Quantum Interpretation Poll (2011)

[A. Neumaier]

another thing, let me continue the Nick Herbert quote to emphasize that he meant the position doesn't exist in principle.. not because it is fuzzy. Here:

"Quantum theory was developed almost solely by Europeans. J. Robert Oppenheimer, one of the few Americans to have participated in Bohr's Copenhagen Institute, here explicitly denies the existence of the major attributes with which classical physics described in particle's external motion: "If we ask, for instance, whether the position of the electron remains the same, we must say 'no'; if we ask whether the electron's position changes with time, we must say 'no'; if we ask whether the electron is at rest, we must say 'no'; if we ask whether it is in motion, we must say 'no.'"

All but the last statement follow once position is not definite, but the last statement is simply wrong.
You shouldn't take every word of a book written for laymen as scientific gospel.

 

[harrylin]

All but the last statement follow once position is not definite, but the last statement is simply wrong.
You shouldn't take every word of a book written for laymen as scientific gospel.

That was a claim about what Oppenheimer said about his interpretation; the intended audience is irrelevant! Either that claim is true or it is false. "Scientific gospel" has nothing to do with such a citation.

 

[A. Neumaier]

That was a claim about what Oppenheimer said about his interpretation; the intended audience is irrelevant! Either that claim is true or it is false. "Scientific gospel" has nothing to do with such a citation.

Indeed; I didn't realize that it was a quote within a quote. The claim about that Oppenheimer said that might be true or wrong, what he sid is certainly wrong (though it may have been his belief).
One would also need to know the context, in which Oppenheimer said this, and whether he intended to represents the official Copenhagen interpretation (which cannot be seen from what was quoted).

 

[Rap]

What I interepret from Nick Herbert is that those attributes don't exist in space and time at all, but more like outside it. That is. They still exist but outside spacetime. This means that during quantum superposition, position doesn't exist in principle because position requires spacetime. Since the attributes is outside spacetime, then there is nothing in spacetime to contribute to it. Maybe quantum gravity can provide more details of what is occurring.

Or let's go to HUP. When momentum is known to precise degree. Position is so smeared out. It is not because of the limitation in the instrument but because the position isn't there in principle. This is what I mean there is no position at all, akin to HUP.

Shouldn't we constrain our language to avoid classical physics language when speaking of quantum phenomena? In other words, say "the position is indeterminate".

This conveys the facts and nothing more. "fuzzy" is next best, implying indeterminate. "smeared" implies multiple positions at once, which is not testable. The probability density of a measuring a position is smeared, but the position itself is indeterminate. Saying it does not exist implies existence is testable, which it is not.

 

[A. Neumaier]

Shouldn't we constrain our language to avoid classical physics language when speaking of quantum phenomena? In other words, say "the position is indeterminate".

This conveys the facts and nothing more. "fuzzy" is next best, implying indeterminate. "smeared" implies multiple positions at once, which is not testable. The probability density of a measuring a position is smeared, but the position itself is indeterminate. Saying it does not exist implies existence is testable, which it is not.

In this sense, even classical position of real objects were indeterminate. For one cannot give a position more accurately than half the diameter of an object.

 

[Rap]

In this sense, even classical position of real objects were indeterminate. For one cannot give a position more accurately than half the diameter of an object.

Yes, I should have clarified that by "position" I meant a point-like position, such as the center of mass , or center of volume, of an extended object. With this clarification, I believe the above statements apply.

 

[gpran]

I find the poll question very interesting: ‘Which Quantum Interpretation do you think is correct?’. The decision is being obtained in a democratic manner based on assumption that majority may choose the best amongst the available options. The ‘Copenhagen Interpretation’ has got maximum votes followed by the ‘some other deterministic hidden variables’ option. Does it mean that probability of finding the ‘Copenhagen Interpretation’ to be true is more than other interpretations?

Still in my opinion this is the BEST option. So I have voted for it. In any case I am trying to understand issues raised by experts in this poll and also to read material available on all such options as probability of such options being true also exists. This poll has resulted in good collections of all the available options and information about them.

