This vision of the cosmos sees various components coupled to and driven by circuits at ever larger scales, so electrons and other ions accelerated through intense electric fields radiate “shouts” of energy in many bandwidths. It is that story that should be told and not the one about omnipotent gravity. [link to www.thunderbolts.info]

Particles moving through a medium faster than the speed of light in that medium can produce visible Cherenkov radiation. [link to www.thunderbolts.info]

While electrodynamics holds that the speed of light in a vacuum is a universal constant (c), the speed at which light propagates in a material may be significantly less than c. For example, the speed of the propagation of light in water is only 0.75c. Matter can be accelerated beyond this speed (although still to less than c) during nuclear reactions and in particle accelerators. Cherenkov radiation results when a charged particle, most commonly an electron, travels through a dielectric (electrically polarizable) medium with a speed greater than that at which light would otherwise propagate in the same medium.

Moreover, the velocity that must be exceeded is the phase velocity of light rather than the group velocity of light. The phase velocity can be altered dramatically by employing a periodic medium, and in that case one can even achieve Cherenkov radiation with no minimum particle velocity, a phenomenon known as the Smith-Purcell effect.