr himself, as I know Copenhagen interpretation, used to rely on an arguably meaningless segmentation between "quantum" systems and "classical" systems, and to maintain that the two are complementary in the measure process. But relying on mere observation means that you have no "continuity" among different models, and in my view you have trouble even in using the result of an experiment as the basis for another. Assume you are using the fact that the electric charge of a new particle is -e, in order to tune the experimental setup for measuring its spin: the setup you used for measuring the particle's charge is incompatible with the one you are using now, therefore how can you use that previous result now? Is it not like assuming that "out there" there is a "real" particle, and that it has a definite charge even if you are not measuring it? Agreed, charge is not a dynamic observable, but once you give up objective reality where is the difference?
    In the end, Bohr position cannot help being reduced to "shut up and calculate!", which is just as good as any other fideistic position.

    I do not have a "solution". If I had to answer your question, I probably would argue that our headache comes from spacetime observables, and that for many reasons spacetime is likely (to me at least) not to be fundamental. If spacetime is "emergent", it is inherent to the level where our cognitive processes ("observations") are performed. At this level, you have QM and Albert's drawers. But if spacetime emerges, say, from an underlying discrete "reality" based on things like spin networks or any other, I still wonder if the "spooky actions at a distance" (or entanglement) are a fundamental feature of reality, or rather a feature of how spacetime emerges.

    Johannes Koelman

    Bohr himself, as I know Copenhagen interpretation, used to rely on an arguably meaningless segmentation between "quantum" systems and "classical" systems
    That is correct. However, that artificial segmentation was introduced to justify the wavefunction collapse postulated to occur in measurement. But we don't need that here, and I have not introduced any segmentation.

    Just for clarity: I don't subscribe to the full Copenhagen interpretation, and certainly not to the wavefunction collapse mechanism. I think this holds for a majority of contemporary physicists, many of whom hold a view that is a happy mix between Copenhagen and decoherence.

    I look at such problems from the perspective that "pictures that could have been taken along the road not taken" are a model of reality. I can make a model of the socks in rows and columns I do not look at. But as I have not observed these socks, they are nothing but a model of alternative realities.

    And this model of reality can be wrong, just as every other model.

    The two fundamental axiomas of science are 1) Reality is regular and 2) We can understand this regularity. We know these axiomas can be false (and they most likely are false in their strict form). But these axiomas have served us well. However, they do not say what the regularity of reality actually is. QM is just as good an acceptable regularity for science as Newtons mechanics.

    I most certainly can live with a science that says that only things that are (or can be) observed exist.

    Observation is nothing but a physical cause-effect relation. Only events that can cause consequences are relevant to the universe. What cannot be observed, cannot be a cause to an effect. So the existence of what cannot be observed is irrelevant for the future of any part of the universe, e.g., my future.

    I think that the unwillingness to accept that a reality that cannot be observed cannot be a reality at all, underlies the difficulties of your "paradoxes".

    This unwillingness might be caused by the use of "observed" (tree falling in a wood without being seen nor heard kind of thing). Because, in physics "Observed" means "Caused an effect". The cause and effect are then part of the great causal chain of the universe (no religious or mystic interpretations intended). No need for a watching human eye, just a physical effect. I find it easy to accept that things that cause no effect have no existence. Much harder to accept that things not seen by an experimenter do not exist.

    Johannes Koelman

    No need for a watching human eye, just a physical effect.

    I believe Einstein's question:
    Is the moon there when nobody looks?
    can be answered:
    Yes... as long as at least a single photon/graviton/whateverton interacts with the moon.
    Flippo, there is no record of Bohr maintaining that quantum systems and classical systems are complementary.

    In the previous blog on this topic I outlined my understanding of the situation and also noted there how some people have twisted the Copenhagen interpretation into what it is not.

    How that happens is a psychological study in itself.

    Our Hammock Physicist has pointed to a recent arXiv article titled "The quantum state cannot be interpreted statistically".  I pretty much got lost in the simplest version of the theorem they prove and was not so convinced that the proof translates into the plain English they claim it does.
    Like so many other articles of this type, the authors roll out the abstract machinery and write about "properties" called |0> and |1> or |+> and |->.  Soon the poor reader is racking his brain over terms with tensor products * (superpositions) involving elements like |+>*|-> + i|->*|+> where |-> = |0> - |1> plus normalization factors. It hurts.

