Wheeler–Feynman absorber theory

Summary

Wheeler–Feynman absorber theory is a time-symmetric formulation of the classical electrodynamics of point charges, proposed by John Wheeler and Richard Feynman. Each charge acts on the others through half the sum of its retarded and advanced fields, and no charge acts on itself. If the universe absorbs all radiation, the theory gives the same equations of motion as ordinary retarded electrodynamics, including the radiation reaction force. It thus explains radiation reaction without self-fields and shows how the arrow of radiation can come from boundary conditions rather than from the laws.