A spaceship is of length 1000 meters (to the observer standing in the spaceship). It is travelling so close to the speed of light that to the observer in the spaceship, the 'length' of the universe has contracted to 900 meters. Q1: If I am the observer in the spaceship, what do I think the front 100 meters of my ship is 'in'? This is probably only sensible (if any of this is sensible) if we assume the universe is finite. I just thought of a photon which as I understand it has the universe at 0 length, and this question popped into my head. If the answer is "we don't know, what ever is outside the universe" does this mean there is definitely an outside of the universe? Q2: Is a photon (in its frame) simultaneously in all universes as they are all length 0 and the photon is moving? I find understanding of relativity extremely hard to keep a hold of, so forgive me if the basic premise of this question is wrong altogether. EDIT: Oh I see this is my first post. I think I joined a long time ago but I obviously just read. Hi!