Figure 1.

Comparison of the concept of mass from the perspectives of classical and quantum mechanics: (a) In classical mechanics, there is hardly any region outside of a mass that affects it. (b–e) In quantum mechanics, the electromagnetic fields resulting from a given mass exert an external sphere of influence over it like the Lorentz force. Mass in classical and quantum mechanics is intuitively distinguished by the presence or absence of these regions. When these factors are corrected, the two concepts can be unified.