EDIT: Let’s cool it with the downvotes, dudes. We’re not out to cut funding to your black hole detection chamber or revoke the degrees of chiropractors just because a couple of us don’t believe in it, okay? Chill out, participate with the prompt and continue with having a nice day. I’m sure almost everybody has something to add.
It’s by no means clear that this is true; it depends on where you fall on interpretational questions. Hell, probably the leading approaches suggest that the wave function doesn’t collapse at all, it just appears to when our brains become entangled with the experiment.
Aren’t you just moving the point of the wave collapse from the experiment to inside the brain? I mean if the wave function never collapsed, shouldn’t we see all superpositions at once? But instead, the brain seems to collapse to one possibility, i.e. still collapsing the wave function.
Kind of, but technically no. The idea is, when doing the double slit experiment, that you start with two essentially separate wave-functions; the wave function of the particle, which is in a super position of going through slit A and slit B, and the wave function of the experimenter/surrounding world, which is in a singular defined state.
However, by doing a measurement, the experimenter entangles their wave function with the wave function of the particle, forming one wave function for the whole system, which evolves into a super position of ‘particle goes through slit A and the observer measures the particle going through slit A’ and ‘particle goes through slit B and the observer measures the particle going through slit B’.
Importantly, the super position doesn’t contain a portion for ‘the observer measures both outcomes at the same time’, so there’s no way for us to see all superposition’s at once.
The question of why we only experience measuring one outcome is exactly the same as the question of why an identical twin only experiences one life, and not both, essentially.
I feel like here you’re just moving the goal post again, if you’ll excuse the expression :)
Even if there is no superposition in which an observer sees both outcomes, there must be some point in space and/or time that decides which of the two superpositions we see. Whether that is in the experiment, in the brain or in consciousness or whatever. I mean we only see one superposition, so there must be something that “decides” (randomly as far as we know) which one it is. And that decision is a kind of collapse of the wave function, no?
I am not a physicist though so this is just me rambling from my limited understanding.