Is wave-function collapse a REAL incident

[eaglelake]

Scientists/Physicists/Truth-seekers,

I am looking for answers to some questions, which I confess are issues of gobbledygook debates. But this time I want serious and simple answers. So no debates please. My questions are as under:-
Is wave-function collapse a REAL incident or just a back-calculation to justify unexpected results of experiments on particle behaviour? Some say that we end up with absurd results while trying to LOCATE the position of a particle, because in the attempt to do so, we shine light on them which PUSHES them towards the – so called COLLAPSE. Is that the WHOLE TRUTH or is there something mysterious indeed? Does the observer’s KNOWLEDGE in any way PARTICIPATE in what results as a wave function collapse? Is there any direct EVIDENCE that the observer’s knowledge is RESPONSIBLE for the collapse? And also whether there is any precedence where the “wave-function collapse” has occurred even in the ABSENCE of an observer (simply because light was shown on the particle, although NO ONE WAS PEEPING)? I am looking for RATIONAL AND UNBIASED answers. Any help?

As far as I know, there is no experimental evidence for wavefunction collapse. There is no evidence for the existence of the wavefunction in space-time. It is not an observable and we do not measure any of its properties, if it has any. All we know is that the wavefunction is a mathematical construct used to calculate probabilities. It is an element of a Hilbert space. There is no known mechanism that brings about any collapse.

A quantum experiment requires a result that is a measured value of a specified observable. This gives the experiment closure. (Bohr) In the absence of a result, there is no experiment (Wheeler, Peres), and no corresponding wavefunction.

The point is this –a quantum experiment requires a result, not an observer, and not a collapsing wavefunction. Someone suggested that we throw away the word “observer” because of the confusion it engenders. I agree. Quantum events do not require a human observer. No one ever killed a cat by looking at it! There is no mysterious, lethal interaction going on between the human observer and the cat. The observer can choose what experiment to do, but his presence, or absence, does not contribute to the results. It does not matter whether he is “peeping or not”. Nor does an observer have the “power” to collapse any wavefunction. His knowledge is irrelevant.

This, of course, reflects my own bias on the matter.
Best wishes

 

[San K]

As far as I know, there is no experimental evidence for wavefunction collapse. There is no evidence for the existence of the wavefunction in space-time. It is not an observable and we do not measure any of its properties, if it has any. All we know is that the wavefunction is a mathematical construct used to calculate probabilities. It is an element of a Hilbert space. There is no known mechanism that brings about any collapse.

A quantum experiment requires a result that is a measured value of a specified observable. This gives the experiment closure. (Bohr) In the absence of a result, there is no experiment (Wheeler, Peres), and no corresponding wavefunction.

The point is this –a quantum experiment requires a result, not an observer, and not a collapsing wavefunction. Someone suggested that we throw away the word “observer” because of the confusion it engenders. I agree. Quantum events do not require a human observer. No one ever killed a cat by looking at it! There is no mysterious, lethal interaction going on between the human observer and the cat. The observer can choose what experiment to do, but his presence, or absence, does not contribute to the results. It does not matter whether he is “peeping or not”. Nor does an observer have the “power” to collapse any wavefunction. His knowledge is irrelevant.

This, of course, reflects my own bias on the matter.
Best wishes

agreed Eagle. the word "observer" should be replaced with something like "ability to know which way-path information" via instruments etc

this would reduce the number of theories going into consciousness etc

 

[DrChinese]

you could recreate the superposition by erasing the which-way info...prior to the photon striking the screen...this makes it even more interesting/complicated since this means that the photon still carries the ability/information (even after we determined its path and subsequently erased it) to go back to the earlier interference/superimposed state

That's what I was trying to say. The correct application, of course, is to consider the initial setup and final measurement as forming a context. Anything in between is considered "supposition".

 

[dm4b]

Understood, but isn't the quantum eraser thing complicating the simple point I was trying to make (in a long winded sort of way!). At the, as DrChineese called it, final measurement, the superposition is broken, and the wave function is collapsed?

Or, is this incorrect?

 

[dm4b]

Correct. But what I'm saying is that on the surface it looks as though a quantum system is in a definite state, but it can also be considered to be in a superposition too.

I was reading up on some QM interpretations and came across one I was not familar with before, relational QM.

"The essential idea behind relational quantum mechanics, following the precedent of special relativity, is that different observers may give different accounts of the same series of events: for example, to one observer at a given point in time, a system may be in a single, "collapsed" eigenstate, while to another observer at the same time, it may be in a superposition of two or more states. "


Anyhow, jives up with what you're saying to some extent, if I understood you correctly. Not sure if you are coming from the observer dependent viewpoint, such as above, though?

 

[San K]

Now at night we get refractions from the moon or other stars shining through. At a given distance the light still comes through, but, in the deepest darkest cellars and dungeons you cannot see a thing, so, light does not let some of itself penetrate solid matter, but the gamma rays go right through, you can check the wiki pedia for verification.

So, light just carries on...