 

[harrylin]

I find the poll question very interesting: ‘Which Quantum Interpretation do you think is correct?’. The decision is being obtained in a democratic manner based on assumption that majority may choose the best amongst the available options. The ‘Copenhagen Interpretation’ has got maximum votes followed by the ‘some other deterministic hidden variables’ option. Does it mean that probability of finding the ‘Copenhagen Interpretation’ to be true is more than other interpretations?

Not really: see my posts 38 and 147. The interpretations have not been grouped in a way that allows that kind of statistics, and I wonder if that is even possible. The only thing that I could conclude from this, is that there is no majority interpretation.

[..] In any case I am trying to understand issues raised by experts in this poll and also to read material available on all such options as probability of such options being true also exists. This poll has resulted in good collections of all the available options and information about them.

Yes indeed!

 

[PTM19]

My "other" interpretation is a work in progress. What i would find most appealing though would have space and time as fundamental entities and all the contents of reality captured by a locally rotated and dilated frame-field defined everywhere.

In this interpretation particles are only an approximation, wavefunctions are more fundamental but also an approximation since separability is only approximate. An electron is best described as a certain pattern of frame-field dilation and rotation extending throughout all of space and time (which describes both the electron itself and its radiation field) and superimposed on the patterns due to all the other entities in the Universe - Dirac equation specifies this pattern in an idealized case. Electron doesn't really have a well-defined position or velocity in itself (any more then a complex wave pattern on the water surface has one), those concepts only become useful in certain circumstances.

For example the pattern responsible for a measured electron when superimposed with the patterns defining fundamental constituents of measuring device (and everything else in the Universe) can be modified in such a way that concepts like velocity and position become useful in classifying behavior of the resulting pattern.

 

[ZealScience]

I find Copenhagen interpretation very wierd, and non-intuitive. Decoherece or the Multiverse can explain the problem with more logic and mathematics, though they are extremely bold and imaginative ideas. But Copenhagen's idea about conciousness is too vague and is very hard to falsify (talking about falsification here), because we can hardly know distinguish whether the observer has conciousness

 

[Rap]

I find Copenhagen interpretation very wierd, and non-intuitive.

By non-intuitive, you mean non-classical. Classical physics is intuitive, because our brains are designed to deal with classical physics problems, because that's what's necessary for our survival. We don't need to intuitively understand QM or relativity to survive, so we might ask QM to make classical sense, but we should not demand it. We should demand logical consistency, however.

Decoherece or the Multiverse can explain the problem with more logic and mathematics, though they are extremely bold and imaginative ideas.

Decoherence does not explain wave function collapse, and Multiverse makes untestable assumptions. Untestable means you can never test the theory. Like the theory that angels push the planets around in their orbits. Maybe they do, but until we can experience them, they are not part of science.

But Copenhagen's idea about conciousness is too vague and is very hard to falsify (talking about falsification here), because we can hardly know distinguish whether the observer has conciousness

I agree, there is vagueness here. However, not every Copenhagenist believes there has to be a conscious observer. Some believe (and I agree) that the wave function is a calculational tool. This means that what you need is a machine that is capable of doing quantum mechanical calculations. That "machine" can be a computer or a human scientist.

 

[ZealScience]

By non-intuitive, you mean non-classical. Classical physics is intuitive, because our brains are designed to deal with classical physics problems, because that's what's necessary for our survival. We don't need to intuitively understand QM or relativity to survive, so we might ask QM to make classical sense, but we should not demand it.

I can understand your argument, but Copenhagen interpret the "famous cat" mostly by conciousness. By non-intuitive, I mean we cannot understand the conciousness interaction part of the explanation. The Multiverse theory clearly described how the wave function "chooses" the result, but not that something we can't even select (which observer is consious? Maybe cat isn't, what about dogs? elephants? Gorilla?).

Decoherence does not explain wave function collapse, and Multiverse makes untestable assumptions. Untestable means you can never test the theory. Like the theory that angels push the planets around in their orbits. Maybe they do, but until we can experience them, they are not part of science.

I think here you mean Occam's Razor or the Anthropic Cosmological Principle. But Occam's Razor isjust a logic operator, by now we cannot observe the other universes by any means, and in current theories there might be no way. But something like String theory can also be "Razored", as no single string or 12 dimensional space can be never observed, but the theory is powerful because it can explain perfectly.

In my understanding, the Decoherence theory states that wave function doesn't necessarily
have to collapse, the theory is good because it says that Schrödinger is always correct, and I can see something similar to Multiverse theory.

