So one of the things I get asked a lot after telling people I study Astronomy is "How can space be infinite?".
Well it's one of the hardest questions to answer, as not only is it mind boggling and stray a little towards some philosophy, but it is something that we as humans can never experience!
The way that I was always taught to begin imagining it is a balloon with dots on it, you blow the balloon up and the dots move further apart. Now imagine that the universe is like the surface of a balloon, and the dots are the galaxies, or massive clusters of stars. The universe expands like the surface of the balloon and everything gets further apart. Now if we are on the surface of this universal balloon, how will we know when we get to the edge? We don't, it would be like trying to find the edge of the Earth if you are on the surface. So the Universe is massive, bigger than we could ever imagine, but you would be travelling forever in it, trying to find an edge.
Mathematically infinity is define as the biggest something can be, it goes on forever, and is denoted the symbol ∞ (and if you ever have to do many integrals you know the joy of seeing a function that goes to infinity).
So is our Universe infinite? Our best guess is yes, in the way the us humans perceive the world anyway. That is the wonderful thing about something being infinite, there is always gonna be more of it.
So as our favourite Astronaut says 'To infinity and beyond'.