All Questions
Tagged with quantum-entanglement wavefunction-collapse
43
questions
20
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4
answers
4k
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How is it possible that quantum phenomenons (e.g. superposition) are possible when all quantum particles are being constantly observed?
I don't understand how quantum mechanics (and therefore also quantum computers) can work given that while we work with quantum states, particles that this quantum state consist of cannot be observed, ...
- 333
19
votes
1
answer
7k
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Is my interpretation of the underlying idea behind this 2022 Nobel Prize story “How physicists proved the universe isn’t real” more or less accurate?
I’m not very good at math but I frequently watch PBS Spacetime on YouTube to try to satisfy my curiosity about physics despite that.
In a recent video by Dr Ben Miles titled “How Physicists Proved the ...
- 1,821
14
votes
3
answers
3k
views
When light reflects off a mirror, does the wave function collapse?
This question is specific to the Copenhagen interpretation, which states that the wave function collapses on interaction. If we have a beam of light reflected off a mirror, whether you see this light ...
- 12.7k
7
votes
3
answers
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What processes cause the collapse of a wavefunction and break entanglement?
This question states that measuring the spin of an entangled particle causes the collapse of the wavefunction and thus the entanglement is broken.
Then this question states that we don't know what ...
- 363
6
votes
4
answers
2k
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Doesn't the Schrödinger's cat inside the box cause the probability wave function to collapse long before a human opens the box?
My point is that there is no superposition of dead and alive. The cat will cause the probability function to collapse long before we open the box. What am I missing here? Isn't the cat capable of ...
- 89
6
votes
3
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335
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Are combined fermion wavefunctions still antisymmetric after wavefunction collapse?
If we have two electrons in a state $|\psi\rangle=\frac{1}{\sqrt2}[|\uparrow\downarrow\rangle+|\downarrow\uparrow\rangle]$ and we measure the spin of the first electron to be up, does the wavefunction ...
- 2,604
6
votes
3
answers
260
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Is wavefunction collapse “global”?
I have the feeling that the premises of this question may not be coherent (so to speak), but here goes:
Suppose we have a system $X$ in a quantum superposition between states $0$ and $1$, say, with ...
- 357
5
votes
2
answers
390
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Causality in space-like separated collapse of entangled pairs
Suppose two spacelike-separated measurement events take place on an entangled pair of particles, both of which events, in isolation, would cause the entanglement to collapse.
It is impossible to say ...
- 51
5
votes
1
answer
583
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Mathematical formulation of partial wave function collapse
If given a wave function which is an element of a Hilbert space $\mathcal{H}$ which is a tensor product of two other Hilbert spaces $\mathcal{H}_1\otimes\mathcal{H}_2$, how do you formulate ...
- 161
5
votes
2
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519
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Does Quantum Entanglement have a preferred reference frame?
What I mean by this is, with wave function collapse,--and by extension, collapse between two entangled particles--being nonlocal (instantaneous across space), in what reference frame does the ...
- 365
4
votes
2
answers
2k
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Entropy before and after collapse of the wavefunction and interpretation?
Seems like it might be pretty rudimentary but I want to see if my thinking is on the right track as well as what the result means.
The question is, is the entropy of the collapse of a wavefunction or ...
- 293
4
votes
1
answer
184
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Does an entangled pair remain entangled after the first measurement?
Consider an entangled pair described by the wavefunction
$$\lvert1,0\rangle = \frac{1}{\sqrt{2}}(\lvert\uparrow_1\downarrow_2\rangle-\lvert\downarrow_1\uparrow_2\rangle)$$ in in the $S_z$-basis. If ...
- 11.8k
3
votes
3
answers
221
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Was Einstein "spooky action at a distance" about entanglement or about wave function collapse?
I've been watching Sabine's videos and this is my understanding:
There is no "spooky action at a distance" based simply on entanglement. Entanglement is a correlation. There is no ...
- 39
3
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4
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4k
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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 ...
3
votes
1
answer
222
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Can we tell if a particle has collapsed due to a measurement?
Suppose we have two electrons A and B.
My friend measure the spin on electron B the value is +1/2, and he writes on a piece of a paper the value.
Electron A has not been measured, so the spin is in ...
