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Reading some science history, Werner Heisenberg and Bohr created the Copenhagen interpretation, but what I didn't get is how can we connect this interpretation to Schroedinger's cat and the double slit experience? Are they confirming Heisenberg and Bohr's work?

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    $\begingroup$ AFAIK, Schödingers cat was originally designed to make fun of the Copenhagen Interpretation by exposing its unclear definition of a "measurement". $\endgroup$ – Konstantin Schubert Sep 8 '14 at 18:08
  • $\begingroup$ yes by being dead/alive at the same time,but the double slit experience prove that the Copenhagen interpretation is right? $\endgroup$ – Astrofoufou Sep 8 '14 at 18:11
  • $\begingroup$ For all practical purposes the Copenhagen interpretation is as "right" as the many-worlds interpretation, it simply has the advantage, that it passes Occam's razor, while Everett's model does not. In general I would stay away from Schroedinger's cat. It does nothing good for the topic but tends to confuse people. The double slit experiment is merely one of many experiments in quantum theory that all agree with each other and the standard interpretation. It is mostly important as a teaching tool. The real kicker for QM is atomic physics, for which there is no other explanation but QM. $\endgroup$ – CuriousOne Sep 8 '14 at 18:18
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    $\begingroup$ The Copenhagen Interpretation establishes two domains: The quatum domain and the physical domain. But it is unable to define the border between those two. That is what the cat was supposed to illustrate. The double slit experiment shows that particles have wave character and that this wave function somehow collapses when they interact with the screen. This does not necessarily mean that the copenhagen interpretation is the only way to understand this process. In fact, it is terribly flawed. $\endgroup$ – Konstantin Schubert Sep 8 '14 at 18:19
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    $\begingroup$ @Konstantin: The double slit experiment doesn't show either wave-particle duality nor does is demonstrate the collapse of the wave function. Both are phantasmagoric elements of the early confusion about what the quantum world really "looks like". They are interesting from a historic perspective, but it's time to remove either from the language of modern physics. Neither concept works or has ANY useful application in handwaving arguments about quantum mechanical systems. We have gotten over these things professionally around the early 1940s (at the latest), which was 70 years ago. $\endgroup$ – CuriousOne Sep 8 '14 at 18:45
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If you really want to understand how QM formalism relates to the Schroedinger's cat and the double slit experiment, you should study a QM textbook.

To answer your question in a simple way:

The double slit experiment is indeed consistent with the Copenhagen interpretation, in the sense that wave mechanics predicts the outcome of the experiment correctly.

On the other hand, Schroedinger's cat is not really an experiment, it is just an illustration of something Erwin Schroedinger did not like about the Copenhagen interpretation, the collapse of the wavefunction during the measurement. Being an illustration, it can't really support or falsify the interpretation.

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  • $\begingroup$ in the box where the cat is stuck with the poison,the particle either it is decay or not,so if it is decayed that means that the wavefunction collapse or no? $\endgroup$ – Astrofoufou Sep 8 '14 at 22:27
  • $\begingroup$ The wavefunction collapses when you look at the cat (when you "measure" it), regardless of what you're going to measure. $\endgroup$ – miha priimek Sep 9 '14 at 5:49
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Maybe I should read Schrödinger's original article first, but I think its purpose is more to highlight deficits in the way some proponents of the Copenhagen interpretation presented that interpretation, rather than to highlight any fundamental problems in the interpretation itself.

You are simply not supposed to ask questions or talk about any unobserved intermediate state. This quite reasonable restriction becomes unintuitive in case the time between two successive observations significantly exceeds the coherence time of the system. An unintuitive situation can arise by coupling a system with a very long coherence time (the supposed radioactive decay in this case) to a system with a very short coherence time (the cat in this case). Because the exponential distribution is memoryless, "virtual" intermediate observations wouldn't really change the predicted probability for the "final real" observation. The consistent histories approach may be used as a clarification of the Copenhagen interpretation that allows a more intuitive understanding of such situations with different time scales.

But the fact that such a simple example like Schrödinger's cat can generate so much confusion points to a much more serious deficit in the presentation of the Copenhagen interpretation. If this interpretation is sufficient for understanding everything that needs to be understood about about quantum mechanics, then it should also be presented in a way that people realize that they understand everything that needs to be understood. Other mathematical theories have similar problems (take for example intuitionistic logic), but here the proponents at least realize that there is a problem which can only be addressed by the proponents themselves.

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