Comment by westurner

> which are then detected via Cherenkov radiation which is produced when a charged particle moves with speeds larger then the speed of light in the medium. (That is only possible because it is less than the speed of light in vacuum which cannot be exceeded.)

I have been researching applications of FTL as well;

Where is there an actual vacuum on Earth or in microgravity? So, there are Proca waves within dielectric Proca metamaterials and plasmas and waveguides; and photons can have effective mass and/or longitudinal charge Ez in ionized plasma?

So, Maxwellian waves with no longitudinal (Ez,) component can exist in what fraction of the universe if they can only exist in a vacuum?

A Twistor model can model such;