And still be re-emitted at the same wavelength, even after being absorbed? I imagine visible colors, to hit a dark colored surface and become absorbed. In that process some of the object's electrons (I believe the outer shell) become energetic or is raised higher. To achieve equilibrium, it must re-emit a photon so that the object can cool. And it is usually an infrared. Now when that infrared photon gets absorbed by a GHG, how could it be re-emitted at the same wavelength AND impart energy to its surroundings? Would not that violate the laws of physics? Or is it re-emitted as a lower infrared, and so on into the microwave during successive absorption and emission? I also want to know if there really is a difference in the amount of infrared emitted in the following: One sq meter of sunlight concentrated in a (tiny) 1000 sun CPV cell, as compared to the same amount of light on an equally efficient flat solar panel? I ask because if the "world was covered" with dark panels, the infrared heat would be too much (because their efficiency is low), but it seems that if the same amount was concentrated, the higher temps of the CPV cell would emit at higher, more visible rays that would reflect back out of whatever concentration system used (dish or freznel) and go back out toward the sun unimpeded by excess CO2. Thus less infrared, right? Thanks!