Several points related to your query.
1. Objects emit electromagnetic radiation as a means of releasing some energy into the surrounding space. In the case of heat at the molecular level, "heat" means that the molecules or atoms in the solid crystalline matter have a certain amount of energy and hence are vibrating about their central locations with respect to each other. The vibrations may be linear, bending, or rotational. The energy emitted to release some of this energy is in the microwave and infra-red region of the electromagnetic spectrum, because that is the frequency of the energy level differences in the system. Other types of energy level differences occur at different frequencies: For example, the light emitted for changes in excitation levels of electrons in their orbits falls into the ultraviolet region, and sometimes extends down into the visible light area. Changes in energy levels in the nucleus usually emit X-rays and Gamma rays. So electromagnetic wave emission is not is not limited to the visible light region, and it depends a great deal on the mechanism of change of energy state.
2. When electromagnetic radiation from an external source falls upon an object's surface, three types of results can occur, often simultaneously:
(a) Penetration of the waves into and beyond the surface of the object and then absorption of the energy by being used to excite some portion of the matter to a higher state. What excitation happens depends on the frequency of the radiation and again is linked to the differences in energy levels. Visible or ultraviolet light might be absorbed by increasing the energy of an electron to a higher state; vibrational and rotational energy of the molecules or atoms might be increased by absorption of infra-red or microwave radiation etc. What gets absorbed, and the mechanism for it, depends on the frequency of the incoming radiation and on whether the material in the matter has energy level differences that match the incoming radiation frequency.
(b) Refraction - that is, the waves may penetrate the matter and then have their paths bent by the electromagneitic fields of the electrons in the solid matter, emerging on a path somewhat different from their original incident path. This radiation does not get absorbed, merely passing through.
(c) Reflection at the surface - the incident radiation does not really penetrate the matter, but has its path changed by interaction with the fields of the atoms at the surface of the matter. Again, this radiation is not absorbed in any way, but is merely redirected.
For MOST cases of our "seeing" an object, what is happening is that light from an EXTERNAL source in the visible range of electromagnetic frequencies falls on the object and is REFLECTED from its surface. We "see" the light that has been reflected. Some of that light is reflected in slightly different directions, giving us the perceptions of surface irregularities and shape of the object. All that light has not been absorbed and hence has not changed the energy state of the object. Moreover, in these cases the object itself has not emitted any light and hence has not lost any energy. This mechanism certainly would apply to our ability to see an object at minimum or ground state (or zero) energy. What we "see" never was part of the object's energy; it came from an external source.
However, this also raises a well-recognized aspect in science. Merely by observing an object we make some change to it. In the case of visible light falling on an object at absolute zero temperature so that it is reflected and we can see it, what we will see surely we will perceive as having some colour. That is, the colour we obseve will not be the same as the colour of the light source. That is because SOME small part of the visible light from the source was not merely reflected; it was actually absorbed and increased the energy level of some components of the object. Because we are talking of visible light, most likely the change affected the energy state of some electrons, and not the vibrational or rotational energy (molecular or atomic motion) that we consider absent in an object at absolute zero temperature. Still, by applying an external light (energy) source to that object, we have altered its total energy state.
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