I've read this answer regarding the difference between mere reflection and absorption followed by emission and I am struggling to understand some concepts. To begin with, we have some matter-light interactions that are notable:
- Emission: occurs when an excited electron emits a photon at a random direction (that explains fluorescence)
- Reflection: occurs when an photon elastically collides with an atom, bouncing back at the same angle (that explains reflection)
- Absorption: occurs when an photon gets absorbed by an atom and heats it up.
The questions are:
1- Where in the atom do absorption and reflection occur, exactly? If it's in the electronic shells, then how electrons (particles) and photons (waves) possibly collide elastically?
2- Moreover, following the premise that absorption occurs on electronic shells, how does an electron absorb a photon, get energetically excited, and then doesn't emit another photon? That is, how the energy from absorption gets converted into vibrational energy and not in other photon?
Vibrational energy is also quantized. Having in mind that the quanta of vibrational energy and the quanta of light are energetically the same (both follow Planck's length), what differentiates absorption transformed into thermal energy from absorption followed by emission of another photon? In other words, if both cases of absorption follow the same criteria of initial conditions (in that case, the wavelength), how is it possible that two different determined outcomes exist?
3- How can transparent objects possibly be explained by these interactions? Why do light waves that pass through a window don't bounce off its surface (reflection)?