A modified double slit screen scenario- what would happen?

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Discussion Overview

The discussion revolves around a modified version of the double slit experiment involving high-energy photons and the implications of recoil on the wave function and coherence. Participants explore theoretical aspects of quantum mechanics, particularly the effects of measurement and path determination on interference patterns.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests that the recoil of the emitter, which occurs when a high-energy photon is emitted, could provide information about the photon's path, potentially collapsing the wave function before detection.
  • Another participant argues that if the recoil is sufficient to determine the path, coherence would be lost, and interference patterns would not be observed.
  • A participant reiterates the scenario's connection to Einstein's Weighable Light Box concept and references Bohr's arguments regarding relativistic effects that must be considered in the thought experiment.
  • One participant humorously interjects with a personal anecdote but also inquires about the quantitative reasons behind how large recoil affects coherence.
  • Another participant posits that different evolutions of the wave function for each slit would occur due to the recoil, suggesting that the phase of the emitted photon would vary unpredictably based on the emission angle.

Areas of Agreement / Disagreement

Participants express differing views on the implications of recoil on coherence and interference, indicating that multiple competing perspectives remain unresolved.

Contextual Notes

There are unresolved assumptions regarding the conditions under which coherence is maintained or lost, as well as the specific effects of high-energy photon emission on the wave function evolution.

bcrelling
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This scenario is identical to the classic double slit screen experiment except that the photon is at extremely high energy. The energy is so high that the photon's momentum maybe registered by a mechanical measuring device(i.e spring or accelerometer attached to a receiver).

At the moment of emission(before the photon has hit the screen/receiver) the emitter will recoil with the momentum opposite to the photon's. Surely this would give us information about the path of the photon before the photon is registered at the screen/receiver? What stops the wave function from being collapsed?
 
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You do not get coherence if the recoil is (at least in theory) sufficient to determine the path, and you do not get interference.
Apart from that, the wavelength of the photon would have to be extremely short, and the slits would have to be far apart. That would ruin double-slit effects anyway.
 
bcrelling said:
This scenario is identical to the classic double slit screen experiment except that the photon is at extremely high energy. The energy is so high that the photon's momentum maybe registered by a mechanical measuring device(i.e spring or accelerometer attached to a receiver).

At the moment of emission(before the photon has hit the screen/receiver) the emitter will recoil with the momentum opposite to the photon's. Surely this would give us information about the path of the photon before the photon is registered at the screen/receiver? What stops the wave function from being collapsed?

This is Einstein's Weighable Light Box idea and it was a precursor to the EPR paper. Bohr used Einstein's own Relativity works to show that at each step, there are things such as Time Dilation that must be accounted for in the thought experiment.

Bohr 1, Einstein 0.

CW
 
I ate a meatball sandwich today.

Bohr 1, Subway 0

Anywho, is there a quantitative reason why a large recoil would ruin coherence?
 
It gives a different evolution of the wavefunction for those two different slits.
Alternative description: The phase would depend strongly on the emission angle in an unpredictable way.
 

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