Is wave-function collapse instantaneous?

is wave-function collapse instantaneous?

>mfw I can't answer this question after studying theoretical physics for 5 years

It collapses when the position of a particle is precisely measured, a wave function is a probability of the particles most likely positions since it can assume all those positions simultaneously, another particle like an electron whose values are known upon being used to measure the other particles position decreases the probability of likely states isolates the particles location and collapses the function. Its instantaneous.

This is me guessing its been awhile

There is no such thing as wavefunction collapse, OP.

are you suggesting that eigenstates can't be reduced?

No, I am saying that superpositions don't reduce to eigenstates.

but every physical quantity has a Hermitian linear operator associated to it

And? I'm not saying that superpositions don't have eigenstates. I'm saying that superpositions do not, by some process, turn into a SINGLE eigenstate.

uhh thats not what brian greene said LOL fucking retard

how do you preserve unity then? if it doesn't collapse then you would have a system that is violating the probability sample it represents by having a wave integral greater than 1.

How so? Time evolution per Schrödinger's equation is still unitary, and that is simply all there is.

an observation would force the unity to be collapse to a region smaller than the original wavefunction would sustain by adhering to the fourier transform of the position wavefunction and momentum wavefunction, or else it would violate the uncertainty principle.

No.
Let's consider wave function for space of particle's position. If our detector (that have finite size, which gives us limitations on resolution for measured position) caught a particle - there is no longer any state, after the absorbtion. The act of measurement also has to take some time, otherwise we'll encounter conflict with special relativity. Wave function collapse theory is unphysical, quantum state does not jump instantaneous into measured state just by itself - there is no experimental evidence for this. All you can is to recreate measured (and destroyed) states and it obviously takes some time.

Why would it? The observer goes in superposition itself by becoming entangled with the observed system. That does not violate the uncertainty principle at all.

if you have a detector or observer who can confirm the presence of a particle over a given region, then the integral has to be 1 over that entire region. if the wavefunction itself is larger than that region, it must collapse to adhere to still be unitary.

>if you have a detector or observer who can confirm the presence of a particle over a given region, then the integral has to be 1 over that entire region.
Right.

>if the wavefunction itself is larger than that region, it must collapse to adhere to still be unitary.
But it isn't, because the wavefunction evolved in a unitary way to begin with. It started having an integral of 1, then evolved in a way that preserved that integral, indefinitely.

but there are no parameters that would make it evolve in such a fashion. observation isn't a quantum number.

Wait, what? Quantum number?

Observation is simply a process that entangles the observer with the observed. It is a physical interaction like any other, and it follows the normal rules of quantum mechanics (i.e. Schrödinger's equation) like any other.

you were saying that the wavefunction evolves naturally into the state that will keep it unitary, but to do so it needs to have some valid parameter that adjusts it, or else it would appear as though it just transforms without any interaction, which would violate the conservation laws. observation in itself is a physical interaction, but how can you represent it as a parameter that the wavefunction adheres to in a conservative matter?

Einselection occurs after a nonzero decoherence time.

He's saying (I think) that there's no such thing as observation, just a process of becoming merged with the quantum system so that you can only detect one eigenstate. He's describing more or less the many-universe interpretation in such a way as to make it apparent how obviously correct it is.

By observing a system you automatically become entangled with it, and in a sense become a part of the state, or superposition of states. You're also constantly measuring yourself and thus have a well-defined energy etc. Therefore when you measure something, that thing must also instantaneously adopt a well-defined energy from the observers point of view.

>Hermitian linear operator
for now, just wait and you'll see there is more

>uncertainty principle
biggest meme in physics