The causal structure and the principle of relativity look to be in conflict when we consider an inertial moving charge in flat space. How can the field of a moving charge be pointing to the charge's actual position rather than an older one? Retarded potentials can help, but also a wavelike information output (as a postulate) is needed for an explanation, where two effects cancel exactly and lead to the observable result, to the principle of relativity and to the effect of length contraction. Is special relativity an epiphenomenon of wave superposition? Is the wavelike description of physics fundamental to relativity and quantum mechanics?