Quantum Mechanics - Schools of interpretation

[skakos]

Quantum mechanics (QM) is a field with strong controversy on interpretation matters. It could be said that philosophy has found a new friend in QM. Never before did philosophy matter most in a scientific field. There are currently more than 14 different interpretation schools on the (at leat) weird/ paradoxical results of quantum experiments, including superspotition, non-locality and the wave function collapse.

I personally feel closer to the interpretation of Wigner according to whom the CONSCIOUS observer is the key for the collapse of the wave function. According to him, we are the ones who (literally) formulate "reality".



In the double-slit experiment, the electrons do interfere with other particles (e.g. on the detectors used) or with various fields (e.g. the gravity field). However non of these interactions suffice for the electron's wavefunction to collapse. We continue to get interference patterns until an observer... observes the experiment.

What is your opinion on that?
Do you think that a conscious observer is what really matters in the wavefunction collapse?

[tillingborn]

What is your opinion on that?
Do you think that a conscious observer is what really matters in the wavefunction collapse?

It's a lovely idea, but as Carl Sagan said, "Extraordinary claims require extraordinary evidence".
As far as I can tell, it is only ever as 'packets of energy' that photons, electrons and whatnot are detected. The wave function is inferred from the gap between emission and absorption of 'particles', for example in the double slit experiment, but no one has ever seen it directly. That being so, is it not more the case that a conscious observer simply isn't going to see a wave function that isn't collapsed?

[Arising_uk]

...
What is your opinion on that?
Do you think that a conscious observer is what really matters in the wavefunction collapse?

No, because you can get results like these by using purely mechanical detectors at the slits with no conscious observer in attendance.

[skakos]

...
What is your opinion on that?
Do you think that a conscious observer is what really matters in the wavefunction collapse?

No, because you can get results like these by using purely mechanical detectors at the slits with no conscious observer in attendance.

For example?

[Ginkgo]

What is your opinion on that?
Do you think that a conscious observer is what really matters in the wavefunction collapse?

The experiment shows that it does matter. That's the Copenhagen interpretation.

[Cerveny]

Schrodinger equation for stationary states tells us that we can "measure" only values corresponding to eigenfunction of appropriate (math) operator. if the normalized square of wave function (solution of the Schrödinger equation) is accepting as a probability of the occurrence of certain status, then Schrodinger actually says that it is permissible only "measurement" (better: "interaction" - each measurement in the quantum world is brutal intervention / modification / interaction) that do not change the probability of density (continuity?) of the system state.

The actual term "collapse of the wave function" is similarly unhappy as the term "measurement". The wave function does not describe the global state of the system in fact, because if we measure the energy, such function is completely different of the case when in the same system is investigating for example angular momentum. If a quantum system interacts (for example is measured), it is the transition from potentially (uncertain) state to the particular (fixed) status. The system passes from the non-causal future to the definite past. Elements (stem cells?) of another, outer phase of the reality (of the future) are glued at the causally arranged past.

The Universe thus "crystalizes" from the "future". Quantum mechanics describes the thin layer of the "time" born, the point of "now" as a thin transition from the future to the history.

This is the essence of the "time" and the essence of the growth of Universe ... :)

[Ginkgo]

Schrodinger equation for stationary states tells us that we can "measure" only values corresponding to eigenfunction of appropriate (math) operator. if the normalized square of wave function (solution of the Schrödinger equation) is accepting as a probability of the occurrence of certain status, then Schrodinger actually says that it is permissible only "measurement" (better: "interaction" - each measurement in the quantum world is brutal intervention / modification / interaction) that do not change the probability of density (continuity?) of the system state.

The actual term "collapse of the wave function" is similarly unhappy as the term "measurement". The wave function does not describe the global state of the system in fact, because if we measure the energy, such function is completely different of the case when in the same system is investigating for example angular momentum. If a quantum system interacts (for example is measured), it is the transition from potentially (uncertain) state to the particular (fixed) status. The system passes from the non-causal future to the definite past. Elements (stem cells?) of another, outer phase of the reality (of the future) are glued at the causally arranged past.

The Universe thus "crystalizes" from the "future". Quantum mechanics describes the thin layer of the "time" born, the point of "now" as a thin transition from the future to the history.

This is the essence of the "time" and the essence of the growth of Universe ...

I think this is the problem with the Copenhagen interpretation. it requires consciousness to be imposed from outside of the system.

The best alternative seems to be regarding the wave as having self-collapsing potential. The actual collapse is then regarded as the moment of consciousness

[tillingborn]

I think this is the problem with the Copenhagen interpretation. it requires consciousness to be imposed from outside of the system.

The best alternative seems to be regarding the wave as having self-collapsing potential. The actual collapse is then regarded as the moment of consciousness

The thing about the Copenhagen interpretation is that there is more than one. As I understand it the common thread is that wave function collapse results in particle like behaviour. The wave function though, is just a mathematical tool for describing probabilities that a particle will emerge somewhere. Whether the wave function corresponds to anything physical is a moot point; I don't think there is any consensus even among those who accept Copenhagen. It is primarily a positivist philosophical point of view, known to critics as 'Shut up and calculate'.
As I said above, in order that a quantum state be observed, as far as I know, it has to be in it's particle mode. I appreciate that some very subtle experiments have been done, particularly on variations of the two slit experiment that, as I remember, can detect which slit a photon passes through, but I think I'm right in saying that it is as a 'particle' rather than a wave, which makes sense as there is no evidence of any medium to carry a wave. In other words, a quantum state is undetectable until the 'wave function collapses'; ie: until it becomes a 'particle', there is nothing that consciousness can perceive, at least not human consciousness, if you are prepared to go all mystical (not me, me old china).
In Cerveny's terms (I think), the future is entirely uncollapsed; as things interact (time passes) the influence of one thing on another, photons being emitted and absorbed for instance, materially affects the universe, turning potential (probabilities) into reality (collapsed wave functions), hence the crystallization metaphor. I'm not sure there is any suggestion that consciousness plays any role in directing it though. You might like this quote from Niels Bohr, after whose home town the Copenhagen interpretation is named: "A physicist is just an atom's way of looking at itself."

