We will never know, we cannot see the edge of the the universe and probably never will, as the size of the universe is increasing faster than the speed of light.
also, if you put 3 grains of sand inside St. Paul's Cathedral, it would be more crowed with sand than the Universe is with stars.
Over the last 2 years BBC has made 2 programs, Secrets of the Solar System, and Secrets of the Universe with Prof. Brian Cox, once in D:REAM (things can only get better) as a keyboard player, now working at Cern on the Large Hadron Collider. Totally amazing, interesting and captivating. I thoroughly recommend to those outside of the UK also if you can find it.
Also we have had over here Stargazing live on the BBc, very entertianing.
All this talk makes me want to explore tbh, so much so, in 1-2 months I will get my own telescope to see some of those amazing things out there.
something like a Skywatcher 200pds Newton Reflector, or if I push the boat out a little, a CPC 800 GPs xlt Celestron.
I hope to get the kids interested too!