this is getting interesting.
from what I understand its not the same as the one that entered , because photons are emitted through excitement.
the atoms get excited by photons entering the medium then they emit photons.etc...etc...etc... then the light exits the medium.
No, I think Orac mentioned that idea, and that it is not correct. The electrons in an atom can absorb radiation only at specific wavelengths. Each atom absorbs a discrete set of wavelengths. So with a white light the only wavelengths of light that would be affected would be the ones that corresponded to the wavelengths that the molecules in that substance could absorb. The index of refraction does depend somewhat on wavelength, that's why you get a refraction pattern when you shine a white light through a prism. But if it was being absorbed and re-emitted it wouldn't work for all wavelengths.
Bill Gill
