The only features of the universe we can observe are those that are close enough for the light they emit to reach us in the 13.7 billion years the cosmos has been in existence. This sets the limit of the observable universe. Beyond that lies the rest of the universe. How far does that extend. To infinity, at least that is what we are led to suppose. Why? Because we cannot envisage what it would be like to come to the ‘edge’ of the universe. But what kind of answer is that? What does it actually mean to say the universe is infinitely big?
We explore an alternative, one that claims that the universe might close back on itself meaning anyone undergoing a long journey out into space would not encounter an edge but would eventually find themselves back where they started.