is heat simply the mechanical motion of atoms and molecules, or is it the absorption of infrared radiation? heat is transported from the sun to the earth by radiation, but is often described as the rapid oscillation of atoms or molecues. when i touch something that is hot, am i feeling the motion of the molecules on the surface of the object, or am i feeling IR eminating from the surface of the object? if it is due to radiation, why is infrared the major carrier, as opposed to higher energy radiation? perhaps because atoms and molecules are most likely to be able to absorb and re-emit these frequencies? if it is mechanical motion, why wouldnt higher energy radiation cause more agitation of atoms and molecules than lower energy radiation? thanks.