Relativistic transformation from dipole to synchrotron radiation
This animation follows the change in form through Lorentz contraction of the emission of radiation by a centripetally accelerated electron from dipole radiation in a quasi-stationary state to highly collimated and intense synchrotron radiation at velocities close to the speed of light. The program scales back the dimensions as the velocity increases, as in the forward direction, the intensity increases with the fourth power of the storage-ring energy. Without this scaling factor, the radiation would soon shoot off the edge of the screen.
The animation tilts from an initial perspective close to the orbital plane of the electron, to one directly above the orbital plane as the velocity approaches the speed of light, in order to better observe the transformation to a pencil beam. Note that the animation stops at = 0.9975; in reality, the electron velocity in storage rings is more like only one part in 100 million less than c.