My question is why the books on laser always use a damped oscillator as a model for the transitions in a 2-level atom? I didn't find any more resemblance between the two except they both have a fixed upper and lower limit( but for the atom it is energy, for oscillator it is amplitude ) Thanks...
Have you heard of bootstrapping? It escaped the question of the most elementary particle by concentrating on the property that they are interchangeable. But I don't know much~