Einstein's famous equation equating energy with mass, revealing that mass is a form of energy, is an elegant and tremendously useful equation. However, is it telling us anything about the nature of our universe? For example, we might ask what is the mechanism by which energy manifest very specifically in the invariant masses of elementary particles: why that mass and not another? Or, even more basically, why do particles have this property of mass at all? When we start to break down the equation