So a blackbody absorbs all incoming radiation and at thermal equilibrium emits radiation according to Planck's law. I have several questions.
How could blackbody absorb all incoming radiations? In order to absorb radiation, electrons would have to jump to higher energy levels or ionize and once an atom reaches that state it wouldn't have the same set of "jumps" left to continue absorbing as efficiently at that wave length. So its absorption rate would eventually change.
Also at the higher energy levels like gamma rays, it doesn't seem likely that a blackbody can constantly absorb gamma ray. Eventually it would be really ionized until the energy cost of more ionization is greater than the energy of the photon at which point the gamma ray must pass through?
At thermal equilibrium, the blackbody is absorption and emission rates are the same. But why does the emission spectrum follow that particular shape (I know it's empirically observed but are there some models that explain it). I thought emission spectrum is described by the distribution of electron movements. Why would that distribution always be the same at a certain temperature? Shouldn't it depend on the energy that is absorbed in some way?