I have seen several questions on the site about this, but most of them get bogged down into new complex interpretations of quantum mechanics. For reference, I am a high school student just starting to learn quantum mechanics and thus sticking strictly to the copenhagen Interpretation.
If I understand the experiment correctly, the probability waves ( wavefunctions) of electrons emerging from each slit superpose to produce a resultant wave function whose modulus squared gives the probability distribution. The electron then appears on the screen due to he immediate collapse Of the wave-function upon interacting with the screen and an interference pattern of electrons is obtained if the experiment is run several times.
From what I’ve read and seen in several videos, if a detector is placed in-front of the slit, Such as Light scattering off the electrons, the interference pattern suddenly disappears and a distribution similar to that of macroscopic particles is obtained.
By what mechanism does detection collapse the wave function and turn the electron into a definite particle? Feynman, in his lectures, says that this has to do with the fact that photons carry momentum and photons scattering off electrons will inevitably affect the electrons in some way and destroy the interference pattern. However, this explanation sounds too specific to electrons and the method of detection (scattering light); I thought the collapse of the wave function upon detection was something universal.
How does this relate to heisenberg’s uncertainty principle?
Heisenberg proposed, as a general principle, his uncertainty principle, which we can state in terms of our experiment as follows: “It is impossible to design an apparatus to determine which hole the electron passes through, that will not at the same time disturb the electrons enough to destroy the interference pattern.”
This sounds more like the observational effect, which I’be read is different than the uncertainty principle, something more fundamental to QM