Entanglement and the double slit experiment

Is the double slit experiment an example of entanglement when it seems as if the photon is going through both slits? Or put another way, is it at this stage when we attempt measurement we see a photon on one side affect the photon on the other side? Do entangled particles have to be made … Read more

How does really the “wave function collapse” work? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 years ago. Improve this question It’s usually said that “the direct observation of a process makes the wave function of … Read more

Why do we need the third axiom of QM to explain the wave function collapse? Why don’t we use the decoherence process as an axiom?

I’ve always seen the standard interpretation and axioms of QM as in some way tricky on a philosophical level. They state the collapse of the wave function is caused by the measurement. 3.b If A is an observable with eigenvalues ak and eigenvectors |k⟩ (A|k⟩=ak|k⟩), given a system in the state |ψ⟩, the probability of … Read more

Does the Copenhagen interpretation (+ “quasi-classical apparatus”) allow one to bypass a derivation’s objection? [closed]

Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 2 years ago. Improve this question Background I asked this question, where I’m thinking about this joshphysics’s answer: And the gist of what I get is … Read more

Where does either Bohr or Heisenberg mention the idea of the wave function collapsing?

Could someone reference a paragraph written either by Heisenberg or Bohr where they mention the idea of the wave function collapsing? Answer Quoting from wikipedia http://en.wikipedia.org/wiki/Wave_function_collapse “The concept of wavefunction collapse was introduced by Werner Heisenberg in his 1927 paper on the uncertainty principle, “Über den anschaulichen Inhalt der quantentheoretischen Kinematic und Mechanik”, and incorporated … Read more

Video of Double Slit Experiment Observer Effect

I have been watching a lot of videos of the double slit experiment and trying to wrap my head around it. I found examples of where the experiment has been done, however the videos cut out and only simulate the effect an observer has on it. I understand that the wave interference pattern collapses when … Read more

Mathematical formulation of partial wave function collapse

If given a wave function which is an element of a Hilbert space H which is a tensor product of two other Hilbert spaces H1⊗H2, how do you formulate measurement of the function in one of the sub-spaces, i.e. H1? For example, say you have a system |ψ⟩ which consists of two qubits |ψ1⟩⊗|ψ2⟩. The … Read more

Does decoherence explain all instances of wave function collapse?

Specifically, how can decoherence explain the appearance of flecks of metallic silver on a photographic plate when exposed to the very weak light of a distant star? EDIT: Perhaps the advocates of decoherence need some context for this question. There is a certain definite quantity of energy on the order of one or two eV … Read more

If there is no collapse of the wave-function does this mean that the many worlds interpretation of QM must be wrong?

If as some people suggest, there is no collapse of the wave function (is there a standard name for this position), then must one rule out the many-worlds interpretation of QM? Answer The term “collapse of the wave function” is impressive but carries little mathematical meaning other than labeling a specific measurement with it. At … Read more

Does an entangled pair remain entangled after the first measurement?

Consider an entangled pair described by the wavefunction |1,0⟩=1√2(|↑1↓2⟩−|↓1↑2⟩) in in the Sz-basis. If the first measurement finds Alice’s particle to be in the |↑⟩ state, then Bob’s particle is found to be in the |↓⟩ state i.e. the entangled state above collapses to |↑1↓2⟩ which is not entangled. Since it is not entangled in … Read more