When any charged particle (such as an electron, a proton, or an ion) accelerates, energy is radiated in the form of electromagnetic waves. For a particle whose velocity is small relative to the speed of light (i.e., nonrelativistic), the total power that the particle radiates (when considered as a point charge) can be calculated by the Larmor formula: P = 2 3 q 2 4 π π ε ε 0 c ( v ˙ ˙ c ) 2 = 2 3 q 2 a 2 4 π π ε ε 0 c 3 = q 2 a 2 6 π π ε ε 0 c 3 = μ μ 0 q 2 a 2 6 π π c (SI units) P = 2 3 q 2 a 2 c 3 (cgs units) where v ˙ ˙ or a is the proper acceleration, q is the charge, and c is the speed of light. A relativistic generalization is given by the Liénard–Wiechert potentials.