Wave function collapse demystified

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No, I would not aggree that it is emperically established. Such an interpretation cannot be emperically established. If it was, we wouldn't be sitting here discussing whether it has been emeprically established. I have already laid out the reasons why I do not hold such an intepreation in my earlier posts.

also,

I think what you are asking is, "If I did not observe the pattern on the plate, would it be there anyways, in a real physical sense?"

My answer to that is yes. We have set up the apparatus so that the source interacts with a target.

Please don't bring up Shcrodingers cat. My answer will be the same.

You said, "If I did not observe the pattern on the plate, would it be there anyways, in a real physical sense?" My answer to that is yes. We have set up the apparatus so that the source interacts with a target."

I agree with you on this one. I am not advocating solipcism.

Nice talking to you.

What is your intepretation?

Interpretation of what? I'm sorry, I don't know what exactly you are asking. Please be more specific.

Thanks,

Pankaj

Your interpretaion of QM in regards to Wave Function collapse(or lack thereof.)

It signifies the end of the Cartesian, Newtonian, Kantian Worldview. If we had not needed a formalism such as wave function collapse, then the former three would still apply. It might take a while to let this sink in... but the implications I think would take us towards something like Buddhism. it will be interesting to see how this unfolds in the context of the modern Western culture. Good things are ahead... the self-created prison is destroyed.

This is a good read... http://online.sfsu.edu/~rone/Buddhism/VerhoevenBuddhismScience.htm

"Western interest in Eastern religions, especially Buddhism, historically coincided with the rise of modern science and the corresponding perceived decline of religious orthodoxy in the West. Put simply: Modern science initiated a deep spiritual crisis that led to an unfortunate split between faith and reason--a split yet to be reconciled. Buddhism was seen as an "alternative altar," a bridge that could reunite the estranged worlds of matter and spirit. Thus, to a large extent Buddhism's flowering in the West during the last century came about to satisfy post-Darwinian needs to have religious beliefs grounded in new scientific truth."

Hi Bubba,

You might want to join the discussion here...

http://www.npr.org/blogs/13.7/

"One Universe Too Many? String Theories, The Multiverse And The Future Of Physics." - This is a blog post on the NPR website written by Adam Frank, Astrophysicist, University of Rochester, and a writer for Discover Magazine.

Here's the direct link to the blog post itself... I should have put this web address in the above post.

http://www.npr.org/blogs/13.7/2010/03/one_universe_too_many_string_t.html

"The great extension of our experience in recent years has brought light to the insufficiency of our simple mechanical conceptions and, as a consequence, has shaken the foundation on which the customary interpretation of observation was based." - Neils Bohr

"Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience." - Neils Bohr

"For a parallel to the lesson of atomic theory regarding the limited applicability of such customary idealisations, we must in fact turn to quite other branches of science, such as psychology, or even to that kind of epistemological problems with which already thinkers like Buddha and Lao Tzu have been confronted, when trying to harmonize our position as spectators and actors in the great drama of existence." - Neils Bohr

Ontology is an idealization, phenomenology being all that is possible, as nothing perceived is independent of perception. We are looking for the impossible. Certainly we can derive mathematical relationships to represent the regularity apparent in the sensory display, but when we abstract the sensory display to be self-existent, independent of perception, then we have already entered metaphysics, but in our case entered not as a 'stance' consciously enacted, but unconsciously, forgetfully; thus we are left chasing our own tails. This will certainly lead to vexation and madness, as Buddha stated. This is the fruit of "instrumentalism" in Physics, along with of course technology, but that could also have been achieved without becoming lost.

"Isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems." - Neils Bohr

"There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature..." - Neils Bohr

In deriving mathematical relationships to represent the regularity in the sensory display we have probed ever deeper and encountered the fact that the sensory display evolves via discontinuous change, a flickering which cannot be measured, except as statistical averages. Here too, we have constructed an ontology, but again without being mindful of epistemological issues. Once again, we have fallen into our abstractions and become further lost in chasing a non-existent, an impossible. Here too, there is the acquisition of technology, but also vexation and madness.

In the discontinuous change, we have seen what to us in our unmindful state are a catalogue of paradoxes. We are confronting the fact that our supposed ontological categories 'space', 'time', 'matter/energy' and 'motion' are but phenomena, and not self-existent apart from perception. But this is not at all an actual paradox. It is reality itself, which in our unmindfulness we had failed to recognize from the outset. We might now realize that in fact, we had fallen asleep to ourselves. If we can internalize this insight, then we may get back on the right track. Another mystery beckons, our mysterious self, the perceiver.

