I have often wondered about the size of the universe. When one considers that when we estimate it's size we do it by observing the red shift of the most distant galaxies that we can see. Suppose the universe is to young for light from the most distant galaxies to have reached us. Suppose our insturments are not sensative enough to pick up the most distant galaxies. If either of these conditions are true then we have no idea how big it just might be. What do learned astromers say about this possibility?