Heat Transfer

Heat can move from one point of a body (or from one body to another) by three fundamentally different mechanisms: CONDUCTION, in which heat passes molecule to molecule through a solid without any bulk movement of the material itself; CONVECTION, in which heat is carried by the actual bulk movement of heated fluid (liquid or gas); and RADIATION, in which heat travels as electromagnetic waves and needs NO material medium at all -- indeed, it is by radiation alone that the Sun's energy crosses empty space to reach the Earth. Of the three, conduction is the slowest pr …