RE: Physics questions about light
September 19, 2016 at 2:14 am
(This post was last modified: September 19, 2016 at 2:17 am by Alex K.)
Not an easy question at all, bennyboy!
Imagine you set up an interferometer involving a beam splitting mirror. In principle, one should be able to tell from the movement of the mirror whether the photon passed or was diverted, bc in the latter case the mirror absorbs the change in photon momentum. Quantum uncertainty in the mirror position and momentum must somehow conspire to render this unobservable, but I don't have a satisfactory full answer yet.
As to the other one, yes, from the point of view of feynman diagrams, the change in dispersion relation must come from interactions with the material, and in QED that always means obsorption and reemission. Again, this must happen in a coherent fashion...
Imagine you set up an interferometer involving a beam splitting mirror. In principle, one should be able to tell from the movement of the mirror whether the photon passed or was diverted, bc in the latter case the mirror absorbs the change in photon momentum. Quantum uncertainty in the mirror position and momentum must somehow conspire to render this unobservable, but I don't have a satisfactory full answer yet.
As to the other one, yes, from the point of view of feynman diagrams, the change in dispersion relation must come from interactions with the material, and in QED that always means obsorption and reemission. Again, this must happen in a coherent fashion...
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
