This may seem like a simple question, but I am hoping to find a rather in depth answer. My father and I were discussing a lesson I had learned in Chemistry on Absolute Zero, when we got to the topic of why Molecules move. I answered him, that it was because they receive heat, and express/transfer that heat through movement. Apparently that wasn't good enough, and now we are both wondering WHY that transfer of energy takes place. He seems to think that it may perhaps take place on a sub-atomic level, but I have a hard time believing that. Is this question just to easy? Or is it like questioning why every action has an equal and opposite reaction... Thanks for all your help.