    Almost always, what the authors have in mind with such symbolism is something completely dependent on one's reference frame called the direction of a spin axis. They do NOT have in mind more fundamental pre-exiting already established properties like the type of particle, its mass and charge, properties which do NOT  depend on how us new-on-the-scene humans cast our frame of reference. 

    People learn easily that the energy of a particle depends on one's frame of reference. For Bohr, it requires only a logical extension of the dependence of reference frames to see how the direction of a spin axis depends on the last-second settings of one's fame of reference.  What is not so easy to manage, is how the formalism gets complexified with many-body systems. Each additional particle or step adds another tensor product and a multiplying of the number of "dimensions" in which everything plays out. That's extra baggage that is here to stay with quantum mechanics.

    What happens in the mathematics of these many-particle examples is that you have a great many independent "dimensions" going on without anywhere near enough equations to give one a deterministic Laplacian model. On the one hand you have the extra baggage of all of these unresolved spin axes. On the other hand you have fewer equations to nail down which particular axis is going to be manifested, and even if you get that far, there is no individual identity with the particles involved, so anything can be swapped with no observable difference in their grand communal existence. So the question as to whose axis it was is meaningless. Everything is shared.

    > Flippo, there is no record of Bohr maintaining that quantum systems and classical systems are complementary.

    > In the previous blog on this topic I outlined my understanding of the situation and also noted there how some people
    > have twisted the Copenhagen interpretation into what it is not.

    This could have happened also because the CI is a bit elusive in itself, and Bohr, like anyone, changed some of his views over time. Admittedly, I have not read much of the original papers by Bohr, but the Stanford Encyclopedia of Philosophy, for instance, discusses the CI at length, also quoting some passages from Bohr:
    "The necessity of making an extensive use … of the classical concepts, upon which depends ultimately the interpretation of all experience, gave rise to the formulation of the so-called correspondence principle which expresses our endeavours to utilize all the classical concepts by giving them a suitable quantum-theoretical re-interpretation". The article in the SEP goes on to assert that "in the mind of Bohr, the meaning of the classical concepts did not change but their application was restricted. This was the lesson of complementarity".

    In essence: the CI will not stand without the concepts of classical epistemology. And the same source states that for Bohr "The classical concepts—and not classical physics itself—are therefore necessary in any description of physical experience in order to understand what we are doing and to be able to communicate our results".
    Regarding classical systems (i.e. systems for which the classical epistemology can be practically applied), these are required in the measurement process: "The quantum mechanical description of the object differs from the classical description of the measuring apparatus, and this requires that the object and the measuring device should be separated in the description, but the line of separation is not the one between macroscopic instruments and microscopic objects."

    This just to summarize that even under the Copenhagen Interpretation the quantum description of phenomena is not self-sufficient, if we want to include observations and communicable knowledge about observations.

    > They do NOT have in mind more fundamental properties like the type of particle, its mass and charge, properties which do NOT depend on how one casts one's frame of reference.

    This implies that Bohr & C. were indeed realists, at least to the extent to assert that there is something like "objective reality", and that the non-kinematic properties of "real objects" are well defined at all times. This should perhaps entail that spacetime properties are not part of the "objective reality", but are supervenient.

    First, great post again. Your blog is what an internet science blog should be.

    From child i have the feeling that all is deterministic i do not know where i get that but i still have a Laplace's thougth, i reach a point in thinking: if universe is ultimately a closed system it must be deterministic, if its an open system, well, we need to know where the inputs and outputs come from and check again if it isnt a closed system :)

    But the real thing is we dont know yet how to explain Albert's chest.

