The universe. Yes, it's pretty fucking big. We all know that.
Current thinking goes that when the big bang occurred, the universe experienced expansion of gigantic proportions at speeds much faster than light (This is called inflation. Note that this is only possible because although you cannot travel faster than light through space, the universe was expanding through nothing. Hence the ability to travel faster than light.). It is thought that the universe still expanding, albeit at a much slower pace.
But where does it end?
Now, let's say the universe is infinite. The implications of this are beyond monumental.
If the universe was actually infinite then we would have to assume that everything, no matter how far fetched, is reality somewhere. Star Wars, Haruhi Suzumiya, Black Adder and all kind of TV shows, movies, books and whatever you can and can't think of is reality somewhere out there. This could be very cool or incredibly terrifying.
Unfortunately... or fortunately, it is not very likely that the universe is infinite. If it was, the night sky would be as bright as day since all the lights of all the stars would have reached us by now. The universe would have also achieved thermal equilibrium. This means that the entire universe would be the same temperature... probably very hot.
What really gets your nogging going though is the fact that our universe could very well be just a simulation. Yup, just like The Matrix.
It might sound bonkers but if you calculate the odds, there's only 1 in 30,000 that we actually exist as opposed to being a program running on some sort of computer. It is very possible that we are just a very advanced version of The Sims.
Now that's just sad.
Listening to: Tokyo Ska Paradise Orchestra
Playing: NFS Hot Pursuit