Youre on a train going the speed of light and you look into a mirror and can see your reflection. Which means that light is reflecting off your face and to the mirror. But to do this the light bouncing off your face would have to be going twice the speed of light to an outside observer. Which is impossible for uhhh reasons? So Einstein theorized that the train would need to be compressed and time would need to be slower on it relative to the outside observer. So my question is why is time slowed and the train compressed to make it equal? Im sorry if this is incoherent and that it is probably so far below other topics on this forum that its laughable but any help would be appreciated. Ive never take a physics class and have almost zero physics knowledge. Im just interested.