When I study any book of Quantum Mechanics like Resnick or Beiser etc all start with blackbody radiation! But how this radiation is produced? Google says due to increased collision of particles causing the acceleration and em wave but what particles? How they are accelerated from what? Like if we heat a iron rod! At 1st it will become red. Is this due to the fact that electron jump to the next state in the orbits and then come back radiating energy? The more heat i give to the rod more the frequency shifts towards blue(white)! Can this be reasonable explanation(i.e. google quora says all trush) or I got wrong deep inside?