LiénardWiechertin
The Liénard-Wiechert potentials are a set of expressions in classical electromagnetism that describe the electric and magnetic fields generated by a moving point charge. These potentials account for the finite speed of light, meaning the fields at a given point and time depend on the position and velocity of the charge at an earlier, "retarded" time. This retardation is crucial because electromagnetic signals propagate at the speed of light, not instantaneously.
The Liénard-Wiechert potentials are derived from the scalar and vector potentials of electromagnetism, which are then
The mathematical form of the Liénard-Wiechert potentials involves the charge's position and velocity at the retarded