    Johannes Koelman

    But the real thing is we dont know yet how to explain Albert's chest
    Yes and no:

    Quantum theory does a fantastic job in consistently making the correct predictions. But at the same time Feynman's remark "Nobody understands quantum physics" also holds true...
    Previous commentator's all seem to know what they're talking about, so I'll throw in my naive layman's notion as a contrast ;-)

    Before reading that it was unpopular I was inclined to go with your "Deepak Chopra" explanation - the entire chest encloses a field of "sock probability" and the drawers aren't truly separate at all - so when Albert opens one drawer that modifies the possible arrangement of socks in the remaining drawers.

    You suggest that this sometimes involves FTL information transfer so let's explore that. Imagine if Albert sawed off the rightmost three drawers and took them to a remote location and assume that this in no way changed the "magic" properties of the chest.

    If he still opens all three drawers in a row himself, then there's no problem - he opens the first two drawers, but he cannot get to the remote drawers ahead of any signal that might get transferred between two parts of the chest.

    If however he gets his friend Bill to open the remote drawers there is an apparent problem - he can, it would appear, arrange for Bill to open his drawers at the same time as Albert opens his and for each to write down the results. When they compare the results the "magic" nature of the drawers will appear unaffected - implying that the two parts of the chest must be able to communicate at superluminary speeds.

    I have two possible rejoinders to that (again - possible naivety alert!) :

    1. Is it in fact possible to assume that Albert and Bill can open the drawers "at the same time"? Doesn't Special Relativity imply that "at the same time" is meaningless until a speed of light communication has been completed between them?

    2. Even if Albert and Bill can manage to take measurements at the same time, they would still be limited to speed of light communications when comparing their two sets of notes. We assume that once the physical notes have been made they are immutable, but what if that is just a flawed perception on our part? What if the results are not in fact fixed until they are compared? - after all the paper, ink, Albert, Bill and everything else are all ultimately composed of quantum particles.

    Johannes Koelman
    David -- it is very well possible for Albert to open three drawers within a time interval much shorter than the time required for signals to travel from one drawer to the next. (Albert best positions himself at a large distance in front of the drawer. From large enough distance he can send a signal that reaches the three drawers simultaneously within any required accuracy.) And as long as Albert is not moving with respect to the drawers, there is no issue due to the relativity of simultaneity. 
    Thanks for the reply Johannes.

    OK, I can accept that SR isn't an issue here, but it seems to me there is an aspect of my second proposal at work here.

    In this version of the experiment the picture I have in my head is that Albert has installed three remote controlled drawer-opening devices on three of the drawers and has retreated to a significant distance from both parts of the chest. Let's say that the two parts of the chest are two light-minutes apart and Albert has placed himself one light-minute away from both pieces. He then sends three simultaneous signals to the three devices to have them open at the same time. He also has three telescopes pointing at the drawers so he can observe the results.

    The initial assumption is the drawers open with a definite number of socks and this information is then conveyed to the telescopes by some passing photons in a manner that doesn't require quantum mechanics to explain. If you allow this, you have to assume that the two parts of the chest must be able to send a signal of velocity of at least 2c to make the magic work.

    However, suppose what happens is because of the entanglement of the two parts of the chest, the decoherence doesn't happen at the point the drawers open and instead all the socks remain in superposition. The photons destined for the telescopes then become entangled with the sock probabilities and the decoherence only happens at Albert's location. Does this get rid of the need of FTL communication?

    1     In the Aspect experiments, last-moment decisions were made with observations many meters apart - exactly equivalent to your sawn-up chest - and no moving frames of reference so no problems of simultaneity and no chance of signalling. And still Bell's inequality was confirmed. 

    2     The notes ought to be in a superposition of states immediately after Quantum Bill and Quantum Alfred have chosen the drawers. However superpositions are fragile and the slightest interaction with the environment creates a system that rapidly evolves into one thing or the other.  So for all practical purposes, decoherence has already turned the result into a simple probability distribution before anyone puts pencil to paper. No need to wait for Alfred and Bill to compare notes. The sock-numbers are determined by the chest, not by messages between Alfred and Bill. 

    I think.
    Thanks for the responses.

    You see the problem I have when I'm thinking about this sort of stuff, is I don't think I really understand decoherence. This is probably because I don't have the first clue about the maths, I just try to struggle with the concepts.