We have thought that the evolving sensory display changes according to its own internal dynamics, and this is correct, but an incomplete understanding. If we have realized that the sensory display does not exist apart from perception, then we may also realize that we ought to co-consider the discontinuous change of the sensory display as a self-movement (i.e. not supernatural) of perception. Either view held by itself is a symptom of unmindfulness, they are complementary and inseparable, non-dual. Because we have probed the sensory display with the attitude that it is self-existent we have seen what it is as a paradox. Once we abandon our dualistic stance for the non-dual, then we begin to turn towards another mystery, our unexamined self, the perceiver.

Our attitude then becomes, "Nothing perceived is independent of perception, and perception differs not from the perceiver." In order to extract ourselves from our predicament we will have to examine not just the sensory display, but also the perceiver, directly and not as an objective existent embedded in the evolving sensory display. Due to these insights, the internal path suggested by Buddhism and Yoga should be considered.

The beginning four stanzas of Patanjali's "Yoga Sutra" - 100 CE (My Translation)

1.1 Now, and exposition on Yoga.

1.2 The aim of Yoga is to induce a non-arising of sensory and cognitive qualia within one's own subjectivity.

1.3 Then, the perceiver is both subject and object, dual and non-dual, self-experience becoming self-evidently complete and absolute, noted as the absence of space, time and matter, self-experience going beyond these phenomenal measures.

1.4 Otherwise, there is an identification with what arises within pure subjectivity, an identification with phenomena, with space, time and matter.

This awakening to oneself is sometimes described by way of analogy or simile, but most times as a negation, "neti neti", meaning "it is not describable this way, nor that way". All attempts at description using concepts derived from the phenomenal, sensory display do not fit. One has passed beyond words, images and thoughts. One of the terms for this level of subjective self-experience is "Buddhi", and one who is situated here is known as a Buddha. "Manas" is the term for mind/subjectivity as it is usually experienced, that which was the starting point of the journey, while "Buddhi" is the term for the "farther shore".

The Yoga Sutra lists the preparations that should be undertaken before embarking upon the process of interiorization, including ethical precepts, intellectual and emotional preparation, interiorization techniques and advice on potential conundrums and potentially destabilizing experiences faced along the way. The only postures listed in the text are variations on the seated mediation pose. The proliferation of postures seen today is a very, very recent development, formulated so as to make Yoga accessible and to enable a gradual introduction to the deeper aspects of Yoga while persons accrue health benefits and calmness of mind.

I have always viewed the ''observer-dependancy'' in pretty much the way. Whether you are an electron, or a macroscopic observer, you essentially cut down on all the probabilities to reveal the most likely reality which will be observed. There is nothing special about our measurements, but are quintessentially just as important as quantum observation.

Hello Folks,

I've given this topic a lot of thought, so I figured I should weigh in. I gave a presentation at the 10th Frontiers in Fundamental Physics conference last Fall, about a common basis for non-locality and entropy, which focused on the role played by decoherence. I have to admit to incomplete knowledge of the subject, however. My proceedings paper here did not pass peer-review, but subsequent correspondence with H.D. Zeh, Erich Joos, and others, has given me a pretty clear notion of what was wrong with it (I will revise), and a clearer idea of what decoherence really means. I'll share what I'm fairly certain of here.

First off; the wavefunction does not collapse. The global wavefunction remains a unified and coherent entity which evolves according to Schrödinger's equation. However; its nature is essentially non-local. It is field-like, wave-like, and pervasive. When we introduce a local frame of reference; this reference frame is automatically identified with the material or particle-like nature, by virtue of its locality. Any local observer exists in contrast with the non-local reference frame of the global wavefunction, and induces (or observes) components of that wavefunction to decouple whenever there is an interaction or observation taking place.

Non-local components of the wavefunction that had been global become associated with one or another discrete or observable entity. In the process; what happens is exactly as Dieter says - "various systems (the observed one, the apparatus, the observer, and the environment) get entangled." In Bell's and GHZ experiments, sequential weak measurements are made that effectively break off one component at a time, so that wavefunction components of the particle under study (corresponding to energetic degrees of freedom) are transferred from that entity to the measurement apparatus (until all the degrees of freedom are linked to it). Thus; components preserving the entanglement of one particle with its distant counterpart become dedicated instead to entangling the particle with the measurement system.

So; there is no collapse as such. There is always an evolving wavefunction. But wavefunction components which had been associated with one system become linked with another, leaving the two systems entangled. One of the chief observations of decoherence theory, therefore, is that there are no isolated systems. Instead, entanglement is universal, and the manner in which various sub-systems are entangled evolves over time.

