Let's say we have a photon. When moving in vacum it has speed c. Due to mr Lorentz it will experience a time t=0 in its own referance frame no matter how far it travels. Is this right? So relative to itself the photon has a lifetime of zero? If so, how is this affected when it is not in vacum? I know we see it as moving slower because the dieletric constant is different, but how does the photon see it? Is this in anywayrelated to referance frames?