A modified double slit screen scenario- what would happen?

[bcrelling]

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?

 

[mfb]

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.

 

[Charles Wilson]

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

 

[HomogenousCow]

I ate a meatball sandwich today.

Bohr 1, Subway 0

Anywho, is there a quantitative reason why a large recoil would ruin coherence?

 

[mfb]

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.