  Motivated by Verlinde's theory of entropic gravity, we give a tentative
explanation to Coulomb's law with an entropic force. When trying to do this, we
find the equipartition rule should be extended to charges and the concept of
temperature should be reinterpreted. If one accepts the holographic principle
as well as our generalizations and reinterpretations, then Coulomb's law, the
Poisson equation and the Maxwell equations can be derived smoothly. Our attempt
can be regarded as a new way to unify the electromagnetic force with gravity,
from the entropic origin. Possibly some of our postulates are related to the
D-brane picture of black hole thermodynamics.
