Rather than be incredulous and faux-shocked, go look up cherenkov radiation. It's when electromagnetic radiation emitted when a charged particle (such as an el

Rather than be incredulous and faux-shocked, go look up cherenkov radiation. It's when electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity (speed of propagation of a wavefront in a medium) of light in that medium.