PS:Only my personal idea, I'm just a high school student who cannot understand the theory mathematically well, please correct me!

 

[Varon]

I wonder if quantum mechanics is like general relativity in the mathematical sense.

In GR, geodesic motion can't be imagined as actually occurring in real world. In fact. We have a hard time making a one to one corresponce in it. We just accept GR as model of gravity and spacetime.

But how come there are no many interpretations of GR?

Could it be possible that QM is like GR, in that only the mathematical part makes sense and there is just no way to map it into the world one on one?

GR is a model of the world. Is QM also a model of the world?

If so. What is the equivalent of GR in the interpretation as far as this similarity in modelling is concern. Is GR closer to Copenhagen or the Statistical Interpretation. What do you think?
I may not be clear. If so. Pls. clarify this somewhat similarity between them as far as models and mathematics are concerned.

 

[Hurkyl]

In GR, geodesic motion can't be imagined as actually occurring in real world. In fact. We have a hard time making a one to one corresponce in it. We just accept GR as model of gravity and spacetime.

What do you mean by this?

 

[Varon]

What do you mean by this?

One can imagine Gravity as geodesic motion but when you are skydiving.. where is the geodesic... or how do you imagine walking inside the 4D spacetime.. something like that.
GR is a model of the world. Some say it is the world.

Could QM be similar to it. QM is the world. If so, then Many worlds, Bohmian Mechanics and others that want to let us go back to the Newtonian picture is falsified.

 

[Hurkyl]

One can imagine Gravity as geodesic motion but when you are skydiving.. where is the geodesic... or how do you imagine walking inside the 4D spacetime.. something like that.

It's somewhat common to visualize 4 dimensional geometry as a "motion picture". This maps somewhat literally onto imagining space-time.

Actually, this is often done with 3 dimensional geometry too (imagine the unit sphere as a point that expands into the unit circle, then contracts back to a point), and sometimes even in two-dimensions.

In fact, I believe this isn't even just a visualization tool -- this idea (and its generalizations) are a powerful technical device for studying geometry.

 

[Varon]

It's somewhat common to visualize 4 dimensional geometry as a "motion picture". This maps somewhat literally onto imagining space-time.

Actually, this is often done with 3 dimensional geometry too (imagine the unit sphere as a point that expands into the unit circle, then contracts back to a point), and sometimes even in two-dimensions.

In fact, I believe this isn't even just a visualization tool -- this idea (and its generalizations) are a powerful technical device for studying geometry.

I mean.. time... our concept of time... what happens in gravity is you put space and time in a graph and a little curvature here and there and bingo.. you have gravity by adding the EFE...

But then GR is just a model. No one questions how time and space so different can be united in Spacetime. We just treat it as is.. as a priori. This means Newtonian is falsified.

In QM.. maybe we don't need to have Newtonian picture like in Many Worlds and Bohmian Mechanics. Maybe somehow QM has the same weird status as GR..

 

[Fra]

Varon, I think your associations are interesting, and I for one can see several interesting connections, between QM and GR, that also includes "interpretations" of what gravity is. But the topic if shifting so much that it's to find the focus where to comment. After all we are in the QM poll thread :-)

My preferred association; that relates to previous discussions is that gravity and Einsteins equations is not a forcing fundamental law. It's more to be thought of as an equilibrium state (meaning there is also off-equilibrium possibilities). There are several lines of thinking in this direction, where gravity is seen as a kind of entropic force, where the inside view is simple a random action and from perspective you see gravitational attraction. This is interesting discussions but it's speculative and connects also to several unsolved open questions about unification of GR and QM.

About the geodesic: the inside view is that you just do a random walk, or go with the flow as per some rule of minimum resistance. This is why a free falling observer does not infer gravity. It's en external observer, seeing the first observing that infers gravitational interactions.

There is an interesting analogy with QM if you ask me. What hte inside observer "sees" is different from what an external observer sees.

So both in QM and in GR do we have the issue of different observers and how to secure that the views of different observers are "consistent". The main difference is that in GR, we do not have the issue of non-commutative information sets. All there is is classical information. This is I think why the interpretations of GR are not as common.