    When, for example, an electron hits a detector and we measure its spin, we say that the electron has undergone decoherence and has a definite value of spin - it's either clockwise or anti-clockwise but it's no longer both. But, I often find myself wondering if this is a 'real' effect. After all, the electron didn't really hit a macroscopic detector object as such, it actually had a quantum interaction with one or more of the atoms making up the detector. Is it just that this quantum interaction and any subsequent ones within the material of the detector can just be ignored as they do not affect the result of the experiment?

    What I think I was groping towards in my previous post, is that if you are conducting an entanglement experiment and you are trying to measure the spins of a pair of entangled electrons, maybe you can't ignore the quantum nature of the detectors - maybe you have to continue to trace the quantum interactions right through to the point where you can bring the local and remote parts back together and only then perform a 'measurement'.

    Does this make any sort of sense?

    Decoherence is when the particle or system correlates with the rest of the universe. Anything that causes other particles to depend on which state the system was causes decoherence.

    The Stand-Up Physicist
    I have a sixth approach. My big issue is not with the weirdness of quantum mechanics. That is an outcome of its math. There is also normal, classical physics as you pointed out. The issue for me is how does Nature know to use classical math in some situations, while using quantum math in others? 
    What is classical is ordered in time, even if it is as complicated as Rube Goldberg's self operating napkin:

    A leads to B leads to C leads to D leads to Poly the parrot... That is our everyday experience.

    Quantum math is never ordered in time. Quantum systems have many systems that are so similar we cannot give each player a name. Given a room with 20 cats, old ladies can still tell the difference. No investment of time or money can label an electron. There are stupid big numbers of electrons doing darn similar things at the same time. One might dare say the unnamable electrons are doing their own things in parallel. With all these independent actors, the best you can do is measure what they will do on average. Make an actual measurement and the act does not involve every single independent actor, only one of them, still unnamed.

    Max Tegmark gave a seminar on this subject at Harvard that I attended. He put this question up to a survey. The Bohr interpretation got zero votes. Bohm and Everett were the big vote getters, but those might be too hard to explain in this blog. The fact that an MIT prof was conducting a survey on such a deep subject means we don't understand the issue at this time.

    The Bohr interpretation got zero votes. Bohm and Everett were the big vote getters, but those might be too hard to explain in this blog. The fact that an MIT prof was conducting a survey on such a deep subject means we don't understand the issue at this time.
    Sounds like asking whether they prefer the Air-Water-Earth-Fire theory or the Phlogiston theory!
    How quantum theory can be applied on sound energy particularly anahat sound?

    Deepak Chopra position (Non-local socks seem less weird than all this "moon doesn't exist when you don't look at it")

    Aaagh! I have come to an abrupt realization that certain things that I thought I understood, I do not. I have therefore removed some of my comments (they were not followed up) where they served only to dilute the dialogue with noise. There is no quantum unreality going on. Hope nobody's bothered by this.
    Derek, your post with equations following mine was pure cosmic genius. Now I'm left flapping in the breeze. Our Hammock physicist has a habit of dozing off after making a few comments and not returning to previous blogs. So here I am again, carrying the water. 
    Our dear Hank recently recalled the excellent 3-part article by Don Howard on Quantum's Lesson and Einstein's Dilemma. I had seen it earlier outside of Science 2.0 and had it in mind with my emphasis above on the complex ways that quantum mechanics treats many-body systems. 

    Howard emphasizes how young Einstein, from the beginning of his introduction of the photon as a particle, was uncomfortable as to whether the photons in a gas could be truly independent of each other. This independence is inherent in Wein's Law which works for Black Body Radiation for highly energetic photons. Wein's Law breaks down for low energy photons. How is that possible? Do they loose there mutual independence? Einstein's solution after 20 years of rumination was the introduction of what is now called Bose-Einstein statistics. It was his minimal attempt to sacrifice individual identity and independence and save the appearances for low-energy physics. 

    This history lays the foundation for the modern notion of "asymptotic freedom" in which particles asypmtotically approach a free and indendent state as their energy is raised to extreme levels. 