I shall have lots more comments on this topic, especially if someone responds to these. I want to talk about the observer's role as participant. I just skimmed professor Leiter's Journal of Cosmology paper and feel that it bears some commentary relating to this subject - especially as it seems to offer some confirmation of my non-locality and entropy linkage. I thought the new paper explained his ideas much more lucidly than his FQXi contest essay, and I commend him on his clarity.

All the Best,

Jonathan

I have read a lot about the "action at a distance" problem of quantum mechanics -- it was mentioned in Craig Callender's article in the June issue of "Scintific American" magazine. Murray Gell-Mann, in his book "The Quark and the Jaguar" says that "action at adistance is just a misinterpretation of what quantum mechanics says. Any comments?

Does God allow we apply 'natural number' to 'electron' ?Especially , We konw that electron isn't 'Apple' or Richard Feynman's 'clicks' . as he said that all the surprising wisdom of quantum mechanics is hiding in the double slit experiment. I think maybe the field of natural number's application is restricted by nature, e.g. quantum phenomenon. If we do not reconstruct quantum phenomenon on the old picture(natural number) , that could be think as another reality?

Jonathan,

Very interesting. Here is what I think. In nature, what defines a particle is the number of constraint to its freedom i.e quantum numbers(Pauli exclusion). When we observe/interact with it, we are adding one more constraint or quantum number. We don't collapse the wave function; we simply create a new one. I call that "temporary quantization". Any parameter may, under constraint, give rise to a quantum number. Light can travel in any directions. Send it through a slit and you add one quantum number and the output, as direction, is now quantized; diffraction.

Marcel,

Pankaj, I'd like to take your reference to Buddhism a step further and say that what emerged from the South Asian subcontinent 4500 years ago from the Vedas, while obviously not Buddhist but surely has a common thread, was dialectics. That is, something is apprehended in terms of what it is not. It is a process epistemology, where we cannot identify anything except in terms of its "other". A modern rendition of this is Hegel's Phenomenology. It seems that paradoxes, such as the wave-particle duality, arise because people try seeing something in isolation - an either-or thinking. Yet, if one views a wave (a continuum) in terms of particle (discreteness), it starts to make sense. In logic, these are called "duals", and the more we open our eyes, the more we see of them.

Logically it makes sense why they act like particles when observed and waves when not observed. Quantum physics is common sense to anyone who understands the statistics of 2 coin flips and how those statistics are affected by observing the coins. I will explain why the double-slit experiment is the same experiment as something you can do with 2 coins.

In the double-slit experiment, an electron (or other particle/wave) has 2 holes it can go through and then is detected hitting somewhere on the back wall. If it goes through the left hole, statistically it will paint a pattern on the back wall. If it goes through the right hole, it paints a different pattern. It goes through each hole equally often as the other. Most peoples' common sense tells them that statistically it doesn't matter if you know which hole it went through because you can simply average the 2 patterns to get the pattern on the back wall for when it could go through either hole. But its a very different pattern from the average of the left-hole-pattern and right-hole-pattern. Its the same pattern as waves interfering with each other.

Sometimes electrons act like particles and sometimes like waves, but why? I'm going to explain why that happens using common sense instead of equations. The problem is most people don't have all the parts of common sense that they think they have. If you understand the following about 2 coin flips, and you see the patterns created in the double-slit experiments, then you can put them together and understand why electrons (and other particles/waves) sometimes act like particles and sometimes act like waves. Logically, without considering the specific equations of physics, we can know there has to be something like that in physics somewhere. Here's the 2 coin question:

If I flipped 2 coins and at least 1 coin landed heads, then whats the chance both landed heads?

Its 1/3, not 1/4 or 1/2 like most people think, because there are 4 ways 2 coins can land and I only excluded "both tails" when I said "at least 1 coin landed heads" so that leaves 3 possibilities and I asked what is the chance of 1 of those 3 things which happen equally often. Its 1/3. If you still don't believe it, flip 2 coins many times and only ask the question when at least 1 of them lands heads and you will see that 1/3 of the time you ask the question they both land heads. The flaw in Human minds is the need to choose 1 of the coins and say it certainly landed heads, but I did not tell you any specific coin landed heads, and it does change the answer if you take that shortcut.