The interesting thing is that when you try to combine QM and GR all these interpretations of GR and of QM are blurred. Here there are different approaches, wether you think that GR must "somehow" be applied as a constraint on QM/QFT, or wether gravity is "somehow" emergent and thus is not a fixed constraint but evolving (like an equilibrium state).

You can also "interpret" that GR is about geometry, or you can try to release yourself from that abstraction and think that GR is about the relativity of inferred event indexes, in a more information theoretic view. So I think there are interpretations also here. Just like with QM, no one denies the success of GR in the tested domains. But the question is open how to understand it when considering unification of all forces in one coherent abstraction.

/Fredrik

 

[Rap]

There is an interesting analogy with QM if you ask me. What hte inside observer "sees" is different from what an external observer sees.

So both in QM and in GR do we have the issue of different observers and how to secure that the views of different observers are "consistent". The main difference is that in GR, we do not have the issue of non-commutative information sets. All there is is classical information. This is I think why the interpretations of GR are not as common.

I think there is a measurement problem, even in special relativity. Special relativity presents a bunch of particles, world lines, etc. which exist in a "frozen" spacetime, and puts constraints on the spacetime geometry of these world lines. Then comes the "observer" who is forced by his concept of "now" to create a coordinate system separating experience into space and time. To predict your or any other observer's experience, move yourself or the hypothetical observer along their world line at the speed of light. This whole measurement scenario brings in elements outside of special relativity, including the vague idea of "consciousness", similar to the situation in QM. How can there be "motion" when time has been subsumed into spacetime?

Also, what if we carry the "Wigner's friend" problem to SR? We conclude that the observer we are observing has no "choice", their development in time is determined. Do I, the outside observer, have choice then? This is "Laplace's demon" which exists in classical physics as well. Is there a counterfactual definiteness problem in SR, ignoring QM?

 

[rodolfoalvare]

I think what I call "Statistical Quantum Continuum Universe interpretation" SQCUI is more in accordance with what we see, than the many worlds interpretation, what is your opinion?
I wrote it in form of a letter to explain the interpretation to a friend.
I will appreciate any comments. If you are interested the 2 first letters are posted in: https://www.physicsforums.com/showthread.php?p=3299340

QUANTUM LETTERS TO ANAHI #2 Thursday, May 12, 2011
Statistical Quantum Continuum Universe Interpretation. (SQCUI)

Hi Anahi in this letter I will try to explain a little about my Interpretation, of quantum reality.
WHO WE ARE? WHAT WE ARE? WHERE ARE WE?...
Ever since we are little kids, we are broad up to believe that the Universe surrounds us, which is to say that we are immerse into the reality that we perceive.
One of the reasons that the concept of this Statistical Quantum Continuum Universe is so difficult to grasp is because of the misconceptions that this perceived reality give us.
To commence to explain this new approach to see the world in which we live on, we must define a few ideas that even though are common sense, they are the basis of who we are.
Every living organism of certain complexity, has two parts that are common to them; Some way of connecting to the environment (sensors); and some center were this data is use for the benefit of the organism (intelligence) This definition is very broad and you could argue that at certain levels of organization this characteristics bluer out (like in plants and bacteria).
If we think of ourselves is becomes pretty obvious that our connection to the Universe are our senses, (close your eyes, cover your ears and you’ll begin to realize that). Every single thing that you know of, it has arrived to your brain through one of these senses (there is other information that was hardwire to your brain genetically, but we will cover that latter), your brain takes this information, and makes sense (little by little) of your surroundings, in essence sees the Universe that surrounds you.
A cockroach will have the same parts (sensors and intelligence), but is very clear to us that if we see one on the floor next to us, their interpretation of the universe that surrounds it, (molecular markers, vibrations in the ground, pressure waves, etc.) will be very different than ours.
We tend to think that our interpretation of the universe is the correct one (the complete), and the cockroach is limited to their senses and intelligence. But we have to realize that our interpretation is limited by our senses (we cannot see at infrared wavelengths, etc.) and very probably by our intelligence.
Now with this bit of information let’s step back to what we know about Quantum Physics, and let’s see if we can make a little more sense of what we see around us.
Remember the tree in the forest, quantum physics says that the tree does not exist until you see it fallen or standing. In reality it says that the tree exists in the Multiverse (a fancy name for a Universe we don’t see but that it has all the possibilities in it, of all possible Universes) in a superposition of states (standing/fallen being only two of them), but when we get to the forest you only collapse one of them.
Well, to make sense of this “mambo Jambo” we will have to agree in a couple of things:

1. If what we see is one of the possible outcomes of the Multiverse (I like to call this the statistical Universe, the term Multiverse was used by Everett’s and could be misleading in my interpretation), then we are inside this “Multiverse” (Statistical Universe).