    Gerhard Adam, a rather prolific and enthusiastic commentator at Science 2.0 has written quite a bit recently as to how freedom, free will and personal independence are phantasma ~ will-o'-the-wisps ~ that can (at best) only faintly exist in the collectives that we call society and culture. However, if everyone did have millions of dollars to spend, unlimited energy and resources, then yes, we would all asymptotically approach Freedom. 

    Low energy particles from photons to slow neutrons to lugubrious humans are curious creatures indeed. Heisenberg's uncertainty relations tell us that they are smeared out in some way. More accurately, what is happening is that their individual identity and independence is being lost as their attributes are intermingled and shared throughout the system. That's why above I called it a grand communal existence. For the correct equations, I defer to Derek.
    If I had a sock draw like that, I would be laughing! Why open anymore draws? If I open the first draw and I know am going horizontal, I would always have a pair of socks to wear and there would be no point in looking in the others.
    There must be a pair of sock in the first draw you open, because albert could change his mind if he found only one sock and go horizonal insead of vertical.
    If Albert find one sock he must know that there is a chance, no matter how slim it is. He will get odd numbers in the horizontal rows.


    >> The Bohr position does accept a reality, albeit a minimalistic reality that does not extend beyond observations made. << That's OK (very reasonable), but there also exist things (“hidden realities”) that we have not - yet - observed (realized). This is true because (at least) in retrospect we know that things we formerly did not know (comprehend) actually were true (existed).

    Thank you for this. It made me think.

    Human beings have difficulty relating to quantum phenomena because their brains are finely tuned to experiences encountered in their everyday lives, which are adequately described by Newton's laws.

    Quantum phenomena require a totally different type of thought, more related to information theory. For example, particle entanglement is best thought of in terms of 'one time pad' encryption in which, in the right conditions, a vital message exists only between two widely separated blocks of information and depends upon both - however far they are apart.

    The model of Albert's chest was a wonderful thought experiment. However, it beguiles the reader into thinking of quantum parameters as if they were life-sized objects such as socks. This is where the fallacy lies, and further explanation is unnecessary.

    Graham Goddard

    For example, particle entanglement is best thought of in terms of 'one time pad' encryption in which, in the right conditions, a vital message exists only between two widely separated blocks of information and depends upon both - however far they are apart.
    Look, the Bell and other inequalities are theorems, not arm-waving speculations. Either Bell and so on have made serious mistakes in the maths or quantum mechanics is false or else it remains true that no local, real, hidden variable theory can account for the facts.  OTPs are strictly real, local variables. Bell's theorem applied to delayed choice experiments as performed by Alain Aspect et all proves that any kind of "answers in advance" is incompatible with QM.  And that would include hiding them away in OTPs, which actually add nothing to the picture at all except another layer of obscurantism.

    Just ask yourself, how does the message get into the block of information when the message is the answer to a question that has not been asked yet? No nonsense about tables of possible questions either - that just gives normal probabilities, not entanglement. Try it.

    ... thinking of quantum parameters as if they were life-sized objects such as socks. This is where the fallacy lies, and further explanation is unnecessary.
    Then you haven't understood the problem. Einstein and Bohr were not fools. Schrodinger realised the problems his equation would cause within days of discovering it and had something like a nervous breakdown as a result. Even if you didn't get the point about Albert's chest, it's a pretty fair bet that "further explanation" is most definitely necessary.

    Perhaps another way is possible. My sympathies lie more with the last option given in the article along the lines that: pictures not made along a road not taken don't exist. My take on this might be termed the Kantian alternative, in that we can accept that we can have no viewpoint from where we can coherently explain both phenomena without introducing a contradiction into our account. We can accept the reality that the observed draws in a horizontal row all have even socks, and we can accept the reality that the vertical columns all have odd numbers of socks but we also accept that there is a reality beyond these two real appearances where the chest exists as a whole, and also outside any observation. 

