3 ms·

The interaction with the slits is governed by Schroedinger’s equation because it is not a measurement (if it is a measurement the interference pattern disappear

by kgwgk 7y ago

The interaction with the slits is governed by Schroedinger’s equation because it is not a measurement (if it is a measurement the interference pattern disappears).

scotty79 7y ago
Sort of. Shrodinger equation doesn't so much describe interaction with the slit barrier as it describes propagation through space not occupied by the slit barrier. The only difference between passing through a slit and the measurement at the screen is the size and location of the "hole". Measurement at the screen is just a silt of the size of single atom. If your measurement is just ensuring that photon passed through one slit not the other you no longer have interference pattern at the screen but you still get diffraction pattern. Your measurement didn't collapse a wave to single point because it wasn't precise enough.
- kgwgk 7y ago
  > Shrodinger equation doesn't so much describe interaction with the slit barrier And what would describe the interaction with the slits according to you?
  - scotty79 7y ago
    If you want to have precise description you would have to look at how interaction with wave functions of electrons bound in atoms of the barrier reshapes wave function of incoming wave reshaping it in a way that some of it bounces off, some of it dissappears to encompass the act of potentially absorbing the photon on the barrier. And part of the wave is left undisturbed to propagate through the slits. Completely infeasible to calculate but I argue valuable to think about. :-)
    - kgwgk 7y ago
      You know that is all happening according to Schroedinger’s equation, right?
      - scotty79 7y ago
        Culling of the the wave function due to absorbtion by the atoms of the barrier that happens or not with some probability is a consequence of Schrodinger equation? I thought it describes evolution of the wave function in spacetime empty or not (like around nucleus) but doesn't cover any kind of decay, absorptions, emmisions and such. --- We reached max thread depth and I can't reply to your response. Not sure if you are going to see this. If you are using electrons instead of photons for double slit experiment barrier still absorbs them. They get caught by atoms of the barrier or exchange virtual photons with electrons of the barrier. Shrodinger doesn't cover that I think.
        kgwgk 7y ago
        Absorption of what? If you’re talking about photons, strictly speaking they are not described by Schroedinger’s equation at all (it applies to massive, non-relativistic particles). The double-slit experiment is often discussed in quantum mechanics in terms of matter waves (having interferences in light is not particularly surprising anyway).
        kgwgk 7y ago
        In principle you can model the interaction between the electrons and the particles in the barrier and the whole system evolves according to Schroedinger’s equation and will be described by a wavefunction. This wavefunction may be a superposition of states where the electron goes through the slits and states where it doesn’t. Until there is a “measurement” - a “detection” which is “amplified” - you cannot say what has happened to the electron: every outcome remains possible and the system remains described by a wavefunction. If the detection happens first at the screen there will be a probability of finding the electron at each position and a probability of not finding it at all. Note that the detection on the screen is done using a scintillator/photomultiplier or something like that to amplifify the detection of a single electron into a measurable electric signal.

by kgwgk 7y ago

The interaction with the slits is governed by Schroedinger’s equation because it is not a measurement (if it is a measurement the interference pattern disappears).

scotty79 7y ago

Sort of. Shrodinger equation doesn't so much describe interaction with the slit barrier as it describes propagation through space not occupied by the slit barrier. The only difference between passing through a slit and the measurement at the screen is the size and location of the "hole". Measurement at the screen is just a silt of the size of single atom. If your measurement is just ensuring that photon passed through one slit not the other you no longer have interference pattern at the screen but you still get diffraction pattern. Your measurement didn't collapse a wave to single point because it wasn't precise enough.

kgwgk 7y ago
> Shrodinger equation doesn't so much describe interaction with the slit barrier And what would describe the interaction with the slits according to you?
- scotty79 7y ago
  If you want to have precise description you would have to look at how interaction with wave functions of electrons bound in atoms of the barrier reshapes wave function of incoming wave reshaping it in a way that some of it bounces off, some of it dissappears to encompass the act of potentially absorbing the photon on the barrier. And part of the wave is left undisturbed to propagate through the slits. Completely infeasible to calculate but I argue valuable to think about. :-)
  - kgwgk 7y ago
    You know that is all happening according to Schroedinger’s equation, right?
    - scotty79 7y ago
      Culling of the the wave function due to absorbtion by the atoms of the barrier that happens or not with some probability is a consequence of Schrodinger equation? I thought it describes evolution of the wave function in spacetime empty or not (like around nucleus) but doesn't cover any kind of decay, absorptions, emmisions and such. --- We reached max thread depth and I can't reply to your response. Not sure if you are going to see this. If you are using electrons instead of photons for double slit experiment barrier still absorbs them. They get caught by atoms of the barrier or exchange virtual photons with electrons of the barrier. Shrodinger doesn't cover that I think.
      - kgwgk 7y ago
        Absorption of what? If you’re talking about photons, strictly speaking they are not described by Schroedinger’s equation at all (it applies to massive, non-relativistic particles). The double-slit experiment is often discussed in quantum mechanics in terms of matter waves (having interferences in light is not particularly surprising anyway).
      - kgwgk 7y ago
        In principle you can model the interaction between the electrons and the particles in the barrier and the whole system evolves according to Schroedinger’s equation and will be described by a wavefunction. This wavefunction may be a superposition of states where the electron goes through the slits and states where it doesn’t. Until there is a “measurement” - a “detection” which is “amplified” - you cannot say what has happened to the electron: every outcome remains possible and the system remains described by a wavefunction. If the detection happens first at the screen there will be a probability of finding the electron at each position and a probability of not finding it at all. Note that the detection on the screen is done using a scintillator/photomultiplier or something like that to amplifify the detection of a single electron into a measurable electric signal.