Most peoples' common sense tells them that since its a symmetric question (between the 2 coins), it can't matter if they start with 1 of the 1-or-2 coins that landed heads, and they think it will get the same answer as not knowing if a specific coin is heads or not. How could it matter? We know at least 1 of the 2 coins landed heads, so I'll just define a variable called coinX=heads and figure out if coinY=heads or coinY=tails. Since coinY was randomly flipped and coins have a 1/2 chance of heads, then the chance both are heads must be 1/2. But then they think about the extra information I told them: at least 1 coin landed heads. That has to change something, so how could coinY be 1/2 chance of heads by itself and with coinX? CoinX and coinY are symmetric. You can trade them in this question and not change the answer. So whatever is true of coinY has to also be true of coinX on average. So maybe the chance both are heads is 1/4. Most people go back and forth between 1/2 and 1/4, but the answer is 1/3 as I explained above.

How is the 2-coin experiment related to the double-slit experiment?

The patterns of the 2 coins (how often they land heads) individually can not always be averaged to get the pattern of both coins together. If at least 1 coin landed heads and you observe a specific coin being heads, then the chance they are both heads is 1/2. If at least 1 coin landed heads but you don't observe any coin, then the chance both are heads is 1/3.

Logically, observing a specific case of something you know has to be true in general, about the 2 coins, produces a different outcome than only knowing its true in general.

The analogy to quantum physics is that when you observe a heads or tails, you collapse the wavefunction (including the other coin you didn't observe) to a particle and the other becomes a different wavefunction, but if you do not observe any heads or tails then its a symmetric wavefunction between the 2 coins.

I can say the same thing about the 2 holes in the double-slit experiment. If I put an electron detector past the left hole, and shoot an electron that could go through either hole, and the detector observes or does not observe an electron, then I get a different pattern (statistically on the back wall of where the electrons hit) than if the detector was not observing the space between the left hole and the back wall. If any part of the possible paths are observed (as containing or not containing an electron), then the other possible paths are affected even though they were not observed. The electron could have gone through both slits or neither or left or right, but still the path on the right is affected by observing the path on the left.

Most quantum physics scientists explain it as the electron going through the left hole, the right hole, both holes simultaneously, or bouncing off the thing containing the 2 holes without going through either hole. If the electron does not go through either hole, they do not count that in any of the patterns on the back wall.

In the 2-coin experiment and double-slit experiment, there are 4 possibilities, and 1 is excluded. I need to label the 2 coins for this, like the left and right holes/slits are labeled "left" and "right". One coin is a nickel and the other is a dime. This is not the only way to pair the 4 possibilities. Its just a way to explain that they are the same problem:

(1) Nickel heads. Dime tails. Electron left slit. Electron not right slit.

(2) Nickel tails. Dime heads. Electron not left slit. Electron right slit.

(3) Both coins heads. Electron goes through both slits.

(4) Both coins tails. Electron bounces off the thing containing the slits and does not go through either. It is not true that "at least 1 coin landed heads" so I don't ask the question or keep statistics of it. The electron didn't hit the back wall so its not part of the statistical patterns.

In the design of both experiments (2-coin and double-slit), cases (3) and (4) are opposites and cases (1) and (2) are symmetric. Exactly 1 of (3) and (4) is not counted in the statistics, but the chance is equally balanced between (1) and (2). It works the same way if you swap the left and right slits or swap the nickel and dime or swap heads and tails or swap going through a slit with not going through a slit. Its practical to test it going through the slit but not practical to test it after it bounces because bouncing is an observation by the thing it bounced on.

Quantum physics is a kind of statistics. So is the 2-coin experiment. In the double-slit experiment and the 2-coin experiment, observing any part changes the outcome statistically. I'm not saying the math of the double-slit experiment is exactly the math of a bayesian-network (which is the kind of statistics used for the 2-coin experiment), but I explained enough similarities that quantum physics scientists should take this seriously.

The double-slit experiment is a variation of the 2-coin experiment that uses continuous angles instead of only heads/tails.

That is why observing things changes the outcome and why electrons/photons/etc act like particles when observed and act like waves when not observed.

If I flipped 2 coins and at least 1 coin landed heads, then whats the chance both landed heads? The most important thing to remember is the question is symmetric between the 2 coins, but observing either of those coins changes the outcome, like observing what goes through either slit changes the outcome.

Quantum physics is common sense to anyone who understands the statistics of 2 coin flips.

Dear Lisi,

You bring up a good question about the role of the observer in quantum mechanics. Answers to all the fundamental questions lie in answer to a simple question, who am I? A fully realized observer becomes one with the absolute or attains singularity. Everything emerges from this state of singularity from with in the absolute. We are all capable of attaining this state if we carefully follow ourselves to that ultimate [link:sridattadev-theoryofeverything.blogspot.com/2010_01_01_archive.html] absoulte truth.[link]

Love,

Sridattadev.