Talk:Wave function collapse

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I'm currently interested in sorting out the various problems with Measurement in quantum mechanics; as part of this, I suggest swapping over some content between this article and that, specifically making this page (with its more technical title) a repository for the mathematical details; see Talk:Measurement in quantum mechanics for more. Bth 19:00, 14 Oct 2004 (UTC)

This conceptually can be combined with the article on Quantum operations. Admittedly that article is quite technical, but I eventually will put in a more expository introduction.CSTAR 20:09, 14 Oct 2004 (UTC)

Afshar experiment

I have removed the section on the Afshar experiment. This now has its own article, and I'm consolidating the same information which has ended up on several Quantum mechanics pages. Samboy 10:04, 21 Dec 2004 (UTC)

Two Copenhagen interpretations?

I don't believe there are two Copenhagen interpretations; one where the wave function is real and another where it is not real. Also, the word 'real' is misleading here since the wave function exists in the complex plane and has both 'real' and imaginary parts. The issue is whether the wave function has a direct physical interpretation, and as far as I know, within the CI, it does not (other than the Born Rule). I have not corrected the text (yet). I suggest the original author do so. green 65.88.65.217 06:10, 3 February 2006 (UTC)[reply]

I corrected the text discussed above. After further consideration, I agree that two CI's exist, but they were not, imo, defined clearly in the previous text. green 65.88.65.217 08:05, 3 February 2006 (UTC)[reply]

There well may be two CIs (probably more, since it so ill-defined, but whatever), with differing interpretations of what the wavefunction is, but in all such CIs the wavefunction still collapses. The significance of wavefunction collapse will be lessened by the extent to which the wavefunction is not regarded as physical, but the collapse still occurs. I suggest someone changes the article to reflect this.Michael C Price 19:56, 22 May 2006 (UTC)[reply]

The "collapse" of the wave function is really just a metaphor. A way of thinking. There is no mechanical like relationship between the wave function and the experimental data. But if you like thinking in mechanical terms you could imagine the wave function as collapsing, ie. yielding the experimental data. But if you don't require a mechanical picture then the "collapse" metaphor isn't necessary. Remember, CI was addressed to a classical audience - with fairly ingrained philosophical assumptions about causality and determinism. It's almost a hundred years since CI yet many of us are still trying to push quantum theory back into a pre 20th century context to which it never belonged in the first place. CI is an interpretation for the benefit of classical thought - not for the benefit of quantum theory. --220.101.184.56 23:53, 22 May 2006 (UTC)[reply]

Very good points all. It seems to me that CI encompasses a range of interpretations about what the wavefunction is (from just information to a physical field), but that collapse still happens. Even in classical physics collapse still happens, it just that the classical model collapse is entirely a mental readjustment of your knowledge of the world, and hence it never had importance until QM came along. I think the page needs to say this. --Michael C Price 05:53, 23 May 2006 (UTC)[reply]

Article updated as indicated. --Michael C Price 20:42, 23 May 2006 (UTC)[reply]

"The 'collapse' of the wave function is really just a metaphor. A way of thinking. There is no mechanical like relationship between the wave function and the experimental data. But if you like thinking in mechanical terms you could imagine the wave function as collapsing, ie. yielding the experimental data." This is how I viewed wavefunction collapse, but then again I haven't formally learned about it yet. I think that the article would benefit from something along these lines to be put in the intro, because after readit the existing one, I am no closeer to understanding the the event. --HantaVirus 15:15, 27 July 2006 (UTC)[reply]

Redirect added

I added a redirect from State vector reduction to Wavefunction collapse. In the physics and philosophy literature, in my experience, "state vector reduction" is more common than "wavefunction collapse." (The quantum mechanical wavefunction is often considered as merely the components of the state vector with respect to the position basis, not the state that lives in a Hilbert space.) Probably more people are familiar with "wavefunction collapse," however, as introductory courses in quantum mechanics use this terminology. Google seems to agree. Solitonic 12:13, 14 January 2007 (UTC)[reply]

=

I would add that if we do not limit the definition of science a priori to certain philosophical or religious pre-commitments, then substance dualism is permitted. It is not contrary to pure logic. Thus, not only can Buddhist and other Eastern traditions be seen as compatible with this interpretation of quantum mechanics, but so also are the traditional monotheistic metaphysics. Indeed, such an omnipotent, omniscient, omnipresent observer being of other substance than the universe, might eliminate certain problems of entanglement.

Rename

Greetings,

On the wavefunction talk page, a consensus has been reached that the page should be renamed "wave function". Should this be extended to this page? MacGuy^{(contact me)} 17:14, 15 February 2007 (UTC)[reply]

"Spiritual Interpretation"?

Isn't the idea of consciousness being the mechanism for wave-collapse an extension of the Copenhagen Interpretation and more of a philosophical ramification of the Copenhagen Interpretation, rather than a third category? It really seems to me as if "consciousness causes collapse" concept is being purposefully seperated from the Copenhagen interpretation page and this page and then colored with terms like "spiritual" to perhaps induce subconscious bias against the concept.

Though the concept of consciousness causing collapse is supported by "spiritualists," it nonetheless is a philosophical concept born from the Copenhagen interpretation and should be so noted.

I also am curious as to know why the "philosophical ramifications" was removed from the Copenhagen Interpretation article.—Lehel Kovach (talk) 22:38, 12 January 2008 (UTC)[reply]

Incompatible with biological Evolution?

Without an observer, the wave function would never collapse. Without wave function collapse, no observer could evolve. I've seen theories that seem to imply that time itself is a cognitive being; how could something without consciousness be evasive to a paradox forming? Either way, this seems to solidify my understanding that theoretical quantum mechanics is quasi-religious by nature.

The more I think about it, the more cockamamie the idea becomes. When does an observer collapse the wave function? It seems as if it occurs when an observer from one wave enters another, perhaps merging the two. But thinking back to the beginning of observers, it would seem as if there is one wave function, not many; as many wave functions are created by the existence of many observers.

It seems like time would continue to compress itself infinitely. On a side note, it seems time would advance at an infinite speed due to the lack of an observer. This is all just a bunch of tail chasing; an excuse for people to flaunt their intelligence and call themselves "gods" with this idea that they are shaping the universe by simply looking at it. --IronMaidenRocks (talk) 04:26, 12 January 2010 (UTC)[reply]

The idea that consciousness collapses wavefunctions is indeed rather unbelievable. But there are many other interpretations of quantum mechanics, the simplest of which is that wavefunctions don't collapse at all. --Zundark (talk) 09:23, 12 January 2010 (UTC)[reply]

An even simpler interpretation is the ensemble interpretation, in which collapse is a description of a selection of a subensemble.WMdeMuynck (talk) 10:02, 12 January 2010 (UTC)[reply]

"Observer"

The article should make clear what does it mean by an "observer". If there is a certain isolated system that evolves according to the Schrödinger equation, this is obviously going to change when the system interacts with something else ie: the measuring apparatus. To speak about an "observer" makes the question to seem different of what the question really is (and that can be find in any other area of physics, not just quantum mechanics): What happens when the (isolated) system that evolves (in this case) according to the Schrödinger equation, interacts with a certain measuring apparatus (say, several atoms of something)? Speaking about an "observer" obscures things.