Causality, the Coulomb field, and Newton's law of gravitation, F. Rohrlich, Am. J. Phys. 70(4), April 2002
Causality in classical field theories must be inserted by hand by choosing the retarded solution. It is shown how apparent contradictions in the Coulomb gauge can be resolved and that a causal Coulomb field exists despite the appearance to the contrary. Similarly, it is shown how Newtonian gravitation leads from action-at-a-distance to causal field when a first-order correction for spacetime curvature is applied.