    Rather than science declare that there is no reality outside the observation this alternative requires science to give up its claims to reductively explain reality. Just because there is no point of view corresponding to an observation of the whole chest (that is non-contradictory) this doesn't mean that there is no whole chest. We can understand the chest either from the standpoint of a vertically aligned observer or a horizontally aligned observer but not both together. The two viewpoints together just don't add up, neither can one claim to be the real viewpoint over the other, yet both are part of the same reality. However I can no more have both observations together than I can sit on my own lap. 

    I think that it is not the idea of an independently existing reality that needs to be jettisoned but the idea of scientific reductionism. Science can explain the real world around us by looking at the underlying level of reality that constitutes it, but it can't claim to reduce the world of appearances to the underlying reality of physics - at least not without becoming self-contradictory in its account. 

    The reason for this is that you can't simultaneously proclaim the reality of the thing observed while denying the reality of the observation, and observer as classical physics did. Neither can you proclaim the reality of the observation while denying the reality of the observer, and possibly the thing observed as tends to be the case in more recent physics. You have to accept the reality of all three: the observer, the observation, and the thing observed. This entails that you cannot reduce any one of these to any other. 

    You have to accept the reality of all three: the observer, the observation, and the thing observed. This entails that you cannot reduce any one of these to any other.
    Absolutely. Johannes has deliberately simplified matters so that the outcomes are definite. The chest no doubt has many interesting properties, the wood it was made off, the date it was made, the magic world it was dragged out of and of course the mysterious round coffee-cup shaped stain that the maid always tut-tuts about. But all we're interested in the fact that it only allows [Albert_Horizontal and Socks_Even] or  [Albert_Vertical and Socks_Odd]. That's a complete description of its quantum side.

    Why it only allows those combinations is another matter. I don't see why one shouldn't ask. At the moment the chest is simply a magic box. Even though the rule "Either [Albert_Horizontal and Socks_Even] or  [Albert_Vertical and Socks_Odd]" fully describes what the chest does, as physicists surely we ought to ask where and what, does the computing; why and how? You are right that it won't be in terms of Albert or socks, but it can't just be a formula in a Book of Spells. 

    My option is "Playing the game according to the rules". First of all, I'm not a scientist, so don't take me too serious. Consider the puzzle at the end of this comment. If you play the game mentioned in a random fashion, your overall result is 25%. Play it according to agreed rules and your common result rises to 50%, despite the fact that your individual guessing doesn't improve. We interrogate nature in a comparable way, according to its rules and get results that seem sometimes counter-intuitive. But we can't smash the chest or open a diagonal of drawers, it's against the rules that nature dictates. So, my option is closest to Bohr's position.

    Here's the puzzle from John Baez, This Week’s Finds in Mathematical Physics (Week 250):

    Here's a puzzle that Jeffrey Bub raised the other night at dinner. It's not hard, but it's still a bit surprising.
    You and your friend each flip a fair coin and then look at it. You can't look at your friend's coin; they can't look at yours. You can't exchange any information while the game is being played, though you can choose a strategy beforehand. Each of you must guess whether the other's coin lands heads up or tails up. Your goal, as a team, is to maximize the chance that you're both correct. What's the best strategy, and what's the probability that you both guess correctly?

    Here's an obvious line of thought.

    Since you don't have any information about your friend's coin flip, it doesn't really matter what you guess. So, you might as well guess "heads". You'll then have a 1/2 chance of being right. Similarly, your friend might as well guess "heads" - or for that matter, "tails". They'll also have a 1/2 chance of being right. So, the chance that you're both right is 1/2 × 1/2 = 1/4. I hope that sounds persuasive - but you can actually do much better!

    Here's the answer to the puzzle.

    An optimal strategy is for you and your friend to each look at your own coin, and then guess that the other coin landed the other way: heads if yours was tails, and tails if yours was heads. With this strategy, the chance you're both correct is 1/2. Or, you can both guess that the other coin landed the same way. This works just as well.
    The point is: you and your friend can do twice as well at this game if you each use the result of your own coin toss to guess the result of the other's coin toss! It seems paradoxical that using this random and completely uncorrelated piece of information - the result of your own coin toss - helps you guess what your friend's coin will do, and vice versa.

