I am kind of curious why they have this directional property when they are re-emitting the EM wave, why they don't re-emit in the direction of the incident wave. Can we make them re-emit in certain direction?
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https://www.quora.com/How-does-a-mirror-work-at-a-molecular-level – Anubhav Goel Jun 21 '18 at 18:46
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It scatter in all directions,, the one with constrictive interference has max amplitude and is visible.. https://physics.stackexchange.com/q/83105/96487 – Anubhav Goel Jun 21 '18 at 18:49
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Your question is whether metals act in some ways to visible light as mirrors. Yes they do.
This is called elastic scattering, Rayleigh scattering and it is a specular reflection.
Now you would think that in this case the mirror image from a metal is created by photons being absorbed and re-emitted. That is not really the case.
Rather, photons are elastically scattered, because only in this case do photons keep their energy level and phase. That is how a mirror image is built.
In any other case, inelastic scattering or absorption-reemission, the photon's energy level and phase would change and you would not get a mirror image.
You are asking why all the photons are reflected in a certain direction, and that is because of the molecular structure of the metal. The atoms in the molecules are arranged so and the molecules are arranged so that the scattered photons will only be scattered in a certain direction.
This is the same as when you ask why is glass seethrough, the same thing happens, elastic scattering, but the atoms and molecules are arranged in glass so that the direction of the scattered photons is almost the same as the original.
Árpád Szendrei
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But for infrared rayleigh scattering is negligible,Can we dissociate metals using infrared? – Anns Jun 22 '18 at 03:37
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Yes, please see here: https://pdfs.semanticscholar.org/1a5e/ad40e8d170e31ff637163ada512a293b87d1.pdf – Árpád Szendrei Jun 22 '18 at 04:05
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does it work for pure metal plate,I know we can dissociate metal alkalis. – Anns Jun 22 '18 at 04:15
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yes, please see here: https://pubs.acs.org/doi/abs/10.1021/jp0111620?journalCode=jpcbfk – Árpád Szendrei Jun 22 '18 at 04:22
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but what would really happen is that the infrared heat would melt the plate – Árpád Szendrei Jun 22 '18 at 04:25
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Yes, a mirror also emits in the forward direction. The field on the other side is the sum of the incident field and the induced field. That sum is zero, the induced field is opposite in phase to the incident field.