2. What we interpret as our reality is only a “slice” of this Multiverse.

3. If we take a very simplistic 2 dimensional plane to model this multiverse, imagine hills and valleys representing the statistical possibilities of an event, and “our reality” as a line that goes on one direction and angles to pass from one possibility or another, the likelihood of an event depending on the fiber of the Multiverse on this region (the laws of physics us we know them), that is to say the possibilities of an event are intrinsic to the laws of physics on this region of the multiverse (the local fiber of the Universe).

4. Our “linea de vivencia” (need a term in English) is really the collapse of the reality that we see, the “thickness” of this line is a representation of how intelligent we are (that is how much can we connect with the Statistical Quantum Continuum Universe).

Up to now you must think that this is like “you say Potato and I say Potairo” but when you start to analyze the Universe under this new interpretation, our whole conception of what this is (the Universe) changes.
Imagine for a moment that the universe is the way I listed above then:

• you are the center of the Universe you are collapsing (interpreting). Even though I see the same Universe, you are seen, is only because we are in the same statistical region of the multiverse, and we have basically the same sensors and intelligence.
• Like we mention before you have to be a superposition of Anahis, because at any given time any of you follows different statistical paths, If the structure of any Anahis in that statistical region ceases to be, (that Anahi dies) the ones that continue interpreting the universe are the only ones left, that is to say YOU WILL NEVER SEE YOUSELF DEAD! (Boggles the mind!, unfortunately this may became like a Quantum religion…)

Note: I know that this sound like total none sense but is absolutely in accordance with the physics that we see, ask any Quantum Physicist.

• Because the Universe we collapse depends of our intelligence and our sensors (or transducers for our sensors, that is to say, a thermal imaging camera permits us to see the infrared radiation translated to our eyes, therefore collapsing that reality).
This is why, when during and experiment we use a detector of spin for example to measure that characteristic of an electron, the electron in our reality (Universe) does NOT exist in any other characteristic but the Spin (in the statistical Universe that electron exists in every possible characteristic there is).
I think this interpretation successfully explains this estrange behavior that we see in quantum mechanics, that has not been satisfactory explained before.

Well Anahi I hope my explanation was good enough to transmit the message, I stop now so that I don’t give you a headache (I know I’m getting one).
In the letter that follow I will explain in detail the four point listed above, also why there is not Grandfather paradox traveling back in time (you never do), if you think you live forever when does it end? If we somehow we get better with time (the only way not to die) then entropy reverses from Chaos to Order? (Nooouu!), if not; how is it possible?
Well baby thank you for been such a patient friend, and I hope I’m a much better Physicist than writer.
Sweet dreams!

 

[Fra]

Also, what if we carry the "Wigner's friend" problem to SR? We conclude that the observer we are observing has no "choice", their development in time is determined. Do I, the outside observer, have choice then?

I'll get back to this later but shortly my take on the symmetries of SR and GR for that matter, which are to be seem as invariants of the equivalence classes of certain groups of observers (generated by poincared or diff transformations) is quite different if I force into the other reasoninig I had on QM.

In my view, poincare and lorentz symmetries are not forcing constraints. They are INFERRED symmetries. The challange for my view, is then to explain the coincidence that several observers seems to indeed infer the SAME symmetry (invariants). Of course it's not conicidence, in my view it's the result of a negotiation, and the status quo of the negotiation (loose analogy to nash equiblirium in game theory; where no player has anytthing to gain by adjsuting it's strategy), is these symmetries. If I am right, I expect (one day) to find a proof for this; from my starting points.

Until I have formal progress, let's just call it my "interpretation" and I have not said too much.

