The wave function collapses anyways whether I wanted to know which slit the electron passed through or not, the only difference there is that in the former case the wave function collapse for any electron at either of the two positions directly behind the slits, i mean the electron still in superposition of all possible locations on the screen, but upon watching the electron passing though which slit, the collapse magically favors only one of two possible location, i.e., the ones directly behind the slits, Is that right?
Asked
Active
Viewed 126 times
2 Answers
1
There are multiple variants of quantum theory. These variants are often called interpretations despite having different implications for the results of experiments.
Many people claim collapse happens but give no explanation of the physical process of collapse: rather, they just give an ad hoc rule of how to change the state after collapse. Since this variant of quantum theory doesn't provide a specific explanation or equation of motion we can't say anything about what happens to the electron in that case.
Some variants of quantum theory try to modify the equations of quantum mechanics explicitly to include collapse. According to such a theory the wavefunction of electron may go through both slits or it may collapse at some point during this process and only go through one slit. Testing these theories is a subject of ongoing research:
https://arxiv.org/abs/1910.00050
For a criticism of these theories see
https://arxiv.org/abs/1407.4746
https://arxiv.org/abs/2205.00568
If quantum theory isn't modified by collapse, then the wavefunction goes through both slits and after the measurement there are multiple versions of the measurement result and the observer. When information about a quantum system is copied into a measurement device or the environment that suppresses interference. As a result the different versions of measurement results and observers don't interact and are sorted into layers each of which looks approximately like the universe as described by classical physics:
alanf
- 11,359
- 1
- 16
- 33
-2
Regardless of the actual ontology, this is easier to think about in terms of the many-worlds interpretation in which wave functions never collapse but your consciousness divides every time it interacts with a quantum system and so you perceive them as collapsing. When you detect which slit the electron passes through you are interacting with it, so your consciousness divides into one version where the electron passed through one slit and another where the electron passed through the other slit, and those two possibilities can thus no longer interfere with each other. What changes isn’t the behaviour of the electron, but how your mind perceives it.
Mike Scott
- 468
- 2
- 7