    But of course it doesn't. You each still have just a 1/2 chance of guessing the other's coin toss correctly. What the trick accomplishes is correlating your guesses, so you both guess right or both guess wrong together. This improves the chance of winning from 1/2 × 1/2 (the product of two independent probabilities) to 1/2.

    "If you play the game mentioned in a random fashion, your overall result is 25%. Play it according to agreed rules and your common result rises to 50%"

    Cute game puzzle. Playing the game with quantum coins, my result will reach an astonishing 100%. No cheating. Just playing the game according to the rules.

    Oh what an annoying puzzle! I can see the numbers working but I still don't quite "get" it.  I shall be worrying about this until I've got it completely clear.

    More importantly what are the situations in which we could make the same error of overlooking a strategy? And could the strategy be embedded in a system's statistics to bring about a correlation that doesn't affect the individual frequencies.   Scream!

    What if it's just an "is" i.e. like an "unchallenged claim" water 32 degrees Fahrenheit (°F)? If it proves itself to be a constant without an understood "theory" does it really matter? Unwavering curiousity aside.

    does it really matter?
    Not to you apparently. There again there are those to whom music is noise, and poetry is "soppy stuff that rhymes". If it doesn't matter for the simple reason that it is good to understand stuff then there's a defect in your psyche. Never mind, I'm sure you're a very good boxer or driving instructor. You may even be a good technologist, turning the handle on "unchallenged claims" which nature hands you on a plate and kidding yourself you're doing science. 
     Unwavering curiousity aside
    That's rather like saying "Does money really matter? The ability to buy stuff aside."

    As far as I can tell, physics, which used to be about how things work at the most fundamental level, has now become all about NOT asking the very questions it set out to answer - generally backed by monstrous metaphysical claims about what is real and what is not. 
    Well I am glad to see you’re not a condescending prick that talks down to people, like you are so much better than they are. I hope you piss off a boxer Technician who teaches driving on the side and see where your mouth gets you old man. I was actually enjoying this sight until you reminded me what giant asses some scientists can be.

    Good job I'm not a scientist or I might think you were talking about me. And then I would have to get cross.

    Sorry if you are upset but this is an avante-garde "sight" and a modicum of civilised banter goes with the territory. Even a condescending giant-assed prick technician like me knows it would be most unwise to ask a boxer "Does it really matter who wins?" What did you expect?

    I read both of the articles and I have probably 0 knowledge of physics, moreover English is not my native language, which makes it a bit harder to really understand terminology used. Regardless of that, I would like to post my humble thoughts and ideas on the subject, since that is what the author asked :) I read about half the comments so if I repeat someone, please don't take it personally. I would like to bring a little of philosophy into the argument.

    I would like to start by saying that reality is what we create it to be. In part this view can be associated with Bohr position if I understood it correctly. Yet the main difference is that he thought that the observation defines existence and I think that observation itself creates an existence which would have not otherwise be.

    I think I didn't make that much sense, so let's give an example using the drawer. My view is that the first events are totally random (meaning insignificant) until the moment that a pattern is found. Human brain is programmed to make patterns(gestalt psychology). So let us assume that the every drawer he opens, it would contain 2 socks. The pattern would be pretty simple and sooner or later he would start believing that the pattern holds true in every case. This pattern would be very easy to spot and very easy to believe in. No paradox emerges.

    Let's continue with the actual example. The spotted patterns were a little more complicated, yet at one point they are spotted. This is the crucial moment of the phenomena. My point is - at the very instant your brain spots a pattern, reality starts to be created using that pattern. For the lack of other words, I will call it faith. He believes that the sum will be an even number, so he creates it and it unfolds.

    Nevertheless the created reality must abide by some fundamental rules, which we call physics. In this example it might seem that these rules are being twisted or even broken, but upon closer inspection, that does not hold true. As long as there is no way to open all 9 drawers, there can be a perfectly reasonable and sane explanation of why the sum is even or why it is odd. The moment the 9 drawers will be opened at the same time, this created reality will collapse for the simple reason of not following the fundamental rules.

    I realize my view is very far from physics but somehow to me it explains this reasonably. I think this view combines Bohr's correlation between observation and reality and at the same time explains why the sum is always even or always odd.