Does it carry on forever? Well being made of energy, and we know that energy has limits to it's 'output', we can safely say that light does 'collapse'.

the "collapse" you are talking about it is different from wavefunction collapse.

to answer your question, even gamma rays will convert into some kind of energy...however to continue with your logic ...you could say that... energy keeps converting into different kinds of energy and is not destroyed (or in rare cases converts back to matter)...and often ends up as change in entropy of some system it happens to interact with...which again could be argued as different kind of energy...

 

[StevieTNZ]

I guess I don't really know here. If the wave function truly collapes to a single state or projection, seems to me it has to be in Box A and no longer in a superposition. Not that it couldn't go back to being in one, but upon measurement, it's not. Maybe some other folks can add more.

I don't know how this would fit into current QM formulation. The projection postulate is in addition to QM. QM = superpositions, all the time.

 

[yoda jedi]

I was reading up on some QM interpretations and came across one I was not familar with before, relational QM.

"The essential idea behind relational quantum mechanics, following the precedent of special relativity, is that different observers may give different accounts of the same series of events: for example, to one observer at a given point in time, a system may be in a single, "collapsed" eigenstate, while to another observer at the same time, it may be in a superposition of two or more states. "


Anyhow, jives up with what you're saying to some extent, if I understood you correctly. Not sure if you are coming from the observer dependent viewpoint, such as above, though?

that happens because that interpretation is observer dependent, if not, relational interpretation dies.

 

[Jangles]

If you believe in rationality, then you'd immediately consider a wave function collapse to be a false depiction of reality, but one which suffices in the mathematical framework of QM, otherwise bad things would happen. Everything pretty much rests on Heisenberg's principle, so it kind of makes sense that chaos would arise in trying to measure something subatomic from the point of view of QM.

However, the realist would argue that the wave function is not the the whole story, that there is outside information (hidden variable) inaccessible by the experimenter due to precisional limitations. Of course, in my opinion, in reality the wave function collapse is simply hogwash. Do you really think the moon is not there when no one's looking? Do you really think you can cause the death of a cat by peering into a box and seeing if it was dead or alive?

Ahh.. but that is precisely the moon question that Einstein asked of Bohr to which Bohr replied to Einstein "But can you prove the opposite, that the moon exists when it is not viewed" ... with respect to schrodinger's cat ... does the the cat coalesce into "reality" once you lift the lid...super stringed electrons drawn into the world of the viewers reality ...the double slit experiment is still a "mystery" about this very issue of viewers changing the experiment. In that experiment the very fact that any detection equipment is present causes the wave state to not occur and single photon state to become real, take away the detector "the viewer" and the electron wave state presents itself again..

any way some musings about the "dot that was" ..

The dot, the force that started the creation of matter, that started the big bang .. what caused the jolt ... was it ”light”?... our one only constant, always here, always an energy, never ending, nothing exists without it?

The proposition that viewing an experiment somehow alters how electrons behave, that it coalesces the objects into being by these moving photons are viewed into your eye or my eye or all eyes participating in the viewing of the universal photon movie, creates the matter into existence as all of the electrons that are here now, super string bouncing from dimension to dimension, matter forms into existence.

Now let's also look at the whole expanding universe or more to the point, the billions and billions of galaxies moving outwards, the emptiness of space that occupies everything from the galaxies as we know them, to the whole realm of delving into the subatomic, (like each power of 10 of zoom in view) that displays the vast similarities of galaxy to the sub atomic realm and the emptiness of the inner cell is so identical to each stage of vast emptiness (as we move from big to small) to coalescence of matter again and that this is a repeating paradigm, ongoing, never ending, as long as it has light and is viewed/can be viewed. We (humans) have come to the point of our limits (for now) of viewing this thing, this universe we bring into being by our very viewing of it, via Hubble, Earth based massive telescopes, to the outer reaches of stars and galaxies and out to the limits of what our current technology can see, then looking inwards down to the sub microscopic and quantum depths we have currently been able to get to. Both (galactic and quantum) at these outer edges display the same thing, the vastness of emptiness and nothingness that comes to a point of matter at some point as long as there exists the ability that allows us to see it.

Now, let's just say that the dot, the force that started our hypothesised big bang was just some other “viewers” outer reach arm of a viewing instrument from some of their technology that we are either at their galactic or their microscopic end of viewable technology. This start of ours was the photons reaching us (or them) and as such the electrons, super strings forming this reality. Either way this is self perpetuating and constant, never ending “viewer of a viewer of a viewer”…

Whew and if that wasn’t enough..lets not even discuss Super Massive Black Holes…where we now seem to have proof that every galaxy has a super massive black hole at its centre…. what happens when we head down into one of these,cresting the event horizon, where even the light now is snatched out of this Universe into the black hole...but we know energy is never ending …where does the light that the black holes sucks down go to .. does it just start the process of a photon of light creating a dot in a new Universe somewhere and a whole new world of absinth affected quantum philosophers are spawned :)