/Fredrik

 

[Varon]

It seems we can only solve the measurement problem or what is the right quantum interpretation after we formulate quantum gravity (or quantum spacetime). Unfortunately.. what if quantum gravity can only be understood after one solve the measurement problem?
Then if we can't solve the measurement problem, then we won't be able to solve quantum gravity.

 

[Fra]

Then if we can't solve the measurement problem, then we won't be able to solve quantum gravity.

You can see this as a problem or a hint on howto solve it.

I think the resolution is that they are related, and that the resolution means we need to understand emergence of observers(matter) and their relations in a single process.

So instead of trying to add gravity to quantum theory, or to find new ways to apply a quantization proceure to Einsteins equations, I think we NEED to reanalyze the foundations of both with fresh thinking. At least it's my considered opinion.

/Fredrik

 

[Ken G]

I voted for "other", because there was no "all of the above." Although I do prefer the ermpiricism of Copenhagen, I find value in using all of the interpretations to help me understand quantum mechanics the way a sculptor would look at their subject from all angles before trying to sculpt it.

 

[yoda jedi]

a possible setback for bohr...

a proposed experimental tests

http://arxiv.org/pdf/1110.0069v2.pdf

 

[Dead Boss]

I never heard of stochastic mechanic before so I looked it up and I instantly fell in love with it. But it looks like it isn't very popular.

 

[al onestone]

You know, personally I'm of the persuasion that the information interpretation (modern copenhagen see Zeilinger 1999), but the options in this pole I find preposterous. "Conciousness Induced Collapse"? Really? 7.52% of the people poled must be nuts.

 

[al onestone]

By the way, you're insistence upon there being some type of a measurement "problem" is outdated. Zeilinger dealt with this problem in three easy steps:

1:What is quantum mechanical IS an amount of information.
or
An elementary system of QM is a bit of information.

2: Information is conservered.

3: When the preparation of a system changes, the amount of info in one representation changes.

With these three rules in place, the conclusion is that any change in preparation must retain the total info of the system, so the system "collapses" or "takes upon the state of the appropriate amount of information".

 

[Ken G]

You know, personally I'm of the persuasion that the information interpretation (modern copenhagen see Zeilinger 1999), but the options in this pole I find preposterous. "Conciousness Induced Collapse"? Really? 7.52% of the people poled must be nuts.

Are you sure information interpretation is all that different from consciousness induced collapse? After all, where is that information in the first place?

With these three rules in place, the conclusion is that any change in preparation must retain the total info of the system, so the system "collapses" or "takes upon the state of the appropriate amount of information".

That sounds like little more than a restatement of the measurement problem, not a resolution of it. It restates the problem in the language of information, which is certainly an interesting way to see the measurement problem from a new angle. But asserting a conservation law is not explanatory, any more than asserting conservation of energy explains F=ma. We can see that F=ma will give rise to the work-energy theorem, so conservation of energy gives us a new angle on F=ma, but it does not explain F=ma, because you then have to answer "why is energy conserved", or in this case, "why information?" In short: you have saying the "measurement problem" reduces to "why is information conserved." A useful contribution to be sure-- but no kind of resolution, just a different way to frame the question. And each interpretation that attempts to resolve the measurement problem will also have a different, and equally contentious, way of saying why information is conserved.

 

[Rap]

You know, personally I'm of the persuasion that the information interpretation (modern copenhagen see Zeilinger 1999), but the options in this pole I find preposterous. "Conciousness Induced Collapse"? Really? 7.52% of the people poled must be nuts.

I sort of agree. The role of measurement is fundamental in QM and an information approach I think is just as fundamental. For example, the Heisenberg uncertainty principle is not, I think, as fundamental as the entropic (information-based) uncertainty principle. The entropic principle is "tighter" than the Heisenberg principle, and the Heisenberg principle can be derived from the entropic principle, but not vice-versa.

I think "Conciousness Induced Collapse" is not totally preposterous. Any entity (robotic or human) which is carrying out QM calculations will modify its description of a system as new information becomes availiable. This modification is the "collapse". The error that some people make is that they believe that the description (e.g. the wave function) is a totally objective entity, like the classical electromagnetic field, and it follows that the collapse must be objective as well. If you have only one observer, that's a distinction without a difference, but if you have, e.g., a second observer observing the first observer, then the two observers will have some disagreements (without being in error) and the less-than-objective nature of the wave function is made more clear.