All Questions
16 questions
2votes
3answers
160views
What mathematical results support the idea that the wavefunction does not evolve unitarily before the experimenter interacts with the system?
Some interpretations of quantum mechanics support the conclusion that, from the perspective of an experimenter, the state of the universe evolves unitarily until the experimenter observes the outcome. ...
- 6,847
-2votes
1answer
90views
Quantum collapse: our invention? [closed]
I'm wondering if a similar scenario has already been proposed, or if this one is somehow valid. I'm a complete layman so be patient.My reasoning goes like this: is the collapse of the wave function a ...
-4votes
2answers
128views
Does a quantum measurement change the state in the past? [closed]
Consider the following very basic quantum mechanics experiment. At time $t_0$, a system $S$ is in superposition of two orthogonal states $|A\rangle$ and $|B\rangle$, which we could describe by $\frac{...
- 1,609
1vote
1answer
112views
The many-worlds interpretation and a free particle
How does the many-worlds interpretation understand the time evolution and spread of a free particle wave function? That is, does every continuously small change constitute a cosmic action that causes ...
- 733
0votes
3answers
230views
Is there a natural principle that forbids real wavefunction collapse?
The wavefunction evolves unitary. We can apply a unitary evolution operator containing the Hamiltonian (which shows the relation between time and energy). This evolution is smooth and continuous. And ...
15votes
3answers
2kviews
Why are wavefunction collapses instantaneous?
From my understanding of quantum mechanics, when a wavefunction is observed, it collapses into a single state instantaneously (or at least in the length of a Planck time.) Is there a reason it has to ...
- 346
2votes
2answers
402views
Is the wave-function collapse real or an interpretation? [closed]
Consider the double slit experiment in which the position of the particle is in a superposition of the 'eigenfunctions' of the position operator before they reach the detector. This process is ...
- 1,797
0votes
1answer
219views
In objective collapse theory, do large objects constantly collapse?
In objective collapse theory, do large objects constantly collapse? So I understood it like this: Wave collapses into one concentrated point, Wave spreads out, Wave collapses into one concentrated ...
user311753
1vote
1answer
82views
Whose state (or wavefunction) changes (or collapses) upon observation: System's or Observer's?
I was learning about Qubit measurement and the basics of Quantum computing. The instructor forced a lot on the following statement : Assume an isolated system S. Let an observer O interact with the ...
- 149
0votes
0answers
58views
Is there a limit of wave function splitting?
It is possible to split the wave function (for example using a semi mirror like in Wheeler delayed choice experiment). I wonder what happens if we split it many times. My "though experiment" ...
7votes
4answers
2kviews
Why is wave function collapse mysterious?
There are lots of questions and answers on this site about wave function collapse (for example, How does a Wavefunction collapse?, Why does a wavefunction collapse when observation takes place?, How ...
- 4,110
0votes
3answers
377views
Why is future 'deterministic' but not the past?
From what I saw, it seems that if theoretically you know the current states of a system (which seems impossible), you can predict its future wave function. But since there are wave function collapses, ...
- 11
0votes
1answer
339views
How to understand the transition amplitude in the Copenhagen interpretation
In Chapter 8 of Townsend's A Modern Approach to Quantum Mechanics, he states that the expression $\langle x', t' | x_0, t_0 \rangle$ gives the amplitude for a particle that is at position $x_0$ to at ...
3votes
1answer
445views
How does the "many worlds" interpretation follow from the "universal wavefunction" idea?
So, I took this class some time ago where we discussed Hugh Everett's approach to QM. The premise seemed very logical to me: Isolated systems evolve according to the Schrödinger Equation. Of course ...
user137661
3votes
1answer
610views
Logic of the 'imaginary wave function collapse' argument in Double Slit experiment
My question is in regards to the stance that the 'wave function collapse' is not an actual physical occurrence. That is, you are not, by observation, changing the particles position from a wave to a ...
- 33
