Infinity is a topic largely concerned with anything related to space and the universe as a whole. Does the universe extend forever? Continuing on to infinity? If so, then is it also possible that every universe is contained within an infinite number of others? Like Ascacs said, the universe could be an atom. Though I partially agree, i think it is definitely possible that our universe is, in fact, the size of an atom, and not actually an atom. Then, since we don't know the limits of our own universe, our universe could be an "atom" to another universe, outside our own. Then is it possible there are an infinite number of universes both smaller and larger than ours?