[Arising_uk]

For example?

Theres a couple, one is the one where you open two slits with detectors at the slits and the photon appears to know which one is open and your double-slit experiment where you set it all up but put it on a timer with the data captured and stored remotely, leave the room, wait a while and then check the results, result - your 'waveform' pattern which according to you is a collapse of some 'wave function' but not due to consciousness doing any observing.

[lennartack]

http://xkcd.com/1240/

On topic: I hope there are no physicists who still believe that consciousness plays a role in wave function collapse. But it certainly is an interesting thought experiment.

Arising_uk: you can actually make that experiment compatible with this consciousness stuff. The wave function will seem to have been collapsed in the past when you observe the date, but it could as well have collapsed at the moment you observed your data, thereby "changing" the past.

[Ginkgo]

For example?

Theres a couple, one is the one where you open two slits with detectors at the slits and the photon appears to know which one is open and your double-slit experiment where you set it all up but put it on a timer with the data captured and stored remotely, leave the room, wait a while and then check the results, result - your 'waveform' pattern which according to you is a collapse of some 'wave function' but not due to consciousness doing any observing.

They try and get round that problem by saying that the recorded data is in a superposition. It is when you come back and read the data that the wave collapses.

[Arising_uk]

Arising_uk: you can actually make that experiment compatible with this consciousness stuff. The wave function will seem to have been collapsed in the past when you observe the date, but it could as well have collapsed at the moment you observed your data, thereby "changing" the past.

Too slippery for me but I just about understand how the physicists now say about what can be included in the calculation of quanta. What always baffles me is that everyone gets off on the idea of this 'wave' but it looks to be all particles and the calculation of where it probably is. Now what I think all budding philosophers of science should be interested and boggled by is the idea that Physics has abandoned truth for probably true and the world hasn't collapsed nor has Maths.

[Ginkgo]

Arising_uk: you can actually make that experiment compatible with this consciousness stuff. The wave function will seem to have been collapsed in the past when you observe the date, but it could as well have collapsed at the moment you observed your data, thereby "changing" the past.

Too slippery for me but I just about understand how the physicists now say about what can be included in the calculation of quanta. What always baffles me is that everyone gets off on the idea of this 'wave' but it looks to be all particles and the calculation of where it probably is. Now what I think all budding philosophers of science should be interested and boggled by is the idea that Physics has abandoned truth for probably true and the world hasn't collapsed nor has Maths.

The wave analogy is used because it best fits the experimental results. The electron goes through both slits at the same time and interferes with itself, thus creating a wave pattern on the detector.

I think the problem is this. It has been long claimed that the conscious mind is not really a problem for science. It is explained adequately by a physicalist explanation. Quantum mechanics is forcing a rethink of this and the role of consciousness in explaining 'reality'. In other words, consciousness is starting to become a fly in the ointment of traditional science.

[tillingborn]

Arising_uk: you can actually make that experiment compatible with this consciousness stuff. The wave function will seem to have been collapsed in the past when you observe the date, but it could as well have collapsed at the moment you observed your data, thereby "changing" the past.

What actual experiment, as opposed to thought experiment, can this been done with?

Too slippery for me but I just about understand how the physicists now say about what can be included in the calculation of quanta. What always baffles me is that everyone gets off on the idea of this 'wave' but it looks to be all particles and the calculation of where it probably is.

You old corpuscularian you.

Now what I think all budding philosophers of science should be interested and boggled by is the idea that Physics has abandoned truth for probably true and the world hasn't collapsed nor has Maths.

Nor did it when physicists twigged the problem of induction.

The wave analogy is used because it best fits the experimental results. The electron goes through both slits at the same time and interferes with itself, thus creating a wave pattern on the detector.

The way the experiment is described is typically that 'even when the photons are fired on at a time, the detector builds up an interference pattern'. This gives the impression that photons are in fact particles, solid little balls, that don't know how to behave properly. Quite clearly, they are not. It's yer hypotheses non fingo, innit? For all that you can treat them like that mathematically, physicists are very reluctant to make any statement about what they think is physically happening. But, as noted in another thread, Robert Laughlin says: "The modern concept of the vacuum of space, confirmed every day by experiment, is a relativistic ether. But we do not call it this because it is taboo"; 'particles' are neatly described as waves, perturbations, knots, twists, call them what you will, in that medium, but to say such an 'aether' exists is metaphysics, because it wouldn't make any difference to the observed data.

I think the problem is this. It has been long claimed that the conscious mind is not really a problem for science. It is explained adequately by a physicalist explanation. Quantum mechanics is forcing a rethink of this and the role of consciousness in explaining 'reality'. In other words, consciousness is starting to become a fly in the ointment of traditional science.

Seriously; physicists are no better at philosophy than philosophers.

[Arising_uk]

...You old corpuscularian you.

If it was good enough for the Democritus and Boyle then I'm going to find a Zuzian and Fredkin metaphysical model to fit and I think it'd also give you your 'relativistic aether'.